3d-aholic

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I've started a little bit of work on my SPAD3D-40. Well at least I cut the engine mount....that was fun !!!!

I want to build light thats why I'm building a plain spad3d instead of the 3dT. Going with a 34" fuse and 34" Wingspan. Anybody found alternatives to the 5/32" music wire at the ailerons yet? I sandwich epoxied two bamboo skewers but I'm not totally impressed with the rigidity of bamboo skewers when the length is doubled up....but I haven't given up on that idea yet. Its very light going this way though and seems to be stronger than any balsa or dowling I've found. Has anybody found a cheap alternative that is lighter than MW?

rlt55

A 36" CF or FG rod is going to cost a lot more than a 5/32 steel.
I used two 18"x5/32" music wire rods on both my 30" & 36" WS SPA3Ds.
Is 3 oz. really all that heavy?
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30"ws/GMS32=3.6 lbs
36"ws/.52mag4stroke=4.25lbs

LittleFolk

I built my SPA3D with a K&B .61 and as you know they're heavy. I used a u-channel fuse and the rest was straight from the plans. The model's total weight came in well under 4lbs. I used (2) 5/32's music wire with the forward wire passing through the u-channel. It makes for a stronger wing. The plane has a 36 x 36 wing span.

3d-aholic

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Oh, No, I didn't know folks were coming in below 4lbs....I thought folks were having trouble getting below 5lbs. I would think under 4lbs....should be fine for a 40 then.

LittleFolk

Yes, I saw that most were 4 1/2 lbs. Don't know how I did it. I built the SPA3D according to plans without much concern for it's weight due to the fact that I was using a .61 size motor. When I placed it on the scale....surprise! I did use superlight wheels saving a little, but as I said, I wasn't concerned. My CG is 6 1/4 inches from the leading edge. I'm told that 6 to 7 is ok.

ChrisSpad

mine, with a 46 fx, and 1 oz weight servos, aaa battery pack, 1 oz rx, weighs 4 lbs 6 oz. I think you need to get your scale checked. I just don't see 4 lbs happening using the materials called for in the plans.

novabill

Mine was 5lb 3oz and I put it on a serious diet.

5/32 MW landing gear
Ultralight foam wheels
Removed tailwheel assy and replaced it with a big control horn. (makes ground-handling way smoother)
Trimmed down the mount.

New weight 4lb 11oz

I have three peices of MW in my wing, one 36" at the ailerons and one 24" at mid cord going through the fuse and one in the LE going through the fuse. I could probably shave 3oz by replacing with CF, probably not worth it.

2much-Stay with the MW if you are not going to use CF, or use the yardstick spar like Chrisspad did.

3d-aholic

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Yes, I'm planning on trimming to 34 inches per Tattoo's recommendation for a 40 sized, I'm going with the spar and looking towards something with the bamboo skewer for the trailing edge. Light landing gear.

novabill

You still might want to use the 5/32 MW for the fulll span of the trailing edge. Your ailerons will work better. I use bamboo alot in my SPADS, but not for wing reinforcement.

WILLIAM

3d-aholic

My Feedback: (7)

Really....Hmm.

Well I'm not definite yet.

But, I have sandwich epoxied 3 together for like 18 inches and 2 together for like 12 inches and was thinking about putting both in next to each other in series (2 adajcent flutes) with the glue bonds opposing each other.

_x_
_x_x_

They were way too flexible by themselves...However, It seemed from my trial of this with the two bamboo lengths together, it was less flexible than the MW and weighed about 1/2 as much easily. Also I was able to flex this about 6 inches either direction without fracture. The strength to weight ratio of Bamboo is incredible....

But, I need more testing.... I really haven't gotten that far. I'm a slow builder and I also got sick...

{Oh, and PS...I'm using the yardstick for the middle....}