Re: I did it! I really did it!

Ken Cook Sat May 06, 2023 3:43 am

What I see in your picture is what typically happens when silk is applied or no plasticizer in dope. I've had several planes like that and it usually dials in a irreversible warp into the wing.

944_Jim Sat May 06, 2023 9:46 am

That's some genius thinking there!

It appears as if you had just the right size scrap for a test, and lined it up just right. I'm curious how you index your wood so the cutter "knows" the cut zone.

Does your cutter have a discreet platen with fixed width x length? Or does it pull the material through front to back and eject out the rear like an old inkjet in "pass straight out the back" mode?

Thanks much,
"lost in the woods"_944

GallopingGhostler Sat May 06, 2023 11:24 am

Just my opinion, but regarding the excessive shrinkage distortion on Mark's plane wing, I'd probably just straighten the parts as best as I could, then overlay the parts distorted (ribs and tips) with stiff 1/32nd sheet balsa or 1/64th basswood, to straighten and strengthen them. Only replace the worst parts.

It would add minimal weight, then with a modern synthetic covering like Litespan, recover it. This would spare a lot of serious dismantling and get it back into flying condition.

Again, just my opinion. Tired w/ Coffee Read

batjac Sun May 07, 2023 12:33 am

The leading edge is not warped, just the trailing edge, so it's not going to be a problem. I'll just straighten the t.e. and install new 1/16" ribs and 3/32" wingtips. I believe the ribs are glued with Ambroid, and not a great job at that, so it's going to be easy to remove the glue and just pull out the ribs which are none too secure. I was going to omit the flaps, but who knows. Should be pretty straightforward. Since it's already really ugly I'll not spend too much time getting it ready. I'll cut the terrible cloth hinges and replace them with thread hinges using Spectra line, and then cover with some yellow leftover Monokote.

The Sloppy Mark

NEW222 Sun May 07, 2023 9:20 pm

batjac wrote:Okay, I had a little time to get back to this so I stripped off the wing covering. Hoo Boy! Worse than I thought.

I downloaded the Super Combat Streak plans from Outerzone. I measured the dimensions on the ribs in the wing so I could adjust the plans for the ribs so they fit in the existing wing. Whaddayaknow! The ribs as shown on the .pdf fit perfectly! So, I drew up the rib in Inkscape and cut a test rib out on my Cricut cutter.

I’ll try it out tomorrow, and if it fits I’ll cut out the other 13 ribs I need.

The Cautious Mark

It kinda looks like the ribs followed the same contours of the 'flame' job on the fuselage.....

Sorry, it is not funny it is damaged, but just thought the look was very similar.

GallopingGhostler Sun May 07, 2023 10:21 pm

getback on Jan 12, 2023 wrote:I seen a kit for this plane is $150 Either way I agree with Ken you can't learn on a half butt plane , I can say i think most the planes i fly/flown have been this issue .And getting over it is a Building experience till you succeed at what your tring to get out of the hobby . Just do it and have fun !!

My problem is not half butt builds, I do them well. It is when I'm a half-b*** pilot. Doh!

batjac wrote:Okay, I had a little time to get back to this so I stripped off the wing covering. Hoo Boy! Worse than I thought.

Actually, it is not worse. I've seen worse. Looks like to me that extra soft balsa was used for the sheet surfaces (ribs, tip, tip ribs, etc.)

The warped ribs could even be fixed with say, 1/16 x 3/16 stiff balsa to straighten along the centerline of the rib on one side. Use a covering sealing iron and a clean sponge with plain water, apply to warped rib with sealing iron to heat and swell / dry the wood fibers back to normal. Then glue the flat balsa stick to keep rib straight. Clear dope or glue (carpenters, Duco, Sigment, etc.), to stiffen up surface of the rib. With a little time and effort working back and forth, existing can be restored without disassembly, maybe except for the very worst parts. But I don't see that type of worseness. (Awaiting the Grammarians Laughing

András @balogh knows what I'm talking about. Very Happy

)

The Combat Flite Streak reminds me a little of my half-A Dumas Tom Tom II that I built in high school for a Golden Bee. Fuselage and wing resembles yours.

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