Retrofitting a 1986 Maho MH400E

Marcin, I can't promis that this will omit all humming but when I changed the toothbelts I came across the fact that the screws where showing massive stick-slip when turning the wheels by hand. I then removed the cross-slide taper and found very thick, nearly polymerised oil in the oil grooves. I decided to take of the entire slide and found even more oil grooves that were blocked by that oil. After thorrow cleaning and new Oil (it might have also been the wrong oil, bedways have Moglice surfaces which can swell if you use synthetic lubes) everything is running smooth now and numming is much quiter.

A possible yet not approved solution instead of dismanteling everything could be to loosen the tapers etc. and then press new oil through the central lube inlets so that any old oil is rinsed. But first of all I would check if there really is significant stick slip when turning the screws by hand. And check the central lube system for blocked valves!

Christian

Thanks Christian, I'll be sure to check all the components of each axis for old grime.

Does anybody who has rebuilt a German-style milling machine such as the Maho, Deckel, Mikron, Kunzmann, etc. have any tips on what lifting equipment would be good to get for the purpose?

I was thinking of a crane style engine hoist, but I don't know if the base wouldn't bump against the base of the machine. I'm working in a garage, albeit a spacious one, but I don't have a lot of room for large equipment and the garage door is too low for a standard forklift.

An engine hoist would be good for putting heavy stuff on the table as well, right?

The mill has the spindle motor on top that needs some sort of crane to remove to check the Y axis, and some heavy lifting is required to take off the table to check the X axis (the table weighs 200 kg).

I'm pretty sure a whole bunch of German machinists have done this many times with their machines but I don't speak German and can't ask on CNC Ecke

What I can find on Youtube in English is only guys who use forklifts or can take the parts they need off by hand with a partner. The gear on the Maho is way too heavy for that.

Maybe one of you guys has a link to some German-language thread that has pictures of a teardown of a similar style mill?

I have a chinese 1t engine hoist. I used it to remove and install the table on my 400E. It doesn't work very well for that job, as the feet are not wide enough to straddle the base casting. It works, as I use a fair length of chain between two T-Nuts, and the table is not that heavy on the 400.

Mark

Thanks Mark, the feet of the crane are my primary concern. Engine hoists are pretty cheap over here at the moment, I can get one online for ca. 150€ that is rated for 2 tons. But it's difficult to eyeball whether the crane will fit where it needs to, and there are a few designs of the base to choose from.

In the meantime, a small update on the retrofit is that DMG will send me the schematics within 2 weeks. I have to figure out how to mount the ATX motherboard from the computer I have in the electric cabinet based on your drawing. Since I cut a lot of acrylic, I thought I might make a mounting plate from that material. The existing rack layout on the Philips computer is really nice, but I don't know if it can be easily replicated with different cards.

Coming up with an idea for a panel is a tough thing for me as well. I'm leaning towards a touch screen that has been recommended on the forum since it's not that expensive and is proven to work on Linux. The rest, though, is a mystery.

Mark , And all the others who have contributed to his Maho retrofit :wishing you-all the very best for this New Year.
The Heidenhain scale error - The only thought I have would be to swap just the read head from one axis to another axis. I wonder if the read head from some other series of Heidenhain scales would work?
Have you stuffed the Maho thru the shop door way yet? Wonder if you considered trying air pads to float your mill on air instead of casters?


Lifting equipment -- Have seen ,and have used the so called engine hoist things. So very not impressed with them. Past summer acquired a gantry crane rated for 2000Lbs.and has 10Ft cross beam and it is adjustable height and width with 4 big casters to move it around. Do remember Nick Muller's You Tube video showing him jerking the transmission out of his MH700? and climbing down a step ladder while carting it along. His comment was that cranes are for wimps.
Bryan Block has just made a You Tube video about making 2 gantry cranes

Mark Hope to read more of your retrofitting journey
Bob the Wimp

Thanks Bob, I have a buddy who's worked with injection molds all his life and he also suggested welding a gantry crane. Gonna have to ask around to have something made for cheap, I don't own a welder and there are at least two fabricators within 200m from my garage.

Surprisingly, DMG have sent me the schematics already! Also surprisingly, they sent me a paper version instead of the CD for which I'd asked. There's also no invoice in the parcel, so maybe I shouldn't rush to tell them about the mistake

Unsurprisingly, the whole thing is in German, so... Google translate, hier komme ich!