Personally I wouldn't mess about, if you want a CNC mill buy a CNC mill instead of trying to convert a manual mill. Of course the conversion can be done but you'll need to change most of the guts of the machine and it still won't be optimum.

Andrew

https://www.cnc4you.co.uk/MM32L-CNC-FF-Conversion-Factory-Fitted

**LINK**

Converting a mill is a lot of work and you'll need a mill to do it. The company linked to above sells all the bits as well as the converted machine.

If you haven't found it already, have a look at *** MyCNCUK ***

John

Ian

I recently purchase a CNC4YOU converted MM25L complete set up, and although all the previous posts have a point I find it works for all my small projects I expect to use it for. At 4k it was far more affordable than a new dedicated machine at 10k , but it all depends what projects you have in mind, space and budget. I looked at old second hand machines but did not have space, time, transport, or expertise to update the electronics that some needed.

This might be of interest (as posted originally on mycncuk.com):

**LINK**

Basically a guy in Oz who is fitting DC servos to normal mills with DROs on each axis and has a novel (?) controller to drive the motors closing the loop so that the DROs do the positioning rather than relying on ballscrews. I think it's novel, however I believe that LinuxCNC has the ability to drive DC servos as drives with external feedback in a PID loop. But I have some reservations about this approach.

• "Backlash compensation" isn't as easy as it seems at first sight. The idea is that when the drive reverses the controller "knows" how much it has to turn the screw the other way before the table starts to move. However for a worn machine that might vary along the screw, so quite a complex calibration algorithm is needed (in principle easy if you have DROs fitted anyway).
• If the calibration isn't quite right, every time the screw reverses a small error can be introduced, which is cumulative.
• Mach 3 has backlash compensation – I use it on my mill which has very small backlash in its ball screws. However you can see that there is still a tiny glitch, for example at an X or Y axis tangent on a circular bulge or pocket, so it isn't perfect. It's not very well documented as a feature either.
• I've tried setting it up on the main L/S axis on my Myford which has ~0.3mm lash and it really doesn't work at all. (Cross slide has a ballscrew.)
• In principle these problems ought to go away when you have DROs measuring the actual position, but there are some problems. Putting backlash in a servo loop and getting precise control is very tricky and it's all too easy to find the motor oscillating through the backlash. It can be tamed but isn't easy.
• Even if you can "compensate" the backlash, this doesn't mean everything is OK. CAM milling programmes can easily generate toolpaths which include climb milling, so the table can be moved by the cutting forces if the feedscrew isn't holding it steady. In the video I linked to above, the machine is shown milling a circular spigot on the end of a square – you can see that where the axes reverse there is a distinct mark left. I guess you might improve things by for example incorporating table brakes to prevent movement while the backlash is being taken up, but then you beging to wonder why you don't just use ballscrews?

As a final point, though the machine might be able to do whatever a manual operation can do, that's missing the point! No one is going to manually mill a circular spigot like in the video – you would put the work on a rotary table. And there are things like profiling gears and other shapes from the flat which would be virtually impossible manually.