Retrofitting a 1986 Maho MH400E

Glemigobles wrote:

I think what Mark is suggesting here is to ditch the old control but retain the servos, they have closed loop feedback with tachos and linear glass scale encoders. Both exist in the cabinet as separate modules which you can easily connect to a LinuxCNC control built with Mesa cards.

Unless you also don't trust the drives and motors, but those will be expensive to replace with new parts.

Got ya! If it was an easy thing, I'd keep the scales. I know Mach Drives out of AUS sells a brushed DC servo drive that also reads a scale.

Sorry db 1981 I should have made it more clear.
You wrote I quote. "You have got an exchange board from germany? But the eproms may be are still old?"
That is exactly what happened. The board was tested but likely came from another dead machine. I sent mine back to Germany. It was replaced not repaired. I forgot that detail.
Thanks Chris

Unless you also don't trust the drives and motors, but those will be expensive to replace with new parts.
I do trust the drives and motors. It is just the TNC

eflor8234 wrote:

Glemigobles wrote:

I think what Mark is suggesting here is to ditch the old control but retain the servos, they have closed loop feedback with tachos and linear glass scale encoders. Both exist in the cabinet as separate modules which you can easily connect to a LinuxCNC control built with Mesa cards.

Unless you also don't trust the drives and motors, but those will be expensive to replace with new parts.

Got ya! If it was an easy thing, I'd keep the scales. I know Mach Drives out of AUS sells a brushed DC servo drive that also reads a scale.

The easiest retro fit is to only pull the Phillips computer. Nothing else.


The MAHO is very modular, and was built with well engineered high quality components. My Heidenhain scales original calibration reports were with my machine. The maximum deviation was under 1 µm throughout the range. Maho used an Invar bar mount to compensate for the thermal expansion of the gearbox. Ripping all the motion hard ware out to replace it with cheaper gear would be a downgrade, which costs unnecessary money.

Assuming the Phillips is the problem, you can get a MAHO x00E running under LinuxCNC for the price of three MESA boards, a cheap PC, and a bit of wiring. Maybe a couple of EXE's if the original three channel is defective.

If you get radical, and rip everything out, you screw up stuff like the spindle gearbox control. Even the littlest MAHO delivers 200Nm of torque to the spindle at lowest gear. It is a beast, and great for pretty large face mills.

Stig did the radical retofit, rip it all out and replace it with new stuff. Must have cost a fortune, and taking an age to wire all the new stuff up. Why?

He no longer has electronic control of the gearbox to give awesome torque, he no longer has µm positioning based on linear encoders which compensate for belt stretch, leadscrew errors, thermal expansion, minor wear etc.

Please, before you rip onto the 600E, read the document I put together detailing the benefits of a minimally invasive retrofit.
Mark

Mark --- chris
The Heidenhain LS-403 scale will work with Heidenhain ( 602 ? ) EXE resulting in a TTL signal that many brands of displays can accept as scale input.
However , I think "chris" should look at his MAHOs scales and verify the machines Heidenhain scales Model # . Are they LS 403 or some other # . A 602 EXE may not work.
Chris , could you verify your scales ?

effor 8234
The two MH600E machines I have use Indramat 3TRM2 servo drives which drive the 3 servo motors. The 3 servo motors are DC brushed (carbon brush ) an have Taco (carbon brush) generator feedback to the Imdramat 3TRM2. Two of the servo motors are identical but the Z axis (vertical or table up down) has a electrical brake and more H.P. than the other two servo
motors. If you don't have a Indramat 3TRM2 manual then ask Mark ,as he may have a source you can download.
Do you have the MAHO machine specific parameters ? Should be on a punched tape with mach serial # noted in pencil. The back up 6 volt battery will not last for ever but you can readout the existing parameters which may have been updated.

Where are you located ?
Bob not your uncle

Hi db 1981, Mark,

I haven't been able to find the Service manual for the TNC 135 on the Heidenhain Web Site but found the TNC131 Service manual.

Chris has LS 803 Scale on his Maho I found some datasheets and they are the same connections which is a good sign Chris has sent me your how-to manual and I have been working through that and starting to get a plan.

Regards

Brad

Scales on my Maho are LS 803 Scale. See note written on my behalf by Brad.
Again listening to what you say. Thanks for your input. With help from other I am going to make things happen.
Thanks to all who have offered advice. Cheers Chris

Thanks for the info.

My shop is near Traverse City, Michigan.