Re: Re: Rubber energy spreadsheet

From: Bill Gowen <b.gowen_at_earthlink.net>
Date: Sat, 28 Apr 2007 19:56:08 -0400

So that means to figure out the points where you plug in your torque values you have to convert back to winder turns? It seems like what you would want is for the top displayed value to be in winder turns out. At least that's the way I take my data.

The motor is 5/99.

  ----- Original Message -----
  From: ewmonda
  To: Indoor_Construction_at_yahoogroups.com
  Sent: Saturday, April 28, 2007 7:12 PM
  Subject: [Indoor_Construction] Re: Rubber energy spreadsheet


  Bill,

  Using a value of 8 in C2 (for your example) will give you a small
  error. I'd recommend just typing "=A2/14" into the block and then
  when you fill in A2, you'll never have to fuss with C2.

  I am curious which batch of rubber you used that gave 4277 ft-
  lbs/lb. Care to share?

  Also, if anyone else has tested 1/05 or 6/06 (the two batches I have
  a lot of) I'd be very interested to see your results. I'd like to
  see what affect winding technique (among other things) has.

  Eric Monda

  --- In Indoor_Construction_at_yahoogroups.com, "Bill Gowen"
  <b.gowen_at_...> wrote:
>
> Thanks Eric!
>
> The test I wanted to enter went to 110 wt. I divided this by 14
  and got 7.85. I put 8 in the C2 block. Does the program adjust the
  last block so you'll come out at zero? The good news (if I did this
  right) is that the motor tested to 4277 ft-lbs/lb. Another test due
  today. Hopefully I can get another one done without breaking the
  motor.
>
> ----- Original Message -----
> From: ewmonda
> To: Indoor_Construction_at_yahoogroups.com
> Sent: Saturday, April 28, 2007 2:33 PM
> Subject: [Indoor_Construction] Re: Rubber energy spreadsheet
>
>
> Bill,
>
> I hope Fred won't mind if I field this question. After Mark's
  post
> I dissassembled the spread sheet to see what it was doing.
>
> The spreadsheet should have =A2/14 entered in cell C2. It is
> entered like that in subsequent examples, (C8). In A2, the
  number
> of winder turns (not rubber turns) is entered. B2 is the weight
  of
> the rubber motor in grams. Once A2 and C2 are filled in, row 4
  is
> populated with the number of motor turns (not winder turns)
  where
> the torque should be read in in-oz and entered in row 5. The
  sheet
> then uses the Composite Simpson's Rule method of numerically
> integrating the area under the curve (for you math geeks out
> there). If you want to use a 5 to 1 winder, you'd have to change
> the coefficients in the equation.
>
> You are correct that the 40 to 1 is a typo. The coefficients in
  the
> equations require it to be a 20 to 1 winder. Comment on the 10
  to 1
> spreadsheet is correct.
>
> Eric Monda
>
> --- In Indoor_Construction_at_yahoogroups.com, "Bill Gowen"
> <b.gowen_at_> wrote:
> >
> > Fred
> > Can you post some instructions on how to use the energy
> spreadsheet? I
> > tried to enter some data and get all kinds of different
  results if
> I do
> > it different ways. I think what I need is some simple step-by-
  step
> > instructions for filling out each box.
> >
> > For instance, how do you determine the unwinding increment? Do
  you
> have
> > to select an increment so you come out at zero winds at the
  end?
> do you
> > put the maximum torque reading in the first box?
> >
> > If I use an increment of 5 winder turns I get an energy that
  is
> double
> > what I get if I use 10 winder turns for the increment.
> >
> > Also the blank sheet says it is for a 40 to 1 winder which
  seems
> to be
> > a typo.
> >
> > Confused in Decatur.
> >
>
>
>
>
>
> [Non-text portions of this message have been removed]
>



   

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Received on Sat Apr 28 2007 - 16:57:13 CEST