Retrofitting a 1986 Maho MH400E

Mark
My High school phsyics class was in 1960 and the high tech device was a 10 Ft. long 2 inch Dia. spring to demo harmonics .
Your slotter attachment plate or where it is bolted to the machine ,wonder if all slotters are the same except for the attachment plate ?
Bob

They still had the same spring in 1985.

Agreed, it does look they had one design of slotting head and switched out mounting plates to suite.
Mark

I keep pondering making my own slotting head, with servo-controlled tool rotation. Then you could use it for all sorts of things, including internal gear shaping . (except that example isn't doing it at all cleverly, with LinuxCNC I would be expecting to rotate both work and tool continuosusly)

Hello db1981 Mark Bob and Jon
I am waiting for Brad to report back to you on progress here.
I was talking today to a ships chief engineer. He looked at the Maho and said the electronics were familiar. He had been on ships of the same era. The electronics were nothing but trouble.
I am stuck with the mechanically perfect Maho but to date been plagued with electrical breakdowns.
Brad has the machine running but we have no DRO.
I have ordered 3 Heidenhain EXE D/5-F to continue a full retrofit. As a last resort I can fit a standard 3 axis digital display instrument. This may be difficult as plugs are likely not compatible.
After talking to my friend. I am concerned what else (Other than the T.N.C.) in the Electronics is obsolete.
I am concerned about the row of enclosed contractors directly above the Indramat T.N.C. I understand Eproms are obsolete.
I wonder what else.
I need to address this before I continue. Please can you help.
Cheers
Chris

Hello Chris,

Those contactors (not contRactors ....) are nothing to worry about! They are standard and still available components that will be easy to replace if they fail! They might, but don't worry about that. I had to replace the most used one (3K2, the E-stop contactor) in my Maho, and it was as easy as to find one with the functions I needed and swap it out. I had seveal spare ones lying around, and the whole thing was done in no time. They are easy to find faults on as well, so dropp your worries about these!

Now the servo drives might be more of a challenge. They are WAAAAY more work to replace, and will involve a considerable rebuild of the machine. But on the other hand they are prooven and reliable industrial units that are known to last. So I woldn't consider replacing them either.
But I would definately have it serviced and as a minimum replace electrolytic capacitors inside the drive. They are very likely to give you problems, and is way cheaper and easy to replace before they fail.

As for DRO, your machine with separate DRO display is unusual, and a sign your machine isn't truly bilt as a CNC only machine. Or trying to be both..... not sure.
¨All normal CNC controllers (including my Maho) have the DRO on the computer screen only. You might be able to split the signal coming from the EXE units in to two (Mesa have encoder splitting units), and feed one of those to your DRO, if you really insist on having that unit showing the position. But you should worry about feedihng the ecoder signal in to the controller (the Mesa 7i77) in the first place.

Anders

Hello Anders
Thanks for your quick response. Sorry about my careless typing. I should have picked that up.
The subject contactor's look very complicated. Pleased to hear they are still available.
On the Maho C 700 the DRO is not on the screen. The machine is T.N.C straight line cuts only. The T.N.C feature has never worked since I purchased the machine.
The D.R.O did work and I was able to use the Maho as a basic mill. A few months ago it died again. Very frustrating half way through a project.
I have had to employ Brad and with the help of this Forum members we have the machine running again but with no D.R.O.
Reading through all the past posts on the forum a full C.N.C Retrofit is a lot of work. Brad is keen to do it for me.
I am concerned about the final cost and further, what happens if a irreplaceable part fails?
As a last resort I could fit a new complete independent digital read out system.
I would like to retain the Heidenhain scales and use another modern 3 axis display reader. I understand this is possible using the Heidenhain EXE 602 D/5F module. I wonder about getting matching multi wire plugs.
I appreciate your efforts to help me. Thank you.
Cheers Chris