Can someone tell me if there is a safe way that I could perhaps change the voltage to a motor that is a non-variable speed and get it to run slower? Does the motor have to be designed that way or can a person put in their own switch to limit the current?
I'd love to be able to slow down my belt/disc sander when I'm doing fine tuning with the belt... ya know? :think:
Anybody know? :dunno:
Know something about tools & electricity?
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KurtHuhn
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The short answer is "maybe".
Some motors can be slowed with an external rheostat like the kind sold to woodworkers to slow down their routers. In those instances it works like a charm.
However, most motors you'll find on large power tools are capacitor-start motors, and require the full 110/220V to start up. Feeding it a lower voltage will result in, at best, a motor that is difficult to get going. Kind of like putting an 8" grinder motor on a 150-foot extension cord and trying to turn it on.
Some motors can be slowed with an external rheostat like the kind sold to woodworkers to slow down their routers. In those instances it works like a charm.
However, most motors you'll find on large power tools are capacitor-start motors, and require the full 110/220V to start up. Feeding it a lower voltage will result in, at best, a motor that is difficult to get going. Kind of like putting an 8" grinder motor on a 150-foot extension cord and trying to turn it on.
What about putting the switch on and turning it after it's started?KurtHuhn wrote:The short answer is "maybe".
Some motors can be slowed with an external rheostat like the kind sold to woodworkers to slow down their routers. In those instances it works like a charm.
However, most motors you'll find on large power tools are capacitor-start motors, and require the full 110/220V to start up. Feeding it a lower voltage will result in, at best, a motor that is difficult to get going. Kind of like putting an 8" grinder motor on a 150-foot extension cord and trying to turn it on.
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KurtHuhn
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- Location: United States/Rhode Island
I have no idea if that would work, but I suspect not - at least not very well. Most of those motors are *very* finicky about voltage levels, and have relays wired in-line to control when the capacitor feeds juice into the motor. If the RPMs drop below a certain level, the relay switches on the power to bring the RPMs back up. You *might* be able to do it, if you keep it above that RPM threshold, but it may not make enough power to sustain it's rotation below a certain point.
In my opinion, you'd be better off going with something like Jack Howell posted about on ASP, and using a DC motor with a controller. You might be able to find everything you need at the local junkyard and pillaging a treadmill for parts. Search the yard sales and stuff in your area. Chances are you can find all the parts you need for very small money.
In my opinion, you'd be better off going with something like Jack Howell posted about on ASP, and using a DC motor with a controller. You might be able to find everything you need at the local junkyard and pillaging a treadmill for parts. Search the yard sales and stuff in your area. Chances are you can find all the parts you need for very small money.
Hey Ben,
I would resist the temptation to buy a voltage regulator suited for a router to use with your motor. I know at least one person who has tried this method and shortly ended up with a motor that was only good enough to weigh his trash bags to the bottom of the can. You're better off with Howell's DC motor idea that Kurt has suggested. Don't waste your motor.
Jeff
I would resist the temptation to buy a voltage regulator suited for a router to use with your motor. I know at least one person who has tried this method and shortly ended up with a motor that was only good enough to weigh his trash bags to the bottom of the can. You're better off with Howell's DC motor idea that Kurt has suggested. Don't waste your motor.
Jeff
What's the slow speed on that Rad?RadDavis wrote:Hey Ben,
I don't know what you looking to spend, but I bought a variable speed bench grinder at Lowes for around $75.00. I'm sure it wouldn't be too hard to take off one of the grinding stones and put on a pulley to run your belt.
And, you'd still have a grinder on the other side!
Rad