Retrofitting a 1986 Maho MH400E

Hi Guys,
Finally had a try at putting stuff on YouTube so I don't mess up the LinuxCNC area so much. It's very much a novice start since i don't know much about it. Pretty raw videos, but I just wanted to see if I could explain stuff and encourage folk to resurrect the old machines. A few plugs to go to LinuxCNC in there. I don't even know how to name it in a way it might be found. If you hunt for "resurrecting a Maho MH 700 C"  you might find it. I've tried to set up a playlist so the videos can be watched in order, but it doesn't seem to work all that well. To my surprise some folk have found it and watched some of it! Ideas on how to do it better would be welcome. There are a couple of other playlists I'd like to do once on a roll. One on my "bat cave" as my great nephew calls it, and another on a rare Topolino I'm restoring that has been put aside due to Covid, then the Maho. I think there is a rule on "mens sheds" that if you make it N in area it needs to be 2 x N no matter how big N is.

Cheers,
David

Hi David
Sorry I seem to have lost you. Thanks for tour help.
Cheers Chris

Nope. Certainly not Chris..
My email is on p174. Drop me an email and we will find what works for us
I think we both go to standard time next weekend so we will still be 2 hours off.
Cheers,
David

I am now having trouble with the Maho 400E. The machine was working normally, had a normal shut down, and the next day started erring out.



It does not seem to be a LinuxCNC or Mesa  issue as it boots into LinuxCNC without error. 
** Note - It is configured as a vertical mill, but Maho configured as a horizontal, so on the original schematics, Y and Z are switched.
** Note - The HAL and Ini are attached to the first posts in this thread.

Consistent symptoms.
- X axis jogs without error.
- Y axis will jog in either direction, as far as I like, but as soon as I release the jog button, it faults with a " Y axis following error"
- Z axis faults immediately as soon as jog button pushed to "Z axis following error".
These symptoms are consistent and repeatable.

In addition, inconsistent symptoms are
- When it first happened the "Control Voltage Fault" light was lit on the Indramat server amp. This has not lit again
- On start up,  sometimes it refuses to latch on, sometimes it drops the latch immediately with a " External estop set" messages:

Troubleshooting:
- The 3Ph power at the wall probed normal. 
- The 3ph  power in the cabinet after the main switch probed fine
- The 2x90VAC and 2x 140VAC which input to the Indramat probe fine at the input to the 7K1 relay.
- The E-Stop chain has continuity.
- The Machine is ready chain through the motor overheat protection (8B2/9B2/10B2) is working.
- Interchanging the Heidenhain EXE's makes no difference to behaviour (withing the limitation that Y and Z EXE's have different resolutions, and therefore the PID tuning is off on the swap).
-manually jogging Y with a hex drive, the linear scale follows motion.

It would seem that the next troubleshooting step is to work out whether the Indramat is faulting and dropping the 7A1 contact.
 

or whether the Indramat is simple reacting to either a fault in the enable circuit
 

...or it the issue is driven by the latching circuit
 

How would you recommend troubleshooting to isolate which is cause, and which is effect, with these actions which occur nearly similtaneously? With pins or signals should I put on the Halscope, and what am I looking for please?
The Indramat 3TRM2 manual is here:
www.ssdservice.pl/FTP-serwer/Aplikacje%2...T/3TRM2%20MANUAL.pdf

Cheers,
Mark
 

At this stage, I would bypass the contactors so the Indramat is on when the power is connected to the machine (maybe through estop chain) without LCNC and manually give an analog signal to the indromat using a 1.5V AA battery. If the Z axis moves, you can continue to troubleshoot the following error. If it does not, then the indramat is dead.

I'm not a Linuxcnc guy, however I do make and fault find control panels for lots of different machines.. 
is there a possibility of you posting the complete wiring schematic for the control panel? It may be something entirely seemingly unrelated is causing the problem. 
 

from what I've been able to figure out from the drawings and manual provided and in the video, the "voltage fault lamp" on the Indramat seems to indicate an internal problem with the -15v/0v/+15v supply..
check the voltages on the relevant pins on the L6 connector.. ( might be one to scope )
the X axis doesn't seem to be causing an issue? but the Z and sometimes the Y axis trip out?
from the drawings that might be one or more brakes not releasing? as that appears to be linked through 19K2?
without the full schematic I'm guessing at the function of some of the contacts shown on what we do have.

You should also measure the voltage drop through the contactor feeding the Indramat, it can be worn out and making a poor connection, failing when under load.