RE: Re: Torque curve equation?

From: <leop_at_lyradev.com>
Date: 15 Oct 2013 12:23:48 -0700

Mike and everyone else,
  
 As Jake says, Fred Rash's torque vs. wind chart are just an estimates. The charts depend on data fits, interpolations, and the winder's technique. It is easy to create your own chart for the motors you use. For F1D, I suspect the motors used by a flier are all about the same length (of course, they are the same weight). So one needs only to make one, or perhaps just a few charts. The charts are easy to make. Just do a full torque wind just has you would do when flying in completion where you are one second beyond for the last flight of the event. In other words, winds as tight as you can. Then, write down the torques as you slowly unwind, perhaps every te winds at the beginning and end but just every 50 when the torque look flat. Fred Tellier took 11 measurements but I take about 50 in total. I also do not touch the motor as I unwind. Others tap the motor they say to settle the torque readings. When I make these charts to test rubber, I repeat for at least 6 motors (broken motors do not count. And I repeat a second time for each test motor two or more weeks later after the motors are well rested from the first wind.
  
 If you make your own charts, you will know what output you get for your own winding and rubber.
  
 Leo P
  
 

---In Indoor_Construction_at_yahoogroups.com, <indoor_construction_at_yahoogroups.com> wrote:

 I should have noticed that but did not.
 
 Thanks, Jake.
 
 
 --- In Indoor_Construction_at_yahoogroups.com mailto:Indoor_Construction_at_yahoogroups.com, Jake Palmer <82.jake@...> wrote:
>
> All of that data is on the spreadsheet that Fred Rash has posted in the
> files section. You can plug in any length and weight for a motor, and it
> creates a table with estimated torque values over the full range of winds.
>
>
> On Tue, Oct 15, 2013 at 11:28 AM, mkirda_at_... <mkirda@...
> > wrote:
>
> > **
> >
> >
> > BTW, I should add that I am almost entirely interested in F1D motors here.
> > That narrows the range considerably.
> >
> > Mike
> >
> >
> > --- In Indoor_Construction_at_yahoogroups.com mailto:Indoor_Construction_at_yahoogroups.com, "mkirda@" <mkirda@>
> > wrote:
> > >
> > > Greetings.
> > >
> > > Before I reinvent the wheel, does anyone have an equation to figure out
> > torque on rubber when unwound say 20% off maximum?
> > >
> > > Given inputs of unstretched loop length and weight.
> > > I'm thinking it should be possible to model the May99 torque curve
> > within a few percentage.
> > >
> > > Thanks in advance!
> > >
> > > Regards.
> > > Mike Kirda
> > >
> >
> >
> >
>

Received on Tue Oct 15 2013 - 12:23:48 CEST