A Performax Mini Wood Lathe Restoration

I picked this up off Kijiji recently.

It's an elderly Performax mini wood lathe model No. 90233. Swing over bed is 8". Swing over toolrest is 5". Distance between centres is about 14 1/4". Headstock and tailstock tapers are both MT1. Spindle thread is 3/4"-16.

I saw when I was examining the lathe at the seller's premises that the machine was flawed -- the motor wouldn't start consistently. But I'd driven quite a distance to see the lathe, and I have a soft spot for decrepit old machinery, so I bought the thing hoping that the motor problem might be something easily corrected

As it turns out, I got hosed. The lathe has a bad motor.

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A Look At The Motor Failure -- THURSDAY, DECEMBER 20, 2018

Here's a view of the failed motor's commutator.

Note the discoloured segments. I don't know enough about how DC motors' rotors are wound to analyze that any further.

Symptoms are erratic starting and 'lumpy' running. Sometimes the motor will start on its own; mostly its shaft needs to be given a nudge to get it going.

I suspect that the failure may have been brought on by a motor stall episode. A stalled motor would, I imagine, draw excessive current through the commutator segments in contact with the brushes. The motor was probably ruined in a matter of seconds.

Replacement Motor

Performax appears to be no longer with us, but Busy Bee carries a mini lathe that's essentially the same as the Perfomax unit -- Craftex model CT172. I ordered a replacement motor from Busy Bee, P/N CT172MOT, and the motor appears to be identical in all respects to the Performax motor. I wired the motor to the Performax control box, and the motor works with that. So, it looks like I'm on my way to having a working mini lathe here. Here's a view of the new motor.

The label on the motor says, "250W -2.3A PH1 CLASS B".

The motor's electronic controller gives the motor a soft-start characteristic. I could live without that on a wood lathe, really, but there we are.

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Restoration Begun

I've torn down the machine for repainting. An addition I thought would be beneficial is a mounting base for the lathe's bed. The lathe bed's 'feet' have M8 threaded holes in them for bolting the lathe down. The holes are not easy to lay out for, so I thought I'd do the layout chore once on a 2"x8" plank, and thereby give the lathe an easy to bolt/clamp base. Here's a view of the lathe bed on its new base.

That plank is 32" long. It gives the lathe bed a nice, solid base that can be readily bolted or clamped to a work surface. There are three M8 x 50mm hex head screws holding the assembly together. The screws' heads are in 1/2" deep counterbores, like so.

Lathe Bed And Headstock Painting

I had to construct a crude stand for painting the lathe bed, like so.

That worked out well. That photo above shows the lathe bed with a coat of grey primer on it. Two coats of Tremclad grey are still to come.

Here's the headstock fully primed and painted with Tremclad grey.

The spindle bearings are in fine condition; it would have been folly to dismantle the spindle for the sake of easy painting. So, I masked both spindle ends and the label. That was quite a chore, but well worthwhile.

Still to be painted are the mounting base plank, tailstock and tool rest.

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Progress -- TUESDAY, DECEMBER 25, 2018

The lathe bed, headstock, motor and motor controller are back together.

It's looking good and running fine. Following are some notes on the lathe's drivetrain:

V-Belt

The V-belt is a miniature, metric-dimensioned thing that I can find no information on. All there is on the belt by way of ID is "KK-516", like so.

The belt is 6mm wide at the top. I imagine that a replacement belt could be had from Busy Bee, as was the motor.

Speed Adjustments

The motor controller's printed circuit board has two potentiometers on it.

You can scarcely see them in the above photo. They're at the upper left of the circuit board, between the circuit breaker and the line cord.

One potentiometer is marked "L" for low speed; the other is marked "H" for high speed. Low speed is supposed to be 750 rpm; high speed is supposed to be 3,200 rpm. It's not a critical or precise adjustment. Ideally, the adjustment can be done with the aid of a digital photo-tachometer, which is how I did it. Use only an insulated tool to make the adjustments; you'd run the risk of zapping yourself and/or the electronics were you to poke around in there with an ordinary screwdriver.

Next up will be to paint the tailstock casting and the toolrest.

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All Done -- SATURDAY, DECEMBER 29, 2018

Here's the lathe running with a blank mounted between centres.

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Further Notes

Spur Centre

The spur centre that came with the lathe was blunt.

I'm not sure how a spur centre's point can get blunted, but someone managed it. I very nearly botched the job, but I managed to give the spur centre a reasonable point on the metal lathe.

For good measure, I bought a new MT1 spur centre from Busy Bee. (Busy Bee P/N B1673.) The Busy Bee item is quite nice.

Tail Centre

A blunt live point centre came with the lathe.

I sharpened up the point on the metal lathe.

I get along fine with only a point tail centre; I seldom, if ever, feel the need of a cup centre. But, to make the lathe complete, I got an MT1 live cup centre from Busy Bee. (Busy Bee P/N B1677.)

Faceplate

No faceplate came with the lathe, and I couldn't see having a lathe without one, so I went looking on Amazon and found just the thing.

It's a nominal 3" diameter faceplate for a 3/4"-16 spindle. It's a Maxwood No. 5106. Actual diameter is 80mm. There are four 5mm diameter screw holes on a 60mm diameter circle. The wrench flats on the hub are 32mm A/F.

Spindle Wrench-Rod

A six inch length of salvaged 6mm diameter steel rod serves as a wrench-rod for the spindle.

Knockout Bar

No knockout bar came with the lathe. The headstock and tailstock both take a 3/8" diameter rod through.

I had a length of 3/8" rod with a 1/4"-20 tapped hole in one end of it, so I cut a six inch length off of that. I made up a 10-32 to 1/4"-20 coupler from a piece of 1/4"-20 threaded rod, and added a salvaged knob. That gave me a nice knockout bar that I'm quite pleased with, like so.

And there we are -- a reasonably well-fitted-out mini wood lathe. To exercise the thing, I made a magic wand on it from a salvaged length of broomstick.

The lathe performs nicely; motor power is quite adequate. One gets accustomed to the soft start feature's time delay on startup. All in all, a pleasant little machine

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