I needed a lathe.
After reading many, many posts in rec.crafts.metalworking and talking to many people in person it appeared that my choices were to find an old lathe for sale and fix it up, or buy a new lathe. My choices in the new lathe department were either way too expensive, or cheap Chinese machines that would need fixing up right out of the box. An old lathe could be found, but that would require repair and re-tooling before I could do anything with it. Then there was the matter of where to put it. A 9 inch South Bend or Atlas would still be a four foot long free standing hunk of cast iron weighing in at 500 pounds or better. I live in a fourth floor apartment.
Somewhere along the way I saw a Taig Microlathe. It was small, lightweight, inexpensive, and for the price of a used lathe I could get a new one with all the goodies. Sure, it couldn't do any threading on it's own, and was small, but in this case small is good, and I don't have a problem with taps and dies.
I placed an order for the lathe and a pile of accessories. For less than $500 I got:
I had ordered the lathe kit meaning that I had to assemble and lap the
carriage to the ways. I spent a happy evening doing just that. and soon had
the lathe assembled on the factory base plate.
Several things became apparent. First, if you want to put the motor behind the lathe like I wanted to, the stock supplied belt is too short. Second, the motor sits alarmingly close to the lathe. It appeared that there might be some interference between the motor and the carriage. Putting the motor off to the left really is a better idea. Second, the lathe sits a bit too close to the mounting plate for it's own good. The lathe is mounted such that the crank on the carriage overhangs the mounting plate. It has to or you end up scraping your knuckles on the plate when you crank the carriage left or right.
The Taig doesn't come with a motor. You have to find one on your own. I spent three days thinking where I might find a suitable motor. I was going to contact some appliance repair places or raid a dumped washing machine or drier when I spotted something sitting on a dumpster at school. Upon closer inspection the rusty, grimy hulk was in fact a NEMA 56 frame, single phase, AC induction motor made by GE. The shaft turned so it went home with me. I cleaned the grease off of it, removed the dead mouse from it and tried the smoke test. It ran strong and silent. I then cleaned it up some more, gave it a good coat of black paint and put it to work.
Ok, I tried to put it to work.
The Taig pulleys are designed for a 1/2 inch shaft on the motor. My shaft
was 5/8 inch. This could be bad. As I had found the motor before I purchased
the lathe I had them send the lathe with two head stock pulleys as those will
fit a 5/8 shaft. Now for the subtle problem, The head stock pulley is not
drilled to 5/8 inch all the way through. It has a lip that seats against the
head stock spindle. When I placed this on the motor, it can only go on one
way. This dictated that the motor would have to go to the left of the lathe
rather than behind it (see the photo for
some clarification). No problem says I, it will be away from the chips
over there. Now which way did the motor turn?
The wrong way, of course.
Now I have to reverse the thing. No problem. I should just have to swap the polarity of the start winding... We'll just open the access panel and... uh... Hmmmpf. Four terminals, two wires, and now I can't remember where the power went either. Get out the meter. Let's see, two terminals are shorted together, and one is floating. That can't be right. Only one way to be sure you don't blow up the motor. Open it up.
Now that I have this thing open, the mystery clears itself right up. There
is a thermal breaker between two of the terminals; that was my "short
circuit". The start winding, capacitor, and centrifugal switch are hard wired
to two of the posts and the run winding is on the flying leads. The fourth
terminal really is floating.
Now that I have the wiring all sorted out, all I have to do is swap the flying leads and apply power. It should run backwards. So I put it all back together and lo and behold, it did. Now I just have to figure out how to get all the wiring squared away to add a reversing switch outside so I don't have to rewire it to reverse it.
Now that everything shows signs of working together, I have to figure out how to mount everything. As I had originally wanted to mount the motor behind the lathe I got the wrong mounting board from Taig. Now I had to find something suitable to replace it. While I was thinking about this part of the problem and looking at some other peoples set-ups I noticed that many of them put their lathes up on some sort of riser so that it would be easier to move the carriage. I just so happens that I found the perfect size piece of scrap chemistry lab bench top. It was the right size and already square. All I had to do was drill holes in it.
Lab benches are made of some interesting stuff. Luckily I have worked with this stuff before (I drilled a hole in a bench to mount a lamp in a dark room) and knew that I could drill it without it shattering. Apparently this is some sort of granite dust in an epoxy binder. Note: The old stuff is apparently granite dust and asbestos in a binder. This was new material they were just installing. No asbestos in the new stuff. Use caution with the old stuff. I used a 3/16 inch masonary bit to drill the mounting holes for the lathe and then counter bored the back to let me use the original 10-32 screws. For mounting the lathe assembly to the bench I drilled and tapped for 1/4-20 hardware. It works well.
Back to the mounting plate... I went into my local Home Despot store and wandered about. I had in hand a laminate particle board shelf that looked good. The only problem is that it was $10. That seemed a little expensive for what I wanted; especially as I figured that I would mess it up at least once. I spent a little more time over in construction materials end of things and found what I was looking for, a 36 inch by 18 inch pressboard shelf. For only $3 it was perfect.
I layed out the lathe base plate, and the motor, marked and drilled all the
holes and put everything together. I wired the motor up with a two gang
electrical box and a light switch. I plan on rewiring things later to include
reversing with a standard four-way light switch. Notice also that I don't
have a real motor mount. I just bolted the motor in place. How do I change
the belt position you ask? Easy. My motor has rubber mounts. They afford
just enough movement to allow me to pop the belt over onto the grooves in
the pulley. Not elegant, but it works. I plan on building a real mount for
the motor some day, but I still haven't gotten around to it.
My goodness, what a mess things are in that picture. Look at all the tools and stuff all strewn about. This is not a good idea. First of all, having the lathe bits bumping into each other and everything else will damage them. Next, I can never find the right allen wrench for whatever it is on the lathe that I am trying to adjust... and where did I put that chuck key...
I solved the problem by making this tool holder out of some scrap wood from
a pallet at school. I even made it in the lathe with the milling attachment.
I think that this was about the biggest piece I could put in it. You can see
that now my cutting tools don't bang into each other and that I can find all
my allen wrenches and chuck keys. There is even room for future expansion.
There. Doesn't that tidy things up? (As does sweeping up the piles of
swarf!)
Well, it has now been some time since I wrote all of the above. I have constructed entire engines with this lathe and learned a few tricks along the way. Here are some notes on using tiny tools like this.
4-jaw chuck
accessories. (yes that is a syringe in the
back. It came from an optical fiber installation kit. It was for putting
epoxy into the connectors. It works well to put oil in places)
closeup of final configuration
the drive pulleys
closeup of the goods
back one level