Friday, February 18, 2011

Notes on the Restoration of a 1964 Powermatic PM45 Lathe

My Powermatic lathe restoration is almost done, here is what I've learned about this machine.

Here is an exploded view of the stock Robbins & Meyers 3/4 hp 3 phase motor. The bearings are SKF 6203-2RSH/C3's, which were $5.64 each. The belt is a Goodyear 4L230, $5.79. The washers are shown on the wrong ends, the spring washer belongs on the pulley end of the shaft, not the fan.

Here's the variable speed drive. The bearings shown are two 6205-2RSH SKF's, $10.39 apiece. The roll pins in the sheave assembly are short, they can be driven though into the centre where they fall free, and re-driven in from the outside.

This is the plate assembly, this bearing is a FAG 6006.2RSR, $19.07. The machine screw required an impact wrench for removal.

It is mounted into the end of the sheave, note that it does not seat all the way in.

The variable speed pivot arm is attached to the mounting bracket, not shown is the bearing, an 88008 MRC. This is the single most expensive bearing in the machine at $57.19. As it is used to ride around a cam and is not subject to great speed, those on a budget may choose to not replace this bearing. Also, the bolt shown on the end of the pivot arm should not have it's nut in the jam position, it should be on the other side of the arm.

Here is the speed selector assembly. I put a large washer on either end of the spring for smoother action.

When looking at the front if the lathe the cam should form the number "6", a clamp provides pressure against the spring while the screw is tightened.

The head casting is located by two spring pins and secured by four bolts.

Upper sheave.

These roll pins will also fall out when pushed all the way in, reseat them from the outside. Restrain the snap ring when disassembling, the spring is still under tension when the sheave is fully closed.

Spindle assembly. Note that the indexing wheel is welded to the spacer. This was done by the previous owner, and a wise move. The wheels are known to have wallowed shafts and be prone to damage. They are the weak point in this machine. Drilling, tapping, and bolting these two parts together is another option.

The inboard spindle bearing gets mounted first, it's a Fafnir W206PP, $47.81. I use my bearing seperator to gently pull the bearing onto the shaft.

Next the wide spacer is mounted. This part is inaccessible from this point on.

A piece of all thread is slipped through the spindle, various washers and wood spacers are used to apply pressure where I need it and keep undue stress off the bearings. Be sure to back off the set screw hidden at the bottom of the sheave. This will hold the pulley open, allowing slack in the drive belt. It's a Goodyear 1422V420, $57.19. The outboard spindle bearing is an NTN R16ZZ, $33.43.

Here's the disassembled tailstock. The quill nut is threaded, and is best removed with an appropriate pin spanner. The handle pin is peened into place.

To dissassemble the banjo, first drive out the spring pin retaining the handle and remove it. There is a bronze bushing which must be driven out from the inside before the rod is freed. I used a small pin punch, first I ground the tip flat, then I bent its shaft for clearance. I slowly tapped out the bushing, rotating the shaft to access the perimeter.

Motor mount.

Outboard stand.

I found it easiest to completely assemble and tune the variable speed drive before the lathe was mounted on the base. The belt must be at the top of one sheave when at the bottom of the other, the fit is adjusted by the bolt pushing against the bearing plate and by adjusting the variable speed assembly bracket.

Here's the finished product.


  1. You must be part mechanical engineer to renovate this lathe! Looking great.

  2. The build on the Pm 45 looks a lot beefier then the walker turner. Your restore is looking mighty fine. Congrats on a beautiful job.


  3. No Jeff, I'm no engineer, but if I stare at something long enough I can usually figure out how it works. :)

    Tyler, they're close. The Pmatic is about 425 lbs compared to the W-T's 360. It was supposed to be done today but I think I shorted out the motor with a careless sheet metal screw. All I had left to do was install the cabinet door. I'm so upset right now. :(

  4. Great job on the restoration. I just picked up a 1967 PM45 and I am taking it apart right now so I can clean and paint it. It's missing a few things, but for the most part it's all there. I wish mine was variable speen, but it has the step pulley. Is there any trick in taking the spindle assembly apart, I'd like to change out the bearing while I have it all apart.

  5. Thanks Steven. The spindle is pulled by removing the bolt retaining the bearing on the inboard side and the collar on the outboard. There will also be at least one set screw in the pulley. Using a mallet, drive the spindle out toward the bed. The information you need is on pages 9 and 18 in this pdf-

    For those that care, it turned out that I had tripped one of three breakers coming from the phase convertor. Once I flipped it back everything worked fine. Whew!

  6. I just finished a restoration on a PM45 myself. Wish I would have found this article first. It would have made my life much easier on the assembly and tuning of it.
    Great job on this.

  7. Thanks Anon!
    Here's a great resource, and it's full of links to others:

  8. A year later, thank you for your post. I just finished a restoration, but only the inside. I cleaned, de-rusted all the internal parts, replaced the bearings and belts, and replaced the motor with a single phase 1HP Leeson motor. I cleaned the rails, primed the inside of the base that was rusty, and cleaned the rest of the lathe. Other than priming the inside of the base, I did no painting. Since the paint wasn't bad, I focused on the function of the lathe, and rewiring.

    Thanks for your pictures and especially the videos. It was extremely helpful to watch the VS in action, as the lathe didn't function when I got it. Bearings were seized.

    Good job!

  9. Thanks Doug, I'm glad I could help. Good job reviving yours!

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  11. Just starting my restoration of the exact same machine and your information will be invaluable. Would you be willing to share your paint formula as it appears different than what I am seeing recommended on

  12. I wish I could, but I neglected to request that they keep record of the formula and when I asked they couldn't help me. I wish that I had, I have other machines that I'd like to do in the same colour.

  13. I also have a powermatic 45 the Spindle Shaft is bent (bought this at a spring sale MARCH 2013)Where can i buy a shaft ?Been on the web for a week no luck please HELP

  14. I had a spare that I sold on eBay last fall, and I've seen them pop up there a couple of times since. Keep looking there, and maybe in the meantime you could try straightening yours if you have an arbor press. A machine shop maybe able to do it for you, or maybe make you a new one.

  15. can any one tell me if the powermatic 45 4 pulley can be converted to a variable speed

    1. I think they can, but you'd need to find a lot of parts if you want to do it how the factory did. An easier way would be to install a VFD and control the speed electronically rather than mechanically.

  16. Hi Darnell, I pulled my PM45 spindle today and am going to clean, paint, replace the bearings and belts. I have a question about putting the upper sheave back on. Above you say "Be sure to back off the set screw hidden at the bottom of the sheave. This will hold the pulley open, allowing slack in the drive belt". Are you suggesting this to make it easier to mount the belt? If so, how did you tighten the set screw once the belt was on the sheave?


    1. The belt is mounted before the spindle is in place. Holding the sheave open gives you slack in the belt so that the spindle can be manipulated into position. Once it's in place the sheave can be held open with one hand while the other tightens the set screw.

  17. I recently found a pm45 and have a question for you. Someone apparently disconnected the stop switch and I would like to get it working again. The switch is still there but for the life of me I can't figure how it comes off. The wires have been removed and the wiring screws are missing. The switch seems to be spring loaded as when I loosen the mounting screws the switch is pushed up. Do you have any suggestions on how the switch comes off and how it is adjusted? I've learned a lot from you already. Thanks

  18. Remove the front plate, it's held on by the screws visible by the switch. The switch is held in the box with two screws, one at the top, one at the bottom. The springing action is the overload protection, like the breaker in an electrical panel, to reset it after it trips. You shouldn't have to adjust anything, and I'm afraid I don't understand the rest of your question. It sounds like the switch is broken, and probably why it was disconnected. I think I still have a switch, minus the cover plate. If you'd like it send me an email with your address.


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I'm a woodworker on the Canadian prairie.