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Jeff Telecky
09-08-2021, 4:29 PM
Want to replace a 3 phase motor with a single phase motor on an old jointer. If I match HP, RPM's, and account for amperage increase is there any reason this cannot be done?
Thanks in advance.
Jeff

Andrew Hughes
09-08-2021, 5:02 PM
I say yes.
But only if the jointer isn’t direct drive.
Belts and pulleys yes
Direct drive noway Jose

Will Boulware
09-08-2021, 5:13 PM
You certainly can (assuming it's belt driven like Andrew said), but it might be easier and cheaper to just throw a VFD on it and run it as-is.

Mike Henderson
09-08-2021, 5:56 PM
You certainly can (assuming it's belt driven like Andrew said), but it might be easier and cheaper to just throw a VFD on it and run it as-is.

If the motor's good, that's what I'd do. Probably be a lot less expensive than a new motor.

And you never have to worry about a starting capacitor failing or the centrifugal switch sticking.

Mike

Bill Dufour
09-08-2021, 6:08 PM
Watch the drive pulley bore and match the new motor to that. Changing to a different bore may require a special shaft key. I did that on my jointer because a VFD has no advantage to me on a jointer. Overloads may need to be adjusted/replaced for higher current on single phase. I would use the switch gear as is and see if it works without changes.
Bill D

Jonathan Jung
09-08-2021, 6:28 PM
I also recommend a VFD.

What jointer you working on by the way? I'm doing up a 1942 Oliver, and powering it with a phase converter.

sean meltvedt
09-09-2021, 12:25 AM
You’ll also likely need a new contactor-but unless it’s a huge monster motor I’m in the VFD camp as the best option.

George Makra
09-09-2021, 6:21 AM
I would change the motor.
Most jointer's are a couple hp and the cost could be similar to a video. I have vfds on my stuff but I miss the simplicity of just a simple on off switch. I just blew up my 7.5 KW vfd which drove a 10 hp motor on my planer.

I'm not a big fan of electronics in a wood shop to much dust.

On close coupled direct drive motors you can put a single phase motor on them too. Look up Woods drive coupling then mix and match the coupling half with the shaft bore sizes.

Tom Bender
09-18-2021, 7:57 AM
I really like having variable speed on my table saw. It might be good on a planer also.

David Kumm
09-18-2021, 9:20 AM
When swapping the motor, you need to duplicate the frame size, make sure the shaft diameter and length are adequate, check that the rotation is correct or can be reversed, and either swap the starter completely or if large enough, change the heaters ( overloads ) . If the jointer is older than 1952, the frame size will be different than current designations so you must measure things for a direct swap. Changing to a vfd you need to wire the start and stop buttons to the vfd and wire the vfd directly to the motor. That is actually easier and cheaper. It somewhat depends on the quality of the old motor and if you have heard it run. Dave