Variable Speed Controller for 110v motor??

[WillisXJ]

Picked up a drill press for real cheap from CL, but only goes down to 550rpm. Too fast. I might be able to put a 3rd set of pulleys in there to slow it down, but if not, is there any way to variable drive a 110v motor? It already has a 1750 rpm motor on it, and I don't want to put a 3 phase on it so I can add a VFD controller to it, that just negates the cheap aspect of it.

Options, opinions, GTFO?

Steve

[miniyota]

i'm interested in one for mine as well.

[Andreb]

Maybe a big ass 12 amps industrial fan dimmer?

http://www.passandseymour.com/productcatalog/product.cfm?cn=94121&mkt=4

[Rory Bellows]

This may or may not work. I always want to pick one pick one up but never remember when I'm at HF.

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=43060

[M CRISIS]

This may or may not work. I always want to pick one pick one up but never remember when I'm at HF.

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=43060Don't know much about electricicals but I do know that this router speed controller is only for brush type motors and not induction types.

[ToddRH]

You'll lose whatever % of torque as you reduce the speed cause you are reducing current.

Example....Reduce speed 50%, you reduce power 50%.

Check into using a 10-1 speed reduction box between the motor and pulleys.....you pick up shitloads of torque, and lower the speed. Used ones are cheap, new are not much more.

[WillisXJ]

Check into using a 10-1 speed reduction box between the motor and pulleys.....you pick up shitloads of torque, and lower the speed. Used ones are cheap, new are not much more.

I'm interested in checking this out. Google doesn't seem to be much help. I'm probably searching for the incorrect term. Can anyone give some assistance on this?

[trkklr77]

x2, running a elec motor that slow with a load will more than likely smooke it.

gear reduction and keep th emotor in its sweet spot.

[ChiScouter]

Washing machine motors are 2 speeds and both speeds below 1750. The ones I have used in the past have had 1/2" shafts so you can use your stepped pully. They don't have a standard flange mount, so you have to do some fabbing to mount it on the press. They are plenty strong and the price is right if you go driving around on garbage day.

[BumpyDodge]

If you want full torque at ultra-slow speed without having to add extra reduction drives, a *DC* motor is the way to go. Constant torque down to about 10% rated rpm.

[87JeepWrangler]

i'd recommend adding pulleys for the reasons mentioned above, but if you insist on changing the motor speed instead, then you need a variac. they are basically small transformers with a dial on the top to adjust the voltage. they are made specifically to handle the loads of motors.

https://id38.securedata.net/sweetmarias/variac_sweetmarias.jpg

[Wicked_S10]

No, an induction motors speed is governed by the frequency of the AC power, not by the voltage alone. Using a variac, or even a triac type speed control will not work with an induction motor. Even if you could slow it down, the centrifugal switch would continually kick back in and try to bring the RPM's back up to the set point, the speed would then fall back off and the cycle would repeat destroying your start cap, windings and switch.

The best way to do it is mentioned above. DC motor and DC motor speed control. The next best way, and probably cheaper than a big DC motor, is a surplus 3 phase motor and small VFD (variable frequency drive). Either way it will not be a cheap project.

Good luck,
Jason

[WillisXJ]

All good points. I mentioned this to my father and he thinks he has a teired pulley that will work for this. Either way, looks like the pulley will be the cheapest and easiest for doing such a thing.

[Pook]

VFD and a 3phase motor is an awesome combo on the drill press. Put one on my work drill press 5 years ago...well worth the $. I'm into it for less than $400 but I use it for work so it was justifiable.

[87JeepWrangler]

No, an induction motors speed is governed by the frequency of the AC power, not by the voltage alone. Using a variac, or even a triac type speed control will not work with an induction motor. Even if you could slow it down, the centrifugal switch would continually kick back in and try to bring the RPM's back up to the set point, the speed would then fall back off and the cycle would repeat destroying your start cap, windings and switch.

The best way to do it is mentioned above. DC motor and DC motor speed control. The next best way, and probably cheaper than a big DC motor, is a surplus 3 phase motor and small VFD (variable frequency drive). Either way it will not be a cheap project.

Good luck,
Jason

any motor i've ever hooked a variac too, has always worked. i guess i just never hooked one to an induction motor. i stand corrected.

thanks for the info.

[ChiScouter]

There was a writeup here some time ago from a guy who used a DC motor from a treadmill on his drill press and it sounded like a sweet deal.