Re: RE: RE: RE: Re: RE: Re: Generally accepted good winding technique?

From: Tapio Linkosalo <tapio.linkosalo_at_iki.fi>
Date: Tue, 15 Oct 2013 09:25:33 +0300

On Wed, Oct 9, 2013 at 10:37 PM, <ykleetx_at_gmail.com> wrote:

> **
>
>
> max turns = motor_length * 45.67*SQRT (motor_length / motor_weight )
>
> motor_length in inch or millimeters ? Guess inch ?
>
> motor_length for loop or rubber ? Guess loop ?
>
> motor_weight in grams ?
>
> max torque =( motor_weight / motor_length / 0.11)^1.5
>
>



I converted the formulas for metric; i.e. motor (loop) length in
millimetres, motor weight in grams. Turns in turns, and torque in
gram-centimetres:

max.turns = motor_length * 1.79031*SQRT(motor_length/motor_weight*0.03937)
max.torque = 72.01*(motor_weight/motor_length*230.9091)^1.5

Tested that with various motors. For F1D (200mm 0.6g) the equation suggests
41.5g*cm 1300 turns, and I have managed to wind to 35, which seems
reasonable. For F1M (350mm full motor or 175mm half motor) the max torque
reads 70g*cm which seems huge; I manage to get repeatedly to 45, but my
motors often break under 40.

What seems interesting is that for "beginners class" with a single 700mm
loop of 3/32" Supersport I get max torque of around 70g*cm. SS rubber is
more tolerable, but again the equations give quite reasonable numbers. And
even for a 6-strand (of 1/8" rubber) 10 gram motor the max torque is a bit
less than 800g*cm, and I can routinely wind to 700+; I would have guessed
that internal friction of the multi-strand motor would have reduced the
achievable max. torque...




-Tapio-
Received on Mon Oct 14 2013 - 23:25:34 CEST