Could you perhaps email Tapio instead of posting your message to him on here? There's people that get these messages in e-mail format. I'm tired of seeing personal messages posted to the groups, Leroy asked me what the reserve on my ebay auction was on the board.. keep it personal and don't clog the message board! I'm surprised Mark hasn't stepped up to this, I guess if it was me doing it.. I dunno maybe we wouldn't have a message board anymore.
Perhaps I should've emailed this to Tony, but I wanted everybody to see it.
Max
--- In Indoor_Construction_at_yahoogroups.com, J MATHEWS <tmathews1@...> wrote:
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> Tapio,I'm interested in your computerized data logging system. Can you E-mail me at: tmathews1_at_... so that we may discuss it off line?
> Tony Mathews
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> To: Indoor_Construction_at_yahoogroups.com
> From: tapio.linkosalo_at_...
> Date: Sun, 8 Mar 2009 08:57:24 +0200
> Subject: [Indoor_Construction] Rubber test figure
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> Leo P. commented that not everybody receives attachments, and requested
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> the pic about rubber test, so I uploaded it to the Yahoo files area
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> (there should be a separate message about that.
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> The tests are made with a stretch method for 30 gram F1B motors, with
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> pull force recorded at intervals during the release phase, after the
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> motor is first stretched to maximum stretch (90% of estimated breaking
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> force). I first tried to measure these by hand, writing down forces from
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> a scale at 10cm intervals, but that turned to depend heavily on the
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> intervals. Thus I built a computerized system, where the force is
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> automatically logged at 1cm intervals (with about 300 measurements per
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> motor, as full stretch of a F1B motor is 320 to 340 cm). I'm quite
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> confident with the results, as they show very little variance within a
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> batch, less than 1% standard deviation, yet show clearly different
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> energy return values for different batches. Also I found out that
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> temperature effect the results, and while having repeats of same batches
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> (made motors to contests at different times), fitted some statistics to
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> the data, with temperature and batch as independent variables, to find
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> out that the energy return changes about 0.8% per degree centigrade.
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> This variation is corrected for in the figure that I posted.
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> http://f1.grp.yahoofs.com/v1/4F6zSeKetyv0SnWxOME8HE2F1BCnP_4F11Vo1iyHVtFVn9DkBjwUjyXFF9mIQzWb6rHu0cU05v9TMKPg8Tz0PNYBxoQGKlU/rubber.GIF
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> (I hope the link above works? Anyway, file called rubber.GIF in the
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> files area...)
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> -Tapio-
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Received on Sun Mar 08 2009 - 08:23:27 CET
