OLY 3 joiner rods

[gklimber]

Hi Guys,

Last weekend we maidened my just completed OLY 3 and then flew it again a few times today. All-in-all it's a very satisfying plane to fly. Predictable, no bad habits.

I built the plane with 1/2+" thick extensions at the wing root on either side of the fuse to give a tape zone. This meant that the original joiner rod was about 5/8" short per side. For the first launch, I just used another longer rod I cut from some 5/16" diameter stock I happened to have on hand. It was regular non-threaded rod I found at a machine supply place.

The first launch was an easy one and it resulted in a slight permanent bend in the joiner rod. Today, I used the original rod even though it was slightly short. The understanding of my flying buddies was that this rod was "hardened". We flew the plane a few times and noticed that there was quite a bit of flex at the center and sure enough, when we were done, the original rod also had bent permanently about as much as the one I supplied myself. I was assured by my friends that it would have bent more had it not been "treated".

My question is this. Is a 5/16" rod enough beef to support the stress imposed on it from a 12 foot wing?? The Bird of Time, I believe, has two rods. Surprisingly my OLY 2 has a 5/16" rod which stands up fine to some heavy footed launches. For that wing span it appears that 5/16" is enough.

IMHO 5/16" is just too small for a 12 ft. wing. What are the alternatives given the size?? Increasing the rod to 3/8 would be difficult given the tight fit which exists in the spar as it is.

Fire away.

jer

[dwells]

I have an O3 on the bench myself and will be watching this thread. Ray will chime in on this I'm sure...

[lincoln]

First off, according to the site it's more like an 11 foot wing.

Second, the original Oly 2 had a 7/32" rod, which, if you have restraint, is just barely adequate. Your joiner, proportionally, is a little stronger.

I had a 134" wing on which I bent a number of 3/8" wing rods. That glider had carbon spars so I didn't baby it enough, I suppose.

Third, people have lost the fine art of pulsing the winch.

However, if you want to launch harder you probably need a larger diameter somehow. Meanwhile perhaps you can get some ejector pins from McMaster Carr or Dixie Pins. (I hear the latter are quite good.)

[gklimber]

Doug Barry mentioned those pins. Glad to hear they are available at McMaster Carr.

We're looking at finding some aircraft aluminum rods as well.

I purchased the OLY 2 from a friend. He did a few modifications to it which may have included a beefier rod.

The winch we use is strong and we have to pulse or else........ These launches were not particularly aggressive.

Stay tuned.

jer

[gklimber]

PS -- that OLY 2 has stood up to some pretty hard launches -- fluttered the wings etc. The wing tip joints as well as the central joiner boxes have been wrapped in kevlar. Turbulator pars were added to the leading surface of the wing. Flies really well.

jer

[rogerflies]

FWIW, the 134" Lovesong has a 11/32" wing rod.

Roger

[Ray Hayes]

Hi Guys,

Last weekend we maidened my just completed OLY 3 and then flew it again a few times today. All-in-all it's a very satisfying plane to fly. Predictable, no bad habits.

I built the plane with 1/2+" thick extensions at the wing root on either side of the fuse to give a tape zone. This meant that the original joiner rod was about 5/8" short per side. For the first launch, I just used another longer rod I cut from some 5/16" diameter stock I happened to have on hand. It was regular non-threaded rod I found at a machine supply place.

The first launch was an easy one and it resulted in a slight permanent bend in the joiner rod. Today, I used the original rod even though it was slightly short. The understanding of my flying buddies was that this rod was "hardened". We flew the plane a few times and noticed that there was quite a bit of flex at the center and sure enough, when we were done, the original rod also had bent permanently about as much as the one I supplied myself. I was assured by my friends that it would have bent more had it not been "treated".

My question is this. Is a 5/16" rod enough beef to support the stress imposed on it from a 12 foot wing?? The Bird of Time, I believe, has two rods. Surprisingly my OLY 2 has a 5/16" rod which stands up fine to some heavy footed launches. For that wing span it appears that 5/16" is enough.

IMHO 5/16" is just too small for a 12 ft. wing. What are the alternatives given the size?? Increasing the rod to 3/8 would be difficult given the tight fit which exists in the spar as it is.

Fire away.

jer

__________________________________________

The wing rods supplied in all the Sky Bench kits are ejector pins. It doesn't matter where the ejector pin is purchased. There are several sources.

The brass tube gap ( as related to the wing rod ) you created is causing the problem.

Remove the brass tube from the fuse and replace with the correct length.

This is done easily with a hand drill.

Remember the instructions on the plans:

The brass tubes must exit the plywood root caps on the wings and the plywood root cap used on the out side of the fuse ........

Ray
http://www.skybench.com
Home of Wood Crafters

[gklimber]

Hey Ray,

Ejector rods are good. I've enclosed a picture of the plane so we can talk about apples and apples.

The brass rod extends through the ply wing roots which have been relocated about 1/2" out from the fuse on each side. There is solid balsa beneath the ply root ribs. The blue stuff if Icing Fairing compound.

I got the impression from your comment that you thought that I had simply used a longer unsupported brass tube and longer rod. As you can see that is not the case.

I got this idea from another thread where it was described. You seemed to think it was a good idea at the time. Do you think now that the additional effective width of the fuse in the area between the wings would cause the rod to fail ?? If so, it looks like I would need to remove the root extensions entirely and figure out how to retrofit screweyes to the wing roots.

Some smart mechanical engineer out there should be able to figure out if the stress on the rod increases in the new, wider configuration.

Cheers,
jer

[gklimber]

OOPS -- I mispoke in the above post. In the second paragraph I stated that the "brass rod" extends ....... I should have said the "brass TUBE" extends.

Sorry for the confusion. The point is that the tube does in fact penetrate all layers like the instructions stress.

Jer

[lincoln]

If the extended root ribs are firmly in place, so that they support the brass tube, then there shouldn't be much more stress at all. (Unless there's something going on that I'm missing.) However, you do need to go for a bit longer rod.

Forget about the aluminum. You ought to be able to get up close to or over 200kpsi with steel, but I doubt you will find any aluminum over 60kpsi or so. Aluminum is good if you have room to increase the diameter, however. I think you're going to have to learn to tap.

If there's no carbon in the wing, then the rod may be a good match to the wing's strength. A bigger rod might bust the wing instead of bending.

[rogerflies]

Adding the extra width to the fuse doesn't increase the stress on the wing rod. It just moves the point at which the stress is applied.

I'd definitely get a longer rod, though. The shorter one increases the localized stress in the socket in the spar. That could lead to big problems that are much harder to fix.

As I recall, the Sagitta 900 had a 5/16" rod. I think you're definitely in the pedal-tapper range with a 134" wing on a 5/16 rod, carbon or no carbon.

Roger

[gklimber]

OK -- I didn't think the width was a factor.

There's carbon. The central sections have Dave Brown's carbon strips and the tip segments have the tape. I can never remember the designations of those products -- anyway, the central section has the solid strip and the outer section has the wide carbon tow. I think the wing will break at the joiner between the sections before it snaps in mid section.

OK, so the consensus seems to be that I should get a longer rod which will fill the space available in the joiner sockets etc., use 5/16" ejector pins and soft pedal the winch. Right ???

Jer

[dwells]

Got a pic of the bent rod/s?

[Brner]

Is the brass tube through the fuse one piece or did you just add extensions on to the kit supplied one?

[gklimber]

I cut a new tube from stock I had on hand. I'll get a picture of the bent rods, but it's not very impressive. They didn't bend a lot. I was still able to get them out with difficulty.

jer

[Ray Hayes]

OK, so the consensus seems to be that I should get a longer rod which will fill the space available in the joiner sockets etc., use 5/16" ejector pins and soft pedal the winch. Right ???

Jer

________________________________________

describe where the bend in the rod occurred, left side .. right side ...both ... in the fuse... ???

I am very sure the brass tubes beyond the end of the rods did not bend if the rib bay space around them between the spars is filled with epoxy. But if a wing rod is in one wing panel more than the other than the bending load is concentrated and can cause a wing to fail at the end of the rod, brass tube and all depending on how severly short the rod is in one panel compared to the other panel..

Length of rod is very much dependant on joiner system. All the Sky Bench kits have plywood joiner systems that when put together proerply are very strong. Our history proves that.

You are the first to bring a bending wing rod to my attention. Measure the exact length of wing rod your modified OLY lll needs and if it is under ten inches, I'll send a replacement rod to you. If you built your wing according to the kit, the replacement rod I will send can be shorter to some degree than the rod length you created with your shoulder mod.

Another thing to think about is the wing slipping away from the fuse. I presume you have your wings taped to the fuse. Any gap between the fuse and wing is where the rod wants to bend. Does your plane have a gap between the wing and fuse, 1/16" is like the Grand Canyon if zoom launching.

At Wood Crafters this past week, we held a one of a kind contest for Gulf Coasters, MOM from Hi Starts. The winds were scary at times and one of our flyers had a wing failure on launch. The Gulf Coaster is sold as a laser parts only kit and the plans are from the original design. So the builders are left to their own skills. It was very disheartening to see how the wing joiner system was built. We could not come to a consenus of what broke first because the epoxy surronding the brass tube in the wing that failed had the consistancy of old bubble gum. Ca was used in place of wood glue or epoxy where plywood shears were glued to spruce spars. The plywood shears were attached to the sides of the spars just like the Sky Bench kits, but were only part way up the sides of the spars, about a 1/32". Now the amazing thing about this is, the plane flew in last years Gulf Coaster MOM contest. So it took a lot of flying to finally have a wing failure.


Ray
http://www.skybench.com
Home of Wood Crafters

[Ray Hayes]

I cut a new tube from stock I had on hand. I'll get a picture of the bent rods, but it's not very impressive. They didn't bend a lot. I was still able to get them out with difficulty.

jer


Out of what ::::

the brass tube in the fuse


the brass tube in the wing .... which wing .... or both ....

"I was still able to get them out with difficulty."

What does this mean ... the rear wire alignment too ... maybe ???




Ray
http://www.skybench.com
Home of Wood Crafters

[gklimber]

OK -- here is pix of the rods. The longer one is the rod I substituted for the shorter one which came with the kit. They bent in the middle because in the case of the longer one, it was centered due to the fact that I made it with about 3/32" clearance at each end when the wings were fully on -- taped with NO gap (well maybe 1/64") -- and in the case of the shorter one, I made spacers out of dowel to fill the void in the brass tube at each end of the shorter rod. Close tolerances again.

The joiner rods were removed with difficulty from the brass tube in the fuse. They slipped right out of the brass tubes in the wings -- both wings.

There was also a bent alignment wire with the second, shorter rod (supplied ejector rod), but no such bent wire with the first launch using the longer rod I had on hand.

I don't think anything in the wing was damaged. The brass tube sockets were potted in a fairly thin mix of microballoons and 30 minute epoxy. Like wise the spars were properly built avoiding gaps between ribs and webs and between spar and webs. 30 minute epoxy was used with plenty of weight for the spar-web joints and properly fit, clamped vertical grain stock spanned from one spar to the other. The spars couldn't be stronger what with the addition of full length carbon.

I have ordered half a dozen ejector pins from Dixie Pin -- $4.00 a pop. Appx. Rockwell 64 surface and 53 center. Should do fine.

The rod is 9 5/8". Do what makes you feel right. I'm not worried about it.


Jer

[Ray Hayes]

Jer,

When you receive the rod from me, put a permanent identification mark on it with a drill in the end of the rod.

Since you built your fuse with an open hatch above the brass tube fuse that allows access, so here is what you can do:

remove the brass tube from the fuse, but inspect the shoulders first to detect any damage. Also, before removal, insert a straight rod into the fuse brass tube and try and determine when the bend in the brass tube starts. I suspicion there is damage to the shoulder area.

replace the brass tube and add lots of 3/8" wide spruce under the fuse tube from side to side and against the former with epoxy. Likely, the wider shoulders have put additional stress on the rod .. AND WHERE.. the brass tube is the weakest. Compare the fuse brass tube's lack of support to the support the brass tubes have in the wings.

If there is no bend in the wings brass tubes, there won't be any damage. A rod never brakes inside a brass tube that is surrounded with support like your OLY lll has. Rods break/bend at the weak areas ... between the wing and fuse and in the fuse brass tube if not supported. The initial bending/breaking force starts in the middle of the rod ( fuse ) and spreads out from there seaking a weak spot. In your case, the weak spot was the unsupported fuse brass tube and you can easily fix that.

Since you launched the OLY lll the way it is, with the fuse brass tube bent, means the bent tube has reached a point where it can support the wing rod from bending further.

From the pic, it looks like your steel rod has bent at the center and between the fuse and wing junction, but it is hard to tell for sure from the pic.


Ray
http://www.skybench.com
Home of Wood Crafters

[gklimber]

I have maple (or oak) I can use beneath the tube in the fuse. How about 1/2 x 1 1/2" and all the way across the fuse. I'll have to find a way to keep from epoxying the push rods to the hardwood. Sounds like something which will help.

I think your analysis of the bends in the rods is correct.

I assume you have my address??

Stay tuned.

jer

[Ray Hayes]

[QUOTE=gklimber]I have maple (or oak) I can use beneath the tube in the fuse. How about 1/2 x 1 1/2" and all the way across the fuse. I'll have to find a way to keep from epoxying the push rods to the hardwood. Sounds like something which will help.

I think your analysis of the bends in the rods is correct.

I assume you have my address??

Stay tuned.


________________________________________


why so big, why so heavy, 2 - 3 pcs of 1/8 x 3/8 spruce epoxied to the former and bottom side of the fuse, side to side, will do it without adding much weight and messing up your pushrods.

For those reading this thread, you can use two brass tubes, one inside the other, and the support above to create a very strong joiner system in the fuse. Two tubes system is also good in a glass fuse application. Two tubes are not neded in the wings.

Please don't forget to permanently identify the rod I'm sending.

Ray
http://www.skybench.com
Home of Wood Crafters

[Oldcoot2]

And this is another reason why I am sticking with Skybench! Where else can you get this kind of personal response and concern over a product.
Way to go Ray!
Gerald.......Waitin' on my Oly III :p

[atmosteve]

My fuse wing joiner tube recieved some reinforcment inside with cross timber lengths incorporated into the epoxy setting of the tube.
I have only 0.014? Dave Brown carbon capping on my spars, but all this should do the job with moderate pedal pressure.
Thats one pretty strong rod all things considered?- depends on a lot of things.
Honestly, your rod bending is a good thing, better that than your wing folding.
It could make you respect the thought that goes into the engineering behind these birds.

[Ray Hayes]

And this is another reason why I am sticking with Skybench! Where else can you get this kind of personal response and concern over a product.
Way to go Ray!
Gerald.......Waitin' on my Oly III :p


______________________________________

Gerald,

Today is the first day I have felt fairly normal, doing that Wood Crafters thing down in Muncie takes a lot out of this "Oldcoot". Use to be, I could recover from four days of doing this stuff in one day, but that was back when I ran fast eight mile jaunts three times a week. Now I try to walk everyday for an hour and today will be the first day I can do that since Wood Crafters.

The moldy planes ( cookie cutter look a likes ) require the owner to balance it correctly, install the RC and have it programed right. But, us woody guys can easly modify a woody kit ... for better or worse ... and about the only place the woody builder can get help is an internet group like this one, and sending an e mail to me. It is a good thing until construction mistakes and/or problems are created and the builder posts his problem and receives wrong advice that can hurt the builders plane and the mfg's sales. So I'm here to help protect my products from bad publicity as well as helping guys have good flying woodys. It is a two way street that helps Sky Bench improve the kits, I learn things too, plus I enjoy it.

I'm far behind on shipping after Wood Crafters, but I'll have your OLY lll kit shipped next week. Appreciate your order.

Ray
http://www.skybench.com
Home of Wood Crafters

[gklimber]

Ray,

For some reason I assumed that the spruce would go side to side under the tube, but it sounds as if you are thinking that they would run vertical. The side to side orientation is what prompted me to consider hardwood.

Would the 1/8" side of the piece contact the former and the 3/8" stick out under the tube? Would the several pieces side to side be in contact or spaced out across the fuse?? I understand that whatever the configuration, they would all reach the fuse bottom.

Thanks for your help.
jer

[Ray Hayes]

Ray,

For some reason I assumed that the spruce would go side to side under the tube, but it sounds as if you are thinking that they would run vertical. The side to side orientation is what prompted me to consider hardwood.

Would the 1/8" side of the piece contact the former and the 3/8" stick out under the tube? Would the several pieces side to side be in contact or spaced out across the fuse?? I understand that whatever the configuration, they would all reach the fuse bottom.

Thanks for your help.
jer

Just another reminder of how hard it is to write instuctions that everyone reads as intended.

Hmmm, how can I explain this. the brass tube is 3/8" wide, it is touching the plywood former. A 1/8" x 3/8" wide spruce stick would fit under the brass tube and touch the tube and the former. the spruce piece would go side to side ... that is, fuse side to fuse side. add another 1/8" x 3/8" to the bottom of the first and a third to the bottom of the 2nd . You will have a 3 layered spuce support under the brass tube ( to keep it from bending under load ) that is glued with slow cure epoxy to both sides of the fuse, the under side of the brass tube and to the plywood former. The spruce support demensions will total 3/8 x 3/8 x width of fuse.

and does not reach the fuse bottom.

Ray
http://www.skybench.com
Home of Wood Crafters

[Oldcoot2]

Sounds perfectly logical to me, Ray. I believe I will incorporate it in my build.
Very little weight gain, and tremendous support for the fuselage tube.
Thanks for the heads up,
Gerald

[schrederman]

Sorry if this sounds wrong, but I'm glad Ray is behind in shipping kits... it gives me some hope to know there's still some demand for KITS instead of ARFS!

Vader

[gklimber]

ok -- NOW I GOT IT. And "it" sure wasn't what I thought at first.

It is devilishly difficult to write clear instructions/documentation that is not subject to misinterpretation. That's why a picture is worth 1000 words I guess.

Thanks for your help. I'll report back here after I try the new arrangement.

I second the comment re kits vs ARFs. There are so few folks now-a-days who want to or have the time to build. They'd rather just spend the money and fly. I enjoy the building every bit as much as the flying.

Cheers,
jer

[Ray Hayes]

"I enjoy the building every bit as much as the flying."



Hey Jer, That is where I come from too, I love to build, it is very relaxing and rewarding. I know a lot of guys that do more building than flying. The hobby of flying RC Sailplanes can be enjoyed in many different ways and it is not all about contests. A couple of years ago I posted there were more guys in the hobby that don't fly in contests than there are those that enjoy contests. I got clobbered by a few contests guys that thought I was nuts. They were the guys that buy and not build.

From my experience in this hobby, I can see the guys that build are in the hobby much longer than the buy and fly guys. Many, when they crash, have their final flight because they will need to replace the damage with a whole new plane and don't have the skills to repair the damage. So keep building guys .. it is very enjoyable for many.

Instructions: some builders need every step spelled out for them, some need photos, some need just the plan. I would say the new builders as a group haven't learned to "read" the plan. I agree, pictures are worth a thousand words. I'm a plan reader, reading instructions slows my build down. For years I have built all kinds of kits and have always just read the plan.

FEW BUILDERS : Many, if not most of my Sky Bench customers have never joined a sailplane club or have exited a club. The result is fragmentation of builders, they have no one to learn from or to teach. This is one of the values of a club that the builders are missing.

Enjoy flying the OLY lll

Ray
http://www.skybench.com
Home of Wood Crafters

[jihlein]

Please pardon me for the slightly off topic question, but has anyone electrified an Oly III, and if so, what equipment and what kind of performance did you get?

Please PM me back rather than cross pollinate this thread.

Thanks,

John Ihlein
Albuquerque, NM

[kwmtrubrit]

:eek: :eek: :eek:

[seanpcola]

:eek: :eek: :eek:

:eek: :D ;)

[seanpcola]

I am in the middle of an Oly III build myself. About to do the wing root fairings as shown above. It will be 3/8" each side. Guess I'll do the reinforcement as Ray says but I wonder how hard everyone is launching to actually bend the rod in the first place? Just asking for reference.

Sean

[gklimber]

Hey Sean,

Please remember to put a longer rod of some kind in the plane. The ejector rods from Dixie Pins are reasonably priced. They have a head (usually 1/4") which will need to be cut off.

I thought we had not been launching that hard. It was a pretty strong winch though. I'm not sure how to quantitate it.

I agree with everything you said Ray. I enter contests just to fly & have fun.

Recently I've been thinking of a design I may try. Don't hold yer breath though.

cheers,
jer

[seanpcola]

Hi Jer,

Yep, I already have rod in stock and was planning on it.

Sean

[merlinmurph]

Sorry if this sounds wrong, but I'm glad Ray is behind in shipping kits... it gives me some hope to know there's still some demand for KITS instead of ARFS!

Vader

Good point, Jack. I agree, it's definitely a good sign.

[seanpcola]

I would like to think there are still plenty of builders out there.

Maybe one of us should do a poll on here about that. ;)

[dwells]

I would like to think there are still plenty of builders out there.


For me the Spirit ARF was a perfect way to get into this hobby/sport. I have learned to launch, thermal and land and I love it (now an OCD). But there is something about building your own that for me brings back childhood memories of a rainy day and a box of balsa and tissue that is very comforting and stress relieving in these chaotic times. The Oly III will be a long build for me but that's okay. I know that when I get home from the rat-race each day there is something I can tinker with and relax and enjoy and daydream about. The therapeutic value of "makin" is priceless to me and works wonders for my attitude.

[gklimber]

Ray,
I got the rod yesterday I think it was. I "engraved" an "H" on the smooth end. Today the ejector pins from Dixie Pins came so I can fly the thing at least seven more times for now -- :>).

I ran your pin into the tube which remains in the fuse and this time I couldn't get it to go in past the half way point in the tube. This means the tube is bent in the middle. I'll replace it when I do the the repair/bracing we talked about.

I'll let you know how it goes after the next flights.

Cheers,
jer

[Brner]

......For those reading this thread, you can use two brass tubes, one inside the other, and the support above to create a very strong joiner system in the fuse. Two tubes system is also good in a glass fuse application. Two tubes are not neded in the wings........


Ray
http://www.skybench.com
Home of Wood Crafters

I like this idea......tks Ray

[Ray Hayes]

This text is being added to the OLY lll plans today, and two layers are shown on the fuse side view plan drawing.

NOTICE … To eliminate the possibility of bending the wing rod and brass tube
inside the fuse, place two or three layers of 1/8 x 3/8 spruce under the brass
tube the width of the fuse with epoxy before adding the fuse top.


Enjoy building a woody ...

Ray
Http://www.skybench.com
Home of Wood Crafters

[gklimber]

Hey Ray,

I'm glad to see the additions to the OLY III plans. I'm going to see if I can do both the double tube and the spruce support when I fix the OLY -- I may get to it today and possibly will test fly it this weekend. Stay tuned.

Jer

[dwells]

I think I'll wrap around the spruce/tube assy with kev or something...

[gklimber]

I thought about putting a layer of glass over the tube and spruce, but just didn't have the energy.

I did the mod and used double tubes. I enlarged the hole by using the old tube as a guide. I cut teeth in the edge of a section of the new, larger tube and chucked it in my drill. Then I put the larger tube over a section of the original smaller tube and let the smaller tube guide the drilling. It worked like a charm. A neat new larger hole. I put some CA between the tubes and then epoxied in the spruce supports with slow epoxy thickened some with cabosil. There was room for a 3/4 x 3/8" support. I sawed the spruce into three pieces as was suggested and stacked them. I suppose the lamination gives some added strength. Maybe.

I'll fly it this weekend if I can and we'll see whey happens. I'm not sure the spruce support will make up for lousy rods if that's really the issue. If these ejector pins really are what the specs say they are, then probably we are good to go, but if they are of poor quality (Chinese) then we are back at square one.

Stay tuned.

jer

[IHAVAWDY]

I boxed in the brass tube that goes thru the fuse with 1/8"ply and filled it w/epoxy & micro balloons. I'm pretty sure that I would fold the wings before the rod would bend. Instead of just supporting the bottom of the brass tube w/mutipule layers of spruce I think it would be better supported on all sides and filled with epoxy? my 2 $

[gklimber]

Hey H,

I take it the rod didn't bend on the hi start ??

Did you build out the wing roots on the fuse or did you mount the wing so it's root bears directly on the origional fuse sides ??

jer

[IHAVAWDY]

I built mine with 3/8'' shoulders on the fuse and have pulled out of some serious high speed dives with no problems. This new high start is very strong. I know it's no "super winch" but even if I had one I wouldn't want to launch any harder than this thing gives me. A eight to ten mph wind was lifting the "hose" completly off the ground and allowed for a pretty decent zoom off the top. Wing flex was noticeable but no issues with rod bending.

[gklimber]

Sounds like we may have the rod thing licked.

One more thing -- How much carbon did you use in the fuse and did you leave the root - tip section joiner stock?

I noticed a little flex outboard in my wings, but the vast majority was concentrated in the center. I have put carbon all the way to the end of the wings ( Dave Brown strips in the center section and his tape - tow - in the tips). This makes for a very stiff wing, but centers the stress more I think. If you didn't put in as much carbon, reinforced the center tube and launched a little lighter you may have put yourself in a good place.

My weekend plans to test my baby fell through -- maybe this week or weekend.

jer

[IHAVAWDY]

Yes, I also ran carbon the full length of the wing top and bottom of the spar as well as cap striped the ribs. The wing is very strong and I have no concerns. At 134" a little wing flex on a balsa wing is to be expected. IMHO

[Ray Hayes]

Yes, I also ran carbon the full length of the wing top and bottom of the spar as well as cap striped the ribs. The wing is very strong and I have no concerns. At 134" a little wing flex on a balsa wing is to be expected. IMHO


____________________________________

What carbon thickness and width are you fellows using on the top spar ?

And a little flex on a 134" balsa wing is necessary ... so the pilot can "read" the launch load.

Ray
Http://www.skybench.com
Home of Wood Crafters

[IHAVAWDY]

Ray; I used dave Brown's carbon fiber strips laminated to spars[both sides, upper and lower] full length of the wing.

[gklimber]

I used the strips inboard and the ribbon outboard.
jer

[Ray Hayes]

What carbon thickness and width are you fellows using on the top spar ?


Ah ha, Now I know why the question was not answered:

I went to Dave Brown's web site and the thickness is not stated there.

I sent an e-mail to Dave Brown asking the thickness of the strips.. no answer yet.

Guess I'll have to buy a package and measure.

Ray
Http://www.skybench.com
Home of Wood Crafters

[atmosteve]

Hi Ray, we measured the Dave Brown strips at the shop with an electronic vernier and it measured out at 0.014", or 14 thou.

I've used this for top and bottom spars, mostly because the next thickness up thats available here is 0.5mm, to heavy for me.

EDIT; 0.014, not 0.007, but not 100% sure.

[Ray Hayes]

Thanks for the info.


Ray
http://www.skybench.com
Home of Wood Crafters

[atmosteve]

Just edited my post, I think I got it wrong, its 0.014" by memory. If not its 0.007.
My apologies, let us know if a definite answer is out there.
Steve.

[gklimber]

The tow (Brown's Ribbon) will be thinner than the Tape. I'll measure if I have any left laying around. I finally emptied the trash the other day so don't be too hopeful. I used the lighter stuff outboard.

Cheers,
jer.

[gklimber]

Yesterday we flew the modified OLY 3 with the "H-Rod". We tried to simulate the first two launches. The wing flexed quite a bit both at the root and out each wing. The rod did not take a set and remained straight.

Looks like the fix worked. Thinking about it, it's understandable. Before the fix, the wings were acting on a longer moment arm -- half the length of the rod. After the fix with the central ~1/3 of the rod held rigid, the wings only could act on the rod which stuck out of the fuse -- shorter moment therefore more resistant to bending.

By the way -- I specked out the plane on the second flight and could have floated all day up there. I had to get used to the fact that the turn response is not at quick as with the OLY 2, but this is understandable given the longer span and the resultant inertia. It was a little puffy, but the plane penetrated the gusts well and seemed solid on final approach.

All-in-all a fun plane to fly. I think I'm gonna like it.

Jer

[kostuk]

Hi,
I'm about to finish my OLY III and found this thread about the joiner tube. Interesting read. I have a question: I measured the length of my joiner rod and it is exactly 9.5". I thought I saw Ray Hayes say it is supposed to be 10". Is it supposed to be 10"? If so Ray can I get a 10" one?
I also added a 1/8 by 3/8 spruce box around the tube in the fuse, but it seems that some additional load transfer should be added since this puts a lot of stress on the sides of the fuse in one small area around the tube. A 1/8 lite ply former just does'nt seem like it will be enough but I guess I can see if it fails and then beef it up if necessary. I did add 2 oz FG cloth to the outside fuse in this area to help.
On the spar I added 0.030 carbon on the center panel and tapered carbon on the outside tips. I wrapped the spar with kevlar thread since the shear stresses on the carbon will delaminate it after a couple of wing flexes if you don't.
Overall the OLY III is a beautiful sailplane. The one modification I would have liked would be for the wings to be joined at the tip sections so you could bolt the wing to the fuse. All of the full pedal RES planes like the AVA, Topaz, etc use this approach since it is stronger and lighter.
Ray

[dwells]

The picture of JER's original rod is 8.5" :confused:

[gklimber]

Indeed the rod was 8.5". The plans are a little open to interpretation. It looks as if they were first drawn with 4.25" of rod extending into the wing rod tube as measured from the root. The drawing was apparently modified and the tube "shortened" by filling in the area of the tube to indicate epoxy/microballoon fill leaving a tube length of 3.5" Presumably this is the way it is in my wing.

I've measured new rod, old rod etc.. My new rod length is ~9 5/8" -- it is custom fit to my wing. With the ~1/2" I added to the wing root on each side of the fuse this gives 3 3/8" sticking out each side to enter the wing root tubes. Those tubes are ~3.5" deep according to my reading of the plans -- just enough room for the new rod.

When I used the original 8.5" rod there was only 2 3/4" extending into each wing so that's ~1/2" less per side.

All that having been said -- I looked at the plan and it looks like there is room for about 5" max of bury for the wing side of the joiner rod if you want to add a longer tube and do it. The angle in the wing will be a little less, but that won't matter. This would give a rod length of ~12" for the stock version and ~13" for the wide version. A handy size ejector pin is 10" so.........?? Take yer pick. I can't remember the available pin lengths in the 5/16" size.

While I feel that these planes should take a moderate winch launch, they are wood and as such just won't stand up to the same stress as a Supra (Ray may disagree). The spruce brace under the tube in the fuse seems to help. Repeated flexing etc. may loosen it, but I'll wait and see. Meanwhile, I'm flying it.

Jer

[kostuk]

Thanks Jer.
I'm not a big fan of zoom launcing. I like to tap my BU sailplanes. The OLY III should really be able to haul a lot of line out with all that wing area. I've also built a Big Bird, Marauder, Mirage, and Majestic so i will be interesting to see how th OLY III compares. It will be nice to range out and explore lift.
Also any idea of where the best tow-hook location is? I was going to put mine at the CG (90 mm back from the LE) as a start.
Thanks,
Ray

[dwells]

Soooo, what is the proper length of the stock rod for the Oly III? Mr. Hayes could you please clarify? I'll measure mine when I get to the house...

[seanpcola]

Soooo, what is the proper length of the stock rod for the Oly III? Mr. Hayes could you please clarify? I'll measure mine when I get to the house...


My stock one measures 9.5".

Sean

[dwells]

Mine measures 8 3/8". Does this look right :confused:

[seanpcola]

I haven't even really looked at the wing plan yet. After reading above maybe the rod is to be shortened? I'll take a closer look but guessing there is some "fiddle" room. I will be adding the root extensions anyway so I may modify the wing tube/spar to the next longer length.

Tomorrow I am going by a local mill supply to see if they have suiteable drill rod. Depending on the length it comes in stock and price I may get several if anyone needs a longer one.

Probably should start another thread but I'll ask this here:

I am building this one for a good friend and he wants ailerons. Anyone on here that has gone that way please chime in on what di and polyhedral angles you went with and are you satisfied? I am thinking it may be best to not lose too much angle and keep the stability.

Sean

[dwells]

Drill rod or pin stock is not as hard as this stuff I'm afraid.

[seanpcola]

Drill rod or pin stock is not as hard as this stuff I'm afraid.

Well, I'll see what's available and report tomorrow night anyway. ;)

Sean

[gklimber]

8.5, 9.5, 8 3/8, 9 5/8, 10 -- are we all building the same plane ??

jer

[seanpcola]

8.5, 9.5, 8 3/8, 9 5/8, 10 -- are we all building the same plane ??

jer

Hmmmmm. :confused: I was running with the assumption that the rod is to be shortened after the wings and fuse are complete as I have done on other models. Guess we have to wait for Mr. Hayes to sound off.

[dwells]

With everything else in the kit cut so accurately, I would assume these most stable materials to be at least the same. Perhaps they're mixed up with the Bird series?

[gklimber]

Tow hook -- I put mine right under the CG which ended up being just aft of the former where the wing rod goes. The plane balanced level when suspended from the hook. It launched well with that arrangement. I also use just a tad of down flap on launch.

I;m sure Ray will clarify the rod situation.

jer

[kostuk]

I have a 9.5" rod checked the length that fits exactly into each wing joiners and through the fuse. I did'nt notice any extra space. I've been working on this kit for about 9 months so I forgot that when I was setting everything up I made sure that the rod and tubes were as close in length as possible. Glad that I did.
Thanks gklimber on the towhook location. I'll do the same. I hope to maiden mine this weekend - weather permiting.
Ray

[dwells]

Last night I said to my wife "Look honey, I think they gave me a short rod". Without even looking up she said "I told you it was hereditary". Now I find out mine's the shortest of the bunch :o .

[seanpcola]

Last night I said to my wife "Look honey, I think they gave me a short rod". Without even looking up she said "I told you it was hereditary". Now I find out mine's the shortest of the bunch :o .

Now now, it ain't the length of the rod, it's the........well, never mind. :D

[atmosteve]

Mine is 8.5", about 1.5" short.
I'll be replacing it with a 10" rod.
It's a lucky dip!

[IHAVAWDY]

Sean: I got your scan of the rib detail and have tried everything I could think of to make it work but can't manage to get it to "scale" :confused: They are too small. Any ideas? Also about your question on wing with ailerons... I kept the center sections flat and lowered the tips to 2.5" at rib # 28. I'm very pleased with the handling of my plane. I did mod the wingtips on mine as well as a full flying stab. c/g is at 92mm and tow hook set at 90. Climbs out very steep from high start and I've had quite a few pop-offs in 8/10 mph winds if I don't apply some down elevator on launch. I don't use any flaps or launch camber on tow. My wing rod measures 9.5'' so I guess I'm average :rolleyes:

[seanpcola]

Sean: I got your scan of the rib detail and have tried everything I could think of to make it work but can't manage to get it to "scale" :confused: They are too small. Any ideas? Also about your question on wing with ailerons... I kept the center sections flat and lowered the tips to 2.5" at rib # 28. I'm very pleased with the handling of my plane. I did mod the wingtips on mine as well as a full flying stab. c/g is at 92mm and tow hook set at 90. Climbs out very steep from high start and I've had quite a few pop-offs in 8/10 mph winds if I don't apply some down elevator on launch. I don't use any flaps or launch camber on tow. My wing rod measures 9.5'' so I guess I'm average :rolleyes:

Unless a computer-literate guy chimes in here I am afraid I can't help. I got to thinking after I mailed it that there may be some problems along that line. I'll ask my wife tonight since she has forgotten more about that stuff than I'll ever know. :o Also, I am thinking there is a "sizing program" that I downloaded for free that may do that but I'll have to research it. Wonder if we should post this problem in the Chat forum.

PM me your mailing address and tomorrow I can Priority mail the original trace to you. That is absolutely no problem on my end and the only solution I can think of and would probably be fastest.

Thanks for the input on the angles. We were thinking to keep the original center dihedral angle, flatten the outboard poly angles almost flat and leave it at that. May just copy your specs.

As for your rod length: At this point it looks like you and I are the big dogs on here. ;) :D I was gonna try to buy a longer one today but scheduling got in the way. I know everyone here must be sorely dissapointed. :p

[IHAVAWDY]

Sean: LOL. I knew I should have traced templates before I built my wings but didn't. :o I thank you for the attempt. I'll pm you with my address.
The ''other'' Keith

[dwells]

Hey Woody, what format is the file?

[IHAVAWDY]

It's just an E-mail from Sean. No file

[dwells]

26 and 27 right...hold on...

[IHAVAWDY]

Dwells #26 27 & 28 I need

[dwells]

Here Woody, just print this from MS Word. I just did and it is perfect scale.

[IHAVAWDY]

Dwells Unbelievable!!!! Thanks so much. This forum is fantastic.
From the other Keith, up north, flying by himself into the powerlines

[dwells]

You're very welcome...piece of cake...

[IHAVAWDY]

Dwells if you fly anything like you run a computer....we need to get together and talk :D thanks again. If I put on my three-d glasses I can pick the ribs right off the page! Saves a lot of time on the re-build.

[dwells]

Unfortunately, my computer skills are better than my flying. Still learning alot about this sport. Only been flying since January but my plane still looks good and flies great. Only some minor Monokote rips and one broken bone so far after about 150 flights. I hope for the same luck with this Oly III.

[IHAVAWDY]

I'm sure you'll LOVE the III. I've been crashing sailplanes since the late 70's and I'm starting to see a "little" improvement lately. :D

[kwmtrubrit]

Last night I said to my wife "Look honey, I think they gave me a short rod". Without even looking up she said "I told you it was hereditary". Now I find out mine's the shortest of the bunch :o .

It may be short, but it's hard and won't bend as much as those with longer one's. :D

[gklimber]

Jesh -- what has happened to this thread. :>)

The power line thing reminded me -- Last weekend after I flew the OLY 3 a couple of times, I dragged out the OLY 2. At one point I was near/over some trees and a weird gust rolling over the trees hit me and in the chaos that ensued I ended up beyond and behind the trees out of sight. I thought it was a goner, but my friend Doug was near and grabbed the xmitter out of my hand. Two seconds later the thing comes rising up over the trees right back at us. I don't know what he did -- he doesn't either -- but only our laundress will know.

Cheers,
jer

[seanpcola]

It may be short, but it's hard and won't bend as much as those with longer one's. :D

Typical Brit, always finds the silver lining in any cloud.....Cheerio, stiff upper lip.......on and on. :rolleyes: :D :p

Yep Jer, I have had a couple of flights like that. I stalled one once, it went out of sight BELOW :eek: the top of a huge drainage ditch (ground level). As soon as I lost site of it I just froze and gave up. Just as I started walking towards the ditch to retrieve the pieces it zoomed up about 100 yards past the point it went in just flying merrily along. :confused: . Best thing to do at that point, and a technique I use often, is to casually continue flying as if you meant to do that. Maybe throw in a comment like "hmmmm, usually there's some lift down there this time of day, guess I'll try back over by that treeline again".......... :D

[seanpcola]

I'm sure you'll LOVE the III. I've been crashing sailplanes since the late 70's and I'm starting to see a "little" improvement lately. :D

Your progress sounds faster than mine. :(

Guess that means I don't need to mail the drawings? If you still need them let me know. I'll still trace the rest of them out in case someone else (most likely me :o ) needs them. ;)

[dwells]

Guys, how about I just scan the full set and post them. It will be very easy to do.

[dwells]

Question. The aft balsa fuse sides in my kit have a terrible upward bow in them. The intructions say to maintain a flat bottom on the fuse. How do you dewarp something like tthat when it's running with the grain?

[atmosteve]

Don, my aft fuse sides have a slight upward bow to them, I'm not to worried as setting the horozontal tailplane AOI to the wings can be a normal part of trimming in certain types of builds, like the Oly.
A terrible upward bow like you described (got a measurement of the bow warp off the deck at the rear?) sounds much more dramatic though.
There are probably better methods, but we used to lightly steam and try reset balsa parts yonks ago with some success, depends all on the grain and quality of the balsa sheet.
If its really bad, and it isn't a result of weather changes, forget them.

[dwells]

Thanks Steve, it probably measures about 1/2" from the tip of the nose to the tail. That is, if you align the fore ply piece on the stright edge, the balsa tail tip is 1/2" up. I was thinking about jigging and steam ironing. I think if I can get it reasonable right before all is assembled and cured, it will stay

[IHAVAWDY]

dwells, Scanning the ribs for your own use is a good idea but posting "all" ribs is not as it's Ray's design and I would imagine has a copyright. That would be essentially a short kit and would affect sales of the Oly III IMHO. About the warp in your fuse sides, use the same procedure as you would with warped spruce for spars; place apposing or opposite warp so when glued to formers the warp is neglegted Does that make any sense? Or are you saying that the warp is actually affecting the horizontal trueness of the part

[dwells]

Got it Woody, and I understand about the ribs and hope I violated nothing with what I posted for you. From what I can tell, the former positions don't look like they will have much of an impact on pulling this down. The top and bottom fuse planks will help though and maybe the combination of all will bring it in. What if you do the opposing bend, steam iron it, then brush a pattern of thin CA on it. Has that ever been tried? Would that help "lock" it in?