Powermatic 72A Motor Info Needed & Sheave

[Mike Palmer]

I recently purchased a PM 72A at a very good price but the machine did not have a motor. I know there are many similarities between the 66, 68, and 72 machines. I would like to find a used 5 HP or 7.5HP off eBay. I have gone to eReplacement parts and found the Powermatic part numbers but I am needing the Baldor, Leeson or Marathon Part numbers to begin searching. Are there any PM72 owners here that can help out? I have a 3PH Rotary converter so I am capable of running 1PH or 3PH motors. Since this saw is capable of running a 14" blade I am leaning toward the 7.5HP motor if I can find one at a reasonable price.

Is the 7.5 HP available in the 184C frame? (7/8" shaft diameter and C face bolt pattern to fit mount)

Are all PM sheaves (diameter and internal bore) for the motor and arbor the same between models? (7/8" Motor & 3/4" Arbor)

Has anyone converted their triple belt sheave to the new wide belt design found on PM2000s and PM3000?

Any guidance would be greatly Appreciated. Thx

[Patrick Kane]

Hey Mike,

I went through the exact same thing a couple months ago with a few powermatic 72s. I would search for those threads, because people answered a few specific pulley questions. To answer the motor question, you can buy a new baldor from Mikes Tools. Its one of the few sources i found for the proper motor mount. You will quickly learn that the 184C frame is antiquated and not common. After weighing all my options, i ended up selling the machine without a motor and buying another machine with a 3 phase motor. I hope you got your machine for free, because the numbers and budget didnt really work out for the original motorless PM72 i bought for $150.... Motor, pulleys, and a few other missing pieces add up really quickly. I remember the replacement pulleys with a tapered sheaves were $80-100 a piece. New motor is $600-700.

I would search craigslist or ebay for a used 3 phase motor off a PM66, 68, or 72. Im 99% sure they all have the same motor mount. I would personally go 7.5hp if you are sourcing a new motor. Mine is 5hp. For perspective, i am into a mostly restored 72 for about $1900--paint, belts, bearings, VFD, shark guard, motor bearing and cleaning.

[Mike Palmer]

Thanks Patrick for your insight.

On the 72 you have now are the sheaves 7/8" on the motor and 3/4 on the Arbor or does the 1" arbor on these saws have a different Arbor sheave? The reason I ask, I would think the 14" saw would have different size since the blade tip speed would be higher than a 10" PM66 is the sheave size was the same as a 66. thx

[Don Jarvie]

Place an ad over at OWWM and see what you can get. It will probably be cheaper than eBay.

[Patrick Kane]

The motor pulley is 3" diameter and 1.75" wide, and i think the arbor pulley is the same. Motor pulley is 7/8" bore. I agree, i wasnt suggesting to buy pulleys from a 66, i was saying the motor frame and mount should be the same between a 66, 68, and 72. Ive seen 66 switches and motors for sale somewhat frequently from people buying 3 phase machines and swapping electricals to single phase. If you find a 5hp 3 phase motor off a 66 for cheap enough, id go that route.

Here, just found your motor for you:

https://indianapolis.craigslist.org/...792287482.html

Contact that guy, he has a 7.5hp for $200. Just need to get it to your shop somehow.

[Mike Palmer]

Patrick, thanks for the info. I will reach out to him.

The 3" motor pulley diameter is smaller than a PM66. Its motor pulley is close to 3.5". This steps up the speed from 3450 RPM to close to 4200. With the PM72 using a larger diameter blade looks like they both need to be the same size diameter but with different bores.

[Patrick Kane]

3” is the outside diameter of my 72’s motor pulley. I need to measure the arbor pulley, but that is slightly more difficult to get to.

[Don Jarvie]

Surplus center sells 3 belt pulleys. The shaft for the motor is 1 3/8 and The arbor shaft is 1 inch so you should be all set. Change both pulleys so they match.

[William Hodge]

My Powermatic 72 motor was taken out by lightning. The motor shop said it was ruined. I needed a replacement one in a hurry, and paid $750. for a new one from Powermatic. That might have included shipping. The motor is small diameter to allow the blade to go up all the way. I put a plug on the saw, and I unplug it every night, and when there is a storm nearby.

[John Gulick]

The motor pulley is 3" diameter and 1.75" wide, and i think the arbor pulley is the same. Motor pulley is 7/8" bore. I agree, i wasnt suggesting to buy pulleys from a 66, i was saying the motor frame and mount should be the same between a 66, 68, and 72. Ive seen 66 switches and motors for sale somewhat frequently from people buying 3 phase machines and swapping electricals to single phase. If you find a 5hp 3 phase motor off a 66 for cheap enough, id go that route.

Here, just found your motor for you:

https://indianapolis.craigslist.org/...792287482.html

Contact that guy, he has a 7.5hp for $200. Just need to get it to your shop somehow.

+1, looks like a done deal. Our PM 74 has the 7.5 hp, it's a beast. Good luck

[Mike Palmer]

John, do you know the make and model number of the motor in your PM74? Not sure if the Craigslist deal will work out yet because the bearings need replacing. Not hard to do but with shipping and potential risk of other issues, I may keep looking. thanks

[Don Jarvie]

A 3 phase motor is fairly simple and hard to kill so other than beating which are relatively inexpensive it’s not going to need much more. Unless the motor for 200 bucks is a complete piece of crap you can’t beat the price.

[Mike Palmer]

Don, the motor needed bearings plus the shipping was going to cost close to 100 more. The motor also sat outside for a year so there is the possibility of moisture inside plus corrosion. All in all, I decided that I will keep looking for a newer Baldor motor.