Dynaflite Standard Hi-Start seems weak

[Roy Walton]

I recently bought a Dynaflite Standard Hi-Start and when I pull tested it at 300% elongation it was only 4 1/4 pounds. This seems a bit weak for most standard class planes as the rule of thumb is 5 times the weight of the plane for hi-start pull.

I checked the tubing against the size specs that Dynaflite gives and it was quite close. I decided to e-mail their support to make sure the 4 pound pull was right as they give no pull specs. A polite letter got no reply. One reminding them that customers expect answers to letters did. However, it did not answer the simple question of what is the pull specification. A third letter pointing out that the question was not answered got a response that did not answer the question, but, wanted to know where and when I got the hi-start. My fourth letter got an answer to the question. The answer was that they did not know what the tubing should pull test! In other words there was no way for a user to determine if the hi-start was performing as Dynaflite intended it to.

They offered to send me another one if I would pay the postage both ways. The postage would be about $22.00 and I might get another 4 pound pull test hi-start!

I searched the other posts here and found that the Dynaflite did not compare well in strength with other similarly priced h-starts. So, I kept it and have "doubled up" the tubing to get an 8 pound "up-start".

One more remark. The parachute is pretty dinky.

Anyway, this is here for folks who search before buying.

Roy

[Ollie]

"The bitterness of low quality remains long after the sweetness of low price is forgotten."

Buy best high start:
http://www.aerofoam.com/hosemonster.html

[aeajr]

I have had good experience with the NorthEast Sailplanes Pinnacle hi-starts. They are pretty much the standard at our sailplane club.

Yo don't say what you are trying to launch, so I can't make a recommendation.

5X weight is stronger than I have heard. I always heard three times was minimum. mabye 5X is for a strong launch.

[Roy Walton]

aeajr

Thank you, but, I already have a Hosemonster and it is excellent. (See ollie's post for site.) NE Sailplanes seems to have good stuff also.

I was not so much looking for a recommendation as logging a post about the Dynaflite in case some one is shopping and makes a search.

Roy

[aeajr]

For the guys on a tight budget launching Spirits, Aspires and GLs I recommend the Dynaflite HD Hi-start. 5/16 tubing as opposed to the 3/16 tubing on the standard. Launch pull is about 8 pounds. The go up very nicely, but not overly fast. I like a stronger pull myself, but these have been quite satisfactory.

[xtc]

"The bitterness of low quality remains long after the sweetness of low price is forgotten."

Buy best high start:
http://www.aerofoam.com/hosemonster.html

i was under the impression that these highstarts were by far the best as i heard many good comments here online so i ordered one ,my problem is that i mostly wanted it to launch larger sailplanes [100 inch and up] so i bought the 3 metre cord, bad idea! theses cords are to much for a 100 glider and yet a real bear with the 3 metres

i find the thing to be just to much ,it is very hard to hold the glider back with enough tension to launch the 3 metre and at this point i can launch higher with my old wore old dynoflight.

i wish i had bought the smaller highstart that hosemonster sells so be aware dont try to go to large on this cord,it does pack a lot of punch but its not the dreamy highstart i have visioned
i know,its my fault i bought the stronger one and i do get fairly good luanches with it and im sure it will last a long time but it is not twice as good as most like some have said!

p.s. after using my cord for a while i noticed that the joiner was not centered between the two pcs [2 pcs are shipped to save shipping costs] so i checked the lengths with a tape measure,sure enough,i was short about 15 ft of cord

living in canada makes returning things a little crazy and usually just drives the cost up even higher ,so here i sit,with the best highstart you can buy ,in my car ,while i drag out my old dynoflight

xtc

[aeajr]

i was under the impression that these highstarts were by far the best as i heard many good comments here online so i ordered one ,my problem is that i mostly wanted it to launch larger sailplanes [100 inch and up] so i bought the 3 metre cord, bad idea! theses cords are to much for a 100 glider and yet a real bear with the 3 metres

living in canada makes returning things a little crazy and usually just drives the cost up even higher ,so here i sit,with the best highstart you can buy ,in my car ,while i drag out my old dynoflight

xtc

I find your post VERY interesting. Why do you say the hosemonster is too much for your 100 inch plane? While I am sure the 3M rubber is very strong, it should not be too strong for your plane.

I don't have a hosemonster, I have a NESail Pinnacle XL which is rated to 4 M planes. This thing is super strong. At the field they call it the BEAR. I actually bought it by mistake. However I have never been sorry.

I launch Spirits, Gentle ladies and the like with this monster. We pull back about 1.5 times the rubber length and launch at about 12-14 pounds of pull. That is a lot for this class of plane but the launches are great off 450 feet of line. If we get a bit of a breeze, we we stand the rubber almost straight up and challenge the height of the winch on every launch.

Likewise my 80 ounce Legend goes up quite well and very high on the same hi start at 20 pounds of pull.

Now, I have had 3M guys say they won't use my hi-start because they like a softer, slower launch, but I have never had a problem, or broken a plane on this one no matter how hard we pulled it.

I have used the Dynaflite HD hi-start to launch my Spirit. It gives a very good launch using 350 feet of line. Nice a easy and slow. No real stress on the plane. I would hesitate to use it on a 3M plane, but it is probably find for a 100 inch.

Perhaps you are just looking for that slower, softer launch that the Dynaflite gives. But I am sure the hosemonster will be fine for your plane. You just have to get used to the pop and zoom that it provides.

BTW, I get a mild zoom off the end of my hi-start with both the spirit and the legend. The weight of the rubber gives me that end of flight acceloration. not like the molded planes get off the hi-start, but we get some bounce and some added height.

[intheswamp]

Rank newbie here, so take it for what it's worth...

I inquired with Mark at aerofoam about which of their high-starts would be best for me. I explained that I would initially be flying a Gentle Lady but that later on I hope to be flying a 100"+ plane. I inquired about the 3-meter rubber.

His reply was basically that the 3m rubber would fold the wings on the GL. That a better option for would be the "2m competition" rubber (and a little beefing up of the GL wings) and that the 2m competition rubber would also launch the 100" planes.

Also, the reason I was given for having two sections of rubber in the 100' lengths is that there was a quality consistency problem in the solid 100' lengths, whereas the 50' sections don't appear to have that problem. Apparently Aerofoam has been using two 50' sections for the 100' high-starts for quiet some time now.

FWIW,
Ed
Intheswamp

[jdlbusterdog]

I had just ordered my hosemonster bungee. Only to have a gust of wind tip over my ez-up shade pulling up the stakes (I will get longer stakes for next flying season) crushing my Spirit-100's left wing never getting a chance to use my new bungee.

[Vince inTX.]

I use a 2 meter histart from Holiday designs. These are what is now being sold by Aerofoam. 100 feet of rubber which I double over to 2 50' peices and use to launch my 3 meter paragon with authority and also launch my buddies 100" Searcher (fiberglass and foam) with no problems.

If I wanna fly my GL I simply attach one section of rubber to the line and it is a gentle as a kitten. BTW when launching the Paragon, if there is any wind, I will usually have a 20 - 30 foot stretch on the rubber on release. This is 2 pieces 50' of rubber stretched until it litteraly won't stretch anymore. 70-75 paces depending on the temp. You just cant beat mandrel dipped rubber.

my 2 Cents

Vince

[GunsGunsGuns]

I also bought a "standard 2m" hi-start from Dynaflight and was VERY disappointed with its inability to launch my 46 oz 2m Spirit Elite higher than 200 ft.

I think the basic problem here is that hi-starts are rated by the manufacturer by plane wingspan instead of weight and pull. Stupidly, after the fact I did my research and found that the rubber size on the Dynaflight standard ideally pulls at 6 pounds, or just 2x the weight of my plane. Thus it roughly translates to 2x the length of the rubber in height (100ft x 2 = 200ft).

I wish the box has said "6lbs pull" in which case I would have known immediately that it was less than I was used to using the club hi-start. :(

Live, learn, waste some money, have fun anyway.

Clark

[aeajr]

I also bought a "standard 2m" hi-start from Dynaflight and was VERY disappointed with its inability to launch my 46 oz 2m Spirit Elite higher than 200 ft.

I wish the box has said "6lbs pull" in which case I would have known immediately that it was less than I was used to using the club hi-start. :(

Live, learn, waste some money, have fun anyway.

Clark

IN your case, that hi-start really is too light. Try what I suggested above, use it with less line and see if you get a better launch. Or try what others have done which is to double it so you get 10-12 pounds of pull. Use it with about 250 feet of line and see how that works. You may be very pleased.

[Smoking Joe]

Roy:
Put every thing on charge let's fly till sundown.See ya at noon. Joe

[xtc]

Roy:
Put every thing on charge let's fly till sundown.See ya at noon. Joe

modified for this location, put the chg in the car,we`ll chg everything on the way to the field,come on,i dont want to get home to long after dark!

xtc

[xtc]

I find your post VERY interesting. Why do you say the hosemonster is too much for your 100 inch plane? While I am sure the 3M rubber is very strong, it should not be too strong for your plane.

I don't have a hosemonster, I have a NESail Pinnacle XL which is rated to 4 M planes. This thing is super strong. At the field they call it the BEAR. I actually bought it by mistake. However I have never been sorry.

I launch Spirits, Gentle ladies and the like with this monster. We pull back about 1.5 times the rubber length and launch at about 12-14 pounds of pull. That is a lot for this class of plane but the launches are great off 450 feet of line. If we get a bit of a breeze, we we stand the rubber almost straight up and challenge the height of the winch on every launch.

Likewise my 80 ounce Legend goes up quite well and very high on the same hi start at 20 pounds of pull.

Now, I have had 3M guys say they won't use my hi-start because they like a softer, slower launch, but I have never had a problem, or broken a plane on this one no matter how hard we pulled it.

I have used the Dynaflite HD hi-start to launch my Spirit. It gives a very good launch using 350 feet of line. Nice a easy and slow. No real stress on the plane. I would hesitate to use it on a 3M plane, but it is probably find for a 100 inch.

Perhaps you are just looking for that slower, softer launch that the Dynaflite gives. But I am sure the hosemonster will be fine for your plane. You just have to get used to the pop and zoom that it provides.

BTW, I get a mild zoom off the end of my hi-start with both the spirit and the legend. The weight of the rubber gives me that end of flight acceloration. not like the molded planes get off the hi-start, but we get some bounce and some added height.

i think the problem with my hosemonster cord is that i didnt expect what was advertised,by that i mean ,i didnt think that this cord would be as strong as it is therefor its just to much for my 100` gliders

it launches them fine but it gains tension real fast on the pull back and the glider zooms off in a hurry for the first part of the climb but usually slacks off for release unlike the weaker stuff that has a more consistant pull

if i was to pull this sucker back hard enough to keep tension for a screaming pop off,im not sure that it would get any high but there is a danger of spar damage etc

when i use it for my 3 metre f3j it works very nice but its near impossiable to hold for very long with any kind of sweat on your hand

i just simply bought the cord that was to strong ,if i had to do it again ,i would buy the 2metre comp. cord to launch 100 gliders.

now,OTOH if i had bought the cord that dynoflite req, for a 100` glider,i would have been left wanting more!

maybe others can comment on this as well but my hosemonster cord is getting better with more use,its getting softer.

i might also add that im operating with less bungee than was intended,i was stiffed for about 15 ft [one length was shorter]

xtc

[aeajr]

Thanks for the clarification.

Let me offer these further thoughts:

It would be EXTREMELY hard for you to damage the spar with the hi-start. My Spirit is a light weight floater that I got as an RTF. It has no carbon or other reinforcement in the wing. I have launched it with 12-13 pounds of pull ( measured on a scale ) into a 10 mph wind with no problems. Under that extreme of conditions there was some flex of the wing, as I could see the monocote wrinkle a bit, but never any breakage. We launched a brand new Gentle Lady ARF the same way, one after the other for 5 hours. If your 100 inch plane can't handle that, you have a problem and you better never take it anwwhere near a winch.

Believe me, I know breakage. I have snapped the Spirit's wing on the winch due to too strong of a launch and have seen a GL broken, a Sagitta 600 and an Aspire snapped on the winch. Never have I seen a failure on a hi-start. I believe it is the flexing of the wing introduced by the pulsing of the winch that break's planes that launch fine off the hi-start.

Knowledge is power! Pick up a cheap fish scale for $5. Measuere the pull on the hi-start as you stretch back. Forget paces, take it to at least 3X the approximate weight of your plane. So, if it is 48 ounces, 3 pounds, 9-10 pounds is the MINIMUM you want to have on the pull.

Consider this, my plane weighs about 2 pounds and I launch it at 12+ pounds of pull or 6X weight. So if you pull to 5X your plane's weight, 15 pounds, you should be very safe. Start at 3X and see how she launches. Then try 4X, then 5X, and if your hi-start will handle it, try 6X. If you break that wing, believe me, it was already broken and had just not let go yet.

If you are having trouble holding the plane at that pull, glue some 600 grit sandpaper to the sides of the plane where you grab it. It won't interfere with the flight of the plane, but it will give you a good solid grip.

Another technique used by the 3 meter guys at our club is to grab the plane around the fuse behind the wing, like a javeline pole. Hand all the way around. Now you have a very good grip. Then give it a good throw when you release. I do this with my Legend as I launch that at 20+ pounds of pull on the hi-start and that is very hard to hold.

I have over 300 hi-start launches, mostly on my Spirt and my Sagitta 600 2M. No problems. Other Spirt, Gentle Lady and Aspire pilots have launched off my hi-start with no problems.

I have seen countless hi-start launches by others at the field sending off 2M floaters off 3M hi-starts. I have NEVER seen a hi-start, no matter how strong, damage a plane.

And remember, I have a super strong hi-start! I am using a hi-start rated up to 4 meter planes. It has 1/2 inch rubber with a 3/32 wall. When I went to hi-start my Legend at 80 ounces, the guys said it was too heavy to hi-start, that I would crash. Up she went! No problem. This thing is a beast, yet it launches the Spirit just fine.

If my Spirit can handle it, if a Gentle Lady ARF can handle your plane can.

Pull that rubber and send that plane a huntin' for thermals!

[xtc]

no offence but i have been flying highstarts for some 23 yrs now [winchs too] i do understand the whole concept and its not that i dont get decent climbs its just that i dont think the hosemonster is as good as some would make it out to be or at least there many advantage is there life expectance,not just there launch height

my advice would be to simply get the two metre cord rather than the larger stuff

the fishing scale is a great place to start for me because i HAVE in the last 10 yrs gotten a lot weaker in the arms ,it will be of interest to see what i may call strong in comparison to whats expected to perform a good height

xtc

[aeajr]

no offence but i have been flying highstarts for some 23 yrs now [winchs too]
xtc

Sorry! You sounded like a new flyer who was afraid to pull back on the hi-start. Clearly you know what you are doing.

Just trying to help.

[intheswamp]

xtc: Thanks for prompting aeajr to post those thoughts on using a high-start.

aeajr: Thanks for posting those thoughts.

Though a touch of misunderstanding between the two of you, there sure was some good information that resulted from it for this newbie to soak up there! :)

I've been trying to figure out which size of high-start to scarf up. Max size planes will probably 100". I'd thought about the 2m competition, but...

Ed
Intheswamp

[aeajr]

First, you should be aware that I always, ALWAYS advise people to err on the stronger side. Are you buying strictly for what you have now, or are you looking to the next probable plane. That is a very important question.

As you can see from my experience using the hi-start I know that you can launch smaller planes with a bigger hi-starts, so better to be a little strong than a little weak. This really works out better when there is little or no wind to help "kite" the plane up.

Some people prefer a softer, gentler launch. They are nice and I like them when I use my friends Dynaflite HD on my Spirit. But I would rather have the power to spare if I only had one hi-start.

Now I will make recommendations. Remember I have NEVER used the aerofoam hi-starts so my comments are drawn from readings, not from experience.

Having said that, for a 100" plane the aerofoam hosemonster 2M competition is probably a very good fit and will probably do fine with moderate weight 3M planes too, say to about 60 ounces. However the 3M rubber will probably do a very good job on the 100" as well and give you more room on the higher end for bigger planes, say up to the 3M 75 oz range, especially if you don't have access to a winch.

From NESail, I would encourage you to go to the Pinnacle Large, their 3M launcher, for exactly the same reason. Guys in my club use that for 3M planes all the time, typically weighing into the 70+ ounce range. If you think you will ever get to a heavier "lead sled", like my Legend, up in the 80-90+ ounce range, you can launch it with the Pinnacle Large, but it might not be able to do a good job with a hook position on the CG or when there is no wind.

You could go to the Pinnacle XL, but most people will feel this is too strong. This is a big powerful bear of a launcher as you read above. I love it, but many people find it too strong for their taste.

That is about the best I can give you. Remember this is all a matter of personal opinion and taste. I try to be as quantitative as I can, using pounds of pull, but ultimately everyone has a certain feel they are looking for. I started on a strong hi-start so that is where I am comfortable. Your mileage may vary.

[ejett]

Ok. I have to put in my experiences. I have had a 2m size from NSP (pinnacle), a Pinnacle standard, the 2m standard (not the competition) from Aerofoam and a 3m that I bought from Holliday before he got out of the business.

Here's how my experience has played out.

Both the Pinnacle and the Aerofoam 2m highstarts work fine for 2m planes like the Spirit and others. I successfully launched my Spirit 100 and Airtronics Legend on the Pinnacle Standard and since I bought the 3m from Holliday, I have used it for all of my planes except I have not used it on the Legends, but have launched BoTs and a heavy Alcyone 3m.

As a comparison between the Pinnacle Standard and the Holliday 3m, I find that the Pinnacle "loads up" quicker than the Holliday. What this means is that for the same amount of stretch, the Pinnacle will put up more tension. The Holliday will stretch farther to get the same terminal tension thus storing more energy and I get higher launches for the same amount of tension.

I have not used a scale on either of them, but use the TFAR method (similar to the TLAR method).

To launch my 2m planes on either one, I just don't stretch as far; about 20% less. If I used a 2m highstart on the 2m ships, then I'd get better launches because I could store more energy (more stretch) in the highstart than the 3m at the same tension. I just am lazy about having to set up 2 different highstarts when I take both sizes to the field.

For 2m and 100" class, I would specifically recommend the Aerofoam competition 2m or the NSP Pinnacle Standard.

I hope I am providing useful info here and not just confusing the issue for you fellows.

EJ

[GunsGunsGuns]

IN your case, that hi-start really is too light. Try what I suggested above, use it with less line and see if you get a better launch. Or try what others have done which is to double it so you get 10-12 pounds of pull. Use it with about 250 feet of line and see how that works. You may be very pleased.

Thanks. I might try this but the math doesn't support the doubling idea. The energy in the hi-start is proportional to the tension x stretch length. So if you double up the rubber you will double the tension but you get half the length, so it's a wash I think. Or does something else apply?

Clark

[xtc]

without throwing anybody a real curve ball here but;;;if your using the aerofoam [rubber] cord in a climate like texas there seems to be a lot more energy retension compared to say;;this god forsaken place where temps are near zero

yet another observation that should be taken into account
xtc

[ejett]

xtc:

Yes, you are very correct. Temperature does have a huge effect on the rubber and must be taken into account. You fellows up north would probably be better off with a winch if you can keep your batteries warm.

Ed, intheswamp, AL would probably have similar experience with highstarts as us folks in TX and MS.

So, is it building time in Canada? Do you fly at all in the winter?

EJ

[ejett]

Thanks. I might try this but the math doesn't support the doubling idea. The energy in the hi-start is proportional to the tension x stretch length. So if you double up the rubber you will double the tension but you get half the length, so it's a wash I think. Or does something else apply?

Clark


Yes F=mA applies as well. You need enough force to accelerate the plane up the line as well as good energy retention for a good launch. You might need to shorten the line to match the length of the now shortened rubber. The energy stored will be roughly equivalent, but will be transferred into the plane faster thus increasing the power output of the highstart.

It is a matching game. Too much F = broken wing. Not enough F, no altitude or not enough airspeed.

EJ

[ejett]

xtc:

Re-reading your posts, I would suggest that you get another 50' section of rubber from Mark and tell him about the fact that you were shorted. I'll bet he will make that up. This will allow you to get a lower force on your highstart to make up for the higher coefficient of elasticity you are seeing in the cooler weather. Just making up the length you were short would help some too.

Just a suggestion. I won't charge you for it so I won't have to refund your money if you don't like it. :D

EJ

[aeajr]

Here's how my experience has played out.

Both the Pinnacle and the Aerofoam 2m highstarts work fine for 2m planes like the Spirit and others. I successfully launched my Spirit 100 and Airtronics Legend on the Pinnacle Standard and since I bought the 3m from Holliday, I have used it for all of my planes except I have not used it on the Legends, but have launched BoTs and a heavy Alcyone 3m.

As a comparison between the Pinnacle Standard and the Holliday 3m, I find that the Pinnacle "loads up" quicker than the Holliday. What this means is that for the same amount of stretch, the Pinnacle will put up more tension. The Holliday will stretch farther to get the same terminal tension thus storing more energy and I get higher launches for the same amount of tension.

EJ

Wow! Some great insights and personal experience reports here. EJ, I am especially appreciative of yours as you have had both brands and different models from each. I am really impressed that you got good launches on a Legend off a Pinnacle Standard. :eek:

The guys in the club were very surprised the XL was able to launch the Legend and most of them have Pinnacle Large hi-starts which they use when there is no winch at the field.

There is no substitute for experience. Thanks for sharing yours.

[GunsGunsGuns]

Yes F=mA applies as well. You need enough force to accelerate the plane up the line as well as good energy retention for a good launch. You might need to shorten the line to match the length of the now shortened rubber. The energy stored will be roughly equivalent, but will be transferred into the plane faster thus increasing the power output of the highstart.
EJ

Thanks, EJ, but I don't think that's correct.

Faster, yes, but over a shorter time. Time and acceleration do not affect the energy equation (avg. tension x stretch x efficiency = height x weight), unless this somehow alters the efficiency of the system to transfer energy...

Clark

[ejett]

Guns:

No, energy stored in the system will not be increased because if you double the highstart rubber cutting its effective length in half, you cannot stretch it but half as far as before.

But, the point I was trying to make is that if the tension (F) in the line is not enough to accelerate the plane up the line, then a stall and a crash could ensue with the balance of the energy in the high start possibly dragging the injured plane along the ground until the energy is dissipated. This would certainly add insult to injury.

I am in full agreement with your post, but I think efficiency is definitely affected by the rate. So, yes I think the 'efficiency' of the system will improve if you double the high start.

If you can only get 4lb. of tension out of the single strand, you may not be able to get the plane flying except in a high drag, on the verge of stall, configuration which will reduce the efficiency of the system to convert the energy into launch height. The plane is part of the system while it is connected to the high start. It's efficiency varies considerably depending on its airspeed up the line because the wing produces more lift at higher launch speeds.

It will cost you only a few minutes of your time to try it and see; you already have all the components to do so. Of course, you can buy new rubber from NSP or Aerofoam or even Hobby Lobby and you may well want to do so for higher launches with a full length setup.

EJ

[intheswamp]

Thanks guys, for all this good high-start information! Keep it coming!

I'm leaning towards the 2m competition from aerofoam, but still considering the Pinnacle standard. My flying will be with my Gentle Lady to begin with(once the build is completed). My next plane will probably be a 100"...something along the lines of an Oly II, BOT, Big Bird, etc.,. I tend to like the older styles.

I do notice that there's a bit of $ difference between the aerofoam 2m competition ($110) and the Pinnacle Standard ($79.95). But the absence of specs on the NSF site makes me wonder as does the omission of stating whether the rubber is mandrel dipped or not. Aerofoam gives more info on the product that they're selling. It appears that both are designed for the same weight of planes in mind, so is the $30 extra for the aerofoam worth it?

Mullin' things over in south Alabama,
Ed
Intheswamp

[xtc]

Thanks guys, for all this good high-start information! Keep it coming!

I'm leaning towards the 2m competition from aerofoam, but still considering the Pinnacle standard. My flying will be with my Gentle Lady to begin with(once the build is completed). My next plane will probably be a 100"...something along the lines of an Oly II, BOT, Big Bird, etc.,. I tend to like the older styles.

I do notice that there's a bit of $ difference between the aerofoam 2m competition ($110) and the Pinnacle Standard ($79.95). But the absence of specs on the NSF site makes me wonder as does the omission of stating whether the rubber is mandrel dipped or not. Aerofoam gives more info on the product that they're selling. It appears that both are designed for the same weight of planes in mind, so is the $30 extra for the aerofoam worth it?

Mullin' things over in south Alabama,
Ed
Intheswamp
yes,its sure is worth the extra 30$

i dont think anyone will argue the fact that the aerofoam highstart WILL last much longer and take more abuse..

it will ,with no doubt,out last the laytex cords,period!

xtc

[aeajr]

I do not believe the NESail is Mandril dipped and that is probably the major cost difference. EJ says they have different characteristics in his earlier post and I don't doubt his observations.

I have to say I have been anoyed that NESail does not provide specs, but if you send them an e-mail, they will respond with specs.

BTW, BOT is a 3M or unlimited class plane at about 118 inches. However is is a very light 3M plane at only 41 ounces with a wing loading of under 6 oz per square foot. Big Bird is a 100 inch plane, around 42 ounces. both should do fine on the hi-starts you mention.

[Cyph3r42]

I was thinking about whether to get the Aerofoam 2m comp or the 3m. I'm not entirely sure I'll be getting any bigger planes than what I've got but those are always the famous last words. :D

Wouldn't it be better to get the 3m in case you wind up with a 3m that's significantly heavier than a BOT?

One more Q and I'll be happy: So long as you have the space which would be better 50' rubber/250' line or 100' rubber/500' line? Considering the difference in cost isn't that much.

[ejett]

Let me chime in again. I think it smart to get the 'convertible' model so that you can use the full length or half length. I think it is worth the difference in price for the flexibility.

If you get the 3m highstart you can shorten the line portion a bit and just not pull it back as far and launch 2m planes with it. As I said earlier in the thread, the 3m Holliday (now Aerofoam) highstart is all I take with me to the field unless I only take the 2m plane. You would have great flexibility and versatility with the 3m Aerofoam highstart.

The downside is that you probably can get a little higher launch on a lighter 2m plane with a full size 2m highstart than you can doing what I describe above.

EJ

[ejett]

BTW fellows, you WILL be getting a 3m plane. So keep that in mind. Having matched high starts for each size is not a bad thing, just costs more money.

I am going to be doing some pull measurements on my highstarts today for comparison purposes. I'll post the results this afternoon or tonight.

EJ

[ejett]

Cyph3r42:

Regarding your last question, if you have the real estate to use it, you will get much higher launches with the 100/500 highstart, but see my previous post on the convertible units.

EJ

[aeajr]

Bigger is better when it comes to hi-starts. Longer rubber + longer line = higher launches and more thermal hunting time. :)

[Smoking Joe]

If you email hosemonster with your size of planes and what you anticipate flying he will make recommendations on what to buy. Answers emails promptly and has knowledge of his products. We bought 2M comp. and it launches the 2M and 100 inchers with no problem at all in fact just as well as our winch. 100' tubing and 400' line also has a hell of a nice parachute. Joe

[Soar_dude]

okay I guess it is time I chime in I have a 50' section of Hollyday (now aerofoam's) 3 meter tubing 3/8" OD X 1/8" ID and i have sucessfully launched GL's Sig Riser's and unmodded Olly II's You just do not pull as much tension on it. When I launch the light stuff I only stretch the tubing 200% it length I get a nice calm climb to about 300'. I started out with a dynaflight standard upstart. comparing the 2 of them together well no comparision really the extrude stuff is not as elastic as the mandrel dipped. I could only stretch the extruded stuff 150% the mandrel dipped you can get 300% stretch out it without damaging it. The amber stuff on lasts about 6 months in the sun. My Hollyday rubber is almost 5 years old and is still going strong.
You are better off going with something bigger now and not push it to its full potential until you get a glider that can take it! Trust me you will get something bigger to go further get higher. That is why they call soaring and addiction. :) I went the cheap route I kept buying the crummy amber stuff for what I paid for the amber stuff I could have bought 150' of the madrel dipped stuff!

Soar Dude

[ejett]

Here is the info I promised earlier today in a chart. I was really surprised by the tension of the NSP Standard which was stronger than the Holliday 3m by a significant margin. But I felt that I was at the end of the ability of the rubber to stretch at 125 ft so I did not pull it any further. The nominal unstretched length of rubber tested in each case was 50 feet.

Ambient air temperature was 63F.

Tension was measured with a Fish Scale. None of the measuring equipment was calibrated to a traceable standard.

Your milage may vary.

[aeajr]

Great chart and wonderful that you took the time to do it. I love doing those kinds of tests and comparisons.

Let me take a shot at interperting your chart and how I would expect the hi-starts to act. Tell me how close I get.

I would guess the Aerofoam 2M is very well sized to a 2M plane up to about 40 ounces and could launch a 100 inch 48 oz plane, but might be weak for anything larger.

The 3M Holliday looks like the real winner for balance of stretch and strength. Exactly what I have heard about the Aerofoams. Perfect for a 4 pound 3M plane. You need the room to pull it 300% to get the power, but if you have the space, you should get a solid smooth launch over a longer time than the Pinnacle. Probably carries 4X line length very nicely. They might provide comparable launches but the Holliday would be gentler, smoother.

From the angle of the Pinnacle trace, I would bet it was at its limit. It would appear after about 225% you were pulling at that point more than stretching. That is becoming a pretty steep climb.

I would guess that the Pinnacle would give a strong, faster launch in a smaller space than the others as it hit 22 pounds of pull at 200%. Probably carry 4 X line length fairly well on a 4 pound 3M plane.

While my Pinnacle is two steps up from that, that is the way mine behaves even with my heaviest plane. Strong quick launch if I REALLY stretch it for the big plane. Not bungee cord fast, but quick, almost winch like, but without the pulsing that breaks wings.


So, how did I do? Close? Way off?

How old is each rubber?

Can you provide some dimmensions? I would expect the Pinnacle Standard to be 5/16" rubber with 1/16" walls.

[ejett]

Ed:

You did a pretty passable job at the interpretations. I was somewhat surprised at the NSP rubber values, but it does fit with my experience. I could tell that the tension that I was getting at 100' was what I generally launch with when using that high start.

The rubber dimensions are as follows:
Aerofoam 2m - 1/8" ID X 1/16" wall
Holliday 3M - 1/8" ID X 1/8" wall
NSP Standard - 1/4" ID x 1/16" wall

The NSP highstart is the oldest of the bunch. Age may be taking some toll on its elasticity. I think we bought that highstart in 1991. It has been stored inside and there were a few years that it was not used. The Holliday high start is about 3 years old and the 2m Aerofoam is about 2-1/2 years old.

EJ

[aeajr]

Ed:

You did a pretty passable job at the interpretations. I was somewhat surprised at the NSP rubber values, but it does fit with my experience. I could tell that the tension that I was getting at 100' was what I generally launch with when using that high start.

The rubber dimensions are as follows:
Aerofoam 2m - 1/8" ID X 1/16" wall
Holliday 3M - 1/8" ID X 1/8" wall
NSP Standard - 1/4" ID x 1/16" wall

The NSP highstart is the oldest of the bunch. Age may be taking some toll on its elasticity. I think we bought that highstart in 1991. It has been stored inside and there were a few years that it was not used. The Holliday high start is about 3 years old and the 2m Aerofoam is about 2-1/2 years old.

EJ

Man, I would love to do a launch off between the three with a new NSP hi-start for a closer comparison. That would be fun!

Clearly the NSP is 13 years old and the others are pretty new. Considering that, I am very impressed with the NSP's longevity. To be that serviceable after that amount of time is a surprise. I would have expeced it to have gone dry and cracked after so long. I presume it has not.

It is also a little thicker than I expected at 3/8 inches OD. That means their large must be 7/16 because the XL is 8/16 or 1/2 inch OD with 3/32 walls.

For another qualitative data point, I have a homemade upstart using latex tubing of unknown composition. I bought it on e-bay for $12 for 25 feet of black 7/16" surgical tubing with 1/16" walls. Again, strong.

I launch a Spirit off that with about a 50 foot pull and 150 feet of #18 mason line, or 6X the rubber. It accelorates to the top pretty fast even with that much line and stands the up-start straight up even with little breeze. Great practice launcher for launch/land drills. Have launched 3M planes off it with 100' line.

My conclusion from your reports plus my own experience with 5 different hi-starts of different strengths and differnt size planes:

If you don't mind a fast launch, you can use a stronger launcher with a shorter pull in a smaller space and get good launches.

Or

You can use a softer launcher in a larger space with a longer pull and get good launches.

Either formula seems to work as long as you don't go too soft or too strong.

This has been a great thread. I just book marked it under Gliders/launch related. Too much valuable info to let it slip away. :)

[ejett]

I am sure that my Pinnacle Standard high start at 13 years old is basically at the end of it's useful life. I will probably buy new Aerofoam rubber for it pretty soon, but based on my numbers I'll be looking for something a little stronger than the 3m rubber as a replacement. This little experiment has been very worthwhile I think and hopefully some of you others on the forum can use the info in your decision making process.

EJ

[intheswamp]

Ok, great information overloading my brain here. Somebody want to suggest a good rubber/line/pull-distance setup for launching my Gentle Lady with the 3m Aerofoam? Maybe one setup using a single 50' section and another setup using the entire 100'?

Thanks!!!
Ed
Intheswamp

[xtc]

a very basic rule would be about 300 ft of line for every 100 of cord

in your case it might also help if you use a mono line that will also stretch to soften the launch a bit ,that cord of yours is a lot for a lady
something that i have never heard mention on here is the use of a weak link that may offer some extra security [approx 3 x the weight of the plane ]
hopefully the weak link will brake first
xtc

[aeajr]

People talk in terms of paces and such. I find that too imprecise because each hi-start is different, as ejett has shown us. I like to measure things.

Pick up a cheap fish scale, $4-$6 in a sporting goods or fishing store. Work form these guidelines and find your comfort zone.

Set-out your hi-start. Connect it to the fish scale. Back up till you get approximately 1.5X the length of the rubber or at least 3X the weight of the plane. Don't exceed a pull of 3X the rubber length. So for a 50 foot rubber, don't pull more than 150 feet unless the maker tells you that you can.

A GL is roughly 2 pounds, maybe a little less. So you want at least a 6 pounds pull to launch it and people have said 5X is the target or about 10 pounds. Somewhere in that zone shoudl be good.

Once you find your ideal launch pull, you can count paces to that pull, carry the scale with you for the first pull and pick out a marker, or once you have done it a few times you can use the TFAR method. TFAR = That Feels About Right.

Using Ejett's chart, 1.5 X the 3M rubber is going to put you around 12 pounds, so be prepared for that. That is 6X your model's weight. I have found that to be safe, but you have to be the judge. If you are nervous, try it at 9 or 10 pounds on a shorter pull and see how it goes.

Launch the plane with a good throw. With the hook in the most forward position, send it out flat to about 30 degrees - see how it launches. You can get more agressive with angle and hook position once you have your comfort zone with the hi-start.

This is best done on a fairly calm day as we are trying to measure the launcher, not the kite effect of the wind. A 5 mph breeze might give you a great launch on a 6 pound pull, but 8 might be a poor launch in calm air.

If you are not getting a good launch at 10-12 pounds, try shortening the line. This is the other balancing point; stretch, pull, line length.

Each plane and each pilot is different and each has its comfort zone.

One point about stress on the wings. Watch the monokote on the wings. As the wing flex under any launch, the monokote on the top will become a little slack. The stronger the pull, the more slack it will become. I can see some slack on my Spirit when I launch at 12 pounds. I see nothing when I use my friend's launcher at 8 pounds.

If it looks like the covering has gone TOTALLY slack, you may be approaching the limit of the wing. Again, you have to be the judge. Your mileage will vary.

Have fun! Experiment a lot! Try new things! Be prepared for occasional failures and chalk them up to the learning process.

If you never fail, then you never pushed the limit. I like to push it. That is how I have gotten good at fixing my planes. One failure alwasy teaches me two lessons - where the limit is and how to fix something. To me it is worth the risk and the work.

Clear skies and safe flying.

[ejett]

Ed:

OK. Your talking right down my alley here. I have actually launced a 1.5m Illusion HLG on the 3m rubber.

For the full length of 3m rubber, shorten the line to about 200' and for starters, put about 100' of stretch in the rubber. This should give you about the same launch as a partially stretched half size 2m competition. Based on what the launches look like, you can begin working your stretch up to 150' a little at a time. I would not recommend more than that for the GL wing structure. If you get up to 150' stretch, you will probably need to add more line. My rule of thumb would be twice as much line as the stretch you are putting into the rubber.

I do not recommend the "weak link" idea at all. No. No. No. If the weak link fails it will fail before the launch (best scenario) or just after the launch in the critical initial climb. A broken line when the plane is climbing straight up at low altitude is terror you do not need and unnecessarily puts your plane at risk. The best safety factor that can be applied to launching sailplanes regardless of the launch equipment is to THINK before you launch.

My offer still stands on getting together.

Where will you fly this plane?

EJ

[intheswamp]

Well, I broke down today and ordered my high-start. After asking a few simple questions and getting some very good feedback I bit the bullet and opted for the 100', convertible, 3m Aerofoam.

In reading through the thread I feel that the 3m won't give me the launch height that the 2m comp would give my GL, but I don't think the lower launch height will be detrimental for me in the beginning. If anything, the lower launch altitude will teach me to scratch harder for lift!

Before I hook the GL to the line for the first time there I'll do some rudimentary measuring....tape measure some pull distances and mark them while at the same time measuring the pull via the ol' fish scale (now where'd I put that thing). I'll shoot for the 5x-plane-weight pull...around 9 pounds I'm guessing right now...haven't finished the GL yet for a precise weight.

Later, when I get a larger plane in the handle I'll be set to go. Being as I'm just a country hayfield flyer I figure I'll never have a chance to use a winch except maybe when (not if!) gingerly enter some contests. :) So the 3m rubber will have me closer to being up-to-speed for the winches. Also, it'll get the heavier planes up for me as I polish my skills in the bahaia grass in preparation for my stunning showing at the contests! :D

Well, at least that's how I'm rationalizing all of this. I might have erred, but that's my story and I'm sticking to it! :D

EJ: The 113" mention was an error in my math figuring what 3 meters was.<duh> My present flying site is a ~50 acre hayfield across the road from my house. It's ringed by plantation pines (which I've searched extensively at times for a wayward EZ Star).

To the south of my flying site, separated by a 150' head of pine trees, is a 10 acre plowed field, to the SE about 500 yards and to the east of the 10 acre field is about 80 acres of plowed field. To the east of the flying site about 500 yards is another small 10 acre plowed field. I'm hoping that between the plowed fields, pine forests, and hayfield that some thermal activity will happen. Being as our prevailing winds are *usually* from the SE I think the plowed fields are in good position for me.

I've talked with George Stringwell a couple of times and he mentioned that the pine forest will be good for giving up good thermal activity late in the evening, so if I can fill in the rest of the day... There's no asphalt or large dark surface areas of the like around except for the rural highway between me and the hayfield.

The only problem I really have is the field is not level. First, the hayfield is a terraced field located on one of the tallest hills in sight. There's about 60' of slope to the south that goes down to the bottom where the first 10 acre plowed field is. I've been trying to figure out where a good landing strip would be. For a glider, how long of a strip is needed? I know the longer the better, but is there anything like a "standard" length? I've eyeballed two possible landing strips...one running N and S and another one running more or less E and W. Thankfully the hay has been recently mowed and if it doesn't take that long of a landing strip I might just take the JD lawnmower out there and start working it down to a nicer grass height.

I'm starting to look around the area for other, more flat flying sites in case I need them. It shouldn't be a problem getting permission to fly them...living in a small town, rural area has it's advantages. :) Of course one bad thing is the CRP pine plantations...they're taking a lot of open land in for tree production.

One good thing about the hayfield is that it's family property...I'm thinking of putting up a sign......"Hayfield Innernational Airport". :D

Anyhow, that's the state of the union as of now.
Ya'll take care,
Ed
Intheswamp

[ejett]

It sounds like a pretty good place to fly to me.

Regarding landing "strip", you really don't need much area to land a sailplane. If it is a hayfield then you can pretty much land anywhere except that I don't recommend the end or side of a haybale.

After you get some landing experience, you'll be able to land within 50' of where you are standing. As you get better, you can generally land right at your feet.

It is nice to have a fairly close clipped area in the field to stretch out your highstart and you should be able to land in that area pretty consistently after a little learning curve.

EJ

[aeajr]

Sounds like you and EJ are going to hook up and fly. Wish I could join you.

The Aerofoam 3M is going to give you GREAT! launches. Remember I am using a stronger hi-start than that and I get GREAT! launches on my spirit. You are giving up nothing!

If you don't know of any clubs in your area and would like to find one here is the registry of flying clubs for your area:
http://www.modelaircraft.org/subsec5.asp?sid=3D490C78380448B0A15E31DE4FA6F552

As for losing stuff in trees, read this article!

Plane Locators & Battery Monitors
http://www.rcezine.com/cms/article.php?cat=&id=67

Seems like you are all set. Seems like some other people will benefit from the discussion as well. I know that I did.

Keep us informed as to your progress. And if you decide to add spoilers to the GL, or if you decide to build that next plane, remember we ALL love a build thread.

Clear skies and safe flying! :)

[intheswamp]

It sounds like a pretty good place to fly to me.

Regarding landing "strip", you really don't need much area to land a sailplane. If it is a hayfield then you can pretty much land anywhere except that I don't recommend the end or side of a haybale.

Sounding good. I'll just have to been careful coming in low over the terraces. With the EZ I haven't clipped any terraces, but it comes in pretty "hot" most of the time.


After you get some landing experience, you'll be able to land within 50' of where you are standing. As you get better, you can generally land right at your feet.

It is nice to have a fairly close clipped area in the field to stretch out your highstart and you should be able to land in that area pretty consistently after a little learning curve.

EJ
Yeah, I figured I'd go ahead and start trimming a spot since it's cut low now and winter is coming...if the grass gets back up as usual it'd be rather tough landing! I'm somewhat curious about laying the line out across the terraces. I'm not sure if I have enough of a straight line between the terraces due to them contouring around the hillside. Running them across the terraces will create a "wavey lay". Any thoughts on this? Man, I have a lot of questions, don't I?! :D

Ed
Intheswamp

[intheswamp]

Sounds like you and EJ are going to hook up and fly. Wish I could join you.

Sure you can...just show up at the 2006 Nationals finals!!! (I've gotta give myself a year to get ready.) :D


The Aerofoam 3M is going to give you GREAT! launches. Remember I am using a stronger hi-start than that and I get GREAT! launches on my spirit. You are giving up nothing!

Man, that sounds good! I've heard from both sides of the camp regarding the 3m being too much, or whatever, for the 2m. I'm looking forward to finding out! This hobby is wrecking havouc with my finances, but I broke down the other day and bought a RAM altimeter. I got to try it out last Sunday in some stiff winds and managed to get my little ol' EZ/Speed400 up to 741'. I figure I can use this to really measure some launch heights. It'll be interesting! "Giving up nothing!"...yeah, I like that! :D


If you don't know of any clubs in your area and would like to find one here is the registry of flying clubs for your area:
http://www.modelaircraft.org/subsec5.asp?sid=3D490C78380448B0A15E31DE4FA6F552

There's one down in Mobile and one around Huntsville that I know of, but finding one within 50-60 miles I haven't been able to do. But, when the time comes I'll make it to one somewhere...after EJ and I slice some air! :) In the mean time I'll check the registry out.

As for losing stuff in trees, read this article!

Hey, I know how to do that pretty ol' good, if you need some pointers I'll be glad to help you out on this...

Plane Locators & Battery Monitors
http://www.rcezine.com/cms/article.php?cat=&id=67

Oh, I misunderstood you, I thought you meant...well, never mind. :D I've looked at some of these locators and would like to check them out. I've got a high-pitched deafness...too much rock-n-roll in years past, I guess. :o I wish I could actually hear some of them going off. A piezo-type of buzzer would work, I think, for me...but the little electronic "beep, beep, beep" I think would be worthless. For example, I can be sitting right in front of my Hitec Flash 5x when the low-battery warning beeps come on....and not hear them. :(


Seems like you are all set. Seems like some other people will benefit from the discussion as well. I know that I did.

All I've gotta do now is finish framing the GL up and then to covering it...which will be a whole new can of worms I'm sure! :)


Keep us informed as to your progress. And if you decide to add spoilers to the GL, or if you decide to build that next plane, remember we ALL love a build thread.

Don't worry, rest assured that I'll keep the group posted on progress...I know for sure that it will at least come in the form of questions! :D

Clear skies and safe flying! :)
And the same to you, sir, the same to you,
Ed
Intheswamp

[aeajr]

Sounds like you have some experience getting planes out of trees. Here is a thread on the subject. Perhaps you can add your unique techniques to the general knowledge.

http://www.rcgroups.com/forums/showthread.php?t=167396

[xtc]

for those of you that have been following this thread thus far might remember me whining on post #6 about not being happy with my 3 metre highstart,well as it turns out ,roy [orginal author] sent a e-mail to mark from aerofoam making him aware of this thread and that i had been short shipped on one length of cord

here is the support that comes with aerofoam products,mark has at is own expense offered me a new length of the lighter 2 m cord which im gladly eager to try out

for those of you that want info,mark has again reminded me to view his site warning guys not to go to larger with these cords, please see the follow letter`s
wow,i am very surprize with your responce ,i guess you know my story from your friend roy
and i was not knocking your product but i was also trying to warn people not to get the
larger stuff that you have because it is strong.
most people, at least me ,try to by slightly larger/stronger than what they need but in
this case it true,,this stuff is what you advertise! in my case i simply wish i had bought
the lighter stuff and that along with cold temps ,the short length its like a sling shot
rather than holding retension
these guys on r/c groups got me wondering why i wasnt seeing the same results as them so
that is when i uncovered the short length
i bought the highstart some time early last spring and i had it for almost 6 months before
i starting using it [we lost our flying site]
i honestly didnt think anyone would believe it was short so i didnt return it ,well,to be
honest, i was really upset about loosing our field so i kind of pushed all my equipment in
the closet [at least the pure gliders]
if you were to send me a other pc i would like to give the small cord a try ,i am flying a
woodie [sagitta 900] so i know it would be better thanks again

Losing the flying site is a real bummer.
I actually don't know Roy, he is just a new customer that saw the thread
on the RC Groups and forwarded it to me.
I will send a 2m Comp section this week.
I have a tension chart posted on the site:
http://www.aerofoam.com/rubberspecs.html
All the specs are at the BOTTOM of the scale at 300% elongation.
The rubber is actually rated to 700%, but I don't think it would last
very long with that kind of abuse.
I read through the thread on the RC Groups after Roy sent me post
#6. I was a bit surprized that you didn't email me when you found 15'
missing from your rubber. I emailed this response below to Roy
and I have written a general information article about the rubber
and my history with it.
(Maybe you can post this entire message on the highstart thread.)

"Interesting, I warn people about the pull if they inquire.
He never contacted me about the length.
I don't measure the rubber, it comes in 50' sections, so if
he got shorted I didn't know about it.
I will try to contact him and send another 50'.
Maybe he would want to try the 2m comp instead.....
By the way, I use 50's because they are better quality and
better consistency than the 100' section.
I ship to Canada that way because I can send them in
2- flat rate global priority envelopes for about $7.00 per package,
which saves the buyer about $5 to $8 in shipping."

Everything you never needed to know about highstarts,
bungees and Aerofoam/Hosemonster!

I will give you some history and a run down of rubber specs.
There are only 2 MFG's of mandrel dipped rubber in the USA.
Maybe in the world, extruding is much cheaper, more consistent
and 99% of the tubing is used for delivering liquids, so the elastic
qualities don't matter.
I actually started using it and selling it before Rich Holliday.
I found out about it because some of us at CASL
(Central Arizona Soaring League) were getting heavily into buggee
launching with small EPP planes that would launch at around 150mph.
and end up at over 400'. We started by using Hobby Lobby orange
rubber doubled. That worked well but a few people were
injured when it frequently broke and the elastic properties weren't
as good as a 20' piece of mandrel rubber I had experimented with.
I started selling the 1/2" x 20' mandrel dipped catapults to compliment
the 36" Delta wing which was becoming the bungee plane of choice
at many contests. (the only other plane that could take that kind of abuse
and launch as high was Steve W's "Nemesis")
Rich came along and started selling the full compliment of mandrel
dipped rubber. He was doing such a good job of it that I started buying
the bungees from him and eventually just asked
him if I could just send my customers to him. This worked well
for me because I was busy making airplane kits while the EPP
combat industry was on the upswing.
A few years ago Rich wanted out of the rubber biz. due to a 3rd.
child and good income from stock trading. I told him I was interested
and he was happy that someone with prior knowledge was willing
to step in. I bought out his inventory and took over. I then made a few
minor improvements to the smaller connectors and some minor changes
in the complete highstarts. (larger chutes, 50' rubber sections, spectra option, etc.)
The 100' rubber sections are made on a mandrel that does a U turn.
They dip it until the rubber is at the desired thickness. This means the rubber has
a natural curve in the middle and the mandrel is rather difficult to control, so
the end result was that the 100' sections had an inferior overall quality to the
50' sections. They also took much longer to get. (up to 6 weeks)
I switched to 50' sections with a hard splice in the middle.

My sailplane history:

The guys I flew with at CASL were mostly hard core TD, Scale, and speed
freaks, so I am use to winches that routinely fold composite planes and
100ft. zooms at the end of the launch are considered average.
When I took on the highstart biz. it was with the attitude of supplying
the best flyers with the best product regardless of cost.
All the highstarts are at the high end of the launch spec for that
size of plane. (5 airplane weight)
The suppliers of mandrel dipped rubber have minimums that are fairly
steep and I routinely have at least $3k worth of tubing in stock
just to sell a few highstarts a month.
The rubber orders take from 2 to 4 weeks, so I always have to think ahead.
There is also a shelf life. The MFG only guarantees the rubber for
3 months. This doesn't have anything to do with the actuall life span,
they just don't want to cover anything past 3 months.
I have only had one rubber problem in 3 years, it was a section
of 2m rubber that was rather "porous" for about 10' and it was breaking.
The guy didn't tell me about it for about 6 months, so I asked him to send
me a few inches of the bad spot. It was definitely screwy, so I contacted the
rubber supplier and sent the customer a new 50' section.
I will always make good on the rubber if it is an actual defect, but I won't
cover it if someone has clearly used it in an area with sharp rocks or if it was
somehow abraided. This is easy to discern from looking at the break.
Back to the issue of mandrel vs. extruded.
There are 2 reasons for elastic property variations in the rubber.
The first reason is the material itself. Many of the extruded rubbers
are made for chemical transport (lab use) and the elastic properties
are not even considered in the formula. They mix in other materials to
provide chemical resistance and this degrades the elastic properties.
The second reason is the MFG process. the extrusion forces semi
molten material through an extrusion die, so the rubber shape is formed
under tension and is never in a complete state of relaxation because
it solidifies as it is being pulled out of the die. I have no idea how the
"molecular alignment" actually effects the elastic property, but this
is the basic principal. This can also explain why the tension rises
faster with the extruded rubber, it is already under internal tension before
you stretch it.
Mandrel dipped rubber is formed on a long polished SS mandrel that
is repeatedly dipped until the desired thickness is achieved.
Each dip adds about .005", so this takes awhile. The layers
are completely relaxed. The process also has problems with drips, blobs
and occasional poor adhesion between dips, so they scrap a significant
amount of rubber in the process of making a batch of tubing.
This is another reason for the price being higher.
The rubber I use is loaded with carbon black. This is the best
UV protectant for rubber (look at your tires).
They use the maximum amount possible without degrading the
elastic properties. The final few dips have a bit more carbon and an
additive that makes the outside layer more abrasion resistant.
The only thing you can do to extend the UV protection is to
wipe the rubber down with 303 Protectant once or twice a year.
This stuff really works, it is "sunscreen for your stuff".
You should store rubber in a dark place away from petroleum products
and ozone sources. I keep mine in a soft cooler.
I don't use the protectant on my rubber because it's life span is long
enough that it will fail from abrasions long before it fails from exposure.
So if you are using it, you will wear it out first. If you hardly ever use
it, the protectant is probably a good idea. Stay away from "natural"
colored tubing, it can have UV blockers, but they aren't nearly as effective
as the carbon black. If you really want to use extruded rubber,
the Hobby Lobby orange is a good medium pull rubber that seems
to have a good life span. I have heard that the NE Sailplanes Highstart
is a good product too, but I haven't seen one. I have had many customers
tell me that they couldn't believe the difference between the Dflight highstart
and the Hosemonster, but if it works for you, use it!
The past 3 years have been interesting to say the least. I never thought
I would be doing as much with rubber as I have been.
I have gradually moved away from the combat EPP planes and into the
UAV industry. For the last 2 years I have been making catapult
launching systems for 2 gov't labs and 3 aerospace companies.
I have sent a number of complete highstarts all over the world.
I am always amazed that people are willing to pay that much shipping
to get a good highstart! I have recently contracted a new parachute
from a company that builds them for high end model rockets.
I had them build it to my specs.
I use to use military surplus chutes from 1965, but the supply ran out.
I used the same design, but switched to a stronger fourescent
orange rip stop and black webbing risers. The chute is 18" in diameter.
The 3/8" black webbing risers are sewn all the way through the crown
and capture the ring.
The full highstarts come with 250' of bright yellow line and 250'
of flourescent pink line. This is so you can tell which end of the line
is in a pile and it makes finding the center easier if you have a convertible
highstart. The knots are all soaked with a mild polymer, so they won't
come loose. The rings are SS split rings rated at 220lbs. I see a lot of
huge welded rings on high starts and wonder why........, but if you must
have a welded ring, go buy a foot of chain and cut out every other link,
this will give you a lifetime supply of rings.......
If your plane is heavy for it's size, it may run out of pull
before it gets to the top of the arc. (doubtfull).
If this happens, shorten the line until it powers the plane all the way.
Most highstarts don't have this much line to rubber ratio.
I have always geared this biz. towards the intermediate to advanced
user, so I don't publish any "beginner" information. This is a part
time business for me, If it were full time, I would probably try to sell
more product, supply dealers etc., but the truth is that there is enough
business to be a constant, but still enjoyable interuption, but not enough
to be a full time business. Glider guys are probably the smallest part
of the RC industry.
If you are trying to save $$$, but want the good rubber, just get the rubber
and the chute, the line is #18 braided mason line, the stake is a 12'
galvanized nail and the cord reel is a standard elctrical cord reel.
All the above are available at Home Depot for about $17.00
and you can do the final assembly. I always have an email address
posted on my site .(not as a link, but you can cut and paste)
I am easily accessible and usually answer questions within hours.
I am always looking for ways to improve the product.
The most recent Aerofoam developement is that I am working on
a pair of CNC foam cutters and plan to kit some higher end EPP
planes in the near future....

Mark Mech
www.aerofoam.com

[aeajr]

xtc,

Thanks for posting that note. Great reading and a wonderful insight into his business. Also a wonderful insight into the man that has gained the loyalty of a lot of flyers.

It is interesting that his hosemonster rated pulls are below those measured by ejett. I guess he is being conservative to be sure he meets customer expectations. Good business practice.

Whether one goes up a size or not is a personal decision. Clearly you will get the best balance if you closely match the hi-start to the plane.

When you are trying to launch a range of planes on one hi-start you definately have to compromise regardless of what hi-start you use.

Either the lighter planes will be launched on a shorter pull or the heavier planes may have to go up on less then optimum pull. Regardless of what hi-start you use.

If I ever have to replace my hi-start, I hope he is still in the business so I will have a choice of what to get.

Again, thanks for the post.

[aeajr]

Based on the Hosemonster chart, if I was buying a hi-start specifically for my 2M Spirit and my Sagitta, which are about 2 pounds, I would get the 2M competition.

Since I also have to launch my 3m, 5 pound Legend, I would get the Unlimited rubber and just not pull it back as far to launch the 2 M planes, say only 150-200%. Similar to what I do now. If necessary I would drop off some line with the 2M planes, though I have not had that problem to date. Even at 150% pull they take up the full 450 feet of line quite nicely with even a small breeze.

Of course, this is not optimum, but you have to have enough for the biggest plane, or you need two hi-starts. Even if I didn't care about the cost, I just could not be bothered setting up two hi-starts in order to fly both classes of planes and I usually fly both when I visit the field. Call me lazy.

I have pointed people to NESail and Aerofoam in the past. I see no reason to change that recommendation now, but my confidence in the Aerofoam recommendation is even greater now.

[xtc]

ok,we have reviewed the launching quality etc ,NOW if were talking which cord will last longer! ,what will we learn??

xtc

[aeajr]

Originally I would have said he Aerofoam Hosemonster would last longer, simply by reputation. However ejett says his 13 year old NESail Pinnacle is still pretty serviceable. Reputation is that the hosemonsters retain their elasticity longer, but to me anything over 10 years is forever, so I would call it a draw based on the only sample we have. Even at $130 for 10 years, that's $13 per year/season. Nothing.

Based on other people's comments, if you use your hi-start a lot in rough/rockey, terraine, it will suffer more from abrasion then from the Sun and that is how it will fail. Don't have any way to compare, so I would call that a draw.

UV seems to be the other main cause of damage. Again the Aerofoam hosemonster claims the best protection. I have no way to judge.

Line is cheap and can be replaced for a few $$ so that doesn't matter. Parachutes get tattered, but I don't know that they will likely wear out in less than 10 years.

Hard to fault with the hosemonsters or the Pinnacle.

[ejett]

Well, two things to remember about my Pinnacle highstart. I can't swear to exactly when I got it so 1991 may be accurate, may not. Also, for more than half the time, maybe as much as 3/4 of the time I've had it, it was in controlled atmosphere storage away from any source of damaging UV. So, I certainly will not say that the Pinnacle is "longer lasting" than the Aerofoam when both are used equivalently.

As I said, I have been using only the 3m Aerofoam (Holliday) rubber for the last 2-1/2 years or so and the Pinnacle has been in the closet again.

Yes, my Pinnacle is old. But, if you stick a human body in a glacier, it will last a long time too. Environment means everything here folks.

EJ

[intheswamp]

Sounds like you have some experience getting planes out of trees. Here is a thread on the subject. Perhaps you can add your unique techniques to the general knowledge.

http://www.rcgroups.com/forums/showthread.php?t=167396

<chuckle> I'd already perused that thread pretty thoroughly. :) Yes, I have some experience in retrieving planes from trees, but actually have more experience in *searching* for them. Back when I was learning my "lefts" and "right" I learned two important lessons....

1. Why you don't want to fly downwind very far (especially when you're just starting to learn to fly).
2. Don't fly your plane a day or so before a hurricane is coming ashore when the strong, gusty winds are advancing ahead of it. :o

I lost my EZ Star *TWICE* just prior to two different hurricanes coming ashore. We're located about 100 miles inland from the Gulf Coast, but trust me, those storms make it up here, too! Maybe no storm surges, but hurricane winds and tornadoes definitely reach out and touch us up here. Anyhow, on one occasion the EZ when down in the (downwind) piney woods. I pretty well knew where it when down at but still it eluded me for a while. I looked for part of two days, swatting about 2 zillion golden web spiders out of my way and being very startled on occasion by the dreaded "stick snakes" before I found it. Unfortunately, the storm was coming in, the plane was nestled down nicely in some limbs, and it was sitting about 60' up in the pine tree. It road the hurricane out purched in the top of the tree. A couple of days after that particular hurricane I returned to it with a rod-n-reel and some heavy cord. Throwing the fishing weight over the limb and letting the weight pull the line on to the ground...then fasten the heavier cord to the fishing line and haul the heavy line back over the limb (old ham radio wire antenna hoisting trick). Once the heavy line is over the line with both ends of it in your hands you start snatching and yanking and pulling and, if all goes well the plane will dislodge and fall to the ground. Be careful though, when that plane lets loose and starts coming down it moves pretty quickly...and you're pretty well right under it! Lesson learned here is if the plane is going down keep your eyes on it till you no longer see it...then stare at the spot it went down at for a minute really noting any distinguishing landmarks. Then gaze further around the site for some siting objects. While walking through the woods walk in a stop-go-stop-go sequence. When you stop, scan the ground, then scan the trees...repeat, repeat, repeat,....depending no the tree canopy the percentages of the chance of the plane being on the ground varies. The EZ road the hurricane out in the tree and stayed in the tree for a little over a week, it sustained some pine tree chaffing and it's xtal was zapped. Other than that it was ok.

The next EZ loss was at a further distance, with another hurricane, and...I let it get too far downwind once again...it was the flight flight of the day and I let it really get too far downwind (1/4 mile?) and it was REALLY BOOGYING with that strong tailwind! I realized I was way to far out and tried to turn back and the strong wind too control!

This loss happened just prior to Labor Day weekend...I searched *all* weekend for it. The problem here was of "landmarking", or to be more precise, getting the right depth in your vision. It's easy to mark an "in line" object as a reference point as in "...it went down inline with those two tall skinny pine trees on the hill..."...which it did. But, figuring out exactly where between me and those pine trees it went down was another story.

I went to my flight site *several* times looking towards those two tall landmarks trying to recreate in my mind where the plane went down...looking at the different tree lines, the different types trees, trying to recall what it went down "behind". Well, after close to 30 hours of actually searching I hung my head down and ordered another EZ.

A couple of days later I couldn't stand it anymore and went back for *one* last look. There was one area that I hadn't searched. It was actually well out of line with the "line of site landmarks(skinny pine trees) and much closer to me (maybe a little over 1/8 mile away) than the landmark trees. But, it was the only place I hadn't looked. It was an area of privet hedge bushes, vines, wild plum, briars, etc., etc.,...an intimidating area to search. If the EZ went down in there it would have had to regain some type of flight attitude after going out of site and then glided quite a ways to crash there. But, it was the only area I hadn't searched. So, stooping, crawling, knocking brush out of my way I slowly worked the area...most of the time the brush was so thick I'd have to stop and peer through the canopy looking for the dark outline of a plane. After a couple of hours I decided it was a lost cause, but on my way out of the thicket I decided to try once more. Every now and then I'd come out in a small clearing, maybe 10' square, where I could stand up and peer around. In one of these clearing I stood up, twisting and stretching my back from all the stooping over. As I twisted to the right there she sat, propped up at head height looking like she was on a display stand...looking at me like "whar'ya been?". :o She was in good shape, with a couple of pieces of the elapor chaffed off from the hurricane winds blowing the bush it was sitting in. I later reglued these little pieces of elapor foam. The EZ had crashed close to 100 yards from my "line of sight" landmarks and had apparently regained flight attitude and glided a good distance after I lost sight of it. Of course, the fun part was crawling back out of that thicket carrying a somewhat ackward package. But, the EZ was found and in great shape...it'd ridden out it's second hurricane!

Lessons learned in that crash and search was to not only get your "line of site" landmark imprinted on your brain, but also *really* focus on getting some "depth of field" landmarks. Expand your search pretty widely to either side of the line of sight...after you lose sight of the plane you're not really sure what flight attitude it might acquire. And finally....the thickest, most inpenetrable area that you figure the plane didn't go down in is probably where it's at! :D

The biggest lesson learned from all of this is (at least for a newbie):

DON'T LET YOUR AIRPLANE GET TOO FAR DOWNWIND, ESPECIALLY IN STRONG WIND CONDITIONS!!!!!!

And...don't give up...it didn't disappear on impact, it's there somewhere!

A little off topic, so apologies,
Ed
Intheswamp

[ejett]

I'm somewhat curious about laying the line out across the terraces. I'm not sure if I have enough of a straight line between the terraces due to them contouring around the hillside. Running them across the terraces will create a "wavey lay". Any thoughts on this? Man, I have a lot of questions, don't I?! :D

Ed
Intheswamp

Been there, done that! Up until I moved out here all of my flying was from terraced pastureland. The terraces won't cause any particular problem with the launching as the launch will lift the line off the terraces. The terraces can be somewhat of an aggravation getting your highstart set back up after a flight because of having to drag the line across the tops in places. Try not to have your rubber dragging across a terrace when you are stretching it, because of abrasion to the rubber. You do not have to be perfectly facing the wind to launch, but try not to set up exactly crosswind.

EJ

[intheswamp]

Howdy EJ. Thanks for the feedback on the terraces, EJ. I figure if I peg down the high-start on top of a terrace it will somewhat keep me from being to tight against the terraces in between when I pull back.

I think I'll be able to manage pretty much of a "into the wind" launch angle, really shouldn't be a problem I was reading the other day at the newstand :D and a fellow was talking about launching with a cross-wind. Suggested that when it happens to actually using the cross-wind at the end of the launch to turn into the wind and gain somewhat of a zoom out of it. Of course, being the rank newbie I am I'll wait on (intentionally) trying this.

Ed
Intheswamp

[GunsGunsGuns]

IN your case, that hi-start really is too light. Try what I suggested above, use it with less line and see if you get a better launch. Or try what others have done which is to double it so you get 10-12 pounds of pull. Use it with about 250 feet of line and see how that works. You may be very pleased.

Thanks Aeajr, I doubled the hi-start and it did make it at least usable for now. With 200' of line, in no wind, I pull the line tight at the top of the launch. So I'll try more line. I hope to achieve 250'+ in light wind. Nowhere near the 500' the specs claimed but at least I don't need to throw it away for the short term...

Clark

[aeajr]

Save it for some lighter plane, or sell it to someone with a lighter plane and take that money toward something stronger.

Or you can send it to me. I'll pay the shipping. I can make a zip start out of it for my 20 ounce ZAGI. :)

Glad the launches are going better!