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<div class="moz-cite-prefix">On 02/12/2013 01:30 PM, Frank Shields
wrote:<br>
</div>
<blockquote
cite="mid:001601ce094f$074fcde0$15ef69a0$@compostlab.com"
type="cite">
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Building
equipment for determining the hardness of pellets and biochar
I need something to turn a 9 kg box at a speed of 60 RPM +/-
1.<o:p></o:p></span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">I
have a 1/3<sup>rd</sup> HP motor that is rated at 1725 RPM<o:p></o:p></span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Fitted
with a 2” pulley attached to the motor and going to an 8”
pulley gives me a shaft turning 431 RPM<o:p></o:p></span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Then
another 2” pulley going to an 8” pulley on another shaft gives
me 108 RPM<o:p></o:p></span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">I
plan to adjust the 108 down to 60 using a voltage regulator. <o:p></o:p></span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Is
this a good plan? <o:p></o:p></span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">And
is there another factor I need to include for the weight of
the box I am turning?</span></p>
</blockquote>
<br>
This is a BAD plan.<br>
<br>
Your motor is probably speed controlled by line frequency, not
voltage. Cutting the voltage may or may not help, in fact, it can
fry the motor if the centrifugal switch does not kick out.<br>
<br>
Get a 3 phase motor and a VFD and it will work well., but figure
$100-$200 MINIMUM for the VFD. The 3 phase motor will be fairly
cheap.<br>
<br>
Dave 8{)<br>
<div class="moz-signature">-- <br>
<br>
<br>
<em>"Among the many misdeeds of British rule in India, history
will look upon the Act of depriving a whole nation of arms as
the blackest."</em><br>
<br>
Mohandus Ghandi, An Autobiography, Page 446.<br>
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