F-4 42"ws

[Ralph A. D'Amelio]

Here a project that J Morgan and I want to tackle. My lhs had the GP 10 size retracts so I bougth them maybe for or F-4 or my Spit.

J, I printed out my drawings scaled to 42" WS the fuse is 52" less nose cone. :D Do you realize how big this is? Here are some pics, notice how I took the picture.

It a mini blizzard here today so I think I will try to prototype the gear support etc for this F-4.

I dunno J, maybe we should exchange names. ;)

DAF

[J Morgan]

OK,
Now we're on the same page. I'm sending mine off the Kinkos Monday. I'm getting 40" and 42". Yes, it is BIG. About a 58" fuse by my estimates. No gear on mine though.
It snags sagebrush!

J

[Ralph A. D'Amelio]

J, still don't know about retracts I'll know better tommorow. Will Also posts construction pics. I using the orig as as base and designing and adapting as I go along.

[J Morgan]

Exactly what I'm going to do. How else?

J

[Alexis_Ruiz]

Ralph:

My experience with those retracts is not good if you exceed about 2 pounds, they tend to break at the top over where the moving "plunger" rests on the "down" position, if you look closely you'll see that the plastic is really thin in that area, if you land less than perfect, the rotating part of the retract will press the "plunger" against the top breaking it. On the other hand, they are real easy to convert to a steerable nose retract.

Alexis

[Alexis_Ruiz]

Ralp:

Sorry, forgot to tell you, a better deal are the Robart 600 series mechanical retracts, really light, strong (rated to 5 pounds, can be used on up to .40 glow models)1/8" struts, .75' high(same as the EJF retracts or Springair 600 series) very reliable, I even converted a set to pneumatic by using 1" stroke BVM retract door cylinders.

Alexis

[St. Martin]

What... anutha jet? The DAF and JAF conglomerate should have this flying by sun eve..

SAF

[J Morgan]

Well, you know DAF will.
Steve, while you're lurking around here, care to make a power suggestion?
The original is 30" ws, 30 oz on 2 sq ft WA. I expect this one to come in at around
42-46 oz ( I hope ). DAF and I were wondering about propulsion. Maybe we need to call GE?

J

[Cass]

DAF and I were wondering about propulsion. Maybe we need to call GE?


That might work :)

[St. Martin]

Well, you know DAF will.
Steve, while you're lurking around here, care to make a power suggestion?
The original is 30" ws, 30 oz on 2 sq ft WA. I expect this one to come in at around
42-46 oz ( I hope ). DAF and I were wondering about propulsion. Maybe we need to call GE?

J

Pretty good sized plane here. The object is how well it will fly in a certain area. This requiring a certain prop size to get the desired results. In John's requirements, he has buku open space and can use a smaller prop turning a high pitch speed. Daf and myself, depend more on less pitch speed and more thrust to keep acceleration higher, due to our sometimes smaller areas.

John could use a Mega 22/20/3 and a 8-7E prop on 10 cells or 3s2p lipo. Where Daf could use 22/20/4 on a 10-7E on 10 cells or a 3s2p. Or even a outrunner as he has on the others, to get the static thrust for close-in flying.

Thats my area of thought.

Steve

[Ralph A. D'Amelio]

Alexis, thanks for the input...hate to go to all that troble especially on a flat plate wing. I am reconsidering the idea of retracts on this bird.

Steve, yes glad you chime in and you are correct in term of were we all fly. J can take forever in a straight line to get up to speed........whereas you I must get up there quickly.

Any thoughts on an outrunner, I really like these motors. The typhoon 15 might be marginal. I know my axi 2820/10 will work but its heavy at 6 oz. I was looking at the 2814/12 only 4+oz. At 2.5# and P/W of say 80 is only 200w. Your thoughts.

DAF

[J Morgan]

See! I knew he'd take care of us.
Thanks Steve. Just happen to have a couple of those laying around, at least for a little while.

J

[St. Martin]

You should really use a rule of thumb to try an avchieve a ratio of 75W per# in power application, for a prop plane. This is for safe flying with a margin of power out for a mistake. This of course depends on other factors as well, but a good proximity.

So, for a 4# plane you should have a minimum of 300W. Personally I prefer 85-100W per#. Tho, the power is rarely needed.

Daf, out runners I cannot help you with, never owned one, only to know that they are torky mtrs that can swing large props on "dirty" airframes better than they can swing smaller props on a design needing higher speeds. I guess I should try one someday, but I have been using GB and belt drives so I can use the "can" type mtr in a DD application elsewhere, when applicable.

Steve

[Ralph A. D'Amelio]

Made lots of progress on the F-4-42 basically use my 32" ws and scaled up and did re-design as required for strength. I decided to build a wing midsection as a "fasle bottom. This way I could build the fuse on a solid surface.

First the mid -section with engine nacelle ( or my rr bridge) the main fuse sides.

[St. Martin]

..should be flying it tomorrow..Daf?

[Ralph A. D'Amelio]

Added some top deck out of pink foam and woodland scences foam and puff.

J, auw as shown is 11.2 oz. not really to bad since is more than 3/4 of the fuse.

[Ralph A. D'Amelio]

Now rough shape is complete I need to work on the elevator control, my least favorite part, the wing and final shaping etc. I definetly will fg this one.

Need to charge my lipos just in case the weather breaks Monday :)

DAF

[J Morgan]

Thought you'd be done by now! You better clean off that workbench. You will need the space.
Nice start. Have you decided how you will do the wing?
I think I have the fuse sorted out, been going thru it in my head during the ball game.
I'm thinking maybe a 3 ply wing( foam/balsa/foam) plus some carbon rod to get enough rigidity but yet keep the flat plate.
And I'm going to use balsa for the flying tail. I feel it needs a better glueing platform than the foam will allow.

J

[St. Martin]

go back a page, you missed my post?

Steve

[J Morgan]

I'd say 11 oz is good at this stage. I'd like to come in around 45 oz AUW but don't really know if that is achieveable.

J

[Ralph A. D'Amelio]

Got it Steve. Yes I like 80-100 w/# when ever possible as well, hell you can always throttle down. I'll some more research on the newer out runners.

J, I petty happy this wt so far. Like I was thinking of at least doubling up on the wing. My large Spit wiegh 4# and the wing was a 3/8" balsa flat plate with tapered LE/TE butt glue at the center and a 12"/8" long 1/8 ply spar. We never damaged the wing and the wheels where directly attached to the underside with 1/8" ply strips.

We shall see.

DAF

[GregG]

http://www.hobby-lobby.com/images/ttr3005.jpg

How about these retracts (http://www.hobby-lobby.com/landinggear.htm) from Hobby Lobby? They only weigh 1.2 oz for the pair.

[JerryHall]

Hi Ralph, John...
Nice progress...
I just tuned in to your 42" thread....Ralph I told you some time ago I was going to try this technique, and I guess today was the day...I hope you don't mind if I post a couple of photos of todays progress so you have a bit of an idea of what I am talking about...36" span NA RA-5C Vigillante...
I am sure I will have questions above what you have presented so far in the past threads...In fact I have one already..
My wings are hot wired white foam core, sheeted with 1/16 balsa, balsa LE and TE and with no ailerons installed yet weigh 9 oz together (4 1/2 oz each)...It seems too heavy to me..You just mentioned in a post a bit ago that your previous wings were 3/8 sheet balsa, and I am guessing they ( 3/8 balsa) would be lighter than mine...I have 2 sq feet of area in the wings alone...Any idea what you wings weighed ???
At the point of progress shown in the photos, I weigh about 17 oz.., and I am afraid the AUW is going to be really high..
Thanks for your advice...

[St. Martin]

This is getting good!

[J Morgan]

Well, as we all know, if you put enough watts to it , it will fly. But it gonna be fast! Might be a hoot to fly.

J

[Ralph A. D'Amelio]

Thats really nice lines on that airplane.

Jerry they were heavy and the wing was probably in that range 7-9 oz. especially with the 1/8 wire landing gear , etc.

The axi 2820/10 had absolutely no problem in flying it. and actually it handle fairly well even at low speed. However, the motor was 6oz and will need a lot of nose wt to balance whenput in the tail.

At this size they are great canidates for putting the motor a-mid ship and using a shaft. Tried it once with little luck. Also I wondering how to launch these things, The F-4 is too wide to grip at the fuse for HL. Not into bungys yet so am leaning to put a gas tank under the fuse to grip and launch as I did with my F-15.

What are you considering for power? I am favoring an outrunner.

Jerry at this size and the 42" F-4, they certainly make a statement don't they!

[Ralph A. D'Amelio]

Jerry, just wiegh my wing for a single layer of FFF its 3.4 oz! By the time you double up and put some carbon rod etc.... your 9 oz seems lite for foam/balsa. ;) I'm guessing then the auw less motor/electronics will be in the 22-24oz range for the F-4. Motor/ 2s3plipos servos, etc will add another another 16-20 for total flying wt of 38-42 oz. W/L wouldn't be a problem and T/W at 5 watts/oz around 200 watts which should be easy to get.

DAF

Isn't this fun? You know if we had to do this in all in balsa it would take longer and be considerably more expensive. With foam it goes fast and can make changes even starting from scrach and it doesn't break the bank. It just means more trash bags.

[J Morgan]

DAF,
It won't be a lightweight but have you figured the WA yet? Might still be a very decent WL by the time it's done.
If I remember right, and this is off the top of my bald head, my 22/20/3E is about 5.5 oz.
Won't be abe to use wheel weights in the nose, going to need the whole rim!
Sending my plans off today so as usual, you will be done and maidened before I even get started.
Have we a scheme in mind yet?
I'm going with USAF Col Robin Olds, based out of Thailand, camo scheme.

J

[J Morgan]

Once you go bungee, you'll never go back!
A centerline tank would work good and probably look great. Most pics you see out of the Nam shows them with tanks in place unless they've already made their run in.

J

[Ralph A. D'Amelio]

J, see post above I will calc the area.

[Ralph A. D'Amelio]

J, if I did it right about 4.5sq ft! At 42oz W/L = 10 or a glider once we get it airborne.

[Ralph A. D'Amelio]

Jerry please be free to add/join this thread. This area of large size pusher jets will have its own set of problems and issues and is new to me. Have not been there or done that! So chime in anytime.

DAF

[Ralph A. D'Amelio]

This is my first time working with retracts and having today off I did the following with wing. The wheels will retract into the engine nacelle since there isn't any space with a flat plat. I'm using 2 fff for the wings the retract will be above the top surface by 1/8" will put some blister on to cover.

How to carry the lg loads was somewhat of a chanllenge and came up with the following. The two ply plates that the gear is attach to distribute the load to the fff. The 2 carbon tubes reinforce the wing for bending and also pick up the gear loads. Its solid as a rock :) The carbon rods are on the top surface of the wing and rest about midway on the ply.

J, this wing will not break...guarentee! I may put another fff layer on tap to hide the retract if the blister dosen't look good. By the time you sand away for a wing profile it would be about 1/2 the wt of a full fff wing sheet. The wing as it stands now is 7.7oz ( a little lighter than yours Jerry). The fuse is now at 11.4 for a total wt of 19.2oz. Still in the ballpark. :)

[Ralph A. D'Amelio]

Some more pics.

Geez J, this is a big plane. Are you sure you know what we are doing :confused: ;) :D

[roccobro]

I'm amazed at the speed you guys are working. Good job!

Justin

[J Morgan]

You guys! DAF is doing everything! I haven't even got my plans enlarged yet.
That wing will be solid. Nice job on it.
I know your weight is in control but I'm thinking we're gonna have a tough time staying under 45 oz.It all adds up too quick.
Question, it looks like you stopped the wing LE short of the intake, more of a scale look?
Yes, it is going to be huge! Your centerline tank will work for launching but this plane begs for a bungee.
Finally caught my wife's cold, feel like crap. Didn't get squat done today.
I did finally get my new notrbook and DSL. Heaven! Little rough until I get used to it.
Keep up the great work Ralph.

J

[JerryHall]

Hi guys...
Thanks Ralph for the invitation to join the crowd...I am not sure I can add much of anything important, but it is nice to be included...
Sure wish I had the wing area you have on the F4... I may have to start over and make the RA-5 larger... One question though is the shape of the fuselage lends itself to being an airfoil in itself.... It should yield about 160 inches of lifting area or just over a foot, and bring the total to about 3 ft sq... At 46-48 oz the loading should be around 16 oz...Managable...
At present I am considering the Magnetic Mayhem reverse direct drive with something like about an 8x4 or 8x6 electric prop...I put an 8x4 on 10 cells and by holding it in my hand, I thought the thrust was quite good...Sure did blow all t he paperwork and sawdust off the workbench in a hurry..Sounded like about 8-9K RPMS ..No official tests yet..Weight of the motor is a problem...9 oz... I do have a new Phasor 15-3 NIB, but don't know much about brushless yet...I am sure it is lighter and I will check instructions regardding prop size and thrust later...
Yes Ralph, these jet aircraft of this size do make a statement...Every time I look at the RA-5, it just gets prettier...
Your comment about a centrally mounted motor and driveshaft caught my eye...
I have a catalog from a specialty ( small parts)house that has all sorts of gears and U-Joints etc...I will do some research...
Another possibility is the new GWS twin 350C with gear box coming out $ 26.00 and with a 10" prop and 8 cells was supposed to put out about 30-35 oz of thrust...If that would work, it would be cheap and light..
Oh yeah, keep you fingers out of the prop....I hand launched Randy's new Guillows Stearman Saturday, lost my grip, the model slipped and I instintively lifted my left hand to catch it before it hit the ground, and my left thumb got cut to the bone with one of those 6 inch dia. scale nylon Hamilton Std props...Sp 400 going full tilt...Broke off about 3/4 inch of the tip of the prop on my thumb...After I got it packed in snow and half frozen, the pain sort of went away...40 years of modeling and this is the first time I got hit by a prop...Never too late to join the crowd I guess...
Anyway.. Thanks again...Great project there...Keep us posted...

[Ralph A. D'Amelio]

Hi Guys took a break to watch the Flight of the Intruder which I pick up at Wallmart for $5.50. Great flight shots. Its the first time I noticed a F-4 chasing a Mig!

Yes J, I fix the wing design on this one so it ends in a more scale position...you did notice. The wt is definitely will be a factor. I up to 20 oz with the addition of the nose gear. If the whole thing comes out too heavy I'll build anothe wing w/o gear.

J, a couple of design points to keep in mind. The nose is pretty long and it fracture(you can see it in a pic) so I took off the top/bottom, gotta love contact cement and put in a 6mm depron doubler and replace the foam square rounding stock with 3/8 balsa triangle stock. After doing this the next weakest joint is the nose where in comes into the fuse/nacelle. I think doublers should back past this interection for at 3".

Everything seems ok now, the balsa triangle and the 3/16" balsa cross grain on the bottom really stiffen this up. Of fg/wbpu will also help.

Notice, theres penlty of room for 3s2p TP2100 I'm hopping I don't have to add lead.

Great that you gotten a new notebook and DSL, thats what I have and its lickly split.

Jerry sorry to hear about you finger , I can really empathize with you I gash my finger on a rear-prop Hawk this fall bleed all over the field. Good thing I had duct tape in my field box. I am sure you can add a lot. Yes a reliable, efficient shaft driven rear prop drive would open up a number of possiblity and be more keeping with scale. I imagine it becomes a trade-off between the dead wt up front and the wt of the shaft connectors etc. The twin 350C sounds promising as well.

DAF

[Ralph A. D'Amelio]

Oh, another thing, I was going to epoxy the wing to the fuse but with the gear servo and aileron servo I'm pretty sure I will need access for maint. Geez more wt!

[JerryHall]

Thank goodness for duct tape.. I put my finger back together with masking tape and a strip of paper towel....Works pretty good too...
I dug out the Phasor 15/3 motor and they say it will run well with an 8x4 prop and haul an airplane up to 48 oz...It is about 4 1/2 oz lighter than the Mag Mayhem...so the next step is to get a hi discharge Lipo and save some more weight......What would you fellas recommend for a Lipo ??..
I would like to go with the 3 cell setup ( 11.1 Volt), but what brand and size capacity would you reccomend for up to aout 28 amps ??... And also is a parallel arrangement needed ?? I notice you are running 2s3p PT2100.. What company makes that battery ?
I am probably bugging the heck out of you guys with all the questions, but it is a regular smorgasbord out there with all the brands, capacities, and performances of these brushless motors and LiPo batteries, and at the cost of them it is sort of scarey to just buy a pig-in-the-poke, not knowing some of the ins and outs......
Thanks for your time...

[St. Martin]

Jerry, You willneed a 2p set up in the least. I just purchased a pair of Irate 2200 3s lipos that give 26A constant. 32A bursts. I feel you will be over 30A on the phasor.

The reverse mayhem is fo a GB. The timing is adjusted as so. The phasor has a 20,000 RPM limit, so keep it below that or she will possibly throw the mags. This is basically a torky type mtr. You may prefer a higher ptch speed for the wing area that you have. Possibly experimenting with higher pitch props may be in order, using a whatt meter and tach. I would think a 8-6E would be a good starting point, or it may not get on the proverbial "step".

Steve

[J Morgan]

Jerry,
I'm running a Tanic 3s 2500 in the F-4, good for 12-15c discharge. That should work for you.

DAF,
Don't know if you saw how I reinforced the Me-262 fuse. I laid a strip of heavy FG inside on both sides and used West System epoxy to adhere it. Makes it incredibly strong. that's how I'm going to do the 42" F-4
Man, you are moving right along. Hope the gear works out for you.

J

[Thomas Nelson]

FWIW, I am getting 35-45 amps from my iRate 3S1P 3100 mah pack from cheapbatterypacks.com. In fact, if I start with a warm pack I'll get my CC45 cutting out owing to the current exceeding 45 amps ... easily over 400 watts. Needless to say, I am very pleased with this uber-lightweight approach in my F-16. But if you expect you'll be using full throttle a lot then I'd suggest a 3S2P pack.

I think Ralph's remark about the "2S3P" pack was a typo - "3S2P" is what I think he meant. Right Ralph? :)

[St. Martin]

Wow, Tom! Thats a lot of current. They rate them at 37A constant and 45A bursts.

Am I missing something here? I'm new to use of LiPo's so please understand I'm not being contradictory. Are you using thrtl control to keep the draw less till the draw is 35A?

Steve

[St. Martin]

Tom, disregard the above.. I just found your F-16 thread and downloaded the second clip on CD. I can understand now, that full thtl use is not needed! Great job!

Steve

[Ralph A. D'Amelio]

Yes 3s2p it should have read a pair of 3 cells connected in parallel. I/m using ThunderPower (TP) gen II good for 10-12c.

J, good idea about fg the inside.....fuse at high stress pts.. The other weak structural joint is the tail boom/fuse intersection as you may find out. Good idea to fg the inside here as well. I use 1/16 balsa vertical grain as a doubler as you would in a balsa fuse. This prevents the fuse from splitting. Did same here, guess what, if you go the long way on the fff for the fuse the "grain" of fff runs up an down just like my balsa doubler and does not prevent the fff from tearing vertical. Duh.

The next one ( why you just gotta love fff and foam in general its so cheap compare to balsa), and there will be a next one, I will make a number of structual changes.

This MK wil be a test bed to see some of the issues involved at this size, besides I enjoy prototyping or DOF (Designing on-the Fly) and it wlll it as a testbed.

DAF

[J Morgan]

It's too late now but on the next one try a 2" strip of auto shop weight glass and epoxy. The 262 has survived 3 MAJOR crashes with just minimul damage.
And it would really strengthen the weak area at the tail.

J

[St. Martin]

If it were balsa, it wouldn't need it..

Steve

[J Morgan]

Oh yeah? The way I fly, I've seen some balsa planes that could've used the same treatment!

J

[St. Martin]

You really should stop chasing those flocks of cantelope.. Try buzzards

Steve

[Ralph A. D'Amelio]

Steve, I do miss the smell of sanding balsa. However, with J's method of adding baby powder to wbpu you kinda get that nice smell back. :D

DAF

PS, then I miss the sound of a 4 stroke as well.

[JerryHall]

Well, I really did it this time....After all the helpful information from Tom, John, Steve, and Ralph, ( Hope I didn't leave anybody out).. I decided to go really big.. Found my credit card cowering down in the corner of my billfold and ordered the iRate 3100 3s pack...from CheapbatteryPacks...
My God !! A person should be able to weld 1/4 inch plate with that thing..45 amps...!!! I like the charge tap feature of the battery..What's another $ 15.00 for a new toy.. LOL
Thanks again fellas for the education...Hope I pass the test...

[roccobro]

I still get my heart racing when I smell high nitro R/C fuel. I learned how to fly as a kid on stick and tissue Cox .049 models. It's almost like getting a whiff of tobacco smoke for a person who has quit!

Justin

EDIT: I too found myself hovering ove the "buy it" button on Chepbatterypacks.com site! I bought (my first TP ) pair of 2S TP 1900 packs to make enough oomph for my 16/15/2 powered T-33. A single iRate 3100 (I only owned iRates until now) would knock another 1.5 oz's off the weight and give more rated amps!! *sarcastic tone* Thanks Tomas! :D

[Ralph A. D'Amelio]

Jerry, do you have the right charger for Lipos?

[Thomas Nelson]

He he!

Just to confirm: you can't be drawing 30+ amps continuously from the iRate 3100 pack. I suspect that I'm at <20 amps for much of the flight, with 45 only needed for the vertical lines - right on the limit of the of the Castle Creations Pheonix 45 ESC. Shouldn't be a problem with the higher efficiency of a propeller.

FWIW, in the cold weather I place the pack in a ziploc bag and immerse it in hot (tap) water (tupperware container). It's probably 30 minutes before I end up flying with it. Offers a noticable performance boost. The first video didn't use this trick, the second (much colder outside) did.

[roccobro]

Good idea Thomas. I wasn't too sure I wanted to blow hot air on my lipos from a heat gun before a flight. I had a couple dreams the other night where all my packs had a cell or two starting to balloon! Maybe it's a sign I need new ones...

Justin

[Ralph A. D'Amelio]

J, I found a Kinko a few miles from my office and had the F-4 enlarged. Boy did miss some detail. Its really big when you see the actual drawing. It was only 66 cents / sq ft. Thats relatively cheap. Will definetly start another ..have some new ideas on how to do it.

[J Morgan]

Must be nice, my Kinkos is in Laramie, a long way!
This has been a very enlightening thread on batts too. I appreciate it since I just charge and fly. Haven't learned squat bout the Lipos but i do respect the them.
D@#% DAF, you'll have #2 done before I start #1!

J

[JerryHall]

Ralph...
I do have a small Lipo charger.. Forgot the name...It is at the shop..
It will charge up to 3 cells, with a maximum of 400 mah....I am guessing that it might take up to 7 hours or so to charge the 3100 pack, if I understand electrical formulas right.. I suppose a Triton or such is in the future, but right now the $ `150.00 is a factor...I have been kind of overspending my budget lately and the IRS will need payment here pretty soon too...
Is it permissable to charge such a large pack on such a small charger...?? My thought is that it would just take longer .. Advice please..Again Darn Lipos are so touchey..

[Ralph A. D'Amelio]

Jerry, I did invest in a Triton and takes about 1-1.5 hrs for 2100mah at 2.1 amps so what you say sounds about right. I/m sure its ok, but I/m no expert, it dosen't have all the other fancy stuff but so what. I always set it to the same setting, the nice thing however it does tell you if your cells are down since it shows the voltage and it tells you how much you put in or in effect how much you took out. But with the higher discharge rates we are less likely to over discharge them especially if you set your low voltage cutoff LVC on your esc.

One thing I like about Thunder Power, is they replace 4 of my packs that I screwup by over discharging/connecting wrong for 1/2 price!

J, and they are openning 24 hrs a day. up to 3' wide and any lenght. Can you imagine what's possible.

I have to say again seeing it as a full drawing with all the details is awesome. This is one big mother! You are going to love it. Are you sure we know what we doing?

DAF

PS, In the process of scaling I had to go to an intermediate size and have a plan at 21"ws. Its real cool little guy. I bought thanks to my salesrepXmas gift cert to the lhs the new Eflite outrunner and esc. Puts out 80-100watts on a 10x4. At 16 oz this would really cook...... :D Is there a #3 in the offering? Who knows....only the phantom knows :D

[Ralph A. D'Amelio]

To put it in perspective :D

[Thomas Nelson]

Hey Jerry - your little charger will work fine. Slow, but not a problem. Just like you thought.

FWIW, I believe I've seen the Apache charger on sale for some $50.00. Does up to 4 cells at 2.5 amps.

Also, I've heard that you can use a Wattmeter to monitor amphours delivered to your battery. Haven't tried this, but intend to. Always looking for the cheapo way to do things aren't we modelers?! That way we have the $$ to blow on LiPo magic!

:D

[Thomas Nelson]

Holy Moly Ralph - it's monstrous!

:eek:

[roccobro]

Oh no! That IS big! As for the lipos, you can use the small charger and it will take as long as your math predicts. There are alot of new offerings on the market in the $50-$99 range taht are good for the average user (liek 2s and 3s packs). I use an Astro 109 and love it. I already have a charger for my Nimh's so I don't need that function like Tritons. I preffer a dedicated charger anyways, and this can handle 1 to 9 cells, and 50mah to 8 amps charge. I've seen them for $115 shipped and that is what I paid for mine after shopping around. Of course you'll need a 12V power source (like from a computer, what I use), don't know if the Triton needs that.

*Best nerd voice* Lipos are cool!

Justin

[JerryHall]

Thanks Justin, Thomas, Ralph....I will search for a cheaper charger for large lipos...I think the Triton is capable of charging everything, such a NiCad,Nimh, PB, and li-ion, as well as LiPo.. I already have chargers for those batteries, so the $ 50-75 charger for Lipos probably will work fine...I had not thought of it that way before...Thanks...
With you alls help, see how smart I am getting....LOL

Enlarging plans is one of my favorite functions....Save yourselves a lot of trouble, go to ebay and get an overhead projector that can be focused for its distance from the wall you are going to display on,( about $35-65), get some clear transparancies from your office supply shop..about 50 cents each, get a supply of poster board, about 29 39 cents per sheet, and make a transparancy of your 3 view on the office copy machine.. Put the poster board up on the wall, and back the projector up till you get the size you want, and trace around the lines...You can kill about 3 birds with one stone that way...
For instance...
You want a B-25, you want to power it with a 9 inch diameter 3 blade prop, so you will need 5 inches clearance between the prop shaft and the side of the fuselage...
Measure your image till you get 5 inches, measure the wing span and wing area on the image to see if you have power enough to fly that size model.. If so, trace top view, side view, front view on the poster board with scrap drawings for nacelles, etc as needed...Draw the center of cord line throught the horz stab and extend the line to a point over the wing area, measure off that line for the leading edge and training edge location of your wing airfoil and you have established the incidence... etc, etc..
Total cost for the drawing about $ 2.00 and you can do it in a few minutes and at 2 AM if you want to...and not have to drive to a print shop during their hours of being open..

[Ralph A. D'Amelio]

See Jerry you already contributed............$2.00 vs 18 that's, 1/2 bundle of fff, two 4'x8'x1" pink foam, 3 sheets of depron......I got to see if we have one laying around the office somewhere..............

Now that you mentioned it, we have a overhead projector that attaches to a PC in our classroom, that way I don't even have to make copies.

[J Morgan]

OMG! I almost fell out of my chair! I already knew it was big, but.........
And I'm sure the wife enjoys thenew wallpaper! It surely does put it in perspective.

J

[St. Martin]

Jerry, get the Astro 109 from MEC www.modelelectronicscorp.com. It will do what the Trton users wish they had. I made a Y-chord so I can chg both Poly Quest packs at the same time. I chg them at 2c, or 4.4A.

Steve

[roccobro]

Saw a couple Astro 109's in the "for sale" section for $110ea shipped, and another pair of Tritons (used) for $115-125ea.

I charge mine just like Steve does :p Saves time and balancing as they usually get paired together in most of my planes.

Justin

[St. Martin]

Aren't lipos wonderful, Justin? The astro is capable of doing three cells of this size at once.

Steve

[roccobro]

Yes they are Steve. I get warm fuzzy fealings when I try to explain the awesome power Lipos have over my life...I mean on an aircraft! It's like trying to explain a BL setup to a brushed motor guy. Yeah they're more $$ initially, but totally worth every penny as your smile grows from ear to ear. What can I say? They are the future.

Justin

[JerryHall]

You are quite a salesman Steve....I ordered the charger...Your comission will probably arrive in a day or two...LOL

[St. Martin]

I have found, Jerry that in electrics, get the most flexable chger you can right off the bat. If you buy one that can only chg 2-3 cells, then you are limited till you fork out more money. Then you find youself using the "good" one while the other gathers dust.. I have three chgers that can only do 6-7 standard cells. Never use them anymore. About 150$ wasted.

Steve

[J Morgan]

I have a drawer full of chargers that will only charge 7-8 cells. I never open it anymore.

J

[Ralph A. D'Amelio]

Hey steve, couldn't I do the same with the triton , make a y connector and charge 2 packs at a time at 4.2 a?

Ralph

[St. Martin]

DAF, is the triton capable of puting out that Amp chg? I would not trust a borderline capability. If it is capable of a 4A chg and you need a 4.4A chg to be 1c... hmmm..Astro recomends not chrging at less than 1c. And I have read this else where.

It would still be charging two 3s packs as a single 3s pack voltage wise, just the Amp draw is doubled. The astro is capable of 8A. Don't know if I'llever use that much, but good to know I have it. My only problem with the Triton is my personal dislike of a single chger being so multi faceted for diff types of cells. Esp. concerning hazards of lipos.

Steve

[PhilLin]

To put it in perspective :D

Oh my! That is impressive!!

It is almost as big as the JHH F-4 conversion I'm doing (44inch WS). And I'm pushing it with two 90mm fans @ 2400 to 2800watts total.

Keep up the good work!

Phil

[Ralph A. D'Amelio]

Steve I will check tonite But I'm sure it put out at 5 amps

Phil, I've been looking at your thread as well, my F-4 is still a dream that may never materialize. Only kidding J.

[PhilLin]

Steve I will check tonite But I'm sure it put out at 5 amps

Phil, I've been looking at your thread as well, still a dream that may never materialize. Only kidding J.

Sorry if it is going over my head. Did you mean that my conversion is still a pipe dream? I've shelled out for the kit, which is more than 50% of my cost to get it in the air. I've almost got the fan mounting finalized on CAD. The kit is what one of my club mate call a 100-hr build type. I've been running such fan/drive combo pretty reliably for over a year. Hope this works out.:)

What I like about your approach is the simplicity, lower cost; & once in the air, probably looks just as real except for maybe the speed :cool:

Phil

[Ralph A. D'Amelio]

:o So so sorry Phil, bad phraseology on my part. What I meant to say MY 42" ws F-4 is a dream that may never materialize.

Ralph

[PhilLin]

No apologies needed, Ralph. That drawing on your wall is so impressive it should push you to get your project done. :)

Your F-4 also keep my energy going to get mine going; although so far I've been in the gestation stage, but the ideas are finally gelling.

Keep up the good work.

Phil

[J Morgan]

DAF,
You're not fooling anyone here. We know you'll finish it.

J

[rcjetpilot]

DAF,
You're not fooling anyone here. We know you'll finish it.

J

I'm guessing it's already painted and he's waiting to spring it on everyone :D

You guy's are having way to much fun :rolleyes:

[Ralph A. D'Amelio]

Hi Guys.
Lots going on today as far as work and fun stuff. Started by unintentionally insulting Phil :o Found a Mega 22/20/3 brand new I bougth a couple yrs ago to use in a belt drive for my N17. This may work, I got to check what Steve told us a few replys up.

I went to my favorite lhs during lunch (it's 1.5 miles from my new office :D ) a great bunch of guys who all fly from small to a 1/3 scale pattern and compete in national scale events. As modelers they all have special skills.

Anyhow I really want to explore putting the motor a-midship and need some bearings. They had plenty but adapting a American .215 carbon tube to Boca metric bearings is imposssible. As I explain what I wanted to do one of the guys said he will mill be an adapter to fit the boca bearings for me. :cool:

J, if we can do this. we most likely will not have to put dead wt in the nose. Since I want to bench test this setup really didn't want to work on the 42".

After dinner, I was looking at the small 21" F-4 drawing and a stack of FFF So...oooo..I did this for my new Eflite outrunner or maybe the Fergerio(sp) bl. I could fly this over the pond at my office and chase the @#&^% geese. It wieghs 4.2 oz as shown with ailerons linkage install. Fitting the all flying stab will be a challege.

J, as you can see I also pulled a canopy on your vacumn box......only kidding.

DAF (aka Edward ScissorsHand)

[AirX]

Sweet looking Ralph, the bearing and shaft idea is a good one as others have looked intoand exploited with the F-14. The big problem is getting the alignment right, I have looked into a hollow titanium tubing for a drive shaft and it seems that the pricing is comparable to carbon fiber with out the problem of inconsistent finishing of the shaft. I had looked into a shaft for a 3.2cubic inch mid mounted UAV, the titanium needs ends made up to be bonded into the shaft and the machine work for those items are not that difficult to produce, also using epoxy to bond them onto the ends would work if the tolerance is kept close enough. Anyway we had decided to use 3 bearing blocks located in formers. the mid bearing block would be left unbonded till the ends were bonded and then the shaft would be inserted thru the 3 blocks and then the middle block bonded. This would ensure the alignment would be correct. Just ideas for you to look at.

Cheers,

Eric B.

[Ralph A. D'Amelio]

Eric something like the mega 22/20/3 do you think the carbon tube would be ok, or should I use carbon rod? My thought was not to have any universal joint , just anothe variable and could cause vibration as well. But a direct connect via a coupling for motor to drive shaft to 3 bearing blocks. The problem with carbon tube is if you squeeze it, it will break apart. my thought was to insert/expoxy a piece of mw at the motor/prop connection.

Also where did you find titanium tubing.

Thanks,
Ralph

[AirX]

Yep the carbon should be ok if the finish is clean enough. The titanium tubing we were going to use in the UAV was only .375 diameter and .035 wall thickness, super light. The need for the middle bearing block was for vibration damping because the span was over 30". I think if you use some smaller rod in the ends it would be fine as it would make them solid. The tubing came from the company I work for, I could find an outlet for you if you like.

Eric B.

Thinking about it the mid bearing block was needed because of the 2 stroke engines power pulses. You should be able to do without it being electric driven and no large pulses to dampen.

[Ralph A. D'Amelio]

No thats fine Eric. I will experiment with the carbon tubing first since my guy at the lhs is milling for it. Thanks for your input....BTW hows the A-4 comong along. I put mine aside for now and will use as part of my spring/summer fleet. Not enough motors/esc to go around. I having loads of fun with the 32" F-4, T-38 and now the SU-27B. They slide about 100' along the snow/ice covered field have to adjust making landing approach so I don't have to walk for it.

Ralph

[St. Martin]

I believe that you will need a "soft start" esc when using the carbon shaft. I have a Tmm 40A BL ESC that has this feature.

Steve

[Ralph A. D'Amelio]

Steve, sounds good I will check the cc to see if has a soft start I thought it did. I wonder if J as a 22/20/4 to trade for my 22/20/3 :)

Ralph

[AirX]

I am still putting stringer cutouts in the fan version, the pusher is ready to go to the laser. I have had a lot to do lately and I do everything a little on the slow side so I am doing the crawl on them. One thing that is moving forward faster than I can keep up with right now is my wifes imigration case with the INS and getting ready for vacation next week. I need a rest from everything... :)

Eric B.

[St. Martin]

I belive he is using the 22/20/3E(E-Star) which has a little less KV than the /3.

Steve
http://megamotorusa.com/Brushless/ACn22-20-3.htm?id=22
http://megamotorusa.com/Brushless/ACn22-20-3E.htm?id=23

[J Morgan]

Ralph,
I have 2 of the 22/20/3E's ( Me-262) and a 22/30/4 which I'm going to put in a 5' FW-190 A-4. Those are my big ones. Have a slew of 16/115/4"s. they are awesome on my 40+" ws birds.
YOU BUILT THAT AFTER SUPPER? Is this like Vegas? Can I surrender for half?


J

[Ralph A. D'Amelio]

Thanks Steve & J,

These are some powerfl motors pulling a lot of amps w/o good throttle management flight times are relatively short. I will experiment with it this weekend. Need to build lighter to get the watts down. This F-4 will be our test bed to try different combos. BTW the F-4 is easy to balance for handlaunching if you use the wheel wells as a finger grip. Could do a wing with w/o wheels and smaller holes for handlaunching.

Steve, you really gotta love ffff for prototyping.

J, started at 5:45 finished at 9:45 with a couple of breaks in-between. I use 3m77 exclusively and its just; cut, spray, wait 20 sec and press. I call it the "1-2-3" method of prototyping. BTW J, I epoxy some 3/4oz fg and added a 3mm depron doubler in the tail and nose section...real stiff now. Gotta do that on the big one.


Is surrender like insurance? I'm not much of a blackjack player.

Eric, understand.

Ralph
This motor then would be nice in a 48-52" Spitfire.......

[J Morgan]

DAF,
You have an amazing system going. Your work shows that.
It would be interesting if a shaft system could be used. It would save alot of nose weight. But of course, with the inherent cconstruction ( foam), I would suspect it might be tough to keep the system stable and vibration free.
Good luck because it would completely solve the nose weight problem.
My plans are at Kinkos, hope to have them Saturday.

J

[Ralph A. D'Amelio]

We will see what my friend Joe at the lhs comes up with , he bring it in sat. Yes I love the 3m77 system I have not had any failures that I could blame on it. I wish I could!

Ralph

[St. Martin]

DAF, you may get away with using the 16/25/4. It will swing a 8-6E prop on 8 kans or.. the 16/25/6 and a 9-7E, using a 3s 2100. I'm using the /6 and the 2200Po;y Quest with a 10-7SF and drawing 18.5A @ 195W In my hurricane. With the 9-7E you will have a high V/low amp system with a very good pitch speed. This will knock off 2oz off the tail.

Steve

[Ralph A. D'Amelio]

Steve where do I find this motor, I don't see it at HL

Ralph

[J Morgan]

DAF
Try Model Electronics Corp ( MEC). Nice people, if they don't have it, the stock is just down the street from them!
Do a search, I lost all my favorites when I changed computers. DUH!


J

[Ralph A. D'Amelio]

Thanks J, yes they are nice I bought one of thier drives for the N-17 and their bat pack setup. If you are like me I had about 200-300 favorites if I lost it I would cry.

Ralph