gearchange

Maybe some sort of sensor detecting the motor fan blades?

This might not be necessary with a modbus-controlled VFD. The one on my mill is controlled by analogue voltage so I don't have the actual motor speed, just the commanded.

yea same here. just analog out. But I think it can talk modbus. but why would this be better compared to an analog control?
Couldn't I calculate from the voltage and the rpm of the motors it speed.
can't simply set the gear with an hal input

anfänger wrote: yea same here. just analog out. But I think it can talk modbus. but why would this be better compared to an analog control?

With Modbus the VFD reports back the current speed. With analogue control your motor speed is only the programmed speed once the ramp up and ramp-down have finished.

can't simply set the gear with an hal input

Is that a question or a statement? You certainly could enter the currently-selected gear in a VCP box and connect that to the gearchange comp in HAL, but that seems inelegant.

My lathe has only two gears, I think that I am glad about that (And I have managed to program it to switch speeds on-the-fly during G0 moves)

Yes it would be an quick and dirty solution. An alternative start would would be using 2400 and 1600 rpm with the electric clutch.
I am slowly getting an idea how I can build something to automatically change the manual gears

anfänger wrote: I am slowly getting an idea how I can build something to automatically change the manual gears

That might actually be easier, unexpectedly enough.

Though you probably need to cycle the motor to get the gears to slide through. Wath the Rotary SMP Maho videos on Youtube for an automatically-selecting gearbox.

Yes I follow hin on you tube.

I would use two steppers with a belt drive for handle turning.
An an bunch of switches for gear detection.
But this would be to much for now. I want to have an easy solution to get started.