Powermatic 66 underpowered?

[Kyle Jones]

I just picked up a used Powermatic 66 at the Local ISD auction. It has a Leeson 1.5hp 3 phase motor on it (#110192.00). If I spend the money on a rotary phase converter will this saw be underpowered? Or how big of a deal is it to swap to a new 3hp single phase motor? Any suggestions would be greatly appecriated.

[Van Huskey]

I would definately put a 3hp 1ph in it. You will have a lot more power (1.5 is underpowered) and be cheaper than buying a convertor. In fact I would look at the price difference to a 5hp motor and consider that as well.

[Ramsey Ramco]

I have a 66 with a 3hp Baldor motor. It has plenty of power but if I had to upgrade I would step up to a 5hp the price difference is minimal between the two. Good luck GREAT SAW!!!! you will not be disappointed mine was the best purchase I have ever made.

[Jamie Buxton]

No, 1 1/2 hp is not underpowered for a cabinet saw. I have a 1 1/2 hp Unisaw that I've used for nearly thirty years. The only time I've bogged it down is when I've done something I shouldn't have been doing in the first place -- like ripping twisted lumber that is trying to pinch the kerf closed. (The correct answer there is to use a splitter. Or to use the bandsaw.)

Just for clarity, the only thing more power gets you is a faster possible feed rate. If you're ripping thick stock with a power feeder, okay maybe you can use 3 hp. But if you're a garage shop like most on this board, there's no need for the bigger motor.

[Carroll Courtney]

Check the starter and see what it is rated for?You may also need a starter as well,but one can be purchase off that auction site.Lets see some pics----Carroll

[Heather Thompson]

I to have a PM66 3hp single phase, plenty of power and have never needed more, but as has been mentioned above if I were upgrading I would seriously consider the 5hp for the price difference. I have a friend that runs a commercial shop with a PM66 and a power feeder, the 3hp lasted 15+ years, when he replaced the motor he opted for the 5hp even though the business will be gone long before the next 15 years.

Heather

[Glen Butler]

It would be foolish to buy a phase converter when a 3hp motor could be had for the same or less cost.

[Chuck Isaacson]

It would be foolish to buy a phase converter when a 3hp motor could be had for the same or less cost.

I agree with this completely... You could sell the 1.5Hp motor to help it out too.

[Paul Ryan]

No, 1 1/2 hp is not underpowered for a cabinet saw. I have a 1 1/2 hp Unisaw that I've used for nearly thirty years. The only time I've bogged it down is when I've done something I shouldn't have been doing in the first place -- like ripping twisted lumber that is trying to pinch the kerf closed. (The correct answer there is to use a splitter. Or to use the bandsaw.)

Just for clarity, the only thing more power gets you is a faster possible feed rate. If you're ripping thick stock with a power feeder, okay maybe you can use 3 hp. But if you're a garage shop like most on this board, there's no need for the bigger motor.


I completly agree with Jamie that 1 1/2 is not underpowered, especially for an older motor. But if it is 3 phase, to me is doesn't make any sense to get a phase converter and restrict the small motor, when you could buy a 3 hp single phase for the same or less money. If you can get a 5 hp motor for cheap then that would be good too, but it again will require a larger breaker. Unless you are doing heavy ripping for long periods I really don't see the advantage of a 5hp motor on a 10" saw.

[Ron Jones near Indy]

I completly agree with Jamie that 1 1/2 is not underpowered, especially for an older motor. But if it is 3 phase, to me is doesn't make any sense to get a phase converter and restrict the small motor, when you could buy a 3 hp single phase for the same or less money. If you can get a 5 hp motor for cheap then that would be good too, but it again will require a larger breaker. Unless you are doing heavy ripping for long periods I really don't see the advantage of a 5hp motor on a 10" saw.

I agree on this. I had one a 1.5 hp 3 phase at work from 1975 to 2009 and only thought underpowered when ripping 2 x 10 x 18' using the only blade in the shop at the time (DULL). I would go the 3hp single phase in a heartbeat.

[Alex Shanku]

It would be foolish to buy a phase converter when a 3hp motor could be had for the same or less cost.

It would be foolish to buy a 3hp 1phase motor when a freq drive could be had for ~$100

[Dave Cav]

It would be foolish to buy a 3hp 1phase motor when a freq drive could be had for ~$100

I agree. I would get a TECO FM50 VFD
http://www.factorymation.com/s.nl/it.A/id.196/.f

and call it good. That way you won't be messing around with new pulleys, motor controls and other odds and ends. The VFD is pretty much plug and play, and it will replace all of your existing controls, mag starter, and so on. In addition a VFD will NOT derate your motor like a static phase converter will. A 3 phase motor also tends to run more smoothly than a single phase.

1 1/2 HP is plenty for a 10" cabinet saw as far as I am concerned. I have a '49 Unisaw with a 1 1/2 HP RI motor in it and it works fine for regular cabinet and furniture work. I honestly can not tell the difference between it and the 3 HP Grizzly cabinet saw it replaced.

[Paul Atkins]

When you get a kickback the 5 hp will throw it a lot harder.

[Steven Satur]

The three phase motor will outlast the single phase.

[Frank Drew]

The three phase motor will outlast the single phase.

No doubt, but it's unlikely that a new single phase motor won't outlast most of us here.

I like three phase, but I didn't have to pay any extra to have it run into my shop; in general, I'd opt for more h.p. rather than less, even if that meant getting a single phase motor. I know a sharp blade is key, but, still, 1.5 seems on the light side.

[Michael O'Sullivan]

The other thing to consider as regards the 5hp motor is the existing wiring. I don't think 5 hp will run on a 20 amp/220v circuit, and I believe to go up to a 25 (or, better yet, 30) amp circuit, you would need to run a heavier gauge wire. Around here, at least, having that done by a pro will cost more than the motor.

[keith jensen]

Pretty much been covered but there are four ways to go on this, VFD, Static, Rotary, Single Phase motor.

I have the same saw, PM66 with 1.5hp Century Motor 56C. I went through all of the same dilemmas that you are right now. I started out using a static converter since I was not sure if the motor even ran. Though that I would just add the idler motor and use the static to make the rotary converter. I started looking at used three phase idler motors and then realized that I needed a three phase disconnect etc. Started to look like the rotary was going to cost about as much as the VFD or more by the end plus the idler running all of the time while in the shop turned me off. Wound up going with a VFD in the long run.

Here's what I learned while going through my progression, it ALWAYS costs more than you think.

Starting with the static converter was a $98 mistake, should have just bought the VFD in the first place.

The 3hp VFD was ~$172 shipped. Spent about another $100-150 in cables, sockets/plugs, connectors, enclosure, etc. Could have went cheaper but wanted to make the VFD plug/play in case I bought more three phase equipment someday. Four wire tool cable is pretty expensive, HD had 10ga 600V but it was ~$2.25 per ft. That was all they had so I just went with it.

If you change to single phase you need to change out the starter as well. Make sure you match the frame size on your current motor so that you can use the same sheave. Michael covered the current draw problem if you try going too large on the motor.

I'm keeping my eye out for a Baldor 56C 3hp 3ph motor as a possible upgrade someday.

In hindsight, I should have probably passed on the three phase PM66 and waited for a single phase but the thing cuts so dang nice!! I think I've reached the tipping point with the spouse though...one too many trips to the hardware store on the debit card!!

[Chip Lindley]

Yep, It's all been Covered! Boils down to keeping a smaller 3-phase motor and adding VFD, or going for BIGGER BETTER single phase 3 or 5hp motors. You will spend some BUCKS but will have much better resale value of your *66*! (I assume you got a really good deal on this 3-ph. machine)

Few want to mess with 3-phase in any form--thus the bargain status of that machinery. I would recommend an RPC only if you plan on running other 3-ph. machines in the shop. Otherwise, too expensive, considering all other options.

Converting to single phase may cause you to add a heavier magnetic starter. Look inside the cover to see if it is *Size 1*, rated for 30A. If you are this lucky, you can use 2 of the 3 contactors for your new 1-ph. motor and match two new overload heaters to the motor's amperge range.

Unlike the Unisaw, which has a special mount, you can shop around for a PM66 motor. I stand corrected on frame/shaft sizes used on PM66s.


There were two frame size motors on older PM66's. The 56C is a 5/8" diameter shaft. The 145TC have 7/8" shafts.

You may well luck into a used motor online.

[keith jensen]

There were two frame size motors on older PM66's. The 56C is a 5/8" diameter shaft. The 145TC have 7/8" shafts.

[Kyle Jones]

Carroll, pardon my ignorance, but where would I look to find the starter and what am i looking for to make it usable for a single phase motor. I am really leaning toward buying a 3hp 1ph motor. Picture of the saw is attached, i picked it up for $560.http://www.renebates.com/cgi-bin/mnlist.cgi?bates106/1794

[Mike Zipparo]

As my primary cabinet saw I have used the following:

Delta unisaw - 2005 Model w/ 3 HP single phase motor. Adequate for 99% of cutting tasks.

Delta unisaw - 1950's vintage w/ 1.5 HP three phase motor. Adequate for 80%, but missed the extra power.

Powermatic 66 - 1970'w vintage w/ 2 HP three phase motor. Better than the 1.5, but still underpowered.

My perspective may be skewed by gocking backwards in HP. I don't think 5 HP would be too much motor for any one of these saws, but probably not really necessary. The only time I have really noticed the motor limitations of 1.5 and 2 HP are when ripping 8/8 hickory and white oak.

If I wanted to get the saw running without investing in 3 phase power, I would go with the 3 HP motor.
___________________
Mike