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[davidk]

This has only an 1100mm wingspan but there's so much bulk to it.

[sihinch]

That looks imposing!  What is the model?

Bravo David.

[Frank v B]

Looks like a Formosa biplane- a mid-air collision between two Formosa pylon racers.
Love the two-tone elements.

Frank

[davidk]

Big surfaces on this plane.

[davidk]

Wings done.  Electronics next.

[davidk]

Finished the Lower Wings.  The features built into these designs are really well thought out.

[davidk]

Setting up the Elevator and Rudder Servos showcase some nice design features.

[davidk]

From the backplate motor mount to the prop I need 61mm.  I had 55mm with the 4mm motor mount so I printed a 10mm part.  I used PETG instead of PLA because it's a bit stronger and withstands heat a bit better.

[davidk]

Motor is in and tail is on.

[sihinch]

Super nice build David.

[Michael]

Amazing design and engineering.

[davidk]

Just ran the Watt Meter to get an idea of prop size and numbers... but this always confuses me.

Motor : Turnigy SK3 3548 1050Kv : Max 50A : 720W
ESC : Turnigy Plush 32 80A
Battery : 4S
Flying weight : Around 6 pounds

The specs on the motor claim a 10x5.5 prop will draw 48A and 665W.

I tried 3 wooden electric props, the numbers are below.  I only ever got just over 1/2 throttle before I chickened out.
The motor might have been a bit warm... it was so slight I couldn't tell.  The ESC and battery were cold.
PlanePrint recommends a 12 x 7 prop for this plane.

10 x 6 : 10A  :  Underwhelming.  I can't see using the motor recommended prop.
11 x 5 : 13A
12 x 6 : 18A and 300W

The 12 x 6 prop was blowing me away, literally.  Stuff in another room started moving.  At that's just a touch over 1/2 throttle.

If I'm getting 18A at just over 1/2 throttle, is there a way to extrapolate out to full throttle?

[sihinch]

You could see if you can find an equivalent motor on ecalc. Like this:

https://www.ecalc.ch/motorcalc_mobile.php

[davidk]

Thanks Simon,

I've paid for eCalc here and there over the last few years... maybe I will again.

I'm going to stick with the Turnigy SK3 1050KV and a 12 x 6 wood prop.  I'll never run at full tilt and I'll check the motor and ESC after a few short flights to make sure things will not melt.

[davidk]

So proud to show an image of an empty Zap bottle.  First time in 5 years that a bottle has been completely used, not gone thick and gummy, not had the top so badly crusted and broken that it won't work.

The wheels have a nice suspension system.  The front is hinged and the back suspension is possible with these tiny elastics I found at the dollar store.  The wheels incorporate ball bearings so they spin beautifully.  This may be my first printed plane that has wheels that will survive a landing.

The Cowling Lock is a clever design.