Clearpath or DMM

[Neale]

I'm very happy with the performance I get out of the smaller Clearpath servos but my machine does use profile rails which reduces running friction. However, I am sure that the A axis would be fine with the smaller motor as the inertia loads and speed are quite low compared with moving a table.

I have had mills with MT2, R8, and SK30 (the Wabeco - although all the fittings I have for it appear to be marked BT30**). The combination of SK30 and self-ejecting drawbar work well but you do have to read the instructions carefully - getting this wrong can result in the drawbar and fitting getting effectively locked in place!

I also have the high-speed spindle - 2HP and up to 7500RPM, and I am very glad to have it. I seldom use much larger than 6mm carbide cutters and the recommended speed for the 6mm cutters I use is 4100RPM. This is one reason for avoiding a conversion of a manual mill as these seldom have such high spindle speeds. I have heard that this bigger motor is also a washing machine motor, but it seems to work fine and has a good speed range.

My machine is also from MDA, which is why it has the Clearpath servos and not the steppers that Wabeco fit. However, being American, it also had an Ethernet SmoothStepper motion controller and Mach3. I found that about once a week, this would fail (buffering problems and other things) which was a real nuisance. I ended up replacing the ESS and Mach3 with a UC300ETH and UCCNC software. This did mean rewriting macros for tool-setting and one or two other things but the actual hardware change was fairly easy. I have not had a single problem with the hardware or software since the change. I have not heard good things about the NCCAD software that Wabeco supply and I have no idea what their standard motion controller is, or how easy it would be to upgrade.

It's interesting that MDA are still basing their "desktop CNC" machines on Wabeco hardware, but they have switched to US-built (and probably very much more expensive) spindles with pneumatic drawbars, toolchangers, etc. Very nice but at a cost, I suspect!

These Wabeco machines are nice little units, but not cheap, and especially when you start adding in the "improvements" like ballscrews. I was fortunate to find a second-hand example with almost all the bells and whistles - like hens' teeth in UK/Europe, I suspect, and I've never seen another one like it for sale. I am a hobby user and do not have to make a profit with my machine, so I am happy to accept lower machining rates that suit my "little" mill.

**Edit - thinking about it, I am not sure if the spindle on my machine is the Wabeco SK30, or an MDA modification for BT30. I'm not sure what the compatibility between SK30 and BT30 is. I know that SK30 tooling seems to be much harder (or more expensive) to find than BT30.