HPA

Jeremy, thanks for all those thoughts. Plenty to consider for me there.
As far as winding to 90% goes, I suspect scale modellers' reluctance to do so stems from the fact that damage resulting from a burst motor in a scale model is much more of a hassle to repair than it is with duration models. And winding tubes don't eliminate the risk of leaving the dreaded angry ball of rubber bunched up at the back.

......true.......          

My Potez 33 Peanut suffered another longeron failure a while back - too soft wood I guess! Anyway, gave it a go to try straighten it out - by cutting tissue from the bottom of fuselage so it's less visible - and pushing in some stays. So far so good, but the repairs are making the overall weight go up. Tim

Quote from: g_kandylakis on Sep 24, 2026, 07:22 PMHopefully we will return to the BD4 of Markus now...

As a help to that or perhaps a reason for more discussion... might explain the need for so much up elevator

A nice thing of this video is the exited voices of kids who are seeing this sort of flying for the first time. When the model hit the ceiling beam one said Ow! But another said No, its built to stand this!

26 ounces? Grams perhaps?

Well, if George okays the initial trim settings, you should do fine at the IIFI!

Many thanks Jeremy,

However, the gym we are currently using is rather narrow/tight and would not endager any flight there.

George also said it's better to try it in IIFI. The airplane is balanced to the proposed balance point, so I'll take my chances!

Quote from: Spiros on Oct 01, 2026, 08:05 AMThank you so much!

First flights will be in IIFI 2026, hopefully!

Spiros

You have a month or so until the IIFI.  It might be a good idea to start trimming it before then

Thanks George for oofle dusting the upload!

Link to the book:
https://hpa.aeromodelling.gr/plans/details.php?image_id=2204

Quote from: Squirrelnet on Sep 30, 2026, 02:34 PMSurely though if you are winding a 10 x 1/8 motor to full turns or presumably 80% of breaking turns then a smaller motor even if wound to breaking turns will not produce as much power and therefore not climb as much ? I wondered if you needed more power ...11 strands ?

If you look at the turns/torque curves (eg on page 24 of the JOD collection soon too be available in the Plans Gallery), the high torque part of the curve doesn't come until at least 90% of the break turns are applied. At 80% you are just in the early part of the cruise part of the torque curve.  Duration models are always wound to 90% or more - that's why you only get 2 or 3 competition flights from a motor.

I think it was looking at the reluctance of scale modellers to wind into the high torque part of the curve that led JOD to say that the motors were under-wound.