So after all this great discussion, I am still left to wonder. Would it be
better to "warm up" a rubber so that the change in temperature is less? If
you have a smaller Delta T would that make the rubber less brittle, reducing
the chances of breaking? Or would it help to cool down the motor
significantly while winding in hopes of keeping the whole temperature range
lower than the 100 F ceiling?
I have always used a 10 to 1 winder for my F1D motors, and I wind very
slowly. I always seem to break 5 or 6 motors though before getting one up to
the desired torque. I have had better success of late getting turns into
3/02 vs the 5/99 batch that I have.
In the salt mine I had cold fingers. I guess in serbia they will be
sweaty....
On Wed, Jun 23, 2010 at 12:53 PM, Bill Gowen <wdgowen_at_gmail.com> wrote:
>
>
> At Lakehurst last summer and at USIC this year I broke many motors (mostly
> 5/99) at torques about 90% of what I can wind to in my 75 degree home work
> area.
>
>
> ----- Original Message -----
> *From:* Tapio Linkosalo <tapio.linkosalo_at_iki.fi>
> *To:* Indoor_Construction_at_yahoogroups.com
> *Sent:* Wednesday, June 23, 2010 11:04 AM
> *Subject:* Re: [Indoor_Construction] Re: Thermodynamics of rubber bands
>
>
>
> nick wrote:
> >
> >
> > 'Above 40C (something over 100F) the rubber tends to get soft and break
> > abruptly.'
> >
> > Aha - Belgrade temperature!!!
>
> Yup. The temperature sensitivity varies from batch to batch, and the
> best (like 1999) are most sensitive. I recall that way back then in F1B
> Eurochamps 2000 I had prepared motors of May 1999 (it was ample then!)
> for morning and fly-off -rounds, and had some motors from 1998 batch for
> the heat of the day, as that latter batch was known to stand the heat
> better. Quite needed, for in the afternoon the temperatures were above
> 40C in the shade, but no shade around on the open flying field! That was
> one hot contest!
>
> -Tapio-
>
>
>
--
BEN SAKS
www.bensaks.carbonmade.com
Received on Wed Jun 23 2010 - 10:09:25 CEST