Retrofitting a 1986 Maho MH400E

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21 Nov 2019 08:41 #150812 by akb1212
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
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21 Nov 2019 10:27 #150822 by chris mcm
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

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21 Nov 2019 10:52 #150824 by chris mcm
Anders wrote.
¨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 I need to get Brad to help me understand this paragraph.

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21 Nov 2019 14:36 #150827 by J Green
Hi Chris
I think Anders(akb1212) has a MH600E or MH600E2 with tool changer , wish he would go into more description on how it is working.
To my thinking relays are for small current loads and contactors are for higher current loads ,such as motors. It comes down to the amp capacity of the electrical contacts which arer making or breaking the electrical circuit . Motors have locked rotor currents , light bulbs have inrush current and transformers also have inrush currents . I just picked up some used contactors and relays for spares. Still think your 24 volt buss is too high in voltage.
As to the Indramat drive and the DC servo motors, think replacing the capacitors has merit and also picking up several SCR modules plus carbon brushes for the motors.and their feed back tachometer. Maybe even track down spare servo motors. The vertical axis servo motor should be different than the X an Y servo motors. I felt that good used motors were cheaper than having a motor rewound or new design servo drive an motor . Even picked up a dead motor for it's tachometer . Yes I do wear a belt and suspenders! And I would much rather tinker with a boat than sail a boat. But my impression of "Wind in The Willows" should not be your problem.
Your Ship Engineer friends account of electronics is interesting .Back when Northern Ohio rivers would catch on fire. I remember when a Cleveland Cliffs Ore Boat ,having a new Foxbouro engine room computer control, steamed into a dock and tried to steam on down the street a ways. The Westinghouse Hagan Controls division R&D dept. was interesting. Remember a coal fired power plant where the steam turbine-generator rolled into the plant parking lot. Plant Superintendent missed his golf outing ,which could have been due to paper work he just incurred or maybe because the generator had just crushed his truck and destroyed it's designated parking spot sign. Then there was the Arkansas Nuclear 1 tripping off line which forced #2 unit to trip out ,so I was informed ,incident.
As to converting your MAHO
Linux CNC would enable you do threading of any pitch or thread form you wanted without a tap or die ,even pipe threads. There is going to be a lot of plumbing involved in hooking that steam engine to it's boiler. To me pipe nipples are only sold as too long or too short. Looks at Marks video on threading. For gear making look at the Mueller Nick-You Tube and his MH700C video. Don't understand why Nick can't remember how to ride a bike. To me Linux CNC means all those things that were near impossible are now easy. Even making patterns for casting patterns , type in the shrink factor for flavour of metal and go. Look at the video of Andy P. making his lathe patterns . It's your time- money- opportunity cost , just keep flipping that coin until the side you want comes up.
Think spring
Bob
P.S. Might consider having a total of 4 Heidenhain EXE D/5-F (belt and suspenders)

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21 Nov 2019 15:52 - 21 Nov 2019 15:57 #150840 by akb1212
Yes, I do have a 1990 MH600E with tool changer.
Mine fortunately also is a bit newer than the ones you are discussing here, with propper AC servos (Indramat). And also a good fully controlled (speed controlled Inverter) AC induction motor spindle with only 2 gears (so no complicated gearbox to interface).
The difference from only a few years back is huge! Mine also has full encllosure and is a more modern machine.
I have a thread on it over at Practical Machinist forum, with lots (!!!!) of details, although it's a long time since I have worked on it (years......). It's the quite long "fix your maho" thread in the CNC Maho section.

I have taken up the project now, and hopefully I will be able to get it to work soon!

The ATC and programming that have been part of what kept me from finishing it. At the time I put it on hold it was to big of a challenge to make that work. I would have had to make my own logic for it in ladder, somthing I didn't fancy. But now we have carousel.comp and the possibility to do it all in g-code with remap. So now I believe I will be able to get that done. I will post updates when I get some progress. First I have to install a new version and get it to move with the new versions of configs.
Anders
Last edit: 21 Nov 2019 15:57 by akb1212. Reason: Spelling

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21 Nov 2019 16:49 #150848 by J Green
Anders
Thanks for the update.
I wonder if your MAHO is designated MH600E2 or just MH600E without the #2 ? Also will your tool changer change tools in both the horizontal and also the vertical spindle ?
Wonder if you have considered posting the configs for others to use ?
Interested in what is the new version you intend to install .
Bet you are enjoying the snow
Bob

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21 Nov 2019 17:45 #150851 by BradMck
Hi All,

Regarding ChrisMcM Maho MH 700C, the LS807 are connected directly to the TNC135 via a plug and socket located in the cable way of the machine.

I powered the machine and pressed the CE button twice and no changes to the display. We powered up the machine while pressing the CE button (Chris found this note somewhere on this site) and got some action on the display. . We cycled the power (left off for approx 30seconds) to the machine and let it complete the start-up without any buttons pressed to see the result and got no information on the Display We cycled the power again with the CE button pressed and got the following message We left the machine at this state for 30 minutes to see if the display would keep displaying the information this time there was no information. We managed to get the TNC to get stuck in a cycle photos.app.goo.gl/V4HRLgBcpmt2kFx49.Cycled the power again and got an image for a short period and then it faded away

Regarding Bob's reference to boilers, my background is boiler Automation nothing too big (up to 25MW).

Brad
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21 Nov 2019 19:50 #150855 by J Green
Brad
I think db1981 is the most knowledgeable as he has a TNC 135.
To me with the change over that time frame ,I would be checking the DC voltage buss of the several different supplies during the 30 minutes. Think I would leave the Heidenhan scales disconnected until the TNC 135 is in a more usable condition. The scales read heads do not need over voltage, also will show if a read head is causing the problem. Can you somehow have the TNC 135 opened up such you can lick a finger and probe for overheated IC , regulating transistor ,Tantalum capacitor (orange drop appearance) ? A finger is great for quick heat compare an contrast checking. Hope it is just a tantalum cap .transitioning into a high leakage state.

25MW boilers Guess you arn't referring to Mill Watt ! Walking around with a long handled broom checking for leaks is something I only want to hear about ,not do.
Bob
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21 Nov 2019 22:32 #150864 by akb1212
Bob,

My Maho is not given the name E2, but I know why you ask, and it IS built like the E2's. The difference is that they had by then discontinued the E version, and dropped the 2 in the name as this was no longer an option but standard on all machines. As I mentioned, the vintage of a machine like this is as important as the model, or even more important. Because the differences are so huge between them! Mine also had the 432/10 with the last verison of the software. And an Intel 80386 CPU on it!
To those who doesn't know what we are talking about here: The E2 is an upgraded spindle motor and with a fully controlled VFD drive capable of direct speed control. The drive even have C-axis capabilities (it can be used in a lathe spindle for full C-axis, with position control), and can therefore do rigid tapping. It can also rotate and align the spindle to preppare for a tool change (M19).
This is easily identified by the shape of the spindle motor. If it has rounded edges, like a normal induction motor has, with a fan attached to the axis of the motor, it is an old style. This doesn't have electronic speed control, and needs a lot of gears to be able to change speeds. These motors also was normally the same green (or gray) color as the body of the mill. While the new VFD spindle motors have a separate fan and is black and looks like a big servo motor. And is capable of full speed and position control. It has a very simple 2 speed gear box, to give it high torque at low speeds (50 RPM at the lowest) and a top speed of 5000 RPM. There is a 1024 pulse encoder on the spindle shaft for position control, which is feed to the spindle drive. The drive have an ecoder output that I now have hooked to the 7i77 (for rigid tapping).
I had to fix this drive as the first thing I did when I got the mill. It had experienced exploding electrolytic capacitors that took other components with it (and burned traces on the PCB). And thanks to information I got in the large thread over at PM I was able to fix it. It was also a good thing it was in one of the phase drivers, with many similar sections, with only one of them blown. So I could use the others as referance when fixing it. I have since also had an axis drive blow electrolytic caps. So at that point I changed all caps in all the rest of the drives and power supply. At least the ones that was likely to fail, as they were in the power and switching parts that is what is wearing them out.

My toolchanger will only change tools in the vertical head. I'd have to say thankfully. Because the ones that changes in both spindles are way more complicated, and will be a huge job to retrofit with LinuCNC. The one I have now is way complicated enough for me!

I will definately post configs when I get something to post (so nothing yet!). I know why you ask, and find myself very frustrated by others who isn't posting their configs. Sometimes even after promising to do so, only to forget about it as soon as they get their machines working and no longer frequent this forum. It's understandable you'd want to go out to make chips instead of reading forums. But it is one of the downsides of how thigs work around here.
So..... I can promise I will not forget to post my config files.

BTW; it will be kind of advanced. I have mounted extra encoders on my servos, to use dual encoders for increased speed and accuracy (I have tested it on one axis at one point, and it works).
My Y-axis have a lot of stick-slip as well, so I will need to do something to that. I have started to work on hydraulic pistons under the table for weight relief. But I suspect I have to remove the carriage and do some scraping on the box ways of it too......
But for now I will work to get the ATC to work. It has been kind of a nemesis for meg with this mill. And now that I have found enough other configs to give me a clue on how to proceed I hope to get this milestone done in the near future.
I did find a very similar ATC being controlled by LiunxCNC. And was also able to find the configs..... posted in a Hungarian forum I think it was. To my disappointment it was unreadable to me as all comments was in..... hungarian.... and google translate doesn't work at all with this. I know there are others here reading that in this forum. So they might be able to help. But I have found out how to do it now anyway. So I just have to put in the effort to make it happen.

When I talk about new config I mean the change from 2.7.xx to 2.8.xx (or 2.9 i my case). I understand there are changes there, and my old setup from way back is 2.7.7 of something. In particular with Mesa cards.
So I'm kind of starting from scratch (as I'm unable to find the HD with the last known working LinuxCNC installation on it......crap!).
And I do want the reverse feed and other features in the new version. So this time I intend to set it up with 2.9 (I'd like to make an EDM wire cutter with LinuxCNC at some point, possibly as a unit to set on the table of my Maho, so I need that feature for that).

And NO, I'm not enjoying the snow. I hate it! Thank god it's gone again for now. But I hate it and hope it waits a long time to come back...... My daugter likes it though....

Anders

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22 Nov 2019 04:32 #150880 by J Green
Anders
Thanks for the update about your machine. I am glad you are still at least working on it. Seems as if some conversions just stop before completion.
Interesting your using two encoders per servo motor. Are you using their signal as feedback to Linux CNC along with the Heidenhain LS403 scales ? Just wondering how you are using the extra feed back loop. My guess would be scales for position loop with extra encoders tied some how into the velocity loop of Linux CNC.

Thanks for the comment about snow ,but I wonder if you are not just trying to make me feel better. Think we could con Chris into room an board plus suntan lotion.
Stay warm
Bob
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