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New (Ancient) Maho MH 700 - Little help please? :D

R9000

Plastic
Joined
Apr 27, 2022
Hi all,
I've browsed this forum for a while but just signed up today, this is my first post. So I recently bought an MH 700 "Toolroom" machine, made in the 70s I think. It's a beast, works mostly fine but needs some real TLC for sure. It's had three coats of paint, the original green, blue on top, then white clumsily slapped on top of that. I really like the white though - at some point I'll repaint it properly and I think I'll keep that look. What scared me a little bit was the fact that when I finally wiped away the puddle of oil in the tool trays, the bottom of the tray was still green - meaning some of that dirt and oil was probably 40+ years old. :D

Anyway, speaking of oil I have a few questions. Please bear in mind I'm not a professional machinist, my only other machine tool is a Boxford Model C. So some of these questions might be very, uh, naive.
-First the oiler itself. I'm wondering what oil to use. There's a plate above it that says "10-14°E / 50°C". Now don't get me wrong, I love to measure things in Degrees Elcius as much as the next guy, but I don't know what this means when it comes to oil. I have some pretty generic way oil that I use for my lathe, but is that adequate?
-Secondly, the machine seems to have two oil baths for the gearboxes. From the looks of the little oil window, it's pretty parched in the feed gearbox. So what do I put in there? Same stuff for the spindle? There doesn't seem to be an oil window for that.
-Thirdly, there's a switch on the top-left of the panel and I have no idea what it does. I can't seem to post images yet, but it looks like some sort of... clutch or something? Like a circle with some sort of brake being moved up against it or away from it. Any ideas? I'll post the image once I'm able.

Now you might be asking why I don't just get a manual. Well, it came with virtually zero documentation, Lathes.co.uk doesn't have a manual for this exact model, and DMG Mori came back to me after about three weeks of "searching" with... nothing at all, nice though they were. Everything on the machine so far I've had to figure out myself. So if anyone has access to MH 700 documentation (the angular version, NOT the old rounded version) I'd be forever in your debt if you could share it with me. There was another post on this forum where someone claimed to have documents for an MH 700, but the links now make you ask for Google Drive permissions, so that's a lost cause too.

Any and all nuggets of wisdom greatly appreciated. Thanks all. :)
 

R9000

Plastic
Joined
Apr 27, 2022
Wow, thanks a lot Karl! The MH 600 manual seems very useful. A shame it's not in English but it's way better than nothing. I'll go through it and translate some.

°Engler! Never heard of that before. That's excellent though, I'll get some ISO 150 oil. Any idea of what to put in the gearboxes?

Thanks again
 

R9000

Plastic
Joined
Apr 27, 2022
Thanks so much for your help guys, Karl actually sent me some documents from a guy on a german forum, Zerspanungsbude, so massive thanks to him.
I also found the oiling plan on the MH600 manual, or "Conseils pour les produits lubrifiants". Thankfully someone has scribbled in the ISO equivalents here before scanning! I've translated some stuff in red, so here it is for anyone who needs it in the future.

3ZWPQHX.png


One more dumb question for you guys - is all ISO 150 oil interchangeable? Like, I see ISO 150 slideway oil, but also like, ISO 150 gear oil, etc. I'm guessing you can't just use any ISO 150 right? That's just the viscosity?
 

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AlfaGTA

Diamond
Joined
Dec 13, 2002
Location
Benicia California USA
One more dumb question for you guys - is all ISO 150 oil interchangeable? Like, I see ISO 150 slideway oil, but also like, ISO 150 gear oil, etc. I'm guessing you can't just use any ISO 150 right? That's just the viscosity?

You are correct....Way oil often contains chlorine to help it carry loads plus usually has something called "tackifiers" which help the oil cling to vertical surfaces.
Cheers Ross
 

Milacron

Super Moderator
Joined
Dec 15, 2000
Location
SC, USA
The MH 600 manual seems very useful. A shame it's not in English but it's way better than nothing. I'll go through it and translate some.
No need to "translate some" as it's easy as falling off a log to translate the entire manual via Google Translate. I recently translated 278 pages of the operations and programming (Fanuc) manual for a CNC grinder in Czech to English and was astounded how perfect the translation was.... no "Czech-lish" but near perfect English sentence structure...especially impressive considering it was translating technical terms not just common language.
 

R9000

Plastic
Joined
Apr 27, 2022
No need to "translate some" as it's easy as falling off a log to translate the entire manual via Google Translate.

Google Translate is definitely amazing, despite its limits. Although since the manual is all images and not actual plain text, I'd have to run an OCR over it all to translate it. And I believe that's only available in Google via Google Lens on Android. I was looking for a way to do it on PC last night, but to no avail. Otherwise I'd have to type out the stuff beforehand, then paste that into Translate. Or go through it page by page with my phone camera.

For no particular reason whatsoever...

other than it's a Maho (MH400)

MAHO is Filthy!! (Whose Milling Machine Isn't?) - YouTube

And it's Tony :-)

I've genuinely lost count of how many times I've watched Tony's videos, including the Maho CNC conversion ones. I hope he makes more content on the Maho, although I know not everyone likes CNC stuff. I want to see how he fixed that crunchy ballscrew in the head! And how that vertical axis leadscrew/nut is holding up. And maybe a 4th axis for some really funky parts? But yeah.. such good vids.
 

AlfaGTA

Diamond
Joined
Dec 13, 2002
Location
Benicia California USA
Seems like a lot of re-invention of the wheel. Lots of his "discovery" could easily be answered here on this forum , But i have never seen "tony"post here.....Guess that would torpedo his quest and shorten his revenue stream....
Its all about the money.....No profit here ,,,But U-tube that's another matter....Drink it up boys....Hell why would i want to know how this thing really works, when i can stretch it out for 10 episodes....You watch i get paid.
Cheers Ross
 

R9000

Plastic
Joined
Apr 27, 2022
Seems like a lot of re-invention of the wheel. Lots of his "discovery" could easily be answered here on this forum , But i have never seen "tony"post here.....Guess that would torpedo his quest and shorten his revenue stream....
Its all about the money.....No profit here ,,,But U-tube that's another matter....Drink it up boys....Hell why would i want to know how this thing really works, when i can stretch it out for 10 episodes....You watch i get paid.
Cheers Ross

I mean, of course you're correct that it would've been possible to just ask all his questions here. And there is a monetary incentive for more content. But although I don't want to sound like I'm defending him just because I like his videos, here's why I think he deserves credit:

-Some people find it much easier to learn the harder (and more expensive) way by trying things out first and foremost. Perhaps that's how Tony likes to do things? And even otherwise, it illustrates the process a lot better to the viewers to do things from first principles (to some extent) rather than just say "I did it this way because that's how the pros on the forum said would be best". All that said:
-I don't know if he's on this forum, but he did post on the LinuxCNC forum so it's not like he just went at the project blind. Genuine question, just trying to understand; would you rather he make a forum thread accompanying/instead of his YouTube vids to show what he did? Speaking of which:
-There's something to be said for "edutainment" that is easily digestible such as what Tony makes. It might not be perfect, but if people are learning and having fun watching, doesn't he deserve to get paid? It's not like we're paying him directly besides, even if he turned ads off, YouTube would still run them as is the case nowadays. And furthermore, there are much easier, quicker and cheaper ways to make a buck online than spending thousands of dollars on a lump of old iron and CNC gear, and then making highly-edited videos for a (relatively) niche community. And there are other people on YouTube who would (and have) stretched out machine project videos for many, many more hours of content.

TL,DR:
I don't think Tony is solely "in it for the money", but I don't think the channel/vids are a bad thing even if he was. I agree that he covered a lot of old ground that's probably obvious to machining and CNC pros, but I think the "first-principles" approach aids learning, for his audience if not for himself.

Maybe I'm misunderstanding your point? Please tell me if so.
 

R9000

Plastic
Joined
Apr 27, 2022
While I'm here, I promised pictures, so here you go:
PXL_20220421_204116241.MP.jpgPXL_20220427_163829921.jpgPXL_20220406_105039912.jpgPXL_20220427_163952804.jpgPXL_20220406_094523427.jpg
I think this forum squashes them down a bit, so there are full-res photos in an imgur album here.
I've been attacking it with degreaser in various places for the past couple of weeks, so some photos might look a tiny bit cleaner. But honestly there's a very fine line between removing the dirt and the flakey white paint. :rolleyes5:
 

Charles P

Aluminum
Joined
Jul 24, 2009
Location
UK
Hi all,
It's had three coats of paint, the original green, blue on top, then white clumsily slapped on top of that. I really like the white though - at some point I'll repaint it properly and I think I'll keep that look.

My MH600 has a coat of badly applied blue over the original colour, and the repaint is now flaking in places. I'm not one for repainting machines so am looking for proven minimally intrusive ways to assist the flaking process. Suggestions welcomed

Thanks

Charles
 

ballen

Diamond
Joined
Sep 25, 2011
Location
Garbsen, Germany
My MH600 has a coat of badly applied blue over the original colour, and the repaint is now flaking in places. I'm not one for repainting machines so am looking for proven minimally intrusive ways to assist the flaking process. Suggestions welcomed.

My Deckel mill had two badly-applied coats of green paint over the original gray. Some of it flaked off very easily, and some of it really stuck. I think it was just a question of where they had cleaned it before painting.

I experimented with different solvents, but couldn't find anything that would take off the green without damaging the gray. But worth a shot.

I found that a piece of very hard plastic (phenolic) with a sharp edge would glide over the original hard gray paint but knock off the green. A 6mm (1/4") square HSS lathe blank in a wooden handle also worked well. If I got the angle and pressure right it would slide over the gray paint but scrape off the green, with little or no damage to the gray stuff.

But in the end I bit the bullet and repainted the machine. But I only did that after I had used and fixed it for 7 years first. Paint should be one of the final steps, don't even contemplate it until you've used the machine enough to understand its quirks and problems.
 

tomp

Aluminum
Joined
Feb 27, 2003
Location
austin tx
Seems like a lot of re-invention of the wheel. Lots of his "discovery" could easily be answered here on this forum , But i have never seen "tony"post here.....Guess that would torpedo his quest and shorten his revenue stream....
Its all about the money.....No profit here ,,,But U-tube that's another matter....Drink it up boys....Hell why would i want to know how this thing really works, when i can stretch it out for 10 episodes....You watch i get paid.
Cheers Ross
Sad and true. All that info is likely to get disposed of before its consolidated and shared.
Ross what way lub do you like for your Deckle CNC machines these days?
 

R9000

Plastic
Joined
Apr 27, 2022
Hi guys, it's me again, back with another frustratingly noobish question!
So to set the stage, previously my Maho was sat at work, with 16A 410V sockets on almost every wall. Very convenient. Now though, I've moved house, and finally been able to take the machine home with me. Of course, there's no 3-phase at home, and I had this in mind since I bought the thing. But I'm still pondering the best way to sort this out. Electrically the machine is very basic. 3-phase+E 410V in, no neutral. Bank of ceramic fuses, a transformer with a few coil taps for convenient voltages, and some sort of latching contactors that go basically straight out to the motors, actuated by buttons on the control panel. There's an old-style filament lamp too, though I have a good mind to replace this with an LED setup. All motors are 3-phase 410V. Spindle motor is 3kW, power feed is 1.1kW, coolant pump is 0.12kW. ALL are Insulation class B. With that in mind, I'll lay out my options:
1. Just get 3-phase power run to my house - Obviously the easiest and simplest option. I haven't got a quote just yet, but I'm guessing it will be prohibitively expensive. Like tens of thousands expensive. So maybe not. The good news is my house happens to have a nice fat 100A fuse in the meter box (and just in case it wasn't clear, I'm in the UK, which means single phase is 240V and a neutral line). So as cool as it would be to get the grid to run 3-phase to my house in particular, I don't think it's happening.
2. Change all the motors to single-phase equivalents - Pretty damn easy, assuming I can source the motors. However I've heard single-phase motors don't run as smoothly as 3-phase, and changing all the motors like this seems like a big waste of the originals. Plus I won't end up with a 3-phase supply, which means I'm back to square one if I decide to pick up another boat anchor in the future. Also no potential for speed control via VFD. Not a deal-breaker because gearbox, but that brings me onto:
3. Just use VFDs, ya idiot! - Wellll... yeah. So you can get VFDs that basically convert the single-phase to 3-phase to run your motor. Problem is like I said, all my motors are Insulation class B. According to The Internet®, you need at least class F insulation to use a VFD with your motor, because of the harmonics caused by the square edges of the digital waveform that approximates 3-phase coming from the VFD. Not only this, it seems most single-to-3-phase VFDs max out at around 2kW. So I'm out of luck for the spindle. Now I've heard that *potentially* motors from the 70s could be marked class B, but the insulation used was basically class F anyway. But I have little way of knowing if this is true. From my research it seems insulation class is to do with the temperature rise that the insulation can deal with. Is this the only thing that means B-class can't be used with VFDs? Or is it also to do with insulation breakdown voltage and arcing between windings during voltage spikes? Anyway, VFDs carry the same problem as the single-phase motors. Not only will I have to buy one for each motor, I'll still be stuck with no 3-phase for future projects.
4. "Digital Phase Converter" - I've spent hours looking at these things and what's available, and it seems like without importing, I have two options - JFK Electrical NI and Drives Direct. These are both basically glorified VFDs that are ostensibly rated to handle multiple motors. Direct Drives supply Teco Westinghouse inverters, apparently with some extra filtering and such. The guy on the phone told me they give a "perfect sine wave" output, so maybe there's something to them. Looking at older units they used to use Teco 7200ma inverters, however apparently the new ones they use are made specially for Drives Direct. Company seems halfway legit at least. The problem is these "converters" are £4k/5k for the size I'd need. That's going on for 3 times the cost of the machine. JFK Electrical NI supply inverters of various sizes that appear to just be rebadged Winston WSTG600 inverters from China. I raised my concerns about insulation class with the guy on the phone (I think the "company" is just one dude) and he basically said it would be fine and that these devices are built to run machines like that. A nice thought, but I just don't buy it. He couldn't supply any documentation or .pdfs or anything either, presumably because the documentation that does exist would reveal his supplier. However these inverters are around £1k, which I would say is just about in-budget for this project. My question is, can you just slap a line/load reactor/sine wave filter on the output of this inverter to make it safe for the motors? I mean it's not like the motor cares about anything but the electrons in the wires. As long as it's clean enough, it should be just like mains power right? But then it seems like *good* sine filters are £1k or more, which again probably puts this out of budget. The guy on the phone swears it'll be fine, but honestly I'm not taking the risk of buying the thing and then having no recourse when my motors let the smoke out. Just in case anyone wants to suggest Phase Perfect converters, yeah they seem great. But they're also specced for the US market (460V) and the US wallet ($$big money$$). To sum up though, if I had one of these, it would mean a relatively efficient, compact 3-phase supply for almost any future machine, not just the mill.
5. Low-Hanging Rotary Fruit - The old faithful rotary phase converter. I've also had a good long look at these and well, they seem very much like the "it was good enough for my father, and his father before him" option. Basically perfect in terms of waveform, though differences in phasing and voltage abound due to the artificially generated phases from the motor. This can be made up for by some big caps and inductors in the mix, but will likely never be perfect. Still I think it's less likely to explode my motors than the naked output from a VFD. I should mention at this stage that I already bought a Clarke PC60. This is a static phase converter which (I think) couples the attached motor in a steinmetz connection to basically make it run on single phase. On its own this only gives you access to about 60% of the motor's rated power, but I have seen a video where a guy basically uses it as a basis for a rotary phase converter, since it already contains all the capacitors and the transformer needed. So if I were to do this, I would only need an idler motor and a couple of other bits. Would it run an idler big enough to power all 3 mill motors at once? I'm not sure. The transformer inside has no markings on it, so I don't know if it can supply the necessary power, and that's probably the most expensive part. The PC60 is rated for 5.5hp or around 4kW. So enough for the spindle or the feed on its own, but since we're running an idler as well, I don't know if it would manage more. And of course the main disadvantages of a rotary phase converter are the noise and latent power consumption of the idler motor. And the space it takes up with the huge heavy motor stuck somewhere in my garage. And in my place it's not really possible to just put the motor outside. All that said, this is probably the cheapest and nearly the easiest solution of the lot, and like the digital converter, would give me 3-phase shop power.

So, any thoughts? What do people usually use to run 3-phase machines at home? What's my best course of action? Did I miss anything? As always, sage advice greatly appreciated.

EDIT: I've just become aware of another option: change all the motors for new 230V-capable, 3-phase motors *and* run them all on 1-3ph VFDs. This solves the single-phase motor issue of not running smoothly, and it gives speed control on the motors. Plus it seems VFDs without the 230-410V voltage conversion capability are somewhat cheaper than those with. If I choose motors with dual-voltage windings, it also means I can run at 3 phase 410V in future if necessary, and no worrying about insulation breakdown. Plus it adds some value to the machine in the case that I ever need to sell it. The big downside to this being that again, I won't get a 3-phase supply out of this. Also the old 3-phase motors will go to waste, at least in the immediate term. Perhaps I could make a rotary phase converter out of the spindle motor. Ha!
 
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AlfaGTA

Diamond
Joined
Dec 13, 2002
Location
Benicia California USA
Looks like you did your research......
Remember that VFD's need to do the on/off switching within the VFD so your original switches would need to be rewired to operate through the VFD.....

Here (US) i run my entire shop off one 10hp Phase Perfect......No issues in years of operation, no changes needed to motors or machine switch gear. Almost silent an mine has a weather proof enclosure and it sits outside, so no loss of valuable floor space.....Think i paid about $3600.00 for my setup....sound investment considering the long term ease of use and quality of the power supplied.

I have 380 and 415 volt machines as well as 220......use boost transformer down stream of the PP, works fine.
I understand that a PP may not be available in the UK...Pity.

My money would be on a singe source converter like the "Direct Drives" even with a rather high entry cost....Will give you total flexibility at finding other machines (this is usually how it goes, get some iron and before you know what hit you the shop is stuffed with 3 phase toys.
They seem to know about their product and likely have fair support....Over the life cycle of a machine tool the cost of a good converter becomes pretty low.

Not sure changing the motors is a good idea.....don't think having dual voltage motors will pay any dividend on resell.
Run the converter at line voltage and step up the voltage as required for each machine....

Good luck.........
Cheers Ross
 
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AlfaGTA

Diamond
Joined
Dec 13, 2002
Location
Benicia California USA
Ross what way lub do you like for your Deckle CNC machines these days?
I use Mobil Vacouline 1419. ISO 220 reputed to be the original formula of Vactra ,before they took the good stuff out.
Bit hard to find. Only available in 5 gal pails (or larger) and i don't think the mass marketers carry it....
I get mine from the local bulk oil jobber
 

R9000

Plastic
Joined
Apr 27, 2022
I have 380 and 415 volt machines as well as 220......use boost transformer down stream of the PP, works fine.
I understand that a PP may not be available in the UK...Pity.

My money would be on a singe source converter like the "Direct Drives" even with a rather high entry cost....Will give you total flexibility at finding other machines (this is usually how it goes, get some iron and before you know what hit you the shop is stuffed with 3 phase toys.
They seem to know about their product and likely have fair support....Over the life cycle of a machine tool the cost of a good converter becomes pretty low.

Not sure changing the motors is a good idea.....don't think having dual voltage motors will pay any dividend on resell.
Run the converter at line voltage and step up the voltage as required for each machine....
Hi Ross,
Thanks a lot for the advice, and info on your setup. The Phase Perfect converters do seem pretty, well, perfect. Unfortunately there's the issue of cost of not only the unit, but shipping and import duty/VAT. I'm totally with you on the "buy once, cry once" heuristic. But I think both PP and DD are out of my price range for the forseeable.
I'm currently leaning towards the dual-voltage motor VFD approach for the following reasons:
1. I get speed control on all three motors. Not super neccesary but definitely a nice-to-have, and I will have reverse too in the rare event I might need that. Controllable via RS-485 so I can put all the knobs in one place.
2. A single-phase 230V machine. This is why I think it might boost the value a bit - if I ever had to sell it, buyers wouldn't have to worry about getting a 3-phase 410V supply installed like I have. They'd just need a 32A single-phase 230V breaker, and a socket. This also means that if/when I decide to put some other 230V bits in this thing, I only need one cable coming to the machine, and I don't need the transformer inside. Obviously this solution will require a complete rewire of the machine's panel, but given how simple it is, I'm not particularly concerned. I do that sort of stuff for a living anyway, breaking endmills and insert tooling is just what I do for fun.
3. Moving the spindle motor. It seems somehow unnecessary that the spindle motor is hung off the back like that, and all it means is I have to make more space in my garage for when the head moves back. If I buy a new motor, I can get one with the same flange and foot mounting, meaning I can stick it on top of the head at the back, and V-belt it to the spindle, like so many other Maho mills, making the whole thing taller but less... long? I guess there could be some counterbalance that the weight of the motor provides, but I doubt it given the weight of the rest of the machine, and if it is a real problem I can just flange-mount it again and forget all this ever happened. :D
4. It seems to be the cheapest option. I've priced the motors and VFDs up at around £650. Maybe up to £800 once you consider extra wiring, breakers, pulleys, etc. Even if I did keep cramming 3-phase machines into my (admittedly small) garage, I could do this sort of conversion at least 6 times before I matched the cost of a Direct Drives converter. And at my hobbyist level, most machines have smaller and fewer motors than this.

Yes, the big downside to all this is I'm still stuck with no 3-phase supply. That sucks. But unless something makes me cange my mind, I think that's something I'll have to evaluate next time, assuming I have the funds available. Hope I don't seem too dismissive. I'll keep this thread updated if/when I make progress.
 

Charles P

Aluminum
Joined
Jul 24, 2009
Location
UK
I'm in the UK and have a mixture of 3 phase conversions.
My CVA lathe runs off a static type Transwave converter that I connected to a 1.5 HP idler motor. Works very well as a rotary converter for the (mainly) single use application.
I did run my Maho MH 600 off the same converter but after about 6 years the two speed drive motor cried enough, which was a right pain. Two speed motors aren't exactly common. I substituted it for a two speed from a Colchester lathe but it was never quite right so I ditched it and put on a 3 phase motor and VFD, which is great but not as integrated. Rewiring the whole machine would take up too much time. The Maho feed motor is a special 3 wire wire 3 phase one that integrates with the contracting pulley variable feed arrangement, so precludes a simple replacement. That motor currently runs of the Transwave but at some point I'll work out a better way, but it's my home shop, I'm the only one who uses the machines so some idiosyncratic arrangements are acceptable to me.

Charles
 








 
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