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Re: AC Motor Speed Control OR?

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Posted by Rick Crockett/">Rick Crockett on February 28, 2000 19:35:46 UTC

Hi Steve, Dianne:

Good answer Dianne.

Steve there are also some other considerations. Have you completed any optics? Unless you are going to make a full thickness mirror over twenty inches or plan to turn out more than one mirror a month, your time and money is probably going to be wasted in building a grinding machine.

That being said forget the 0-100 range. It is not going to happen. 10 to 100 possibly but not likely. If you are using a 3phase AC motor, you can get a DART 1hp speed contoller for about $800. For about $700 you can get a 1/2hp PM Gearmotor and controller from Dayton. Attempting to opperate any motor at near stall speeds is going to burn out the motor and /or controller. Using pulley to get into the working range is still a good idea and belt coupling is a somoother and quiter way to go. One can also use vari-cone varible speed pulleys.

If it weren't a crying shame, one would tend to laugh at all the newbies that think building a grinding machine is the way to go. I own a 44" grinding machine and I wouldn't even get it dirty for less than a 16" full thickness mirror.

Good Luck, -Rick

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