<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML><HEAD> <META http-equiv=Content-Type content="text/html; = charset=iso-8859-1"> <META content="MSHTML 6.00.2900.2627" name=GENERATOR> <STYLE></STYLE> </HEAD> <BODY bgColor=#ffffff> <DIV><FONT face=Arial size=2></FONT> </DIV> <DIV><FONT face=Arial size=2>Probable not.  Most motors used = for buffers are of the type that can not be used in a variable speed mode.  = These are ac only motors.  Reducing the voltage will burn them out and reduce = power.</FONT></DIV> <DIV><FONT face=Arial size=2></FONT> </DIV> <DIV><FONT face=Arial size=2>That said,  you could use belt = ratio changes if it is belt driven.</FONT></DIV> <DIV><FONT face=Arial size=2></FONT> </DIV> <DIV><FONT face=Arial size=2>Motors that can be speed controlled are = the ac/dc type as used in vacuum cleaners, variable speed drills etc.  They = are usually high speed, load sensitive and can be slowed down using a device = similar to a lamp dimmer.  They build a device that is made just for that = type of motor (Universal Motor) but a plain lamp dimmer will work but is more = apt to burn out.</FONT></DIV> <DIV> </DIV> <DIV><FONT face=Arial size=2>Air driven motors can work with air = volume restriction but usually doesn't have much power at the restricted flow.</FONT></DIV> <DIV><FONT face=Arial size=2></FONT> </DIV> <DIV><FONT face=Arial size=2>I'd start with a 1750 rpm motor and use = pulleys to get the variable speed.  A large "O" ring type belt will be easier = to change.  You can get those "O" ring belts at some vacuum cleaner = shops or maybe at Grainger.</FONT></DIV> <DIV><FONT face=Arial size=2></FONT> </DIV> <DIV><FONT face=Arial size=2>Carl Meyer PTG assoc<BR>Santa Clara, Ca.</FONT></DIV> <DIV> </DIV> <DIV> </DIV> <DIV>----- Original Message ----- </DIV> <BLOCKQUOTE dir=ltr style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; = BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px"> <DIV style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: = black"><B>From:</B> <A title=staff@smithpiano.com = href="mailto:staff@smithpiano.com">Brad Smith</A> </DIV> <DIV style="FONT: 10pt arial"><B>To:</B> <A = title=pianotech@ptg.org href="mailto:pianotech@ptg.org">PianoTech</A> </DIV> <DIV style="FONT: 10pt arial"><B>Sent:</B> Monday, June 06, 2005 = 8:37 AM</DIV> <DIV style="FONT: 10pt arial"><B>Subject:</B> AC variable power = </DIV> <DIV><BR></DIV> <DIV><FONT face=Tahoma size=2><SPAN = class=609193415-06062005>List, </SPAN></FONT></DIV> <DIV><FONT face=Tahoma size=2><SPAN = class=609193415-06062005>Does anyone know of a variable AC power supply thing, that I could use to slow down my = 'bench grinder acting as buffing wheel'. ?</SPAN></FONT></DIV> <DIV><FONT face=Tahoma size=2><SPAN class=609193415-06062005>I = seem to remember seeing something like it. </SPAN></FONT></DIV> <DIV><FONT face=Tahoma size=2><SPAN = class=609193415-06062005>Someone suggested I build one from electric parts, that would match the wattage of my = bench grinder. </SPAN></FONT></DIV> <DIV><FONT face=Tahoma size=2><SPAN class=609193415-06062005>The = electrical guy at Home Depot says it must have enough wattage to handle the jolt = from starting up the grinder. </SPAN></FONT></DIV> <DIV><FONT face=Tahoma size=2><SPAN class=609193415-06062005></SPAN></FONT> </DIV> <DIV><FONT face=Tahoma size=2><SPAN class=609193415-06062005>Any = ideas most appreciated. </SPAN></FONT></DIV> <DIV><FONT face=Tahoma size=2><SPAN class=609193415-06062005></SPAN></FONT> </DIV> <P><FONT face=Arial size=2>Best regards,</FONT> </P> <P><FONT face=Arial size=2>Brad Smith, RPT</FONT> <BR><FONT = face=Arial size=2>www.smithpiano.com</FONT> <BR><FONT face=Arial = size=2> </FONT> </P> <DIV> </DIV></BLOCKQUOTE></BODY></HTML>