Retrofitting a 1986 Maho MH400E

Or we can remove the G80…G4000 and put a comparator in place on ladder that compares the commanded speed with a range of predetermine speeds for each of the gear.

drimaropoylos wrote: “it looks the same”, I was toking about the cabinet

Yep, I got that. That finder relay I got is only about 5mm thick, so hopefully it and the PSU will fit on the end of that DIN rail.

Were you intending to only accept G Code with the discrete spindle speeds the gearbox provides, or a HAL component which takes whatever spindle speed is commanded, finds the closest MAHO speed from a look up table and then engages that speed?

I have been wondering whether it might be a good idea down the road to add a VFD, to keep add spindle override potential while still keeping the gearbox active.
Mark

I have purchased a Mitsubishi FR-V540-3.7K-NA VECTOR INVERTER and I planning to keep only the back gear and middle gear on linux control and the input gear on the right position

The vfd will make possible rigid taping

G code M41,M42,M43,M44 for gear selection is one way.

Have you decided where are you going to put the spindle encoder? I doubt that assumed spindle RPM based on VFD sensed rpm divided by gear ratio will be sufficiently accurate to enable the Z axis to snyc for rigid tapping. There must be a fair amount of backlash through that gearbox. I haven't pulled the hydraulic cover off the head yet, so I don't know how much space is in there for an encoder.

I do not want to implement non standard G codes for gear changes. That would then require more programming for the CAM software to output the required codes. A LinuxCNC internal solution would be much more elegant. Have you seen the HAL component Andy Pugh wrote for this? db1981 has also offered his code for the MAHO gearbox control, so hopefully we can solve this such that the G-code program can contain any S speed, and the MAHO selects the closest.

If we go to all the work of getting the mid and back gear controlled, the input gear must be a minor incremental extra effort,I hope
Mark