Mini lathe: mega cheap

[Chuck Tweedy]

Watch out for that spinning wing-nut Clay! That'll give you a nasty bobo!

[Clay Schaeffer]

Hi Chuck,
I suppose it could. The lathe uses a sewing machine rheostat and normally my body parts aren't near the wing nut when the lathe is running. The motor is also rather small and doesn't have a lot of torque. It wouldn't be too hard to replace the wing nut with a nut mounted in a wheel, which is what the lathe normally has spinning on that end.
I generally don't spend too much time bodging things together initially. That way when they are complete failures I don't feel like I've wasted too much time. If they are only semi-failures I don't feel I am wedded to the pieces and can make new, incorporating improvements. But once things work, I usually just use them and never get around to making the more refined version.
One thing I would like to improve is the dead center in the tailstock. Anyone have thoughts on how to make that a live center with small dimensions?

[Jason Rodgers]

I'm going to go with a dead center on mine, but was trying to figure out a way to incorporate a thrust bearing into a DIY live center. Haven't gotten my brain wrapped around that, yet, but it would be a possible addition later on.

[Clay Schaeffer]

I'm thinking I might be able to use a router bearing and the shaft from a broken router bit as the center. Maybe a plate behind that and a spring behind the plate to keep pressure on the center/work piece interface.
The problem I'm having with the dead center is that in such a small size it wants to bore into the work piece and eventually the work piece is riding against the face of the tailstock. A collar around the dead center might reduce the contact area and reduce friction and that may be a simpler way to go.

[Jason Rodgers]

Yes, it seems like the tendency of the dead center to gradually (or quickly, depending on the hardness of the wood in question) bore through the piece would make it an unsatisfactory end point. Are dead centers polished really well to avoid an abrasive action, or is graphite or some such lubricant just used to avoid this issue?

[Clay Schaeffer]

On a normal sized wood lathe, with the typical 60 degree cone on the center there is less of a tendency to bore into the wood. The one I made had a small point at a sharper angle - not the best. It worked but I had to keep adjusting the tailstock until it was actually bearing against the work (more friction).
Having the center polished and lubricated (candle wax) certainly helps.
Today I modified the tailstock to add a live center. I turned a point and a shoulder on a brass rod and fitted it to a spare bearing I had in my junk box. I used a forstner bit to cut a recess for the bearing and applied a layer of masking tape around the bearing to make a snug fit. Because of the way the lathe bed is made the tailstock is reversible to allow for longer work pieces, so I wanted to be able to switch sides with the live center. The live center worked much better than the dead center. I didn't need to readjust the tailstock at all.

[David King]

Traditionally one used a center drill with 60º angle and a daub of white lead as a lubricant. Graphite would work just fine but the center drill is still important. They come in a range of sizes but numbers 1-5 are handy and can be picked up as a set. If you just wanted one then I'd get a #2 or #3 for woodwork. They also come in 82º and 90º angles but you don't need those.

[Chuck Tweedy]

Clay, that bearing may not last long because you are loading it in a direction it is not designed to take.
Granted, this is a tiny little lathe and you are probably not using it extensively, but that is definitely not a thrust bearing.

[Clay Schaeffer]

Hi Chuck,
Considering the use I will be surprised if that bearing doesn't outlast me (though that might not be saying much <g>). I believe the axial loading (requiring a thrust bearing) is relatively small on a wood lathe compared to the radial loading created by the cutting action of the tool against the wood. Think of the router as being a lathe with a cutter mounted in the headstock. The reason a drill press makes such a poor lathe is it primarily deals with axial loading (compression) rather than radial loading. But you know that.

[Jason Rodgers]

60 degrees on the point, eh? I really know NOTHING about lathes! Sure do appreciate all this info and advice, and we're pushing 5 pages!

[Jason Rodgers]

Between my daughter's weekend dance rehearsals for the big Thanksgiving weekend ballet (in which I'm an adult extra, so rehearsal for me, too), and preparing for my school's Fall Concert (which was Thursday night), I haven't stepped into the shop in a while. Thread....... paused.

[Bob Hammond]

With regard to the point boring into the wood, I have a live center with a point that can be knocked out to make a cup center. To avoid boring in too much, after making a slight depression/dimple in the work piece, I knock out the sharp point and replace it with a loose 3/8" or 1/2" ball bearing in the cup. I suppose I could put a much bigger bearing in the cup if I could find one.

It's possible to use this technique to make offset multi-axis turnings too, if it the offset is not too extreme.

[Jason Rodgers]

Hi, guys! Spent a little time in the shop this afternoon and got the tool rest a little farther along. Actually, I could conceivably get this thing up and running this week (although I think I'm getting a mini lathe tool set for Christmas!).

This afternoon, I took a run over to the Depot to get an electrical box and plug for the switch and wiring. While I was there, I took a stroll through the hardware aisle to see if there was something off the shelf that would work for the center on the tail stock. I was looking through the drawers of bits and pieces, came across acorn nuts, and remembered Bob's last message about using a ball bearing as a dead center. Well, the 1/2" caps are too big, but the smaller ones would definitely work. I'm going to track down a reducing coupler nut (or a series of couplers) to see if I might be able to put a 1/4" acorn cap on the end.

[Jason Rodgers]

Ok, gents, here's my "Mini lathe: mega cheap." It's not complete, but it's mostly assembled. The motor is wired with a switch, but I need to find a piece of ply for the base plate that will hold the lathe and the motor. I'll need to work on that dead center, as well, but this was a big jump forward today. I haven't been keeping close tabs on the cost, but it'll probably clock in around $75-$80 (counting the motor that I picked up for $15 at an estate sale) when all is said and done.

Here is a closer look at the tool rest. It's a 4" piece of cold rolled steel, cleaned up a bit, and glued to a simple adjustable bracket (up/down, in/out) made of maple. The little block of wood mocked up in the chuck is about 3/4" x 3/4" x 2-1/2" and is typical of the pieces I've started with for baton bulbs in the past. The tool rest in its highest position sits at the centerline of spin, and can drop about 1/2" down. The in/out adjustment will be appropriate for the small diameter work I'll be doing. Whether or not it's sufficiently sturdy is to be seen, but it won't be difficult to replace, if necessary.

This is probably the last burst of work I can do on it until after Christmas, but it'll be in operation soon enough. And just in time, too. I noticed this past week that my high school colleague broke his baton! His will be the first test of the Rodgers Mini Baton Bulb Lathe.

[David King]

That motor looks pretty quiet but if it isn't I'd mounted on a separate level on it's own smaller board just to reduce resonance. I hate noisy tools especially late at night when I actually have time to use them.

[Jason Rodgers]

Yes, the motor is very quiet. I bought it mounted on an aluminum L-bracket - the motor floats and has a cushion under the end - with rubber feet. The tool in operation will likely not make much noise. I will, however, be attaching a dust-collection nozzle: it's just one of the wide-mouth shop vac nozzles and it spans the entire back side of the bed. The vacuum is in a sound-dampening box, so most of the noise comes from the whistling air at the nozzle. And the great thing about my shop, despite being directly beneath our bedroom, is that I insulated it well. My wife went to bed at 9:00 last night and I was in there until midnight without disturbing her. Love it!

[Steve Senseney]

It is cute!

Please show some of the finished items!

[Jason Rodgers]

For sure! Gotta show proof that it works!

[Jason Rodgers]

Ran into Ace today after work and grabbed a few bits and pieces for an attempt at a dead center. First, I was able to find a 1/2" 13 to 3/8" 16 reducing coupler nut. Unless I wanted to continue reducing with more couplers, a 3/8" acorn is still too big for centering. But, I found a nylon acorn nut, and that can be shaped. So, I grabbed a 3/8" set screw to join the coupler and acorn nut. When I get the motor and belt on, I'll spin this on the headstock and turn down the nylon to a proper point.

Another thing that occurred to me as I was looking at the nylon components is that I have a fair bit of Delrin scrap. If the nylon wears quickly, or heats up and deforms, I'll give the Delrin a try.

[David King]

I wouldn't think nylon or Delrin (acetal) would hold up very well with any side pressure. I'd just file a point on your spindle while it's turning and try to center it as best you can. It looks like you can do the same with the tailstock shaft by loading it into the headstock temporarily.
You're more than welcome to come up here and turn the points on my lathe too.
You might also try to make a live center for the tailstock using skateboard bearings which are 8mm ID. and 19mm OD. I have stacks of them here too. We could bore out one end of a 1/2" coupling nut to 3/4" for three bearings and then make an 8mm point with a flange on it to press inside. It might be 20 minute's work.