Thread: Variable speed control.

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I scooped this up for free. Can I use it to control a electric motor to make it variable speed. Thinking of making my own belt grinder.

It depends on the Motor

Then I guess the question is what motor to put with it.? I have someone on Craigslist locally with tons of electric motors for sale

Variable-frequency drive - Wikipedia, the free encyclopedia


It just isn't as cheap or easy as you would think

Brad/Undream has a really good thread on here about his Grinder build that you will want to read also.. He goes through the issues the he had to deal with as he home built a grinder...

I have heard that. But got something for nothing so just researching now

http://straightrazorpalace.com/forge...r-project.html


That is a good read

It has to do with the eventual application of the motor you're trying to control. A lot of motor controls are rheostats which control the rpms of the motor by (really basically) cutting the power to the motor. For a grinder, you need to keep the power or else you'll stall your wheel out at the lower levels. I have heard that you can use the controls off a treadmill though! Other than that, VFD is the only way to go.

VFDs are good, but if you don't know how to use them, you should get a professional to do the electric work on it. You can fry a motor pretty fast if you don't know what you are doing, it is really easy to screw up, trust me

well, by the looks of this and my thinking . it's onto a pulley system to control speed . OR take the major plunge into a kmg grinder . my sister has a ton of scrap metal . and 2 welders and i have nephews who know how to weld . the plans for the grinder on this site look good so who knows what a weekend can bring

Originally Posted by jeness

VFDs are good, but if you don't know how to use them, you should get a professional to do the electric work on it. You can fry a motor pretty fast if you don't know what you are doing, it is really easy to screw up, trust me

LOL. Yes it is. I am currently looking for a new 5 H.P. 1720 RPM motor for my dust collector.