Molded verses Bagged Supra problems

[mdennis]

I know Phil Barnes is making, (selling), a bagged version and Kennedy Composites is importing a molded version of the Supra. There may be others that I am unaware of.

I have read many threads concerning the Supra, it's various problems and their solutions, but I have a hard time telling who's version is being spoken about.

Can anybody give me a rundown of the various problems that each version, (molded verses bagged), is having, or are they both having the same problems?

It would be handy information to know about when, in the production number, that solutions for the various problems were resolved.

There are cost differences, and I would think that there are weight differences, but they should essentially fly the same. Do they?
(I suppose the weight difference in the wing farther from the CG would mean a higher wing loading and a slightly slower roll response in the bagged version.)

Thanks,
Mark

[Daryl Perkins]

I haven't had any problems with my Supra. I have an all glass molded version. It's at 64 ounces. Appears to be number 195. I don't see the flex in it that I saw in the earlier versions. Haven't flown it much though. I haven't J'd it yet.

I too have a question about one of the differences. Not between the scratch built versions, but between the Barnes bagger and the Molded.

Can someone tell me what the Barnes Bagger is finishing out at? If it's F3J strength, and in the low 50's, I may have to buck up and get one. I could always fly the heavy one when the winds come up... yeah... 64 ounces... the HEAVY one... ;-)

[rdwoebke]

Phil is selling a Supra? This would be news to me...

Now Phil does make the wings for the Thermal Dancer, and that is Supra eske, but not a Supra. And Phil has made his own Supras using I belive a Mike L. pod, but I was not aware he was selling a complete plane to the general public....


Ryan

[Phil Barnes]

I WAS selling a bagged version of the Supra wings and tails. Actually it was sort of a cross between the Aegea wing and the Supra wing. Details here (http://www.rcgroups.com/forums/showthread.php?t=412772). I only sold a couple dozen or so of those before I stopped. I still have a list of maybe 50 people waiting in case I ever get back to making them and I'm not adding names to the list. I only sold the wings and tails. The fuselages were coming mostly from Mike Lachowski and Terry Luckenbach. I think they tended to build out to about 62oz. If you want a 55oz Supra you'll have to build it per the Drela plan yourself or offer somebody else a few thousand dollars to do it. You MIGHT find a builder at that price. I would never build a plane and give it to Daryl with a guarantee that is "J proof". I may be slow but I'm not that stupid :)

The Supra problems you've read about were all talking about the molded Supra. I don't own one but from following the Rcgroups and RCSE discussions, it sounds like those problems have all been addressed and you only need to pay attention to them if you buy a used model that was built before the production issues were worked out. Even then there are some simple modifications that will likely eliminate the problems.

[mdennis]

Thanks for the reply Phil.

Sounds like there is a healthy market for your version.

Mark

[Daryl Perkins]

Sounds like he's not charging enough to me... ;-)

[Jim Frahm]

Phil,

I see you're not adding to the list, how about just building a wing and sell it to me without putting me on a list. :D

If that won't work, guess I'll order the cores from Compufoam and watch your video several more times and then give it a shot. :rolleyes:

JSF

[brownecg]

Does anyone have (or make) a vertical tail (fin and rudder) suitable for the Luckenbach Pretty Mantis fuselage for the Aegea? I think that a Thermal Dancer tail would work, but Denny has not indicated that he has one to sell. I have some of Phil's Aegea wings that I have been using with Ava fuselages, but would like to switch to the Pretty Mantis fuselage and tail feathers (I do have suitable horizontal tail surfaces.)

[tonyestep]

DP, there are a few threads on making a bagged version. One is:
http://www.rcgroups.com/forums/showthread.php?t=651389
The finished weight of a bagged Supra built as shown in that thread is 53. It will more than likely take a J launch, at least Drela engineered it to do so. When Phil sez a few thousand bucks, I can tell you from experience that at that price the labor would be cheap.

[Daryl Perkins]

Thanks for the info guys, but from scratch... I've looked at the plans.... yeah.. ok... no. :eek: But.... If Phil was producing wings, and they were finishing out at or even close to Drela's designed weight, I'd be all over one. I want to fly a clean 49 ounce one, just once. I think that would be a fun model to land. :cool:

[Badger]

I built a 136" Aegea which weighs under 56 ounces, Kevlar bagged wing and carbon spar stronger than the Drela Supra. The bidding starts at 3.5k$ ready to fly. :)
http://www.badger.rchomepage.com/images/suprab3.jpg

[ThermalThief]

I am currently building a Barnes Supra :) It has a 5 on all the wing roots...Phil, is the the 5th wing produced??
Wing area is similar to Drela but the span is 130'. I just weighed the wing prior to installing the radio gear and have 162 for each tip and 630 for the center so 954g together compared to the 738g of Drela's plans.

630g center
324g tips
149g Pod
60g Boom
27g rudd
30g stab



Ken

[markStockton]

#173 - #78
Fuselage 152g - 162g
Tail boom 65g - 72g
Wing centre 622g - 576g
Wing left 180g - 172g
Wing Right 179g - 172g
Stab 42g - 40g
Fin 39g - 38g

As you can see the fuses and booms are lighter, but the wing's have additional structure to sort out the shear failure issues the earlier models had.

Mark

[rdwoebke]

I want to fly a clean 49 ounce one, just once. I think that would be a fun model to land. :cool:

I think you're going to have to ask Dr. Drela to fly his then. Has *anyone* other than him built a hard winchable (much less J able) Supra at less than 50 ounces?

Bueller?

Bueller?


:-)


Ryan

[jofo1]

#173 - #78
Fuselage 152g - 162g
Tail boom 65g - 72g
Wing centre 622g - 576g
Wing left 180g - 172g
Wing Right 179g - 172g
Stab 42g - 40g
Fin 39g - 38g

As you can see the fuses and booms are lighter, but the wing's have additional structure to sort out the shear failure issues the earlier models had.

Mark
#259 Carbon Supra is 1349g empty.

[mdennis]

1349g !!!
If I calculate it right, that's just a heavy freckle over 47.5 oz

Daryl will be calling you next time he's in your town.

[jofo1]

Empty airframe, no gear, no harness. AUW is 65oz with ballast tube installed (still pretty light I think). Fantastic airplane, flies like a 3M DLG.

[ClayH]

Jofo,

Is that the full carbon version , or just carbon center section. 65 ounces is a great weight for either. My glass version came out at 61.5 ounces with Barnes tailset and the necessary mods for the early glass versions. I'd love a full carbon version at 68-70 ounces for those windy days.

Like you, i always describe the Supra as flying like a big DLG. Fits my flying style.

Clay

[Daryl Perkins]

I just actually completed my Supra last night. Yeah, I know I had already flown it, but I put the servo and linkage covers on, had to pull the wiring harness out to install the ballast tube, etc... It's all glass, nothing special. With the ballast tube installed, it's 65 ounces rtf. But like I mentioned in one of these forums, I don't notice the flex that plagued the initial super lightweight glass versions. I think the pylon and fuse are beefed as well. I think they've gotten the weak spots out of it. All in all, a nicely designed model.

[jofo1]

Clay,

Full carbon version. I tried to go as light as possible. JR790 rx(synth, love it), 368's in the fuse and flaps, 5125's in the ailerons, light gauge wire harness, battery configured to fit deep in the nose, still needed a couple ounces of nose wt though. Lighter h/v would save a couple ounces. DLG style links for h/v. Ran the pushrods inside the boom, used poly exp foam to secure them, four "blobs" of foam spaced in the boom, very light and was super fast (thanks Walter!). I have 36oz of ballast that I plan to load tomorrow in her at the slope as well. Very versatile model with the camber changing capabilities of Dr D's section.

jwf

[glderguy]

Glad to hear the Supra is working out for you Joe. The four "blobs" worked well for me as well, no ele slop either. Easy, fast and if you dont over do it pretty light as well. I have heard of some filling up their entire boom, personally I think thats way over kill. BTW, my Perfect is on its way, excited about having a Supra/Perfect fly off.
Walter

[markStockton]

Hi Guy's

Does anyone have details of the anti-flutter modification I saw on Arend's light Supra in Slovakia. It seems my older model needs a little help damping flutter on in the wing tip panels.

TIA

Mark

[Brian Wa]

My Full Carbon Supra No 231 has the following component weights straight out of the box:
Colour: Yellow upper surface, Blue lower surfaces, Blue fuselage.

Centre Panel: 665g
Tip panel - Left: 207g
Tip panel - Right: 206g
Tailplane: 39g
Fin/Rudder: 38g
Tail pivot: 6g
Tail boom: 55g
Fuselage Pod: 135g
Nose cone: 30g
Ballast tube: 32g
Wing joiners 2 off: 40g
Accessory pack: 53g
Bowden rods/tubes: 25g

Total: 1531g


If I could only get some time to start it.

Brian

[SOAR-Steve]

Mark,
Install a rib outboard of the aileron servo hole.

I saw flutter once in heavy wind. It was either the servo broke loose or the flutter broke loose the servo. Anyway, I didn't install the rib and just go to the Fazer in heavy winds.

Steve Meyer

Hi Guy's

Does anyone have details of the anti-flutter modification I saw on Arend's light Supra in Slovakia. It seems my older model needs a little help damping flutter on in the wing tip panels.

TIA

Mark

[Brian Wa]

The latest batches of Supra (mine is No 231) come fitted with a rib ready fitted to the outboard of the aileron servo hole.

Brian

[trend.ab]

Just finished and flew my glass Supra #308, it came out 58.1 ounces all up. We weighted a couple of planes at the field and confirmed this weight. Key reasons seems to be a lighter boom that seems to have been introduced somewhere after #260.

Beat

[ClayH]

I've been playing with ballast on my Supra since I've read that several guys think they fly better at 70 ounces than 62. Was flying with two Pike Superiors yesterday and noticed how much slower the Supra is in transition than those guys. I decided to try 8 ounces in my Supra to see how it worked and it responded nicely to the weight. Speed and size of thermal turns increased - a little more groovy with the weight.

Any others tried flying it with varied weights?

Clay

[glderguy]

How did it slow up to land Clay at the heavier weight?
Walter

[ClayH]

It slowed up nicely - I just hit partial flaps a little sooner in my approach. It caries the extra weight nicely in the landing pattern. I'm using flaps only, no butterfly.

Clay

[markStockton]

Mark,
Install a rib outboard of the aileron servo hole.

I saw flutter once in heavy wind. It was either the servo broke loose or the flutter broke loose the servo. Anyway, I didn't install the rib and just go to the Fazer in heavy winds.

Steve Meyer

Hi Steve

Thanks, I'm aware of this mod, and will do it. However upon Dr Drela's recommendation Arend Borst cut holes into the aileron to change the weight distribution. This also seemed to have a very positive effect. I'm looking for the dimensions of and layout of these holes. I'm also wanting to confirm that he used Kapton tape to cover the holes.

Mark

[markdrela]

Thanks, I'm aware of this mod, and will do it. However upon Dr Drela's recommendation Arend Borst cut holes into the aileron to change the weight distribution. This also seemed to have a very positive effect. I'm looking for the dimensions of and layout of these holes. I'm also wanting to confirm that he used Kapton tape to cover the holes.


Below are the drawings I sent to Arend.
Keep in mind that he cut the holes and added the stiffening rib at the same time, so there's no way to tell what had the major effect. I suggest adding the rib first, and if it still flutters, then add the holes. It's essential that the covering over the holes be very light, otherwise you'll undo most of the holes' effect. The Ultracote Lite is about 35g/m^2. Regular Ultracote would be too heavy.

[Daryl Perkins]

Thanks Mark!!! That's cool stuff!!!!

[markStockton]

Thanks Mark, this is really appreciated.

Another question for new Supra owners, has Vladimier stopped putting the ali ring's into the pods to reinforce the bolt hard points as well as hold the ballast tube? I installed the tow hook in #173 tonight and noticed the ali ring's wern't present.

[trend.ab]

Mark

Just finished and flew #308. There are rings in the pod that you can slide the ballast tube through. Are these the ones you are referring to?

Also, there is a subrip outside of the aileron bay and a piece of carbon in the aileron to stiffen things up. The angle of the aileron horn is also stepper then in older planes to prevent flutter.

Finally, the boom seems to be lighter then before, this must be one of the key reasons why mine came up 58.1 ounces all up with a CG around 107.

Beat

[jofo1]

#251 has the rings. Must have a lighter boom as well as my AUW is approx 64oz without the ballast tube. My CG is at 97mm, working my way back, must be pretty twitchy at 107mm.

[Bob McGowan]

... It's all glass, nothing special.

Hey Daryl, I’m totally surprised to hear that you got the glass Supra :eek: . You are the guy to always want extra spars and such :D . Why did you pick the FG version if you don’t mind my asking. I’m trying to decide what version to get next myself with F3J in mind. A friend and I just finished a couple FG versions for our boys built with all the light weight tricks and we love them.

I've got to share this with you guys. If there was any doubt in my mind if the Supra could keep up in the launch game (and there was a little), it is gone now. We just flew the Fresno Classic 2-day contest off of standard 12V winches with braided line. Wind conditions ranged from calm to light cross wind most of the time. We had the Z-log in AJ’s extra light Supra. Three of my good friends had Z-logs in their Pike Perfects. On this day at least, in these conditions, with this equipment, the Supra beat all three Perfects no mater how you sliced the data (best, average). Some of the Supra launches were over 700 foot.

Bob

[ClayH]

Bob,

Is AJ's Supra all glass? I have to admit that it's a little scarry to see the wing flex like it does on a hard ping, but Mark says it's designed to do just that. I love the way my Supra launches! With it's light weight and fast elevator servo you can realy squeeze every foot out of the zoom then square off the top in a hurry.

Clay

[Bob McGowan]

Bob,

Is AJ's Supra all glass? I have to admit that it's a little scarry to see the wing flex like it does on a hard ping, but Mark says it's designed to do just that. I love the way my Supra launches! With it's light weight and fast elevator servo you can realy squeeze every foot out of the zoom then square off the top in a hurry.

Clay

Yes Clay, his is all glass. We have not been holding back at all on launch pressure and it takes everything we've thrown at it so far including mono on winches into a stiff wind with a pound of ballast. Even the flex does not seem that alarming to me (his is a late S/N), though some people do wince. We are using Airtronics digital 94761 servos all the way around like I think you are also and I agree with you - they are fast, tight, with no drift and make the zoom work well.

Bob

[trend.ab]

Bob

I just realise that you are probably the same Bob I wrote to on gmail about flying in the Tri-Valley?!?
If yes, I am looking forward to see your Supra!

Beat

[joesoar]

Beat,

Would you mind posting some close-up pictures of the wings, stab and tail? Just wondering why it came out so light? Less paint? Lighter boom/tail?

Thanks!
Joe

[Daryl Perkins]

<<Hey Daryl, I’m totally surprised to hear that you got the glass Supra . You are the guy to always want extra spars and such . Why did you pick the FG version if you don’t mind my asking.>>

Hey Bob,

Congrats on the win(s). I went with the glas version cuz... uh... well... it was already on the way and not spoken for. :D I would have gone with the glass version anyway. I'm only going to use it for a few TD comps, and possibly 2 F3J comps. (Nats and TS) I'm not sure why people want to carry around the extra weight of carbon skins to fly thermal duration anyway. Carbon skins only help in torsion, unless they are throwing more carbon at the spar caps on the carbon versions, which I doubt. But that's just conjecture.

Mine is one of the more recent ones, and I believe they have beefed them up slightly. Mine doesn't flex like the early versions I saw. This one weighs 64.5, with the ballast tube installed, and CG'd at 108. It's borderline unflyable at 108. I'll probably end up about 105-106, and leave it alone.

I'm glad you're having fun with it. I'm having a real tough time to get it to fly slowly on final like I'm used to. I'm still messing with it, but I'm not consistent with it. Everyone else seems to have it figured out, I've read all the set up tips... I just need to keep messing with it I guess.

[trend.ab]

Joe

Just packed it yesterday to be shipped to San Fran, as we are moving.
We weighted all the parts in the clup. The wing is close to the other ones on our club, the weight savings come mainly from the fuse. Elevator is the same weight as others, as well. Here are some things I did:
- no clevis at the tail, L-bend and as in DLG
- stretched teflon pushroud housing from the DLG, certainly a lot lighter then the ones included in the set
- battery and servos further to the front then any plane I've seen
- harness with 32g signal and 24g powerwires, all connectors the one from the DLGs
- 9g Berg receiver (is almost one ounce alone compared to a standard JR)
- Antenna in wing, not in tail
- CG at 107 (used 1.4 ounces of lead in nose)

So no rocket science anywhere. Barry said they were using lighter booms, this might have contributed (#308).

Beat

[Daryl Perkins]

Beat,

Nice job on the build. Not quite sure where you saved the weight. The only difference I can see on our builds is the receiver. but then you're adding noseweight and I'm not. I usually build lighter than most too, but there wasn't much to do to add or save weight on this thing.

dp

[trend.ab]

Daryl

We had the same questions at our club, so we weighted all the planes with the same scale there, they were between 58 and 66 ounces.
A part certainly is CG. Here is a weight list of my pieces, it looks like the fuse is the one accounting for most of the difference compared to the heavier planes.

PartBeatLeft tip7.2Right tip7.2Center panel23.7Fuse without elevator17.3Elevator1.2Joiners and Screws1.5Total58.1

Beat

[glderguy]

Glad to hear about some verified launch heights on the Supra Bob. I think we all realized the Supra could launch w/the other top dawgs at the F3J/practice.
BTW, good flying last weekend man!
Walter

[Jim Frahm]

Okay, time to buy a Supra, but I'm a little confused about the #. Was there a problem in the early production? I'm looking at the FG version and the # is 263; is this a good one or bad one? BTW, I'm also buying an addtional pod, boom, and v-mount so I can build a bagged version.

Jim

[Daryl Perkins]

Beat - the majority of your weight savings is in the fuse and center panel. Like I say, I think my CP is beefed, as it weighs 25.9. There's almost 3 ounces difference right there.

My fuse with ballast tube and stab is 22.1. Without ballast tube and stab (the way you weighed yours), puts it at 19.9. So 2.6 ounce difference there.

My tip panels are slightly heavier. Maybe they were training the new guy the day they built mine... :(

dp

[glderguy]

263=good

[trend.ab]

Beat - the majority of your weight savings is in the fuse and center panel. Like I say, I think my CP is beefed, as it weighs 25.9. There's almost 3 ounces difference right there.

My fuse with ballast tube and stab is 22.1. Without ballast tube and stab (the way you weighed yours), puts it at 19.9. So 2.6 ounce difference there.

My tip panels are slightly heavier. Maybe they were training the new guy the day they built mine... :(

dp

I see, this are the same areas of difference to the planes in our club. Maybe I was just lucky there.
I have no doubts that you would win over me any time with your heavier plane, nevertheless...
Where are you flying?

Beat

[Jim Frahm]

Santa arrived today, actually it was the FedEx guy, but who's taking notes anyway... :D

Here's what he delivered----

Jim


Great packing job; Thanks Barry!

[mdennis]

Oh you won't like a lighter plane. You better get rid of it quick before it has a chance to cause problems with the way you fly your other planes. Just hit the little envelope with the person on it in the lower left corner of my post to solve this problem.:D

[Jim Frahm]

The second fuse (white) is a newer version. It has built in ballast tube hangars which will support the ballast tube in three places; nice touch.

mdennis,

No worries, I already have problems flying the other planes, might as well have problems with this one too.

How goes the flying in your area? I'm heading to Arkansas just as soon as I retire from the Military....

Jim

[mdennis]

This winter has been pretty bad. Usually we can find a day or two to fly, but not this year. When it hasn't been really cold, it's been raining or really windy.

Arkansas may be the place to be if all the global warming predictions come true. You could have ocean front property.

Mark

[markStockton]

Below are the drawings I sent to Arend.
Keep in mind that he cut the holes and added the stiffening rib at the same time, so there's no way to tell what had the major effect. I suggest adding the rib first, and if it still flutters, then add the holes. It's essential that the covering over the holes be very light, otherwise you'll undo most of the holes' effect. The Ultracote Lite is about 35g/m^2. Regular Ultracote would be too heavy.

Just to report back I installed the rib's, however the model fluttered again this weekend. Granted this time it was due to a hard launch on a Hollenbeck F3B winch with monofiliment line. I guess I'll now look for the local agent of Ultracote Lite. Anyone have any ideas on how best to cut the holes in the ailerons?

As a side note, I also got some minor flutter launching my new #173 model. I'm starting to think that if you are planning on mainly flying off strong winches, you should buy the full carbon version.

[Kiesling]

I never had a problem with my Kevlar version - off of winches or hand tow.
I put ribs on each side of the servo. I also made sure the servo was glued to the spar as well as the skin. The key thing to remember is that flutter is a function of mass as well as stiffness. So throwing carbon at the problem is not always the solution. This is where Kevlar is nice - lower density but higher stiffness than glass.

Tom

[oakman7004]

Just to report back I installed the rib's, however the model fluttered again this weekend. Granted this time it was due to a hard launch on a Hollenbeck F3B winch with monofiliment line. I guess I'll now look for the local agent of Ultracote Lite. Anyone have any ideas on how best to cut the holes in the ailerons?



I'm ging to use So-Lite ( Solarfilm Solite (http://www.solarfilm.co.uk/) ) since I have that now and it really feels lighter compared to Ultracote light, Which I've been using for years on various applications.

Difference are 20g/sqrm (0,6 Oz/Sqr yard) for So lite compared to 36 g/sqrm For ultracote light.

However I do not yet know the strength (used for this application) of the So-Lite....test will show if it feels sturdy enough!

/Jonas

[markStockton]

I never had a problem with my Kevlar version - off of winches or hand tow.
I put ribs on each side of the servo. I also made sure the servo was glued to the spar as well as the skin. The key thing to remember is that flutter is a function of mass as well as stiffness. So throwing carbon at the problem is not always the solution. This is where Kevlar is nice - lower density but higher stiffness than glass.

Tom

Having thought about the problem for the last day or so, I'm going to go through the whole set-up on both models. On #78 I'm going to lighten the tip as described. Other thing's I'm going to do is install second ribs on the root side of the servo as well as go through the linkages and either wick cyno into the threads or solder the clevises on directly.

I must say that my foam model didn't show any tenancy to flutter and it simply had 68gram carbon doublers as well as the pre-cured glass facing's as described in Dr Drela's design documentation. In fact I think I'm going to start work soon on another aramid / foam model and use it with my Eish! (see the next RC Soaring Digest) as my primary winch based competition models. I'll keep the miles off the molded Supras and use them for F3J.

Mark

[tonyestep]

[QUOTE=markStockton]...I must say that my foam model didn't show any tenancy to flutter and it simply had 68gram carbon doublers as well as the pre-cured glass facing's as described in Dr Drela's design documentation....
-------------
Yep. The Supra design is not just a 3-view; it's the whole construction technique as well. The airfoil and flight regime was chosen to match the target weight of the bagged version, and the turning behavior was figured out expecting the extremities to be light as they are in the bagged version. Maybe the molded plane is just different enough so that things don't work exactly the same.

[ThermalThief]

It's been maidened and ready for it's first competition this weekend.
59oz auw. Here is the before picture :D

Ken

[SmokinJoe101]

Interesting thread quite a few problems with it's short history. Was there not enough testing before this model was rushed to production? :eek: I do not recall another model with this many issues and still it's pilots continue to rave about it's qualities and line up to buy. Not bashing just interesting

joe

[markStockton]

I do not recall another model with this many issues and still it's pilots continue to rave about it's qualities and line up to buy.

You have to fly one to understand. I've probably had more problems than most (although not all the models fault), yet I'd buy another one tomorrow if I had the cash.

[oakman7004]

After maidened my Supra last night I second that. The concept is really working well. It was rather windy last night and yet penetration and handeling were smooth and precise, this with no ballast. This weeks competition will be fun to evalute performance more.

Or as my friend Joakim Stahl said..." nice concept, works so much better that the superior..."

/Jonas Ekman

[markStockton]

It was rather windy last night and yet penetration and handeling were smooth and precise, this with no ballast.

Another good point, I've flown mine in pumping wind in a storm front sloping it off a line of pine trees with only 250grm ballast. IE still lighter than a Pike Perfect dry!

I actually can't understand why I'd ever want to fill that huge ballast tube.

[markStockton]

It would seem that I owe my new #173 molded Supra an applogy. It looks like the flutter was causes by a bad thread on the rod that connects the two clevises for the aileron. I have now soldered all the clevises on this model and the control surfaces feel very F3B like with only a little movement in the metal gear servos.

For my older model I'm going to punch the holes in the aileron. I just want to practice this a few times on an old broken wing then I'll post details here.

[markStockton]

Following numerous flutter related incidents that have required the regular replacement of JR DS161 gears. I've bitten the bullet and implemented all the modifications as described by Dr Drela in this post (http://www.rcgroups.com/forums/showpost.php?p=7208001&postcount=31) .

My first idea has to use the shank of the Dremel bit running against the hole template as a guide. However to much heat was generated by friction and the template started melting. I eventually cut the holes free hand. It wasn't as hard as I thought.

I also took the opportunity to take out all the aileron and flap linkages and solder the clevis to the threaded rod to take out any slop there.

[Brian Wa]

Surely the first thing you should have looked at was the sloppy linkages rather than carve the wing up.
Slop in the linkages will cause the control surfaces to flutter every time.

Brian

[markStockton]

Surely the first thing you should have looked at was the sloppy linkages rather than carve the wing up.
Slop in the linkages will cause the control surfaces to flutter every time.

Brian

There was very little slop in the linkage. Infact less than the play you find in a high end Graupner / JR servo grearbox. I was working on the principle of every 0.5% helps.

[old dodger]

I know Im going to be jumped on with both feet ? I found mettle clevises
are prone to be somewhat sloppy in the threaded connection. Perhaps
it was the clevises I tried (thaught I tried most of them) Soooo-
Ive been useing the large plastic cleveses. Why?-- Stay very tight at
the threads. If the pin end gets little sloppy I can pinch the pin with a
pair of needle nose to tighted its fit (until I can get a new one out of
my field box). I perhaps believe its the weak link to go befor gears are
striped.
I dont see other high end planes useing plastic. Why? (I told you mine
will to tell me your's)

p.s. just rcvd #316 carbon light

Chris Brundege

[Radian]

I know Im going to be jumped on with both feet ? I found mettle clevises
are prone to be somewhat sloppy in the threaded connection. Perhaps
it was the clevises I tried (thaught I tried most of them) Soooo-
Ive been useing the large plastic cleveses. Why?-- Stay very tight at
the threads. If the pin end gets little sloppy I can pinch the pin with a
pair of needle nose to tighted its fit (until I can get a new one out of
my field box). I perhaps believe its the weak link to go befor gears are
striped.
I dont see other high end planes useing plastic. Why? (I told you mine
will to tell me your's)

p.s. just rcvd #316 carbon light

Chris Brundege


Chris,

The metal ones are WAY stronger then the plastic clevises. With the short control horns typically used on these F3J planes, the pin loading of the clevis is usually rather high.

The "Thread slop" you experience with the metal clevises is easly fixed with a drop or two of white "Elmer's" glue.

Once you set your linkages the way you want, work a drop of Elmer's glue into the threads. It will dry and eliminate the thread slope yet still be weak enough that it can be twisted apart if needed.

Radian
www.phflyers.com

[ThermalThief]

Chris,

We missed you this year at the DLG contests. You'll really like your Supra. I picked up a Barnes Supra this past year and had a great year. In fact Pops and I are building a couple of Drela Supra's for next year.
To respond to your question I use metal but with CA in the threads to stop the extra play.

Take care and hope to see you more next year.

Ken

[nuevo]

I use a drop of CA in the threads of metal clevises. That gets rid of the thread slop.

Same as Radian... except different. :rolleyes:

I broke two plastic aileron clevises during an F3J launch a few years ago, but that's another story.

[tonyestep]

...I broke two plastic aileron clevises during an F3J...
===============
Yeah, I had that happen too on a launch in a strong wind. It ain't easy to fly and land a plane in high gusty winds with no aileron control. Happily, I lived to tell about it. Learned my lesson, replaced all clevises with metal. I use blue threadlock, which takes out the slop.

[old dodger]

Thanks guys,

I knew some one could clue me in


--Ken I'm hoping to get out this comeing year more.

Chris