3D Viper-ST 100-120cc scratch build......it continues!

Bdegan;20248 wrote:

I'm back at work now. But I just realized that stand off length needs to be considered for you to get a proper length fit.

because F1 to the back of the spinner might be different on you viper than this 330.

I didn't measure exactly. But my standoff is 1.75 inch plus the length of the DA70

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Yes, I'd need more technical specs but just for a rough idea I figured this info would let me to a two second sketch. Looks like it may fit but header drop may be tricky and the pipes need to go up at a 1.5* angle from F-1 back in order to clear the belly pan. Radius of the pipes looks like fit would not be an issue. My landing gear is recessed and canted forward a couple degrees, I would have to modify that plate for you as well, but that's only a couple minute cad mod and send them to the laser. Looks like that's the only part needed to be changed. I could also move the engine box out to fit your engine without a huge spacer, with this engine box it only requires a .5" spacer for a DLE120 or a .75+/- spacer fora DA100 so you are only looking at a 1.25" spacer for a DA70.



We are a while out on kits if indeed it comes together so we could discuss via E-mail and maybe get something worked out depending on your header options.

20282=13004-Brad Tuned Pipes.jpg

Got the scale out and did some testing, currently the fuse weighs 2lb. 12oz which is about 1.5 oz less than the same fuse with carbon longerons. I did some of the same stress tests on this as I did on the carbon one with nearly identical results The top load is about 1.5-2lb's less but appears to be focused on the three open bays before the tail section. I may try to add cross members in there, but that area get's a lot of strength with the turtle deck and belly pan above and below so I don't think it will be any issue. There is almost no additional twist in the fuse with wood longerons and it also seems to be focused in only those three bays. With the belly pan installed I expect that will be all but gone.



Side load to 1/8" fuse deflection / bend:

- 27# at center former only

- 43# at 14" out from center

- 58# at 28" out from center



Top load to 1/8" fuse deflection / bend:

- 24# at center former

- 24# at 14"

- 30# at 28"



With fuse blocked at center former and final former I get nearly the same results. With fuse blocked at center former (front of Turtle deck) and F-1 a 14" block it stops at 60# which is all my scale goes to. Going to be one strong fuselage and $70 less expensive in raw materials than with carbon!!!!

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20409=13051-20140925_072259.jpg I picked up s/n 001 last night. Can't wait to get my components in it and get her in the air.

Dude, Terry.... you are killing it!! Ubber nice work brother!! Id devinately love to have one of your airplanes, someday!



It just goes to show that you dont need fancy expensive exotic materials to produce a strong lightweight airframe.

Bunky F. Knuckle;20410 wrote: Dude, Terry.... you are killing it!! Ubber nice work brother!! Id devinately love to have one of your airplanes, someday!

It just goes to show that you dont need fancy expensive exotic materials to produce a strong lightweight airframe.

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Well, next week I get to start over!! We decided I'm going to send the assembled fuselage that you see in this thread over to Rick at Fibertechnmore to check the fit of the foam. I've got two very small mods I'm going to do so it'll be good to start another one.....or two.



For anyone close, I'll have the yellow viper #3 at Rolla this weekend so if you want a test flight track me down.

Damn..... Im about 8hr from.Rolla. Im flying at a heli event this weekend...... I'll be sure to have Kitman fly it for me.

We are about 8 hours from there as well, you are probably closer to DesMoines or Council Bluffs, you'll have to put those on your list for next years events!!!

Terryscustom;19353 wrote: If this comes together I may entertain the idea of doing a small run of RTC or ARF builds. If I build 2-3 at a time it can be done pretty efficiently especially with Rick doing the foam work via CNC!! They obviously won't be ARF prices, but they also don't fly like a stick built ARF. I can't wait to hear what Hawkeye thinks of his.

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Should be next week for the HD maiden flight. I can't wait. I'll let you guys know the results.

Sweet!! We are going to convert Eric's over to an ST with new wings and we're going to retro fit in a DLE120. The engine box is different on the 70cc version that he has so we may have to do a little surgery but only minor out-patient:smile-new:



Can't wait to hear what you think Dave, feel free to call me and I can tell you what I had in there for hands free KE mixing so you can start with that if you like.

Terryscustom;20425 wrote: Sweet!! We are going to convert Eric's over to an ST with new wings and we're going to retro fit in a DLE120. The engine box is different on the 70cc version that he has so we may have to do a little surgery but only minor out-patient:smile-new:



Can't wait to hear what you think Dave, feel free to call me and I can tell you what I had in there for hands free KE mixing so you can start with that if you like.

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Terry, I will call you for mixes and I have a few other questions. Putting a list together so I only have to call you once, don't want to be a pain in your butt.