Tormek Motor Repair

I have used and loved Tormek grinders since 1999. My current machine is my second. (I sold the first one about 2008.) I acquired it from Highland Woodworking several years ago when they replaced it (the old "Super Grind 2000") with a new T8 in their seminar room. I use it for planes and chisels, carving gouges, kitchen and sloyd knives, and occasionally planer knives. 

Recently it began sounding bad, and way too loud:

I took the wheels and axle off to isolate the motor and make sure it wasn't something caught in the bushings the axle rides on, or the inside wall of the leather strop wheel where the motor shaft turns the whole works around. Nope, definitely a noise from the motor.

I wasted several
hours online looking through the various user forums to see if anyone had experience either repairing or replacing the motor. No first-hand accounts there, only rumors, and a few mentions by Tormek employees that these motors hardly ever fail. I priced a replacement motor. Ouch, $300 or so! For that much money I think I'd try to find a local motor shop to rebuild it for me. That motor is a stout little brute, weighing over 10 lbs. despite only being rated for 1.5 amps ("FLA" on the motor's tag).

For the sake of ticking off all the boxes before giving up and spending money, I tracked down the contact information for Tormek support in Sweden. Maybe there was a secret lifetime warrantee on the motor (nope). Maybe their shop has a pile of salvaged motors on hand, so I could get a cheap replacement (I don't know, I didn't find out).

Within an hour, Mats from Tormek support emailed me back. To summarize his message: these motors hardly ever fail. The noise you describe sounds like bearing failure. Sometimes moisture infiltrates a bearing and causes corrosion. Please send a video so I can hear the noise you describe.

So I sent the video above. Next morning, the answer came back: yep, bearing failure.

This was the first good news in the story so far. I have replaced several bearings on my 15" planer. I have removed bearings from the Frankensaw's various donors. I have a small wheel puller. How hard can it be?

Next stop, YouTube. I scanned several videos on replacing motor bearings. What I saw convinced me it was worth trying. One of the better I saw is from Mr. Pete 222 ("Your Internet Shop Teacher"). I've seen a lot of videos on that channel. Mr. Pete seems to be a retired high school metal shop teacher somewhere near Peoria in Illinois. They've got experience, knowledge, and a good simple approach to teaching. Yes, I recommend this channel.

Mr. Pete's video on changing motor bearings


Last week I had a session in the shop with my son, as he repaired an Ikea cabinet he'd found on the curb. During the pauses while he drove screws and didn't need my help, I took the motor off the chassis and removed the ends. Unfortunately I didn't take photos as I went, because of the distraction of having two projects going on in the shop at the same time. But what I found was encouraging. The bearings looked easy to reach. My wheel puller got the first one off without even needing to use a wrench to tighten it! The second one was too close to the windings for the puller to reach. I found, however, that a $10 "faucet valve tool" from the plumbing section at Lowe's reached in and did the job handily. I read the numbers on the bearings and went online. BINGO! the bearings are a very common size, available for $5 each including shipping.

The bearings arrived Thursday and I put the motor back together that night, photographing as I went, so You The Reader can see what the guts looked like. So here you go:

These two photos show how my wheel puller and the faucet valve puller worked. They are out of sequence, posed after the fact with the new bearings installed, but you can see how simple the concept of the puller is. These are NOT expensive tools, and if you mess around with woodworking machines at all, owning at least one is a no-brainer.

Here's the motor's rotor. Note the circlip way inside there. There's one at each end, which locate the bearings. Typically this location is set with a shoulder turned on the shaft. I like that this circlip could, conceivably, be replaced far more easily than a machined, integral shoulder. But I'm pretty ignorant of the engineering and machining considerations at play. Anyway, we'll drive the bearing up against that clip, no further.

I like that the new bearings came in candy wrappers. I found them on eBay, but then realized that McMaster-Carr has them for the same price (shipping not included, but when I order from McMaster I often get same-day delivery because their warehouse is nearby).

Everyone says to check the shaft for burrs or spalling. I didn't find any, but I did clean off the shaft ends with Scotchbrite before installing.

That's a socket from my 3/8" socket set. I picked one that fit over the rotor's shaft while touching on the inner race of the bearing. You want all the force driving the bearing home to be focused there, not on the balls or the outer race - - - you could wreck the bearing.

Even this light (16 oz) dead blow hammer was plenty to install the bearings. Both the rotor shaft ends and the inner bearing races have chamfers to facilitate installation. 

It's home.

Driving the other bearing home. I needed to find a different socket (1/2" drive) that both fit the inner race and straddled the rotor shaft, which was thicker on the other end.

Ta-da! It was about 30 seconds later that I wished I'd taken pictures step by step as I tore it down!

Each end cap has a bearing seat integral to its casting. One end has a spring washer, visible here at the bottom of the bearing seat. This keeps the shaft and bearings loaded so there's no axial play.

Three small screws hold the end caps on the stator. The caps are essentially sleeves enwrapping the stator, and you tighten the screws until you feel them put a little tension in that spring washer. It would have been wise to mark the three big pieces for alignment before disassembly.

The motor mount is also a mounting bracket for the capacitor. The screw holes in the motor mount don't have much play at all, so you have to have the end caps in correct alignment or you can't put it back together.

The final result: it purrs like a tiny kitten once again!

I didn't take any photos of the electrical connections of the switch (3 wires, simple) or the gross mechanical attachment of the motor to the chassis (these are simple, obvious, and readily discernible in the exploded parts drawing you can find online). I did have to replace a crimped-on lug for the ground wire in the switch, but again, that's trivial.

Sure, trivial, but it reminds me to remind you: here are some basic tools you'll need to do this job effectively and safely. None of these tools is dedicated to this job only, that is, they'll come in handy in other places:
-deadblow hammer(s)
-3/16" pin punch
-wire cutter and stripper
-assorted crimp-on electrical connectors (spades and rings and "u's")
-wheel and/or bearing puller.

Now indulge me in a little meditation on the Tormek. The first thing we talk about when we talk about Tormek is the price. (The second is how slow it is compared to a bench grinder.) It's expensive compared to the alternatives. However, when I had the motor apart I saw that both the capacitor and motor plate had manufacture dates of 1993. This machine is roughly 27 years old, and it has not been babied. I know it's on its second wheel (at least), and it's been used and abused in the process of keeping all of Highland's teaching tools sharp, plus sharpening the tools of the thousands of students who have passed through that seminar shop. Then I invested a measly $10 in new bearings and 3 hours of work, and it's ready to go back to the daily grind. I will replace the wheel again, and I noticed the power cable could use a refresh as well, but I fully expect this machine will last me until I'm ready to put all my tools down. I'm 55 now. I don't think it's unreasonable to let me retire at age 70, 15 years from now. So this expensive machine (I think they were around $600 back in the late 90's when I bought my first one), if amortized over my (theoretical) 42-year career, would cost $14.28 per year, not counting the replacement of wear parts like the stone, the stone truing tool, electrical cords, and yes, bearings. My point here is that for the extra money (compared to Machine X), you get the kind of engineering that allows for repairs and replacement parts. 

Sure, I'm smug. In my thank-you email, I told the service department of Tormek that this is the sort of incident that gives me confidence to keep buying attachments for the machine. Chances are, I'll still be using it another 15 years. It feels like an investment, rather than an expense for consumable shop supplies.