Variable Speed Controllers for 110V motors

Inferno

Inferno

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I searched a bit and didn't find any answers.
I'd like to add a variable speed controller to my 110V motors. I know I could do a treadmill mod but that doesn't especially interest me.

My budget isn't all that high so the cheaper (functional) the better.

Any ideas?
 
Single-phase induction motors don't lend themselves to speed control. What horsepower ratings are you dealing with? You might have to change to small 3-phase motors with VFDs, or consider picking up some old treadmills and using the DC motors and controllers to run your machines. You'd have to deal with the higher RPM of the treadmill motors - pulleys or gearboxes.

I have machines running on both VFDs and treadmill motors. Speed control is great to have. VFDs are best, but treadmill stuff is cheap.
 
Well, first off, I don't know what a VFD is.
And I should have looked before I even posted but it appears I have 3/4hp capacitor start motors which will, definitely, not work with a variable speed controller.

So it looks like I need a more clear path for my thoughts. Ideally I'd like to get something that would allow me to, eventually, sync the drive motor with steppers for threading and whatnot. (I'm venturing into CNC but probably won't get CNC on my lathe for years, if ever)
 
VFD stands for "Variable Frequency" device or drive.

Short of a mechanical drive like a "ShopSmith" has (think big $$$$$) there isn't much you can do with a single phase capacitor start motor. The solutions all involve changing the motor. A 3 phase and VFD combination was suggested. As was a "treadmill" motor and drive. I haven't tried either so can't comment for or against.

Another possibility is Horror Fright has a 120 volt hoist that uses a DC motor. I have a couple of them that I play with but never mounted to a machine. You still would need to arrange for some sort of speed control, a router control is too small.(light)

Stick to changing belts and learn more about the machine before you go looking to fine tune speed. That's the best I can offer.

.
 
Router speed controller works for everything I've tried it on. $20 - 30+ available many places.
Aaron
 
There are lots of small motor speed controllers listed on eBay. As mentioned they're usually called "router speed controllers". The big downside is that the ones I've seen only work on brush style motors. They won't work on an induction style motor.

I purchased one a couple years ago to control the speed of an older Black & Decker Professional chop saw. I wanted to use the saw with a metal cutting blade (not an abrasive disk). Most b 14" blades I could find were only capable of around 3,000 rpm, and the saw normally turns at 5,500 rpm It's sort of my version of a cold saw. I did find a couple blades that would turn 5,500 rpm, but they were in the several hundred dollar range. I wasn't willing to spend that much money on an experiment.

The controller is supposed to be able to lower the rpm to 1,500. It works fine at 2,000 rpm, but anything lower than that is not consistent. That's ok for my purposes because it cuts the aluminum stock fine at that speed.
 
I have been looking for a VFD compatible with a single phase induction motor as well.

They do exist but apparently capacitor start motors need to be modified in order to work with them. The issue is that when the motor speeds up or slows down,the centrifugal switch is deactivated/activated to remove/add the start winding to the circuit. When a VFD is used, the capacitor and centrifugal switch are removed from the circuit and the start winding is used as a second winding on a 3 phase motor. The two windings will permit the VFD to vary the motor speed and direction like a normal 3 phase motor but I expect, not as efficiently.

From the reading that I have done, it appears that the biggest use for single phase VFD's is for speed control of large fans. Banggood sells a number of different units. There was a you tube video of someone testing one with a single phase motor.

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homebrewed said:
If you're aiming to eventually convert your machine to CNC, here's an approach worth thinking about: https://www.hobby-machinist.com/thr...lace-plus-big-current-draw.82636/#post-732271

Yes it will be more expensive but gives you a lot of capability. An ELS wouldn't be too far a leap from there.
Click to expand...
Dang, you did exactly what I'd like to do. As you said, it ain't cheap.
I'd have to ask the cats if I could spend that kind of dough on a hobby.
I was actually impressed at how quiet your motor is. I'm used to steppers being noisy but, to be fair, I'm used to machines that run the steppers slower.

Still.... hmmmm.... I have to stay away from the keyboard later in the evening. That's when I make impulsive decisions and also when I make stupid posts where I forget that my motors are capacitor start.
 
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