Deckel Maho DMC 63V Z axis intermittent drop.................need help

[deckeldoctor]

There is a very slight delay from when you press the control on button the brake for the z axis that holds it from falling until the electronics come on and the servos turn on to hold the Z axis up until complete power up.

This could be one of the green PILZ safety relays.

I do not have circuit prints at the moment to give you a place to start.

But I would look at that circuitry for the Z axis brake.

Regards

DD

[uli12us]

Your Pic seems not to be from any Siemens D control. But I think, if you make a small adjustable hesitation switch in the wire for the break, it will prevent the Z-axis falling down, before the Z-Axis motor get current. If this don't work, you can always build a mechanical solution for this problem, In another machine I have 2 Hydrocylinders with a pressure reservoir that makes so much pressure from bottom, that the Millinghead holds his position, if the motor runs or not. You can this realise with air, but need 15 times the area.

[kevork_gr]

Your Pic seems not to be from any Siemens D control. But I think, if you make a small adjustable hesitation switch in the wire for the break, it will prevent the Z-axis falling down, before the Z-Axis motor get current. If this don't work, you can always build a mechanical solution for this problem, In another machine I have 2 Hydrocylinders with a pressure reservoir that makes so much pressure from bottom, that the Millinghead holds his position, if the motor runs or not. You can this realise with air, but need 15 times the area.

The picture is not from my machine, I just found it online to point out the button I was talking about. Also, both for deckeldoctor and Uli, I am not looking to resolve only the drop problem, as I have also said before, the problem comes with an emergency stop, which means the machine has to be "re-loaded" with power to continue working, and I don't know which comes first, the axis drop or the release of power/air.
@deckeldoctor: I attach you a picture from my machine this time, to show the switches/relays we have changed(you can see the old ones on the bottom), noted within the red square. I think you are talking about one of these relays.

[deckeldoctor]

Kevork

Yes those are the relays I was referring to.

On some relays they have a rotary dial on the front these are timers, the third relay and the 5th relay from the left have these dials.

Make sure they are set the same as the old relays at least and maybe increase the time a little.

When you have problems like you are having on power up of the machine, the machine cannot process all the error, problems because there are so many.

The only way to clear all the errors is to reboot the computer, ie turn off the machine wait 1 minute and turn the machine power back on.

The sounds you are hearing could be the lube system turning on, every time you turn the power on one of the things that happen is the lube pump turn on 3-5 seconds.

You may also hear hydraulics turn on and pump up till normal pressure is reached.

This error bothers me

The message that is displayed is "Emergency Stop" & "Emergency recovery module not operative".

recovery module missing.

This sounds like part of the parameters or PLC is missing.

Have you had to reload parameters lately?

Regards
DD

[kevork_gr]

Kevork

Yes those are the relays I was referring to.

On some relays they have a rotary dial on the front these are timers, the third relay and the 5th relay from the left have these dials.

Make sure they are set the same as the old relays at least and maybe increase the time a little.

When you have problems like you are having on power up of the machine, the machine cannot process all the error, problems because there are so many.

The only way to clear all the errors is to reboot the computer, ie turn off the machine wait 1 minute and turn the machine power back on.

The sounds you are hearing could be the lube system turning on, every time you turn the power on one of the things that happen is the lube pump turn on 3-5 seconds.

You may also hear hydraulics turn on and pump up till normal pressure is reached.

This error bothers me recovery module missing.

This sounds like part of the parameters or PLC is missing.

Have you had to reload parameters lately?

Regards
DD

We have tested the different rotary dials settings, now it's on selection 6.
I don't know if the service guys have reloaded the default parameters lately, I will ask this.
As far as the which problem comes first, we discussed it and we believe that the emergency stop etc. problem occurs first, which in turn produces the z axis drop problem sometimes. Are the emergency brakes for the z axis operated with air assistance?

Thanks for the fast reply,

Kevork

[uli12us]

The Pilz relays are always a favoured source of joy, it they don't work. I had one defecive that cost me 1 day to find out which is the bad guy and substitute it temporarily with a handful of other relays. After that I used to buy a replacement part for each relay.

[kevork_gr]

We have been more than a year with this problem, although we can do work between the errors, sometimes the machine works sometimes not. Last resort of course is to isolate both safety mechanisms on the door, as we have noticed that the problem is connected with the door opening/closing and the axis disabling/enabling.

To resume again, we have done these actions:
-Replaced all motor drives, prolem continued, put the old ones back,
-Replaced all Pilz switches,
-Replaced both door safety switches(the small roller on the back end and the safety clamp on the front end), with the roller safety switch we also replaced the cable.
-Cleaned the Emergency stop button contacts, as they were not delivering stable amount of current.
-Replaced the third PLC card, coded: 6ES7-322-1BH01-0AA0
-Replaced a varistor for the z axis motor, coded: MT-VAR/2E60AC

We are now in the process of waiting for a cable to connect with the machine and watch the signals real-time on a computer, instead of video recording the PLC LED signals, and
We wait for a new Z axis servomotor, to be replaced without charge by DMG, as they have acknowledged that some faulty servos were out there with this type of machines, so they offer a free replacement.

Deckel doctor or anyone else with some fresh insight on the subject, please give us any info!

[deckeldoctor]

Hello Kevork,

Sorry to hear you are still having problems.
Can you scan in your electrical prints and email them to me, here drs9293@gmail ?
By you scanning your prints I will have the exact drawings for your machine,I only need electrical prints.

Regards
DD

[deckeldoctor]

regards
DD

[kevork_gr]

Dead deckeldoctor,

All the electrical prints of the machine are too many pages for me to scan, maybe you want a specific part of the prints?
If not, I will try to digitize them through pictures.

Best regards.

[uli12us]

You need only the pages with the Pilz parts and the E/R Modul on it. I have the Nr 209:E/R, 215:Pnozv, 216:Pze5v, 219:PST3.
Maybe one or two more, but I don't have my circuit folder here, right now.

[kevork_gr]

I found the E/R module, and took some more pics from the next pages, on any page I could find written notes
from various technicians that have tried to locate the problem source.
You can find the rar file here: Download DMC63V electic diagrams rar

Waiting for your replies, uli12us and deckeldoctor both.
Thanks in advance.

[DCM]

Hi Guys,
I am facing the same problem as Kevork since last week. The Z axis drops whenever we open the Door or when enabling/disabling the axis using hand wheel. There is no change on the controller when this drop occurs and the Z axis axis goes back to its original position with a jerk and big sound when we close the door or operate the hand wheel. I called Fanuc India as well as DMG office. They both suggested that the problem is mechanical and to check the belt , ball screw coupling etc. I have have know bypassed the door lock and machine seems to be working fine. But I am afraid whether it can drop suddenly while in operation and cause damage. Fanuc engineer is expected to visit us in couple of days time. I suspect there is some problem with the relay or servo motor brakes . Plz help guys.......

[kevork_gr]

Dear Uli12us, please enable the option to recieve private messages, I can't send one.

I have noticed something that hadn't before. Every time before the problem occurs, on manual mode(the key turned on the left side, see attached pics)), just after I close the door and locks, the following information appears on the top of the screen, with black letter, not red: 700344 BA2/3/4 Open door to working area.
On the past I thought this was an information that remained from the previous state of the door beeing open.
But now I realized that this message comes up only after I close the door, so maybe it shouldn't be there.

I really don't know where I could find the alarms beyond 122000 that are included in the Diagnostics Guide.
There is a note about the alarms ranging 400 000 - 810 009 and are labeled PLC alarms/messages. The 700 000 - 799 999 is labeled "User Area".
It reads: "The PLC alarms of range 500 000 - 899 999 are configured and described by the machine manufacturer."
I don't know what this may mean, should I contact my machine seller and ask him a guide?

Thank you all very much,

Kev

[uli12us]

Strange, I have switched on PM since I first came to this blog and don't changed it ever. Have you received my PM from yesterday?. Since you have a younger machine with a (not really) different control, you have some different circuit plots. But I think, the changes can easily tried and if it don't works you can bring it back to the original wiring.

[kevork_gr]

I got your message, but I still can't send you a PM. Anyway, I reply from here.

Thank you very much for the reply and diagrams.
I notice though that the drawings you sent me refer to a different machine(maybe with the 840D Sinumerik?). I tried to compare the drawing you sent me with the ones I have and they don't match. For example, take page 219 on your drawings, they kinda match mine at page 220. I can see the same relays and Pilz's, but the architecure is different. So that makes me think I shouldn't try changing something that may do something else on my machine than it did on yours. Also, I don't have the machine on stand by, it is loaded with work to do, so I can't make any unsure steps..
What do these changes do to the machine? Bypass any safety?

[uli12us]

The main changes are only in the wiring from the Euchner safetydoorswitch on the bottom of the case. What, if you try to change only the connectons from that switch. You unclamp the wire from clamp A8 and connect the same wire to clamp B2. After that you must cut the double connection from clamp 13 of A180 and clamp 61 of relay K185. After that you reconnect the wire to clamp14 of A180.

I Think these changes are easy to do and if the don't work, you can bring the machine back to the original wiring.

[kevork_gr]

I asked one of the technicians that we are seeing to get some help and they prefered not to change the original wiring of the machine, rather find the cause of the problem and fix it.
Since my last post we had the z axis motor changed by DMG technician, without any luck, as we had a couple of z axis drops just after the motor change.
After that though, the drops are almost none for about 2-3 months.
I am suspecting that there may be a connection with the weather change, we will check this out soon when it will get colder.

[kevork_gr]

Since my last post, the machine has begun to drop and E-STOP much more frequently.
Seems like the weather may play some part in all this after all.

[uli12us]

Have you tried to make the changes from the wiring diagrams? Mainly the doorswitch, Safety relays and the E/R/modul.