Retrofitting a 1986 Maho MH400E

Hello Chris,

it seems that your Machine is the same Model like mine, waiting for photos.
My machine was also fitted with TNC and an S5 PLC.

How is the actual state of your TNC? (my english is very rusted....)
-is the screen working?
-does it feel that the TNC is working, but only estop fails?
-Inside the TNC is an safty relay for switching the machines estop circuit, which contacts fail and "self holding" circuit fails over the years. This is an common problem with the old tnc and also newer ones like the 355.
-Do you have the TNC Parameter for your maschine on papersheet?
-in my schematic all pages are numbered E82(XX)

maybe i can help you, but im only frequently online, because of "Rock n Roll" business as main job.....

Thank you for your help. My problem is with filing. Getting the photos from my mail. I never know what file to use.
Here are the photos from Google photos.google.com/share/AF1QipNrnieyve6n...aU5hV3RkSlZNMUMzeml3
If some one would like to help me from there. Thank you. Cheers Chris

Here are the long awaited photos. I hope anyway. More tomorrow evening.
Maho 700C in New Zealand

No failed again to send photos after hour of trying. Almost mid night here.
You must wonder how I could even consider retrofitting my machine.
Yes I have used Autocad but I can't send the photos!!
Sorry Chris

Hi Chris,

this is the same machine like mine,
I have a tilting/turn table.

Uploading photos works easiest if you first save the photos you want to upload to your hard drive, rather than straight from the cloud. I took a look at your photos on the cloud. The electrical cabinet looks nice and clean and tidy, without obvious halfarsed modding, which is good. Take some pictures showing the overview of everything.
Is there a 24VDC control relay board in there somewhere? On mine it is on the cabinet door. If you don't have one, then the control relays are probably wihin the Siemens PLC, and you'll want to keep it.


I also don't see any Heindenhain hardware. Is the controller in the user control module?

I dont see any axis encoder cables. Heindenhain encoders generally terminate in chromed M23 connectors. They are probably under that conduit cover on the floor of the cabinet. If you follow them you'll find the A/D convertors which do the signal processing. If the controller is on the user control panel, then those encoder cables might be routed up to there as well. On mine, that was a Heidenhain 3 Axis EXE board located withint the Phillips rack. It is important for a retrofit, as you will either need to recycle the existing EXE, or get some single axis replacements...


I reused mine, and still needed two stand alones as two channels were dead.
www.ebay.com/itm/Heidenhain-EXE-602-D-5-...4:g:uGAAAOSw8vZXNcEB

Please look up your circuit drawing number and let us know what it is. It is on the side of the machine somewhere...


and confirm it agrees with the number in the drawings itself:


Good that db1981 has the same machine. Definately try to get it running again with the Heidenhain. Normally there is only a single or a couple of discrete failures such as burnt PCB traces, dead capacitors, loose/intermittant connections etc. With a bit of help, hopefully these can be found, and corrected inexpensively.

You may still want to ditch the TNC and modernise with LinuxCNC, but starting with a working machine makes that easier.
Mark

Hello,

the control relais are placed above the indramat.
all Encoder Cables go straigth to the TNC135 in the User Control Panel.
the TNC135 does the position control and has some pins for spindle, colland, bcd for speed command.
All Logic like gearchange, Control Panel Buttons etc. ist done in the good old S5....

I you answer the questions a few posts above, we can locate the error in your system.

one question more: when was the last battery change?

Hi There,

I am working with Chris on the Maho and trying to get it operational. I am an Electrician and also do Automation but I have not had much experience with Milling machines such as this one. I have found the TNC is not closing the output that is in series with the main latcing contactor. I have looped this contact out and the X,Y & Axis move but only in one direction.
The Screen still works but is in German.The TNC appears not able to complete the power up tests and the LEDs stay on. the batteries where changed 6 months to 1 year ago. I can get the Programme setup parameters but they are very minimal an I'm not sure what the values mean, as I have only started to work on this machine since the problems have started.

Regards

Brad