Monday, March 28, 2016

More Machine Shop Foolery

Or fooling around-ery.

Some years ago, I built a CNC lathe to go with my mill.  I went through trying to make it thread properly, had some success, but then never really used it much.  I had gotten used to using the manual lathe by just walking up to it, chucking up a piece of work and doing what I needed to do.  I told Mrs. Graybeard I'd leave both lathes on the bench for a while and whichever got used more would be the one we keep.  It was the manual lathe.  Some time in the last few garage re-organizations (even before moving into the new shop), a wire pulled out of a contact pin and it needed to be fixed.

Yesterday became a bit of a cleanup day in the shop, so it was a natural thing to try and get it running properly again.  First, though, there were some problems to go into.  The computer I've been using to control the mill has been having issues for a while now.  It wouldn't start up, especially on colder mornings.  (Mind you, this is a Florida cooler morning; maybe 68 or 70 in the shop.  That's Canadian skinny dipping weather.)  It would take up to five power-on attempts for everything to run and the system to boot all the way into Windows, but once it was going it stayed running fine.  I had an equivalent system and thought if it was running well, I'd swap them out.  I turned this backup system on and it worked flawlessly.  To keep from having to re-install all the software, I just swapped hard drives, so it was up and running pretty quickly.  I ran the mill long enough to send some motion commands on all axes, and verified it hadn't gotten messed up during the "brain transplant". 

Now it was on to the lathe.  In this picture, it's on the left, almost out of the frame.  To it's right, and just past the orange calculator, is the manual lathe.  The mill is off to the right, in a plywood box. 
Once I re-crimped the wire and got Mach3Turn running, both of the lathe's axes started moving.  There's a large toolpost on the cross slide that I put there to measure backlashes with.  I noticed that the long axis seems to drop steps, even under no load.  That could be something as simple as a noise pickup, but could be the driver board, too.  I'll need to look at that some more.  
All in all, it's a good option to have back, but I really can't think of many uses for it.  It's easier to cut tapers in a CNC lathe than by hand, but that's about it; it would also be good for making pens, with that power feed.  Threading is probably best accomplished on my big lathe, although I have their threading attachment for the manual Sherline lathe, too.  There are developments on the big CNC mill project, but that will be another story for another day. 


  1. What brand are those?

    I *know* I've seen them before, but the name escapes me.

    1. OK, that's what I thought.

      I'm pretty sure we had one of these at Hughes as an alternative to the little German lathe we had.

      The German lathes was a sit smaller, but was extremely accurate compared to the Sherline.

      By "accurate" I mean that it had ZERO backlash in all movement, and it just "felt better" to use.

      I had no trouble doing parts to .0001" on the German lathe, but could never get that kind of result on the Sherline.

  2. I have been wishing for a CNC lathe for more than a year. Pulleys, printer filament guides, spacers, all are better done CNC.


    1. Thanks! Hadn't thought of that. More reasons to keep it.