Indignities - Some to be corrected, some to be ignored

Anything this age has had things happen to it. In this case, overall wear seems light enough. The lathe and steady rest have been painted, the motor is bigger than the stock size at 3/4 HP, there's a new power switch, there are some bites out of the corner of the compound rest where it's been crashed into the chuck jaws, the spindle bearings have been replaced - and that seems to be about it.

Is that a great color, or what?

I have been known to paint machinery in maroon MG engine enamel, partly by virtue of having some left over after a rebuild of a 1957 MGA, and partly because I like it.
Here is Your Host after dropping some small piece of the MGA project. Note that the MGA is the kind of car you can work on while wearing motorcycle gauntlets.

Better find it - no way is the local hardware store going to have anything with British Standard Whitworth threads.

Good, I don't have to worry about it - the Cleanup Crew is on the job.
The stuff I used on the MG engine was from Bill Hirsch Auto, Engine Enamel, MG Maroon, currently $34.00 per quart. It brushes well, and seems to be impervious to everything - gas, oil, kerosene, brake fluid, antifreeze, etc etc. It doesn't need a primer on cast iron, although I did use an etchant/conditioner on the iron first - Dupont Metal Conditioner 5717 S - the bottle says for professional use only - not for retail sale, which I suppose means one shouldn't breathe the fumes too much. Another one I've considered is POR-15 engine enamel, but haven't used it yet.
I was surprised to find that the Logan I drove down to see had already been painted in MG engine maroon. Did this lathe have my name on it, or what? I should post about it on the Fortean Society page. What looks like the original color is still inside the change gear guard, the spokes of the apron handwheel, and the "cam shaft" lever (the one which engages the split nuts). It is a dark gray, with maybe a hint of blue.

I feel no urgent need to repaint it. That Royal Navy gundeck look seems almost appropriate, although I imagine the blood-red vista might someday make it hard to buy insurance.

More Power!

The earliest 200 series lathes had a 3-position toggle switch in the headstock. Sometimes I see them turned upside-down by (presumably) sensible owners who know that FWD should be up and REV should be down. Here is one spotted on a 210 -


My 200 has the 3-position switchplate, but the switch itself is long gone. I have no idea how a DPDT toggle switch can be wired up to run a reversible single-phase motor. I think it would have to talk to a relay somewhere.

Later lathes have a drum switch attached to the front of the headstock. The first time I saw this arrangement I assumed it was a customer mod, but I've seen enough set up like this that I now suspect that for a while the factory made them that way.


Still later (certainly by 1944) Logan mounted the drum switch on a bracket attached to the front of the motor belt guard frame, which seems a sensible place - accessible but not in the way.

When acquired, mine had a drum switch screwed to the top of the drive box cover. This seems to be a pretty good spot. The wires flex when the cover is opened but that hasn't been a problem yet. Maybe after opening the cover a few thousand times the wires will fatigue and break, but my arm is likely to fall off long before then.


That looks like a useful area up there, now occupied by a switch, but it's not really useful space as the Logan design requires that cover to be lifted to change speeds. The eleven inch Rockwell (or is it a Delta? Or a Delta Rockwell? or ...?), now - there's a fine design. I used one of these quite a bit in the 1970s, and became mighty fond of that little tray atop the headstock. The ten inch Rockwell doesn't have it.


Back to the subject .... A drum switch is good for single-phase and three-phase motors. All the big manufacturers still make them - Furnas (owned by Siemens for a while, now owned by Hubbell), Square D, GE, Cutler-Hammer, Allen-Bradley, etc. Unfortunately, there is no standard contact arrangement, and if you don't have a wiring diagram for your particular switch - welcome to the world of industrial surplus! - get out the ohmmeter. Here are two common arrangements. The terminal labels are arbitrary - there's no reliable industry standard.


This may be the most common arrangement. Below left is the wiring for a 3-phase system, and at right is wiring for a reversible single-phase motor.


If the 3-phase motor runs the wrong way (that is, in reverse when the switch says FWD), swap any two LINE wires or any two MOTOR wires (swapping 1 and 3 would be convenient, or A and C).

If a single-phase motor runs backwards, reverse the START windings or the RUN windings. If you reverse both, the motor direction won't change.

Note that if you are running the motor on 110-120 volts, switch the hot wire, not the common wire. As noted on the diagram, here in the US (where the National Electrical Code reigns supreme) the common wire is the white one. The theory is that if you have a short from the hot end of the windings to the motor case, you'll blow your fuses or trip your breakers, and that will be the clue that you have a problem somewhere. But if you have a short from the common end of the windings to the motor case, the fuses won't blow, and you won't be able to turn off the motor by flipping the switch, either - it will continue to run merrily until you shut off the power some other way, like at your fusebox or breaker panel.

If running at 230-240 volts, it doesn't matter which wire is switched, as both are hot. Ideally both wires would be switched, but we don't have enough terminals on a standard drum switch. It will work anyway because both ends of the motor windings are hot, and a short from either end to the motor case should blow a fuse (at least in the US, where 240 domestic wiring has two hot legs).

This is another common drum-switch arrangement.


The notes about wiring for the correct motor direction given above for the other type of switch apply to this switch also.



Here's another common arrangement of drum switch contacts.



Belt Cover Mystery Latch

When acquired, this lathe had a fairly ingenious home-made latch on the belt cover, holding it down in front. It was tacked on where a simple lifting knob was supposed to be, and new holes had been drilled in the cover to attach it. A cam arrangement was stuck onto the front of the headstock housing. It was all very odd.

I don't have a photo of the whole arrangement, but the cam tightening arrangement stuck into the front of my poor headstock is at right. Definitely not original Logan.

As designed by Logan, the belt cover doubles as the belt tensioner. But it's clearly designed to be an almost-overcenter arrangement, so that the cover's weight should be sufficient to tension the belt. The catch should be superfluous. So what was wrong?

Compensating errors, as it turned out. Someone had put a 3/4 HP motor in back. No problem there - 3/4 hp isn't too much for a 10 inch Logan - but the motor was physically larger than the original, and when mounted on the motor bracket, it stuck out too far, and collided with the edge of the chip pan. That pushed the whole bench stand too far aft, and it in turn pushed the aft end of the drive box too high.

At left is a scabrous photo of everything correctly arranged. But when I acquired it, the motor (a) stuck too far to the left, and rested against the edge of the chip pan. You can see that the edge of the chip pan is slightly bent at b, evidently done in a futile effort to get more clearance. Because of the interference with the chip pan, the entire motor mount had to be pushed too far aft (to the right in the photo) at c. The motor mount is bolted to the bottom of the drive box at d, so when the mount moved aft, the aft end of the drive box had to pivot upward. That opened a gap at e between the drive box and the cover. The cover could only close until it hit the head casting (not shown, to the left in the photo), and it never came close to going over center. Therefore it wouldn't close against belt tension, and the belt was only partially tensioned. To increase the belt tension to the point that it would actually drive the lathe, the cover had to be held down with an improvised latch.

To attach the latch, holes had to be drilled in the front of the belt cover and the headstock casting. The big hole in the headstock casting was where the Logan nameplate originally sat. So the nameplate was removed, and attached down on the leg.

This was a thoughtful way of insuring that the nameplate wouldn't be lost, but it left me with the only known Logan lathe with the namplate down on the leg. That caused me a bit of head-scratching until I realized that it was there because the space on the headstock housing was needed for a latch, and the latch was needed because the drive box wasn't in the right place, and the drive box wasn't in the right place because the motor bracket wasn't in the right place either, and the motor bracket wasn't in the right place because the motor wouldn't clear the chip pan. Simple enough, once I realized what was amiss.

To fix it, I took the motor off and used a Sawz-All to trim off a bit of the mounting plate on the bottom. It was a big plate and even with an inch or two lopped off the slotted mounting holes were still useable. Then I could mount the motor back further, where it should be, with plenty of clearance between it and the chip pan. Then the motor mount could sit where it should, and the drive box could sit where it should, and the belt cover could close all the way, and I could throw out that dumb latch. Maybe someday I'll even move the Logan nameplate back where it belongs.

The only thing I had to do, besides saw at the motor flange, was get a replacement for the long-gone knob which one grabs to lift the motor cover. So I went to Home Depot and bought the most garish Art Deco knob I could find. And a lovely thing she is, too.

So, the lesson is - when something is goofy, try to figure out if, sometime in the machine's previous 60-odd year lifetime, somebody hacked it. Then undo the hack, and all might turn out well.

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Updated: December 8, 2004
November 28, 2007