Unisaw Motor Question

[Greg Scarpelli]

Hello, my first time posting here... Lots of great information for the uninformed like myself.

I'm looking at purchasing a second hand unisaw, but the motor it currently has is a 5hp/3phase. Any opinions on what it would take/cost to swap the motor for a single phase? Or am I asking for more trouble than it's worth?

Thanks for any and all opinions.

[Jim O'Dell]

You should be able to google for an electric motor for a Unisaw and come up with some possibilities. Email Electric Motor Warehouse and ask what motors they have that will fit a Unisaw. I know they carry Leeson, may have other brands as well. You could do the same with Baldor and possibly be able to get a model number of a motor that will work. Actually, what you need is what type of face frame it will need, and you can find a motor that will work. Try Delta to see if they have that information. There should be lots of motors that will work. New for a 5 hp if you want to stay with that power would probably be in the 400.00 up range for new. Once you know what will work, you can look for a used one.
Other option would be to get a phase converter for 3 phase and keep that motor. Might even be a little less than a new single phase motor. Lots of information here. Hopefully someone will post that has more specific information than I have.
Oh, and welcome to the Creek!!!! Jim.

[fred klotz]

I'm not positive, but I believe the Unisaws motor is specific to the Unisaw. Two brackets welded to the motor case of an otherwise standard motor, with holes for a pivot mechanism. I have a Unisaw, but haven't paid attention to the motor mount lately.

[David Christopher]

Greg, the Grizzly 1023 motor will work on a unisaw

Grizzly motors are pretty reasonable

[Joshua Layne]

I don't know what vintage the unisaw you are looking at is, but if the current 3 phase motor is a 'bullet' motor, then you will either have to find another bullet motor (single phase tend to be around $300 used from what I have seen in the 1 - 1 1/2 HP range) You can use a Leeson or other (didn't know about the griz) but your range of tilt will be limited unless you cut the cabinet or cut the capacitor housing on the motor (saw this once on owwm - motor wasn't so pretty but it kept the cabinet intact.

Again, this isn't an issue if the saw in question already has the rectangular motor cutout.

HTH,
Josh

[Dave Cav]

I don't know what vintage the unisaw you are looking at is, but if the current 3 phase motor is a 'bullet' motor,


If he has a 5 HP 3 phase motor, it's not a bullet. I think they maxed out at 2 or 3 HP, but I am just about positive they never went as big as 5. Chances are that any replacement single phase Unisaw motor will work, but he will need to check the RPM rating and shaft size of his exising motor to match them so he can use his existing motor pulley.

The other alternative would be to use a TECO FM50 3 HP VFD to run the motor. Even though it's a little undersized, I'm using a TECO 3 HP VFD to run my 5 HP Delta 12/14" table saw with no problems. Lots of discussion on this topic over at OWWM.

[Jeff Duncan]

Don't forget you'll also need to buy a new switch and re-wire for it. It's always better to get a saw plug and play if you can. Once you start adding up costs (and we haven't even discussed replacing the arbor bearings yet) you can quickly sink more money than it would cost to buy one ready to go.
Also for average hobby shop stuff you could probably get by with a 2hp Leeson (or equivalent) motor. That's what I've been using in one of my Uni's for years now and rarely do I bog it down.
good luck,
JeffD

[Ed Labadie]

Don't forget you'll also need to buy a new switch and re-wire for it. It's always better to get a saw plug and play if you can. Once you start adding up costs (and we haven't even discussed replacing the arbor bearings yet) you can quickly sink more money than it would cost to buy one ready to go.
Also for average hobby shop stuff you could probably get by with a 2hp Leeson (or equivalent) motor. That's what I've been using in one of my Uni's for years now and rarely do I bog it down.
good luck,
JeffD

Don't think he will need a switch, the LVC Delta uses will work either way, single or 3ph.

Ed

[Chip Lindley]

+1 on the LVC control. Delta/Rockwell 3- and 1-phase controls are same but for the overload block. 3-phase has three heaters; single-phase has only one. Some LVC's use Furnas heaters, others use GE. The correct value heater will have to be matched to the replacement motor's amperage, along with a little rewiring for single phase. Not a major issue!

3-phase vs. single phase is the BIG debate. Your most economical option is to use a static phase converter and keep the big 5hp motor. The static converter will still give you 3.33hp output, which is more than plenty for general woodworking.

But, if you see other 3-phase machinery in your future, spring for a rotary phase converter. You can run any machine in your shop (up to 5hp) off the RPC. Multiple machines can be run at the same time, if need be--up to 15hp total! I have used a 5hp Arco Model A to run a 5hp shaper and 2hp DC together.

[David Christopher]

Greg, check out the classifieds here, looks like it might be your lucky day....a uni motor just posted

[Greg Scarpelli]

Thanks for all of the input... I'm waiting on the seller to finalize the purchase.

Will running the motor on a converter have any adverse effects(performance/lifespan) if I decided to run it on 3 phase at a later date?

[Chip Lindley]

Greg, running a 3ph motor on a rotary converter has no adverse effects. I've done it for years. You get practically full motor horsepower. As said before, a static phase converter gives about 2/3 of a motor's rated horsepower. Running a 5hp motor at 3.33hp. still gives plenty of BUTT for general woodworking.

[Fred Preston]

I have done this to my 1948 uni. check the RPM's of the old motor. mine was 1725. the new motor was [with unisaw mounts] 3400RPM, [1725RPM was not available w/uni mounts]:mad: I had to buy a pulley and belts too.:eek: I got a baldor from WWS for around 350. close to 400 with shipping and the belts and pulley were about 130 from delta. another 400 or so for a new arbor :mad: and 300 more for a biesmeyer fence w/ rails turned this project saw into a not so good deal. I paid 400 for the saw. could have got a new saw for what I put in this one but it will probably last the rest of my life and at the time the new ones were made overseas so I didn't really mind. YMMV

oh and BTW I also had to butcher the cabinet some to make it tilt.

[Adam Cook WV]

I was wondering what you ended up doing? I also have a 5hp 3 phase unisaw.