Bagged Supra, the light way - Page 7 - RC Groups
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Dec 30, 2008, 04:27 PM
Registered User
You are right Jon. I remember an lenghty discussion on your thread between Phil and some others about this subject.
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Dec 31, 2008, 04:16 PM
Hot Dawg Glider Pilot
schrederman's Avatar
I'll be doing my first bagging in about March. Thanks for doing this thread. LOTS of good information here for on old balsa builder...

Dec 31, 2008, 05:49 PM
Jesper Frickmann
jfrickmann's Avatar
I will second that - this thread is very much appreciated!!

How did you drill the hole in the foam for the RDS shaft from the servo pocket to the RDS pocket?

Happy new year to all!!
Dec 31, 2008, 07:41 PM
Registered User
Originally Posted by jfrickmann
How did you drill the hole in the foam for the RDS shaft from the servo pocket to the RDS pocket?
Thanks for nice comments guys.

I drilled from the RDS pocket to the servo. The aileron one is easier since you can just eyeball the correct angle and all you want is to get the basswood insert drilled properly. The flap is a bit more complex because bending the flap 90 degree blocks the straight line view to the servo pocket (from the top). I used a piece of masking tape applied at the top of wing marking the correct angle.

Happy New Year to all.
Jan 02, 2009, 11:58 AM
But I am learning
I_Can't_Fly's Avatar
Glauco, thank you for showing us your building style. This thread along with several others has inspired me to start my own Supra. Here is a peak of my current progress.
Last edited by I_Can't_Fly; Jun 23, 2010 at 08:34 AM.
Jan 02, 2009, 01:45 PM
Jeff Carr
Excellent looking plug. Keep us updated

Jan 02, 2009, 03:23 PM
Registered User
Very nice plug, it looks really good. I carved one for the Allegro and also made a V mount mold before Bud Elder started selling them. Thought the same for the Supra and even started some templates but then found out Mike Lachowski had these wonderfully made pods which would save me quite a bit of time. Anyway carving your own and building a mold is a very nice way to start it.

Here are the last pictures of "51" building log. I have also uploaded a RDS video at the sailplane video here.
So you can see this rds thing isn't magic, it does work.

Have already started the new planes but not much done, just a couple of hours of work. Will soon post what I've done so far.
Jan 13, 2009, 02:57 PM
Registered User
I'm back. Didn't go anywhere actually, just the flash driver used for the pictures quit so had to get another one.

So I've been building both planes and if you don't remember, one is a regular version per plans and the other is a beefed up center spar version for F3J.
No one told me but found out that building two planes at once is twice the work of building only one I guess the good part is having two planes once I'm done.

Found out as you can see below the 3/8" caps for the center panel were .064 thick instead of .084. Package from ACP says .084 and I had never checked this before. It does start at .021 but it is hard to figure out where are the missing layers. I have added .014 to the center to make up for the missing caps but checking the weights of the previous two planes I've built I see that on mine the center caps were several grams lighter than target. All I can say is the wing flex but I couldn't brake it so far.

While on the subject of weight, spar caps and not been crazy, I spent about an hour on each spar cap sanding off the glass used by ACP to build them. I used to be able to scrape the glass off with a curved knife but these one were really stuck to the carbon. Only solution I found and please stop reading if you are healthy conscious was using a Dremel and the drum sander. I did use the biggest face mask I could find and had the shop vac on by the side. Took about 6 hours to clean all caps. Don't have my notes here to tell the weight savings but the idea was also to create a good bonding surface between caps. It is some work but it is done now.
Jan 14, 2009, 08:26 PM
Chuck it and see!
Wing-span's Avatar
Stunning work. I feel inspired!
Jan 15, 2009, 06:03 PM
Registered User
Was checking my notes and noticed the 6 hours to clean the caps was a bit exaggerated, it just felt like it. It took about 3.5 hours and here are the results.
14 grams of shaved weight on the J center caps, 10 grams on the regular center caps and 12 grams for the tips for both airplanes (6 g per airplane or 3 g per tip).
It may look like it is not much but find two spots to save 14 grams and your plane is already one once lighter.

Some more pictures. Thought that cutting the 2.5 degrees off the end of the center and tip panels now would be easier than latter. Also, applying the balsa plywood now would work fine.
Jan 16, 2009, 02:52 PM
Registered User
Here are some pictures of the balsa plywood. 3 layers of 1/16 medium Balsa.

The square joiner box seem to be not too much trouble to fabricate. Will wait until I can determine the exact distance between sparcaps to figure out if I can use some carbon tow while rolling the Kevlar boxes.

This is all I've done to date. Plans for the weekend are laying down the foam cores to mark the spar, cut off the spar core, round the edges of the caps and maybe gluing the bottom caps to the foam core. Lets see if can follow my own schedule and finish these tasks. I know the 1" spar will need a little bit of thinking how to lay it down since I'll try for both wings to be interchangeable (wink wink Chris)
Jan 16, 2009, 04:47 PM
Chris Lee
No need to be interchangeable, lighter tips go with the lighter plane. Seems simple enough.

Wink back 'atcha.

Jan 16, 2009, 05:35 PM
Yep, Naza-controlled Tricopter
tonyestep's Avatar
So if I understand correctly the plan is to make a box with rectangular cross-section and then fit it between the spar caps. Then I suppose you'll bind the whole thing with Kevlar tow. Will there be room on the sides of the joiner box to add some vertical-grain balsa webs so as to prevent a mishap similar to you-know-what?
Jan 16, 2009, 10:44 PM
Registered User
Sorry to say Chris but all four tips will be light, just bad choice of color in two of them.

Tony, the square box will be glued to the caps and have some carbon tow wraps just like the basswood one. Size will be basically the same. This way we can use the bent joiners with either 5 or 2.5 degrees along the straight ones (for F3B )

By the way if you don't know both Chris and Tony are my good friends and past and future recipients of a light home build Supra. Tony got the first one and always helped me discussing construction methods and theories of Dr. Drela designs starting with an Allegro composite and moving to a composite Bubble Dancer before the Supra. Now for Chris I don't remember why I'm building a plane for him...oh yes, because he is one of the best pilots I know and if I ever beat him he won't have the excuse to say my plane was better than his.
Jan 17, 2009, 12:54 AM
Chris Lee
I'll always have that excuse. Who knows how much tungsten you're embedding in the tips of my Supra? Probably just one tip, so if it ever goes dead stick in flight, it will keep turning tighter and tighter until it hits knife-edge. Oh wait, that already happened. Good thing it wasn't reinforced like Tony's talking about, or some real damage might have occurred.

Great, now you let the cat out of the bag. I feel like the guy with the winning lottery ticket before he's had a chance to cash it. Going to have to watch my back now.


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