[FDavies]

Hi folks,

I've just acquired a MAHO MH600C (with 2-axis rotary table) and moved it into my shop (with single phase 220V 200A service.)

I'd like to start a thread discussing the procedure for bringing a used machine of this type, back online under new ownership. The machine looks to be in great condition by it's appearance, and was used in production by another local company for many years, but may have some minor unknown issue.

It's last settings, fluid levels, and general state are all unknowns.

The manuals are intact.

I believe I need to acquire a rotary phase converter next.

I suppose the next thing to try and discover, is where the power connects to the machine. ...I "think" I know, but it is not confirmed in the wiring diagram, ...at least from what I can tell. The terminal block is labeled X1 in the electrical cabinet, and marked 35 , L1, L2, and ground ...I would have expected more simply: L1 , L2 , L3 , and ground. (The three phases plus earth.)

You can see this in the photos (lower left.)

Suggestions?

[cnc321]

On Maho's that we have retrofitted, the terminals were L!, L2, L3, N, PE; but nothing was connected to the N terminal. (it was expected that the N and PE [earth ground] were connected together at the transformer).

[AndreasL]

2-axis rotary table!!!

This one needs at least one picture!

Hmm, youre thread just reminded me about "my own" MH500C I am supposed to get installed...any day...soon...

[toolnuts]

Hi,

You would be better served by buying a PhasePerfect electronic phase converter. You can find them on Ebay.

I used a rotary converter for many years. They will get you by on-the-cheap,
but not like the real thing. If you want to make your own rotary converter there are several designs on the web. You need to be electronics smart, but if your into fixing your new CNC you should know some electronics anyway.

You don't get true 3 phase with a rotary, and their designs are usually a compromise on load balancing.

Paul

[Luslugger]

You need to review parameters. When you find the battery that may be maintaining the memory, do not disconnect it. I put the same voltage in parelel before removing the battery. Some times you can retain the memory.

[FDavies]

Hi,

You would be better served by buying a PhasePerfect electronic phase converter. You can find them on Ebay.

I used a rotary converter for many years. They will get you by on-the-cheap,
but not like the real thing. If you want to make your own rotary converter there are several designs on the web. You need to be electronics smart, but if your into fixing your new CNC you should know some electronics anyway.

You don't get true 3 phase with a rotary, and their designs are usually a compromise on load balancing.

Paul

Hi Paul,

Thank you. I do have some basic electronics skills, digital mostly, but I am not
an electrician and have a very limited practical knowledge of wiring and code.

MAHO wrote this morning that a 10KVA converter would be adequate.

Have you experienced problems using a rotary converter? (I was a bit concerned about damaging any electronics on the MAHO using a rotary converter.)

I will look into the PhasePerfect electronic phase converter.

[FDavies]

2-axis rotary table!!!

This one needs at least one picture!

Hmm, youre thread just reminded me about "my own" MH500C I am supposed to get installed...any day...soon...

One picture of the 2-axis rotary table coming up as requested!

[FDavies]

You need to review parameters. When you find the battery that may be maintaining the memory, do not disconnect it. I put the same voltage in parelel before removing the battery. Some times you can retain the memory.

Thank you.

So far I have not seen anything which looks like a battery, but I am sure you are correct and will post it's location and picture when either; I find it, or locate the place where it should go.

What type of information will be retained? I am not interested in the programs of the previous owner, but would hate to loose information relating to general setup or calibration etc.

What 'parameters' are important to note and were are they found?

Gauges currently read 'zero' and there are a number of switches which I will try to address here along with photographs to help any who follow this thread.

[FDavies]

On Maho's that we have retrofitted, the terminals were L!, L2, L3, N, PE; but nothing was connected to the N terminal. (it was expected that the N and PE [earth ground] were connected together at the transformer).

Yes, I see this labeling on the machine connected side of the terminal block.

Further inspection led me to note that the '35' labeled portion may have been due to the label itself having migrated from somewhere else in the machine, and just by chance having landed in the proper Murphy's Law Place, i.e. aligned correctly with and directly over a label area of the same size.

I see nothing in the transformer cabinet (not shown) area looking like an uncoupled or empty terminal, so I am assuming this is the correct terminal block, at which power is introduced to the machine. Nearby, there are two circular cut-outs in the floor of the electrical cabinet where I assume the electrical power cabling entered the machine.

Thank you!

[FDavies]

Looks like the diagram that came with my MAHO is for another machine.

Does anyone have a source for the electrical circuit diagram for a MAHO MH600C w/2-axis rotary table?

...MAHO said they couldn't locate one.

[machill]

Have you found a CNC Rotory Phase converter yet.
If not I have one.

Mac

[FDavies]

I'm interested.
Tell me more? (brand? rating?)
Include a photo?

I'm in Olympia WA

Thanks!

[machill]

It's a Roto Phase 10KVA unit. 230 VAC single phase input and 230 VAC 3 Phase output. Model CNC 10. Built by ARCO Electric.

Mac

[FDavies]

It's a Roto Phase 10KVA unit. 230 VAC single phase input and 230 VAC 3 Phase output. Model CNC 10. Built by ARCO Electric.

Mac

Hi Mac,

Yes, I checked ARCO electric and it certainly looks like the critter I need.
I'm in Olympia WA (zip is 98501) if you want to check on shipping and get back to me with a dollar figure.

Thanks in advance,

Frank

[machill]

I'll check the shipping and advise shortly.

mac

[toolnuts]

Hello again,

Fixing up an old CNC machine can be a challenge

I have a 1982 lagunamatic that I have been working on for many years.

On old machines the electrolytic capacitors (caps) go bad because their dielectric dries out and no longer functions well.

I just finished replacing many of the caps. Many of the old caps are no
longer available, and in some cases the vendors can't get you any data on them. Lost in the mists of time.

Another problem area is the old CRTs, they were proprietary, and may
not be replaceable.

The problem with rotary converters is they do no produce true 3 phase.
Another problem is they are usually optimized for a particular load and if you plan on running different loads the voltage/current imbalance between legs can get very bad, and can be potentially harmful to your equipment. There are ways to help this problem with rotary converters, by switching in different caps for different loads.

Paul

[FDavies]

Hello again,

Fixing up an old CNC machine can be a challenge

I have a 1982 Lagunamatic that I have been working on for many years.

On old machines the electrolytic capacitors (caps) go bad because their dielectric dries out and no longer functions well.

I just finished replacing many of the caps. Many of the old caps are no
longer available, and in some cases the vendors can't get you any data on them. Lost in the mists of time.

Another problem area is the old CRTs, they were proprietary, and may
not be replaceable.

The problem with rotary converters is they do not produce true 3 phase.
Another problem is they are usually optimized for a particular load and if you plan on running different loads the voltage/current imbalance between legs can get very bad, and can be potentially harmful to your equipment. There are ways to help this problem with rotary converters, by switching in different caps for different loads.

Paul

Thanks Paul,

Luckily this machine was not sitting idle in a warehouse but was pulled out of production to make room for a much larger machine. The company owner told me that it was in working order, but was then informed by a worker that there was a minor problem, ...yes, he stated it was possibly a capacitor.

My current problem is finding an electrical circuit diagram. The one included turned out to be for another machine.

The circuit diagram should be number:
E 6732
...according to the plate on the electrical cabinet door.

I'm considering a rotary phase converter because of the price. MAHO said 10KVA would be just OK.

Once the phase converter is in place, I will document all current settings and
connections (photographically), check all fluid levels (including the Nitrogen), double check the manual and attempt to turn it on.

I'm sure that diagnostics and troubleshooting will follow.

I'm having fun right now cleaning every last inch and familiarizing myself with its systems and parts in the process. I've decided to paint the 2-axis rotary table bright yellow (using Rustolium's "HardHat" paint.)

A minor problem regarding the physical placement:
The roll-up door at my shop must be open in order to swing the control consul out away from the doors into a usable position. My choices for a solution seem to be three fold: Move the machine off it's 4x4 wooden footings and onto the cement floor and then further into the shop by a couple of feet, or convert the consul swing arm into a pedestal, ...or add an awning.

Any ideas on how to lift such a machine with very very little clearance between the jack and the machine? Looks like the jack may be only a couple of inches tall to fit below the lifting points. Is it safe to lift from the frame? I plan to drop it on some solid steel round-stock and roll it a few inches at a time.

Thanks again, and give me the specs on any capacitors you are having trouble finding. A close friend has a huge bone-yard of electronics and just might have what you need.

[toolnuts]

I have been doing the lifting and moving for 30 years, and one of the very simplest ways is to use a long pry bar and pipe rollers. It is a slow process (for very large machines) and you may need an assistant to help reposition the pipe rollers.

I live in Snohomish ,WA so it would be a long drive for me to come and help.

Without the correct schematic it would be very hard to keep your machine going, long term. You don't need a schematic to replace the electrolytic caps however. Did the fellow tell you what aspect was not working? A good bet, if he didn't, would be the power supply. The electrolytic caps will be the ones with the +- signs on them and on the PCB (if you are lucky). If the PCB is not marked with the polarity then you must make sure you replace them with the same orientation. Otherwise - Boom!

A bone yard full of old electrolytic caps is useless. Electrolytic caps don't die from use but from old age.

Before you get going to far you will need to put your machine on some good steal plates and precision level (.0001/ft) it. If you have the standard concrete floor (no re-bar or pig wire) you will need to use some rather large steal plates. I just put a Brother TC-22 (or is it 122) VMC (5,000lbs) on 18" x 18" x 1" plates and still am having some trouble keeping it level. My shop is new so some movement is to be expected. If your shop floor has been sitting for many years it may not have as much trouble.

If you want to talk off line you could send me an email [email protected], and we could swap phone numbers.

Paul

[FDavies]

I have been doing the lifting and moving for 30 years, and one of the very simplest ways is to use a long pry bar and pipe rollers. It is a slow process (for very large machines) and you may need an assistant to help reposition the pipe rollers.

I live in Snohomish ,WA so it would be a long drive for me to come and help.

Without the correct schematic it would be very hard to keep your machine going, long term. You don't need a schematic to replace the electrolytic caps however. Did the fellow tell you what aspect was not working? A good bet, if he didn't, would be the power supply. The electrolytic caps will be the ones with the +- signs on them and on the PCB (if you are lucky). If the PCB is not marked with the polarity then you must make sure you replace them with the same orientation. Otherwise - Boom!

A bone yard full of old electrolytic caps is useless. Electrolytic caps don't die from use but from old age.

Before you get going to far you will need to put your machine on some good steal plates and precision level (.0001/ft) it. If you have the standard concrete floor (no re-bar or pig wire) you will need to use some rather large steal plates. I just put a Brother TC-22 (or is it 122) VMC (5,000lbs) on 18" x 18" x 1" plates and still am having some trouble keeping it level. My shop is new so some movement is to be expected. If your shop floor has been sitting for many years it may not have as much trouble.

If you want to talk off line you could send me an email [email protected], and we could swap phone numbers.

Paul

Thanks Paul,

I like the idea of communicating online via this forum, as someone else might find the same information helpful. My number is 360 352 0242 and my email
is frankjdavies at gmail dot com if you want to reach me that way anyway.

The moving and leveling information is great stuff. Someone else had suggested using 4 automotive type floor jacks on wheels, but that sounded a bit 'out of control' to me. I'm sure the floor is not level and I could imagine the machine deciding to go where it pleased, ...downhill: and the only place where a floor jack would fit is on the frame work around the machine, not on the actual casting.

Getting a schematic is paramount to maintaining it. I do have the parts manual but that's not enough to help in troubleshooting something as complex as this.
...I'm working on this now.

The 'bad cap' was just a guess on the part of the worker responsible for the machine, so it will be up to me to figure out what really might be wrong. I won't know the symptoms until I put power to it and try to fire it up.

That's good info on the caps. Luckily, we can test anything from the bone yard and not everything is ancient.

Thanks again, more coming soon.

Frank

[FDavies]

This MAHO has a 2-axis rotary table.

As you can see, it is attached where the table would normally be, and so the entire 2-axis rotary table moves left to right (X-axis) and up and down (Y-axis.)

The larger portion of this rotary table is about 18 inches in diameter, and the smaller rotary table with the mounting surface is a little bigger that a foot in diameter.

In the photo is a three-jaw chuck mounted to a plate, in turn mounted to the rotary table.

I've given it a quick rattle can job using Rustolium Hardhat paint, in Safety Yellow, as it is moving part.