Retrofitting a 1986 Maho MH400E

Good call. I had the acceleration too high, and also the min_velocity was too high. The X axis is now nice and smooth.
At 100mm/min the max error is now about 0.015mm.


at max speed of 2700mm/min it is also only about 0.03mm, but has some oscillation in deceleration which are not there in acceleration.


The home switch is the index of the glass scale encoder. I found at about 2mm from the end stop. Homing to it finds it that index, but then errors out with a message saying that the home switch had gone low before it could back off it. Any suggestions how to make this more robust?

I connected the net for the Z axis brake to the machine-is-on , but then had a go at getting the Y axis tuned. I had been having some problems with that Y Axis glass scale encoder stopping working, but it had seemed to magically fixed itself before I got around to trouble shooting it. That was wishful thinking...

There is no channel A output.


I need to trouble shoot that but got too cold after hours in the garage. It is below freezing here, with the light dusting of snow from wednesday still on the ground outside. The garage is the coldest room in my basement.
NMark

The encoder might be bad but your traces show the Y axis Quad- B and the X axis Quad-A

How embarassing.

RotarySMP wrote: The home switch is the index of the glass scale encoder. I found at about 2mm from the end stop. Homing to it finds it that index, but then errors out with a message saying that the home switch had gone low before it could back off it. Any suggestions how to make this more robust?

Try configuring for "index only" homing.
linuxcnc.org/docs/2.7/html/config/ini-ho....html#_configuration

Thanks Andy.

Do I still keep this line if I am using Index only homing? Or do I delete the home switch net?
# --- HOME-X ---
net home-x <= hm2_5i25.0.7i77.0.0.encoder-00-index [Just wrote that from memory, might be wrong syntax]
Mark

I _think_ you would delete it, and only connect the index-enable pin. (You definitely need the index-enable pin)

Then I would test starting very close to the index mark and with a very low latch velocity to make sure that there are no surprises.
(if it is an option I would also suggest reducing the drive current to limit the torque)