onlyonmonday Posted January 14, 2011 Report Share Posted January 14, 2011 I have the one speed (Multi-Pro 275) and wonder if I will do damage if I put a (Volume switch) Dimmer switch in line to slow down and vary the rotation ?? So many attachments to be used but believe some would work better if twirling is diminished.. Quote Link to comment Share on other sites More sharing options...
not a bear Posted January 17, 2011 Report Share Posted January 17, 2011 As long as you get one that can handle the wattage I think this will work. A better approach than a volume switch would be a wall dimmer I'd think. Let us know how it goes! I have the one speed (Multi-Pro 275) and wonder if I will do damage if I put a (Volume switch) Dimmer switch in line to slow down and vary the rotation ?? So many attachments to be used but believe some would work better if twirling is diminished.. Quote Link to comment Share on other sites More sharing options...
Vodkaman Posted January 17, 2011 Report Share Posted January 17, 2011 I have the one speed (Multi-Pro 275) and wonder if I will do damage if I put a (Volume switch) Dimmer switch in line to slow down and vary the rotation ?? So many attachments to be used but believe some would work better if twirling is diminished. This question comes up once or twice a year, so I decided to have a read. Modern dimmers work by switching the power on part way through the a/c cycle and off again when the voltage crosses zero. The knob adjusts where in the cycle the power is applied. So the voltage (110VAC) remains full, but the length of time the power is on, is reduced. Essentially, you are switching the drill on and off 120 times per second. For techy reasons that I won’t go into, this causes an increase in current flow in the motor windings. Your motor may or may not be able to take this extra current. If not, the coil wire will burn through and the motor dies. If the motor manufacturer was generous and spent more money than he needed to, then it will work, but it will get hot. Secondly, the dimmer circuit does not like the inductive load, again techy. The dimmer will work, but sooner or later the triac will fail. From here on it is a crap shoot. If the triac fails close to zero crossing, the motor will survive, but if it fails further away from zero, a massive current surge will destroy your motor. To try to save your motor from the surge, you could fit a fuse in the power line, rated just high enough for the motor. If the voltage is 110VAC and the motor wattage is 135W, the fuse will be 135/110 = 1.22 amps, so 1.25A to 1.5A fuse would work to save your motor from the current surge. Motor dimmers have more electronics to counter the inductive load problems. Why risk your expensive motor for the sake of a few extra $$. Dave Quote Link to comment Share on other sites More sharing options...
onlyonmonday Posted January 20, 2011 Author Report Share Posted January 20, 2011 Si I see that this is the answer, TRUE.. http://www.harborfreight.com/router-speed-control-43060.html Quote Link to comment Share on other sites More sharing options...
rixon529 Posted January 23, 2011 Report Share Posted January 23, 2011 Bob - Thanks for the link to the flex shaft carver / grinder. After reading all the reviews (including yours), I think this is what I've been looking for. For only $50, if it don't perform to my liking, it's not a huge loss. If it does what I want it to do, then I may get another. Thanks again for sharing the info. Rick H. Quote Link to comment Share on other sites More sharing options...
onlyonmonday Posted January 24, 2011 Author Report Share Posted January 24, 2011 The items will work I believe on the prototypes but will not know for sure until I can get back at it anf the cold goes away some.. My chair does not run well in snow and still am NOT done building the shop.. Thanks for any and all info to all that post.. Quote Link to comment Share on other sites More sharing options...
