Lathe conversion to CNC

by John

The carronade is finished, as far as I intend to take it.  At some future date I might make pulleys and ropes etc, but at this stage I am putting it on the mantlepiece.  (mantelpiece groans).   Some detailed pics in a future post.

I have commenced my next project.

I have a CNC lathe but it will accept work up to only 125mm diameter and 125mm long.  It was not big enough for the long gun, and barely fitted the carronade.   And I have some ideas of further larger projects (field artillery pieces, and possibly a model of a Turkish wall smasher like the ones which allow the Turks to conquer Constantinople.  That one was almost 6 meters long, and fired stone balls of 600mm diameter!!!   So even at 1:10 I need a bigger lathe.

OK, so I could use a manual lathe, but that is not the point.  A bigger CNC lathe would be fun.  And I have a Taiwanese one which I think would be suitable for conversion.  It is 600mm between centres, (just big enough for my Turkish smasher), and about 300mm swing.  It is not pleasant to use as a manual lathe due to very noisy spur gears.  So I have decided to convert it to CNC.

The steps are:

  1.  Remove the existing lead screw, cross slide screw, apron, back gears, gear box and more.
  2. Measure for ball screws and buy them.
  3. Buy the electronics.   Stepper motors (7amp NEMA34), break out board, Gecko stepper drivers, limit switches, power supply, 3 phase 2hp spindle motor, etc etc
  4. Fit the ball screws and motors.
  5. Fit the electronic components and hook them up (Stuart, I hope that you are reading this)
  6. Configure Mach3 and Ezylathe on an old computer
  7. Make a Turkish smasher

I have made a start.  Removed most of the unwanted manual components from the lathe today.  It felt very threatening and unnatural to be wrecking a perfectly good lathe.  See the photos.  At this stage I am taking lots of photos in case I have a change of heart and restore it to its original state.  But I will press on.  Watch this blog.  I expect that the conversion will take a couple of months, by the time components arrive from overseas.



The lathe prior to CNC conversion


CNC conversion - 1

After removing the lead screw, apron, gear box, cross slide back gears etc etc.  Looks a bit naked.  Not much remaining.