Winchproof Paragon

[SoarNeck]

Hi all,

I just had the chance to test-glide my new Paragon, and thought I'd share some pictures of it and of the building process.

The model was built from a Pierce Aero kit, with some notable changes to the wing spar. I'll show a couple of photos of that process for those that might be interested.

I'm happy with it so far, though all I've been able to do is hand glide it so far. After a week of beautiful, +20C weather, it's been SNOWING for the last half week or so! 15-20 more cm of the stupid white stuff. Grrr.

First, the finished product (61 oz w/Helios vario & 4 servos).

[SoarNeck]

While I have a couple of spare 0.060 carbon strips that I could have used for the spar, I recently discovered a local source of 2.9 and 4.9 oz uni-cf . I've never tried using that in anything but a DLG, and this seemed like the perfect opportunity.

I ran the numbers through my design spreadsheet (http://www.soarcalgary.com/Extras/Articles/Sailplane Design Spreadsheet/index_html), and came out with a layup schedule that uses five layers of 4.9 oz c/f at the root tapering off to a single layer at the tip. This was using the assumption that 2.9 oz carbon is about 0.007 thick, and hence 4.9 is about 0.012 thick.

Here are a few of the strips as I was cutting them. Simple enough with a rotary cutter.

[SoarNeck]

I wanted to keep the center panel as a single unit, so I had a dihedral break to deal with. This was my solution.

I bagged the layers over a form directly onto the kit spruce spars, which worked rather well. Some of the carbon slipped slightly in the center, so I added an extra couple of tapered layers "inside" the spar afterwards(c/f is usually on top of the top spar and under tte bottom spar). Overkill sure, but these models take WAY too long to build, and I wanted to be sure it would be okay. As it was I think that I doubled the build time compared to a stock Paragon!

I'm not looking to do two-man F3J tows with this model (it would likely flutter to death), but I didn't want to worry about the spar strength.

[SoarNeck]

After notching the ribs a little deeper at the spar cutouts, I built the panels like any other balsa model. I used full-width vertical grain shear webs in the center panel (3/8" wide), and a tapered arrangement of webs in the tip (3/8" -> 1/4" ->1/8" - 1/16").

After they were finished, I wrapped the spars with kevlar thread. I capped the finished spar with 1/32" balsa to make covering a little easier.

[SoarNeck]

The other major change was to make use of a Bubble Dancer-style bolt beam. Rubber bands weren't going to cut it anymore, and I wanted to use steel bolts anyway.

The tip joiners were changed out to carbon rods (3/8" I think).

Finally, I added spoilers with a servo in each wing, and tubes for the antenna for my Helios variometer.

I'd been looking for a RES model for a while, and I think this should do the trick!

Thanks to everyone who recommended this kit, I really enjoyed the build.

[vario]

very nice,i had a gemini MTS back in 83 thats still flying today,im told it had the strongest wooden spar and i believe it

i may just build a paragon myself


thanks for sharing that with us

,,vario

[Vince inTX.]

Soarneck:

I purchased a used paragon last september. I flew it for the first time last saturday. I came off the top of the winch line and proceeded to spec it out on the very first flight. What a rush.

Only problem with the plane is the outer wing panel joiners. The left outerh wing panel flops up and down in the slot. Subsiquently while it is in the air that wing tip is visibly higher than the other. It doesn't seem to affect performance but it sure looks funny.

I was wondering if you went with the stock wing joiners or did you do something different? If you used another method to join the wings could you please post some pictures.....I need some ideas?

Thanks in advance

Vince

[SoarNeck]

Vario - funnily enough, I purchased a Gemini kit along with the two Paragons. It was really a flip of the coin that made me start the Paragon first. However I think I might try a Bubble Dancer next.

Vince: Here's a shot of the tip joiner in place. It's a piece of 3/8" carbon rod, which sits in brass tube carriers. I could have used a lighter Kevlar tube, but this was a little quicker. The tube sits flush against the top spar in the tip, and is angled into the center panel. The small carbon rod is an alignment pin, and the hole is the outlet for the vario antenna.

In terms of retrofitting an existing model, I'd consider getting replacement joiners machined out of aluminum sheet. I'm told that that was a popular fix to the weak tip joiners, which were especially prone to breaking if you accidentally catch a tip on landing.

[Ollie]

The reason the stock wing joiners on the Paragon get loose after vigorous launches is that the side grain strength of the spruce spar caps are not sufficient to carry the bearing load from the birch ply joiner blades and the spruce side grain is crushed.

When making tapered carbon spar caps of constant width, each spar cap takes two lengthes of carbon the length of the semispan. One strip remains the full length. The second strip is cut in half and one piece is added to the root end of the first strip. The remaining piece is cut in half and one piece is added to the root end of the spar cap. The left over piece is cut in half, etc. In this way the spar cap crossectional area is tapered exponentially to closely match the exponentially distributed bending loads applied to the wing. The tapered carbon spar cap can be glued to a piece of spruce stock and run through a thickness planer to get a spar cap assembly of constant thickness to match the rib notches. If the carbon side is placed on the inside so that it faces the joiner tongue, the crushing and loosening problem will be solved. If the joiner tongue is increased in thickness to 3/16 of an inch and faced top, and bottom by a few layers of 0.007 precured carbon, you will get a zoom proof joiner. The joiner boxes need to be wrapped the full length with kevlar tow on both the root and tip panels.

The open bay wings still won't be zoom proof untill thay are stiffened torsionally with D- tube sheeting to prevent torsional flutter on a fast winch launch.

BTW, it would actually be as easy to build a Bubble Dancer wing and get the advantages of a more efficient airfoil.

[Steve Diebolt]

SoarNeck,

Beautiful job on the Paragon! I have always liked purple and yellow color schemes.

BTW How many rolls of covering did she take? :(

Regards,

Steve

[Vince inTX.]

SoarNeck

Thanks for the pictures and info. One more question. Do you use a brass carrier on both panels or only on the outer panel. Looks like it could be a do'able mod. I really want to fix this small annoying problem with an otherwise great plane.

Thanks again for your help and pictures.

Vince

[SoarNeck]

Steve: Thanks a lot for the compliments.

I bought four rolls of covering for it (2xviolet+yellow Ultracote Lite, white std Ultracote), though I probably only used 2(1/2) -> 2(3/4) worth of covering.

Well, that's not strictly true, I bought five rolls actually. That's the second time I bought a roll of that retched transparent white by accident!

Vince: The brass tubes are in both panels, so if I accidentally break or nick a carbon joiner, I can still replace it without surgury.

The tip tube is mounted flush with the top tip spar, and the remainder was filled in with 3/8" balsa, epoxy and microbaloons. It was then wrapped in Kevlar thread, though heavy fibreglass would do as well.

The center panel was done by blocking the tip in place, coring a hole in the ribs using a piece of sharpened brass, then tacking the tube in place (it extends about 1/2 way into the second bay from the tip). Then the same proceedure was followed to finish it.

Finally, the joint was block sanded so the panels met exactly, and a cap of 1/32" ply was added to finish off each panel. Finito.

[Vince inTX.]

Great info....thanks!

I have another question though. Where did you get the carbon rod? My LHS only has carbon tubing and tower, well, dead end there too. Any suggestions?

Thanks again

Vince

[SoarNeck]

I'm lucky enough that my local hobby store carries a lot of Aerospace Composites gear, but that's where my carbon rod came from (www.acp-composites.com). You might not need the heafty 3/8" rod if your spar is stock, so you can happily save some weight by going down to 1/4". ACP is also my source for the kevlar thread.

You could also try the Composites Store (http://www.cstsales.com/) if that's more convenient. I used their 0.050 carbon rods/teflon sheaths for pushrods in this model.

Ollie: You're right, a Bubble Dancer wouldn't have been any more trouble...especially since I already have a pod mold made and a mandrel for the boom.
However, with all due respect to Dr Drela, the Dancer doesn't have the nostalgia factor that a Paragon has (plus it's Nostalgia legal).

[Sparky Paul]

One of the tip panels on my Paragon departed in flight.. I hadn't wrapped the joiner doublers with anything. I was using an aluminum joner.. it pulled out between the spar and the doubler.
And it wasn't winching at the time!
Reasonably benign crash..

[Goinav8n]

Twenty + years ago I flew one of these with the durlene fuse. The original was repaired once to many. Well I was looking at a set of plans to maybe scratch one when one of the older club members (78) says he has one that was crashed and wanted me to take a look at it. So in between some days off I go to his Museum I mean basement and get the grand tour. Lots of scale sailplanes in construction. And the paraon. Fuse broke in half clean and one wing joiner broke. Thats it. I asked him how much and he says some stick time when its back up and flying. I have ripped all the covering off. The fuse is repaired and now working on the wing.

I like the covering on the one here. Im on the east coast so maybe we wont get them confussed if I copy the covering. I am going to mod it for a bolt on wing. I was never crazy about the rubber bands any way. So I hope to have a Paragon up and flying real soon.

Jeff
Downeastsoaring.org

[SoarNeck]

Go ahead and copy away...I'm up in Canada, so odds are that recognition isn't going to be a problem :)

I pretty much copied this scheme anyway, though I didn't realize that I'd end up using the same colours (I thought my purple would be "purpler"):

http://www.rcsoaring.com/gallery/2003/03joeparagon.jpg

I had my first good day with the model today, and I'm thrilled with it. Our field is under a few inches of water right now thanks to last week, so I didn't bother to bring out my winch. Instead, I used my Hollyday zip start consisting of 20 ft of catapult tubing and a 100 ft of mono.

I progressively stretched the start out further and further, but even when my arm was trembling under the strain of holding the model back, on the resulting launch the wing didn't flex an inch.
Then, on the fourth launch, I was out for an hour and twenty minutes.

Yep, I think I'll keep it :D

[oracle_9]

Hello,
I have been searching long and hard for good info. on the Paragon by the flier...rather than the Manufacturer. And this thread is excellent. Good job to all the participates of this thread.

I might me considering purchasing a Paragon myself.
Concerning where to buy, I only know of the Pierce Aero Co. and the one at www.skybench.com ...and difference in quality or design between the two companies?

Anyway, I have like two planes that have sheeted balsa at the front leading edge of the wing to the spar with balsa, like found in Spirit 2m or many other planes, but I noticed the paragon doesnt use this and uses 2 thin strips instead (the section where it has yellow covering. Wouldn't this cause somewhat of a stepped surface of the airfoil as the air flows from the front L.Edge to the center spars in the wing? whereas if it was sheeted it retains the airfoil?

(side note, if I wanted to sheet it, would it strenthen the wing a bit more?)

Oh, and one more thing, I usually cover my plane with opaque white and colored fuse, but your covering looks GREAT with the transparent color scheme, no one at my club has transparent covering, so I am not familar with it.

Can you tell me how visible it is high up in the sky? like is it harder to see or harder to see when one wing tips slighting to indicate it found a thermal?

I would also like to add spoilers like you did, but can I use 1 stock servo in to fuse to do that or would that be weak? My goal is to add little weight to it?

Also, is the sections on the fuse, where you hook in the rubber bands, strong? I noticed for the gentle lady (which it uses the similar thing with the rubber bands of of hooking it the the bands direct in the center of the fuse whereas as the sprit 2m it ues the sides of the fuse) uses the cross sections in the fuse where the bands are attached might dettach due to the thin balsa/ply sheet.
What I did for that was to increase the wall if that part to 1/4inch of Oak, now its strong as an ox, and can hold the pressure of like 12 rubber bands if it comes to that. would this be necassary for the paragon?

Oops, sorry for the long questions, I tend to do that now and then. I just like to get as much info. on it before I buy/build planes.

Any help would be appreciated.
Emery

P.S. I live in Canada too.

[Sparky Paul]

The Paragon design dates way back to "gas-bag" days, and is essentially outmoded.
To keep the look, you're kinda stuck with that old stuff, but if you want to improve the performance....
Here's a wing mod....
http://www.charlesriverrc.org/articles/kitmods/dickwilliamson_paragonairfoil.htm
And from the Oly II...
http://www.charlesriverrc.org/articles/kitmods/peteyoung_olympiciihintstips.htm
And some useful stuff from the Spirit 100.
http://www.charlesriverrc.org/articles/kitmods/bobbaxter_spirit100electric.htm
.
On my Paragon (it's electric)I went to a bolted-on wing. No rubber bands to fool with.
And spoilers. Needed!!!!
About 1x9 on both sides.
The covering works well at altitude, against a broken sky, which is the worst for viewing anything..
The fuselage itself is way clunky and can be usefully slimmed down for the modern radios.
The forward horn on the rudder isn't required. Build the fixed vertical the full height.

[SoarNeck]

Comments inserted:

I might me considering purchasing a Paragon myself.
Concerning where to buy, I only know of the Pierce Aero Co. and the one at www.skybench.com ...and difference in quality or design between the two companies?

// No difference. I think that Skybench is just an agent for Pierce Aero.

Anyway, I have like two planes that have sheeted balsa at the front leading edge of the wing to the spar with balsa, like found in Spirit 2m or many other planes, but I noticed the paragon doesnt use this and uses 2 thin strips instead (the section where it has yellow covering. Wouldn't this cause somewhat of a stepped surface of the airfoil as the air flows from the front L.Edge to the center spars in the wing? whereas if it was sheeted it retains the airfoil?

(side note, if I wanted to sheet it, would it strenthen the wing a bit more?)

// They're called turbulator strips, and they actually work fairly well for lumbering sailplanes. That said, a truer airfoil shape would work better, and sheeting the LE (top and bottom) would drastically increase the torsional strength of the model. I built mine exactly to plan in case I wanted to fly in a nostalgia event sometime in the future.

Oh, and one more thing, I usually cover my plane with opaque white and colored fuse, but your covering looks GREAT with the transparent color scheme, no one at my club has transparent covering, so I am not familar with it.

// Thanks. I like transparents myself, especially since they're lighter than the opaques. I rarely build in wood anymore, but I like to show off the underlying structure when I do. It'll be a LONG time before I work in wood again however (not nearly as enjoyable as I seem to remember).

Can you tell me how visible it is high up in the sky? like is it harder to see or harder to see when one wing tips slighting to indicate it found a thermal?

// I don't have too much trouble seeing it, but I've found that everyone has their own "preferential spectrum of colours". I never had problems flying my trans yellow Kelly, for example...but lots of people hated that colour.
// My Paragon has been at spec height many times without an issue...other than getting it down again!

I would also like to add spoilers like you did, but can I use 1 stock servo in to fuse to do that or would that be weak? My goal is to add little weight to it?

// You could use one servo, but then you'd have to plumb for pull strings and such. Not my idea of fun...I just had to do this for a club one-design Spirit class. Don't worry about weight on a Paragon. I would say that anything over a 5mph wind will require ballast as it is.

Also, is the sections on the fuse, where you hook in the rubber bands, strong? I noticed for the gentle lady (which it uses the similar thing with the rubber bands of of hooking it the the bands direct in the center of the fuse whereas as the sprit 2m it ues the sides of the fuse) uses the cross sections in the fuse where the bands are attached might dettach due to the thin balsa/ply sheet.
What I did for that was to increase the wall if that part to 1/4inch of Oak, now its strong as an ox, and can hold the pressure of like 12 rubber bands if it comes to that. would this be necassary for the paragon?

// No idea sorry...I added a massive bolt plate for a bolt-on wing. My spar is rated for 150lbs winch load (overkill...the will will flutter firs), and there's no way that bands would have supported that load. Looking at the stock system, I'd guess that the center panel spar or tip joiners would fail before the wing mounts.

Oops, sorry for the long questions, I tend to do that now and then. I just like to get as much info. on it before I buy/build planes.

// Not a worry, I do the same myself.

Any help would be appreciated.
Emery

//Let me know if you need anything else.

P.S. I live in Canada too.

//Whereabouts?

[oracle_9]

WOW, I wasn't expecting a reply so soon. Thanks Sparky and SoarNeck. The information provided was GREAT and very helpful.
I have the Dynaflite Heavy Duty Hi-Start so I guess the runner bands will hold for sure. But I will eventually moved onto the winch.

Do you by any chance have a close up photo of the Bolt-On system for your paragon?

I forgot to ask, but can the Paragon do deep turns in low altitude thermals?

Anyway, thanks again for the reply.

I live in the Toronto area. I joined the Central Ontario Gliders Group club.

[John Gallagher]

Skybench sell a wing reinforcemnet kit if you buy from them. Don't know what it consists of.

John

[Ollie]

Nylon bolts which are counter sunk to be flush with the wing surface have low drag. Nylon bolts which are just big enough to take launch loads and flight loads will hold the wing in place more securely than rubber bands. Nylon bolts which are small, close together and properly supported in the wing and fuselage will shear in a crash with minimum damage to the structure. By placing the screws closer together the force on the wing tip to shear the bolts is reduced and the smaller the tip force the smaller or less likely the damage. For the Paragon, two nylon 10-24 (OR 32) screws spaced about 1-1/2 inches apart will do the job.

The threads in the fuselage may be provided by a T-nut, plywood or, a slug of filled epoxy. The minimum number of threads which engage must be at least 6. The grain of the plywood must be perpendicular to the screw and the threads must be reinforced with CA and then chased with a tap. The filled epoxy must be the thin, slow setting kind and the filler must be high strength (such as chopped glass, flox or, silica gel). The fuselage mounting must transfer the loads into the rest of the structure so that the screws shear before anything else gives.

The threads must be chased with a tap and lubricated until the screw turns freely. A dry teflon spray lubricant works well in this application. This will facilitate removal of a sheared screw. A sheared screw may be removed by pressing the point of a No. 11 blade into the end of the screw and using the blade as a screwdriver. If that doesn’t provide enough torque then the No. 11 blade may be used to cut a slot in the top of the screw stub for a small screwdriver blade.

The wing must have a block to take the compression load of the tightened nylon screws. The block should be incorporated into the wing spar structure and the screws located near the thickest part of the wing. The blocks may be made of a hardwood, plywood or filled epoxy. The block in the wing must be tied into the wing structure so that the screws will shear before anything else gives. The block should be carefully countersunk so that the screw heads are flush. Any gaps may be covered with a small piece of tape.

Maintenance is simple. When the nylon begins to turn yellow, the screws should be replaced. The screws should be inspected after each flying session or hard landing. If they show signs of distortion where the wing meets the fuselage they should be replaced. If the screws start to turn brittle they can be restored by boiling them in water.

[Sparky Paul]

I used one 5/16" wood dowel at the front.. and a 10-24 nylon bolt at the rear.
The forward dowel mount is a real ply 1/4" plate glued and pinned with two small dowels to the front wing bulkhead.
I stiffened the underwing portion of the fuselage with a 3/32" plywood plate as I was also leaving the bottom under the wing open for the motor batteries.
Another 1/4" ply plate at the rear of this for the rear bolt.
On the slim glider fuselage (just wide enough to fit servos in line) I made later, the same arrangement for the wing atttach.
Spoilers used Sullivan cable to pull open and push closed, with the servo up front of the wing in the fuselage.
I'd now mount the spoiler servo in the wing to eliminate the attach-detach hassle when assembling the plane to fly or go home.

[Dennis Everett]

I had a paragon about a million years ago ,great plane,i was lucky enough to fly at a club where Gene Wallock used to cd our contests,Gene was the guy who did the cutting of the kit for Ed Slobod,Gene did great work,his kits were a work of art,we built them all different ways,glad to see its still flying,still a great floater,did you guys know at the first world f3b champs one was flown?..Dennis

[SoCalGliderFlyr]

Originally posted by Sparky Paul
One of the tip panels on my Paragon departed in flight.. I hadn't wrapped the joiner doublers with anything. I was using an aluminum joner.. it pulled out between the spar and the doubler.
And it wasn't winching at the time!
Reasonably benign crash..

Was timing for a friend in the late 70's when he lost the tip panel on a Blaine Rawdon Mirage half way up on tow. This left the four foot center section and the other three foot tip.

He was able to fly it straight and only turn to the side with the still attached tip panel. He actually made the landing circle and decent landing points. His duration was a bit short.

[SoarNeck]

Sorry for the delay.

The bolt-on wing system that I used was adapted from the Bubble Dancer. Earlier in this thread you can see the carbon-laminated bolt beam that takes the loads in the center panel, and here's a (bad) shot of the inside of the model.

Three steel bolts are used to hold the wing on, with blind nuts under the big bolt plates. The bolt plates are held to the fuse sides by an exterior wrap of fibreglass, and are gusseted to the interior with balsa tri-stock and kevlar cloth.

Steel bolts are stronger and maintenance-free, and I just accept that they don't give any margin for safety in a crash (neither do molded sailplanes). I don't like nylon in anything but a DLG (and even that is for weight reasons), since you have to monitor them for wear and they can turn a little brittle in the winter. I like to cinch my bolts down securely, and I've popped the heads off of a few nylon bolts as a result. Just don't crash and there's no problem :)

The stock Paragon is a good performer, but a little antiquated obviously. I feel that it could use a fair amount more dihedral since low-speed turn requires a large yaw angle (slow response), but once on a wingtip it will happily stay there. I have many flights over an hour with mine at this point, and many saves from 20-30 feet. It will even roll if you really ask it to, but it protests the whole way around!

Honest model...I like it a lot. As a result I haven't been too tempted to crack out my Gemini MTS kit yet, but I will eventually.

Originally posted by oracle_9
WOW, I wasn't expecting a reply so soon. Thanks Sparky and SoarNeck. The information provided was GREAT and very helpful.
I have the Dynaflite Heavy Duty Hi-Start so I guess the runner bands will hold for sure. But I will eventually moved onto the winch.

Do you by any chance have a close up photo of the Bolt-On system for your paragon?

I forgot to ask, but can the Paragon do deep turns in low altitude thermals?

Anyway, thanks again for the reply.

I live in the Toronto area. I joined the Central Ontario Gliders Group club.

[the bone]

SoCalGliderFlyr:

Paragon questions.

Can you tell me what the rudder and elevator throws are left/right and up and down? Also could you advise on what Hitec servos would be and good choice for rudder, elevator and one in the fuselage for spoilers? Also I am a beginning pilot.

Thank you: The Bone

[oracle_9]

In my opinion, any cheap standard servo should be ok. The tricky part is which micro servo you need, if you were trying to lighten it up, but there is no point too.

[SoarNeck]

HS81's or 85's on the spoilers, standards on the flying surfaces, will be fine.

[jrgospod]

I have a ship on the way and was wondering if any new ideas have cropped up after an extra season of flying. What modifications do you like and what would you skip if you built again. Thanks!

John

P.S. Jerry has the Paragon on sail at this link.

http://home.comcast.net/~bsli40/Specials_page.htm

[SoarNeck]

Can't say I've flown it much, but when I do, it's hard to bring it down! Rarely do I get less than 45 min flights on the days where it comes out, but I don't bother trying to fly it when the wind is above 10-15mph (I have molded models for that).

If I built it again, I'd skip the bolt-beam method (Bubble Dancer spar method) and go with a single bolt plate into the fuse bottom (Supra spar method). That eliminates the bolt beam and the big ply fuse plates, and threads a single bolt through the spar into the towhook block.

[jrgospod]

Thanks for your input. I'll have to do some research on the " single bolt plate into the fuse bottom (Supra spar method). " that you mentioned. I will look on the SALglider and Allegro-Lite groups to see what you mean. Thanks again.

John

[SoarNeck]

Actually, plans for the Supra are on the Charles River R/C site.

[jrgospod]

Thanks, I would have found it but that makes it simple.

John

[SoarNeck]

No problem. BTW, I just realized that I have another example of the mount that I mean:
http://www.rcgroups.com/forums/showthread.php?t=339816

[Rusty P]

Hey, guys (and gals),

I have a Paragon kit I'm getting close to building. Looking forward to flying it.

A note, though. Ed Slobod designed another plane after the Paragon - the Gnome. The Gnome 3m is also available from Jerry, and I can attast is a great kit.

The Gnome features a sheeted wing - at least to the spar. It also has a curved shape to the tailfeathers that I think is cool. The airfoil is faster than the Paragon. Much of the rest of the design is pretty similiar.

So if you want a faster, better penetrating Paragon, think of the Gnome.

I know several Gnome flyers in the area. One maidened his with a full pedal launch. Another put his into a vertical dive, counted to ten, then pulled out. Both planes survived. Both also had precured carbon reinforcement in the spars, but the rest of the planes pretty much as they came in the kit.

Have fun, and think hot air:)
-Russ

[SoCalGliderFlyr]

John Lupperger designed the Gnome handlaunch then the Gnome 2 meter then the Gnome 3 meter. Slobod did the Pargon, Gemini, Parmount, Ridge Rat and a few others but not the Gnome.

[skipinhouston]

First, thanks for all the submissions of great ideas, hints, tricks, and comments here.
I have a new Paragon kit I've been saving to build this fall and have been following this forum since it started.
The part about using kevlar thread on the spar got me to looking for a local source.
I think I've found an excellent product from Bass Pro-shops that you all might be interested in.
$2.95 for a 50 yard spool of thread that is the same diameter as a regular sewing thread. Might not be as heavy as what is usually used, but I plan to make up for that by using tighter closer wraps around the spar.
The up side is it won't stick out of the spar top like the heavier stuff when you're covering the wing.
Any comments?
Thanks again.
Skip in Houston

[lincoln]

I had a Gnome 2M. Flew better than I though it should have. Does anyone kit those gliders anymore? I think a Paragon with a real Clark Y (not a flat bottomed, size 14 Nike outline, but real Clark Y from the real coordinates, swept up leading edge and all).