starting my own building thread of b-17 e-conversion, so far fuse is all built up with replacement of balsa to bass stringers.

will make top cabin section a removable hatch for batt and servo access.

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Having just started the head-scratching for a Guillow P-51 conversion, this is good timing for me. I'm basically still just laying stuff on the plans and trying to guesstimate how things will go.

What are you using for propulsion?

closeup of tail wheel

If you scallop the formers between the stringers it will look a lot better when covered.
Mark

mondomor, i'm definetly going with all 4 turning, leaning towards 280-370 size motor, direct drive and lipoly batts, replacing the balsa with bass wood on the stringers is definetly the way to go for strength and you only add a few grams! but the alternative is a weak structure that is brittle even when handling! as far as the props, i still have to do some r&d to find the right combo.

mritinger please elaborate? scallop?

i plan on reversing 2 of the motors(if i can find reverse pitch props this size) inboards rotating out and outboards in to counter react torque of motors! i'm wondering if by reversing will the timing be off=slower rpm, or should i not worry about this?

also plan on having full house controls ail,ele,rudd,throt and split flaps using all gws pico servos 5 all toll and shooting for a max auw of 30oz.(fingers crossed) but think it can be done, scratch built a trimotor of almost the same size(a hair smaller) and used 3 sp-400's with a 8 cell cp-1300 batt and came in at 35oz.

this had too much torque with all motors spinning in 1 direction!!! a real handfull to rog+ any sudden burp of throt and it wanted to roll over!!! thats why i want to have counter rotating props on the b-17!!

I'd go to IPS drives for cool factor with 3 blade props-

I'd be shooting for very lightweight- use maybe a 2 cell Etec 1200 which should provide about 45 watts or so- maybe a Kokam 2 cell 1500 if you need a bit more oomph-good for 70 watts or so gear the motors to draw about 2A - 2.5A or so swinging scale size props. You don't need a lot of pitch speed for this airplane.

Sam

Originally posted by ESB
mritinger please elaborate? scallop?

Relieving the radius of the bulkhead, between stringers, using a dowel & sandpaper. Makes the covering look much smoother.
If doing any insert planking, the same can be done to the sheeting ends. If they donot run to the next bulkhead.

Steve

This is definetly a thread worth following. I have 2 Guillow's B-17 kits on the back burner. The complications Ive seen is prop clearance, The Nachelles are rather close together.

A little back of the envelope figuring-

Typically, a single prop rubber model in this size range would have a prop of about 12". (This is after all, a rubber powered model- just a bit heavy.) Thus, 4 6" props will have the same effective blade area as a single 12" prop. Can you get 6" props on this thing?

Sam