Mini lathe: mega cheap

[Jason Rodgers]

Hell, okay! I'll be in touch!

[David King]

You'll have to post photos.

[Jason Rodgers]

I'm calling this little lathe project semi-final, pending the discovery of a better motor.

You'll see the tales of frustration and woe with my chosen motor over in the tools thread, "Another motor reversing attempt." After getting that one reversed, I found it was WAY too underpowered. In that discussion, and in several PMs, David King spent a lot of time tutoring me in the ways of motors, both AC and DC. I even spent time researching AC-DC converters to make some 36 volt DC electric scooter motors I saw on craigslist work.

Today, I went to our local building materials recycling center searching for blower/fan motors and found an old 1/6hp attic fan. $5 and 10 minutes worth of dismantling later, and I find it's totally burned out. In the meantime, my winter holiday is coming to an end, and I haven't turned ANYTHING.

So, I built this quick-and-dirty bracket for my power drill, and belted it up to the wee lathe. It works, and the 3-piece pen-turning chisel set I got for Christmas works well, but it's LOUD.

Thank you to all who have educated me in the ways of lathes, motors, and the various accoutrements involved in this particular craft. I'm calling it finished... for now.

[Steve Senseney]

I have watched with interest.

If you placed your motor directly under the lathe, and had small step pulleys, so you could have different speeds, it would allow you to use a motor which turned either direction. (Simply mount the motor the other direction.)

You can use your current set up to turn wooden step pulleys. Use either a round belt or a flat belt.

Suspend the motor so that the weight of the motor tightens the belt.

One advantage of having the belts, is that if something binds or catches, they will slip easily.

Ball bearings are inexpensive.

If you want to really be cheap, you could run on wooden bearings. Lots of old farm machinery used maple pulleys and bearings. If they wear out, you can always add a new piece of wood or move to ball bearings.

I made a turning lathe out of scrap iron about 30 years ago, and still use it.

I used 3/4" shaft so that I could place the commercial end plates and dead (and live) centers.

3/4" 16 threads per inch is a standard for tapping threads. You can make attachments and add them as needed for special turning projects.

I keep thinking of buying or building a better tool (mine is moderately ugly), but it keeps doing all of the things I need to do.

[Jason Rodgers]

Thanks, Steve. Yes, I've considered some of the points you've mentioned. I will take them under consideration, because when all is said and done, I may end up calling this little guy Mini Lathe 1.0 and build another later. Aside from the challenges I've documented here, I've already found some limitations to my design.

As I chucked up that 3/4"x3/4"x2" block of cherry you can see in the picture for a test spin yesterday, I noticed a couple things...

- I misunderstood or underestimated the forces on the frame. I thought the frame would need strength front to back, in the direction of pull from the belt, or the chiseling action. As I tightened down the tailstock screw, the leftmost upright (the flange to the left of the pulley) flexed! Everything is stable in terms of vibration from the belt pull and the tool rest, but I could conceivably snap off the headstock! I should have left more meat on the left side of the frame.

- You can all chime in with a loud "I told you so!" The 1/2"-13 threaded rod ain't the straightest material for a shaft. Once the block of wood settles in between the chuck and dead center, it spins smoothly, but I may not get very straight or predictable alignment for the baton shaft.

So, what have I learned? Well, through the help you folks have given me here, plus the hours of online research I've done, I've gained a ton of knowledge. If I attempt a version 2.0, I'll be able to design with some experience in hand. Things I'll incorporate will likely include:

- A simpler and stronger bed, probably laminated maple with a low, wide 'U' shape, and plenty of material on the ends.

- A design that puts the pulley out on the end of the headstock, like real lathes. The captured pulley on my design really limits the motor arrangement.

- A better choice of shaft material, maybe even something that could accept commercial chucks and tailstock centers.

But all this will have to wait for a while. I'm gonna have to produce something, though, because I went and posted this project on facebook and a band director friend immediately chimed in and said, "I want a baton!"