Re: Rubber energy spreadsheet

From: ewmonda <ewmonda_at_hotmail.com>
Date: Sat, 28 Apr 2007 23:12:24 -0000

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]
>
Received on Sat Apr 28 2007 - 16:13:27 CEST