A list of frequently asked questions about the CNC conversion.
- Question: Will the CNC kit fit all Myford lathes?
Answer: At the moment this kit is designed to fit non-power cross-feed models of the Myford Super 7 lathes. However, work is being done to make it adaptable for power cross-feed models. At the moment I could only provide a saddle bracket (this holds the main Z axis ball screw nut). I will eventually complete the X axis part if sufficient inquiries warrant doing so.
- Question: Will the conversion kit fit the big bore connoisseur lathe?
Answer: The kit will not fit this type of lathe because the connoisseur has power cross feed which uses a completely different type of saddle (see above explanation) Also, as the spindle is a larger diameter the spindle encoder will not fit directly to the end of the spindle without some modifications.
- Question: Will the conversion kit fit a Myford ML7 lathe?
Answer: Not without some modifications which would be extra to the ones needed for a Super 7 (see the modifications needed section). As far as I can see, the saddle is slightly different but could be modified to accept an underside gib strip that fits in the same position as the Super 7 type. The cross-slide would also need to be changed to the long type as fitted to a Super 7. The Saddle may not have been drilled with a 1/2″ hole at the back and in line with the front hole where the original leadscrew passes through, so this would need to be added.
I am building a full conversion for the ML7 at the moment which is nearly completed. Will post details when testing has been finished.
- Question: Do I need a spindle encoder if I only want to profile turn?
Answer: No. But, you will only be able to use G94 (feed per minute) moves and not G95 (feed per Rev) or G76 (screw-cutting).
- Question: Do I need spindle speed control in order to carry out screw-cutting?
Answer: No, but you do need an encoder on the spindle so that the spindle speed can be monitored. The software takes care of the Z axis positioning according to spindle position and speed variations. A standard single phase motor that runs at a fixed speed works fine when screw-cutting.
My advice is to get some use out of the lathe first by using the single phase motor before adding a 3 phase motor and variable speed control. This will allow you to grasp the fundamentals of CNC and enjoy a new way of working without the additional expense of variable speed control.