TopCat the ultimate Woodie?

[soarrich]

I picked up a TopCat by Southwester Sailplanes on ebay a couple of years ago that I'm going to take to the LASS Woodie contest, I think it is the ultimate Woodie as it is soild wood.

[soarrich]

I'm going to start with the wing, it's all here.

Dave Thorneburg wrote on the planes on the modifacations to make to the wing, so I'm doing them. He calls for the tips to be 11 inches, I changed that to 12 inches, I didn't want the poly joint right on the end of the tapered part of the tip, the joint is sometimes hard to sand in, if it took too many trys on the tapered part the wing chords wouldn't match.

The plans call for butt joints at the tips, and Celastic bandage for the center panels joint. I haven't seen Celastic in years, it works ok, but I wanted to use glass and a little CF tow on the panel joints.

[Ollie]

I hope you got very good "contest" balsa. You want low density wood. Don't use any medium to high denstiy wood in this kit. Especially use lowest density wood on the tail and fuselage aft the wing. Keep the cover wood lightest too. One thin coat of polyurethane varnish is enough. Think low weight every part behind the nose.

Be careful of wing strength near the reforcement. Think gentle launching.

It will fly nicely under low wind conditions. I think it was a Dave Thomburg design in the 1970's.

[soarrich]

Hi Ollie

Yea, my friend has one left over from the seventy's, he covered it in Monokote, and it took a ton of lead to balance it, and that was using the 70's one pound radio. :eek:

I hadn't thought of PolyU, I had thought about just clear coating it, but I like color on my sailplanes so I can see them, it's going to look like my avatar.

I plan on doing everything I can to keep the tail light!

Rich

[Norm Furutani]

I have a TopCat kit NIB. Will trade or sell for? Use the PM if interested.

- Norm

[Curare]

HA!

That's a SUPERTURKEY in any any other guise!!

[soarrich]

Curare

Maybe the SUPERTURKEY is really a copy of the Top Cat, this plane was kitted in the early 70's.

I've been working on the fuse. I found something odd, the wing is set at 0*, using the bottom of the fuse as the datum line, the stab has -3*, it really looks odd, it kind of looks like a flying stab with a lot of up in it. I built the stab stump the way the plans called for it to be built, I hated it, so I changed it so the stab is at 0*, the wing will be at +3*. The way it was designed I think it would look like the tail was down while flying, with this change it should fly with the bottom of the fuse level.


I've made some changes to lighten the rear:

I've lowered the stab stump

got rid of the triangle stock on the bottom of the fuse and square stock on the top of the rear fuse.

The fuse calls for a 3/8 inch keel piece for the bottom, I used 1/8 sheet.

These changes will make the plane a little more squareish and not quite as strong, but i can live with that. I was tempted to put CF in, but I don't think CF should be used in Woodies, I couldn't help myself is some places though. :eek:

[Curare]

Soarrich, they're not THAT similar, but the design principle appears to be the same,

the Super turkey, was an RCM plan from about 1978, RCM #716.

I built one many moons ago, and while learning to slope soar, I tried doing a loop, into wind.

you can guess where that landed me. :$

FYI, the super turkey! http://image.rcuniverse.com/forum/upfiles/46729/Ig11057.jpg

[soarrich]

This is how for I've gotten, dope takes for ever to paint.

[soarrich]

I got the fuse painted, and the wing bolts in. I think I'm going to try making water slide decals with my printer for it.

[Curare]

Seems to have some HUGE dihedral there Soarich, should be a nice sailplane...

I found some old photos of my turkey, how I miss my balsa wonder...

[soarrich]

I measured the angles:

8* for the di.
25* for the poly.
18* from the center joint to the tip.

I like 5* & 18*, but it was hard sanding it into the panels, you can't hold the wing like you normally would, pressing it down onto a table then sanding the end, if you do the wing looses it's camber and flattens out. I had to hold just the LE & TE to sand, small differance, but once I got two sets of tips that mated I went with what I had rather than trying to resand the angles again.

I think the extra di angle will just make it groove a little better, and the extra poly will make it a little quicker turning.

[Curare]

Yeech, I couldn't stand grinding dihedral angles into wings without a disc sander, must be really painful!

[ejett]

Yeech, I couldn't stand grinding dihedral angles into wings without a disc sander, must be really painful!

It's not that painful if you've never used a disc sander... :D

Rich:

That is a pretty neat looking plane. Get out there and fly it and let us know how it flys.

EJ
Athens, LA

[soarrich]

I got the name and numbers on it then clear coated it. I used my printer and special water slide decal paper. I think I should have put the decals on after the clear coat though, live and learn. :)

[Curare]

Looks good!

I'm eagerly awaiting a flight report!

[soarrich]

I test flew it today off a upstart. It took four nickles to balance it, it flys very light, maybe a tad tippy, kind of like a Mirage. Total flying weight 1 pound 10 oz.
I'm happy with the test flights, I flew it as the sun was going down so the pictures aren't so great.

[trashmanf]

nice! that tip dihedral is wild!!

[soarrich]

This is what a stock Mirage has, so I figured I was safe.

[wnppmy]

Nice Work, this puppie or cat, was one of my first sailplanes years back, have to see if I can find the pic, it flew very well, is heavy as wing entirely wood, I put a .049 pod on the center wing and it went up super, took strong thermals for best flights, but managed a huge lift it went up to binocular flying, we leaned back and flew for near 60 minutes, used Kraft servos, finally flight battery got soft on the controls and had to bring it down...amazing was so far up took again the binocs to see the wings, best flight todate, great trainer, loved it....BEST..<>..

[schrederman]

The Jedelski wing! I built a Nordic A-1 back in the early '60s that used that wing... flew nice enough to win me a trophy!

Jack

[Mark Miller]

Southwestern Sailplanes = Dave Thornburg. He loves Jedelski.

Mark Miller