[torinwalker]

I am getting a DRIVE AXIS FAULT every time I command the X-axis to move.

The motor doesn't actually move - not even a tiny bit. I can feel no movement.

I replaced the motor. After replacing it, I still got the axis fault message twice, but then it seemed to improve - now only failing with contouring and clamping errors which can be recoverable by hitting reset.

I poked around in the back of the X-axis, found a broken wire and fixed it. Now I'm back to DRIVE AXIS FAULT.

What would make the difference between a drive axis fault, and the lesser contouring/clamping failure, which at least indicates a willingness to command the motor?

So far, I've verified the following:

• The motor is good - I can jog it back and forth with a DC power supply.
• The tach is verified - 20V per 1000rpm.
• I found a single broken wire on the terminal block I hadn't noticed before and reconnected it.

I'm stuck. I could use some help, please.


Torin...

[mike^3]

I think your drive it shot, do this, swap the drive from x axis to z axis, does the error say z axis drive fault now? and will the x axis work as if it were z? if so, one of your axis drives are probably bad.

May I ask you, do you know of anyone that has some extra parts for a chnc? I need 2 things so far:

1. I need the stop dog air solenoid actuator block (a solenoid with and machined aluminum block that fires the stop dog.) Its located in the first compartment facing the operator on the cross slide.
2. The big rear cover for the cross slide its about 12" by 18" and aluminum.

Any help would be appreciated and rewarded!

Mike

[torinwalker]

Mike,

First off, I've been putting in 80 hour weeks for the past three weeks and haven't had time to truly focus on this. I suspect, because of what I just discovered, that if I had a full frickin' day to work on this, I'd probably figure it out.

So to answer your question, yes and no. I am reluctant to do anything to my Z-axis for fear that I will break it too. If my Z-axis works, I'm not touching it. I am also fearful that swapping the X into Z will fry my Z motor. Not good! So, no... I'm not swapping.

I did however purchase a replacement drive H-bridge board off of ebay - the one with the transistors and heatsinks, not the control board that takes the +/-10V analog in from the control. I swapped the amp out yesterday.

I have an ammeter in the path for my motor, trying to catch a glimpse of current as I command the X to move. Normally I normally see a small current, about 10mA, flowing through the motor. I figured it was a minute control current keeping the motor in one position. Occasionally, it will rise to as much as 150mA. But, it could also represent a problem.

When I swapped the amp, this tiny current disappeared, but it still failed with a drive fault. Figuring I bought a bad board, I put the old amp back in and gave it another try. While reinstalling the old amp, my attention was drawn to these two "semi-conductor fuses" that have had me curious for a while. I put my meter (continuity) across the X-drive fuse, and I get some weird reading instead of the usual 0 reading and a beep. I confirm by shorting the probes together - yep 0-beep. I try the Z-axis fuse - I get 0 and a beep! So, now I'm thinking the fuse broke and that's why the drive is faulting.

To eliminate the circuit interfering with the reading, I yank both fuses. Sure enough, Z conducts, and X is open.

So now I try Z's fuse with my original amp. Guess what - it popped the fuse. Now I have two dead fuses (ugh) and a much greater suspicion that the X amplifier is bad. This might also explain why I'm getting leakage to the motor with the original amp, and nothing with the new amp. Zero current when the motor isn't moving makes more sense. Good thing I didn't try this on my z motor by swapping the boards.

So, I'll go pick up two more of these "semi-conductor fuses", and I will try it out with the replacement amp.

Yes, it's a convoluted path to diagnose, but that's what happens when one is distracted from the task. It's funny how in retrospect, I realize I should have checked ALL the fuses first.

My greatest fear right at this moment is knowing I attached a new motor to a bad amp. I remember the last time when I turned on the lathe and hit reset to hear it sing (that sweet high-pitched whine that tells me the lathe is in ready); I was sitting there for several minutes, scratching my head, when I noticed thin wisps of smoke coming from the motor. I hope my careful attention to the ammeter and removing the drive quickly has protected the motor.

That's the constant threat now - frying my new motor. And the short story long, of why I don't just swap boards.


BTW, regarding your blanket request; you must first opine on my diagnoses above, then you get to drool over this.


Torin...
--
www.walker-tech.com

[mike^3]

You have what I NEED! I would buy that whole box from ya. That Mac valve ??? in the middle of the box, thats one of my missing parts .

So what can I help you with?

Basically if your amp board is throwing a fuse its because your drawing to much current, obviously. So this is what you can do....Disconnect the x motor power leads from the cross slide. Open the back middle machine cover. Take off the large x axis cross slid cover (this is the same cover that I am missing ;D) underneath you will the motor pulleys and belt. You will also see a terminal bar with 2 leads going to the motor and two that go back to the machine drives, disconnect the motor wires, do not disconnect the ground though. Turn on your machine, do not move the x axis, even a fraction or you will alarm your machine.

Re-install a new fuse for the x axis.

Does it still alarm?

If no alarm...

Now check the voltage on the terminal where the motor was connected, you should have very low voltage. (the control is not telling the x axis to do anything so you should have close to 0).

Next, while someone is reading the volt meter, command an x axis movement jog, what voltage do you get, if any?

Note: if the power wires were grounded to the chassis it will blow the drive fuse.

I noticed when I stipped my CHNC for retrofit, the x axis wires were pinched in the cable track.

Let me know

Hopefully my help can warrant a sale on some of your parts?

I will help you as much as I can.

Mike ;D

[torinwalker]

Mike,

I may have been editing my post while you were responding to it. (re-read to make sure) I have been under the X-cover which is how I plugged my ammeter into the motor circuit.

In fact, I have full schematics, manuals, etc. I think I'm just blocked by my lack of familiarity with these Siemens components.

Just now, I put the Z fuse into the X motor fuse position, commanded the motor to move, and now that fuse is blown. It's gotta be the amp.

I have been doing everything you suggest in your response - I have the voltmeter in the motor circuit and I watch it when I attempt to command the motor. And yes, if I turn the ballscrew even a little, it errors out with a clamping error. But now it seems that all this time, I've been trying to fix something while the fuse is blown. Now I must replace the fuses (I'll buy a few extra just in case), replace the drive, and see how far I get.

My current suspicion is that the drive amp is faulty and is sending a small current to the motor which, if I let it, will burn out this motor too... if it hasn't done so already.

When you say it should be close to zero, what reading do you get when your motor is at a standstill? With the original amp, I get 0.010 A. When the machine is brought online with the reset right after powering on, it rises to 0.100A, sometimes as much as 0.150A, then subsides. I'm not positive, but I remember seeing 0 current from the replacement amp.

I'm sure we can come to some arrangement - I need my lathe to be up and running again, which may involve parts, or just some friendly help. If your help leads me to get this lathe up and running again, the mac valve/block is yours.

When I get the fuses, and some more time (hopefully soon), I will let you know.


Torin...

[mike^3]

My last post didnt get posted....Er...

So if you are getting random errors, and fuses blowing. I would suspect the motor brushes, have you attempted to swap motors?

If you have the same motors as I do, then you are running DC motors with 2 commutator brushes on the back, you may be able to pull these out without removing the motor, depending on your set up. THE ONLY WAY one of these drives blows a fuse is if it pulls to much current...

That being said, if you pull the brushes out and you see a ton of graphite dust in the back, the graphite might be shorting it out. Take the motor off, but not apart (these are aligned with tight tolerances from the factory). I would attempt to clean off the commutator ring with some alcohol on some q-tips. Them blow it out with compressed air. Hook the motor back up, and see how she works.

You were saying it works ok for single axis movements but only when you move 2 axis at once during radial cutting or angle movements it faults? Moving 2 axis at once tends to pull more juice from the capacitor on the bottom and if the capacitor is going bad you won't have the storage power to move 2 axis together, it will then draw more power and possibly faulting the drives.

If all else fails I will put you in contact with a good friend he has been working on these for years.

Let me know,

Mike

[mike^3]

P.S. do you have a pic of your machine, is it the boxed machine or the kind of bubbled machine?

[mike^3]

Hey I just had a thought, do you have the upgraded black drive boxes?

[torinwalker]

Hey, Mike. Sorry for the delay. I thought I had posted a response, but it's not here. I must have forgotten to hit the post button.

My X-axis is moving again. Replaced the fuse, and my original amp popped it. Plugged in the replacement amp and another fuse, and the X-axis moved! YEAH!! After some back and forth, it errored out again with a DAU-limit reached message, which suggests now either I tightened the belt too much, or the ballscrew (or bearings) were damaged from the crash. I'm not out of the woods yet, but boy do I feel good.

On a side note, get this: I had this rather odd call last night... a guy called me in response to my "Need a motor" request. He told me how he just bought two new motors to replace the old ones and it cost him $180 for the pair (yes, $90 apiece!) So, I said, "Wow, I'd buy just one of those for $180. Hell, I'd pay $200! Then you'd have one for free!" He remarked how these things are like "gold" out in the used market. Yeah. He said he didn't know if he could let one go for that. I said I already bought one and am looking for a spare, and he asked me how much. I said $350. He responded, "I'd love to buy one of these motors for $350" (Huh?? He just bought two for half!)

So I get it. He wants more than he paid. I'm gathering more than $350 as well, but I couldn't seem to get the gist of where he was going. Did he keep repeating paying only $90 per motor because I was offering too much? So I offered $200 for both his old motors. Hell, I would have paid $200 for just one, bad bearings and all.

It was a weird discussion. Toward the end, he tells me he is thinking of rebuilding the motors and putting them up on ebay. I gave up. Either he wanted way more than he paid, like $500+ for his old broken motors, or he was undecided about selling them. I can't imagine why the guy called me, because he either had no idea what he wanted, or he wasn't interested in selling. Perhaps he didn't smell any blood in the water.

Anyway, people, if you're going to sell something, call with a price. Know what you want and be straight up with it.

Mike^3, I'm going to be straight with you - you want parts, I want parts. I want a spare motor (1HU5040-0AF02-Z), because this one is making a ticking sound - I fear the commutator bars may have fused again resulting from trying it with my old amp. (Won't make that mistake again.) I may also need an X-axis ball screw. I'll be investigating this weekend to see why my machine is still faulting. Could just be bearings - I hope it's bearings, and not the ballscrew. You want my parts? Let's figure out a trade. I'm sure you have a ton of stuff that may be of interest to me. I don't care about these parts, but I do care about fixing my machine. I know what I want, which is more than I can say for the guy with the confusing negotiation skills who called yesterday, and I won't dick around with the price.

Thanks for taking an interest, Mike. I really appreciate it.

You can email me directly through my website, below.


Torin...
--
www.walker-tech.com

[mike^3]

Seems you caught me a little late. I just sold 2 of those exact motors about a month ago.

So what wrong with it now? You can have those motors repaired at any shop that rewinds motors. I have my spindle motor rewound for my other machine, cost 350$ and it was a huge 3hp motor 3ph. They can do dc motors too.

Your limit error is because when you put the motor back on, you must have messed with the ballscrew, so now it thinks the machine is somewhere where it isnt.

Can you home the machine? Did you home the machine?

True I would like some parts from ya...but its more of a pleasure then necessity, as I can make that mac valve, but don't really want to spend the day doing it .

[torinwalker]

DAU-limit error is a maximum speed error reached. The remedy in the manual is to operate at lower speed, check pulse generator, check drive actuator (tachogenerator), and parameters MD268, 364, and 368 (none of which I am familiar with.)

I went back and forth with the X-axis some five or six times in each direction at top jogging speed. It wasn't complaining about being out of position until much later.

The local rewind shop wants $900. They'll rewind only the rotor for $600. I too have rewound much larger motors for less. Don't know why.


Torin...
--
www.walker-tech.com

[mike^3]

I might be going off on a tangent but did u mess with Any of the encoder wires? Or tach hall sensor on the encoder plate? That hall switch senses speed for the axis

[torinwalker]

I have been messing with a lot of things, but I have taken into account everything I've done - whether intentionally or accidentally - to root through to the core of the problem.

Basically, this is what I believed happened:
1. I had a crash. A bad one. Tried to face 3/4" of an inch of 2" diameter aluminum. It ripped the billet from the chuck and threw it against the back wall. Can't recall if the machine kept going...
2. I machined 10 new products, each about 5 minutes (two sides) that same day. Went away for a week.
3. Next weekend, fired up the machine, started the program, and on the first rapid move, I got a DAU-limit reached error.
4. Hit reset, tried again. Same thing.
5. Figured my brushes were shot - don't know why - but I opened up the brushes, took a look, they were fine. This is where I potentially introduced a problem.
6. Problem continued. The distance of the X grew shorter and shorted before the error.
7. Opened up the back to see if any wires were loose, disconnected. This is another place I potentially introduced a problem.
7. Ran a test program to make the X go back and forth. The distance of travel grew shorter and shorter before the error.
8. Went back to look at the brushes again.
9. AXIS DRIVE FAULT. This time, machine won't reset. Must completely remove power using rear disconnect to recover.
10. Translate 6RB2025 German manual to English. Determine, possibly, amplifier failure. Order a new amp off ebay.
11. Notice weird ticking sound now coming from motor.
12. Put the machine in ready mode... keep poking around. Eventually, notice smoke from the motor. Take out brushes, photograph commutator bars. Notice charred area on copper.
12. Measure current to motor - it's drawing 100mA constantly.
13. Take out motor. The whole rotor is fried. The encapsulant is bubbly and charred, and the commutator bars are welded together.
14. Buy motor. Get ripped off from Dock Guys who send me a broken motor. Piece the two motors together (used rotor, one bearing, and a small aluminum plate that affixes bearing to front flange (mine broke in half.) Install motor.
15. AXIS DRIVE FAULT again. This time, ammeter in path to motor. Never let it run for more than 5 ~ 10 seconds.
16. Try new amplifier. Same AXIS DRIVE FAULT, but no current to the motor at all. All LEDs on boards say same error as before.
17. Scratch head. Put hands in pocket. Look at sky.
18. Try old amp again. This time, getting new error Contouring + Clamping errors, but reset works. I think I'm on to something.
19. Sunday morning, I roll up my sleeps and prepare to venture forward now. Check tachometer. Producing correct voltage.
20. Check wires. I notice a little yellow wire disconnected (turret encoder) - I dislodged it during my diagnosis, but it gives me hope that this is resolvable. I make a pin removal tool and fix the wire.
19. Try again. AXIS DRIVE FAULT. (insert profanity here.)
19. On a whim, I gaze at the fuse below the drives. I had checked other fuses before, but not these. The X was open. Z closed. Could this have been it?
20. I plug Z fuse into X fuse path. Try again. AXIS DRIVE FAULT.
21. Did I short something?
22. Use temporary fuse block. new motor, old amp, be careful not to short anything. Fire up machine... It pops right on power-engagement. More swearing.
21. Next day, new amp, new fuse. Double check everything. Plug fuse into Z first, power up. No pop. Z moves. 4A fuse is enough.
22. Now move 4A fuse to X axis, double check again. Everything good? Power up. Fuse still good. Control on. Command X.
23. It moves.
24. Move axis back and forth several times... like Homer with the power window. X goes back. X goes forward. X goes back. X goes forward.
25. Then I get a DAU-limit reached. I reset and keep going. X goes back, X goes forward.
26. AXIS DRIVE FAULT. I think, possibly, maybe, I touched one of the Z-buttons. Without a fuse, this would explain, but I think I checked the error and saw 6011 (drive 1, not 2) so I think I popped a fuse. Nope (damnit.) My motor is going through the fricazee process like the first one. I power off, power back on, still no current at a standstill.
27. Fuse goes back in. Does it work? Yes! Perhaps I did touch the Z-button after all.

So there you have it. My theory goes like this - after the crash, perhaps the bearings were warm and fluid, but they somehow were damaged. After ten runs and a hot machine, no problems were noticed. But, after a week of sitting cold, the motors were harder to turn.

The control accelerates the carriage, but the motor cannot reach the speed expected by the control, and it complains it has put as much into the DAC as possible (the +/-10V velocity) to get the motor to speed, but the motor isn't reaching. So, it throws a DAU-limit reached. (DAU is German. DAC in english.)

So this is a lube problem, and was perhaps a lube problem before. What I can't piece together though is how (or if) my orginal AMP blew. It still could be that I've misdiagnosed the amp, and I just didn't give it the college try. Whatever. I'm going to leave the new amp because it gives me better (zero) rest-state current readings.

So I now suspect a dry ball screw, or a rough bearing. Certainly, the motor bearings were stiff. I should probably go and replace the bearings on the motor, even if only to rule them out. Perhaps take a bit of tension off the belt. Check the ball screw with the motor out to see if the ballscrew is screwed, or if it's the bearings. Only way to tell in my estimation is to turn the ballscrew with the allen key and feel for anomalies within one turn. If the anomalies feel the same during every rotation, it'll be bearing(s). If the roughness is aperiodic with the rotation, then I'll blame the ballscrew itself.

Saturday, I intend to rule out the ballscrew. The easiest way is to take off the motor and turn it. (I can't believe I didn't try that already). I'm really reluctant to take the ballscrew out. Work's been a ***** lately and if I get it that far apart, it could be weeks before I'm able to spend the proper time to order parts and put it back together.

I might just call someone from the local hardinge dealer and have them do it. Even though they don't support Siemens controls, the ballscrew work should still apply.

Overall, the Z-axis turns more easily with the allen key than the X does, and I don't get any weird roughness. A little, but if feels like belt cogging, not a ball running over galled metal. The motor is also making a ticking noise in one direction. Hope I didn't fry the new motor when I temporarily tried it on the old amp, which I'm fairly sure is faulty now.

To top things off, I just got an order for more product.


Torin...
--
www.walker-tech.com

[mike^3]

So is it up and running?

Would you still sell me a few of your extra parts as we discussed earlier?

Thanks,

Mike

[torinwalker]

Mike,

So as we discussed over the very long telephone call, you heard me say my ballscrew is in perfect condition, and the bearings are fine - both turn as smooth as butter. I decided to completely reassemble the lathe. I later confirmed with a friend that his 1HU5044 motor (the z-axis), like my X-axis motor, does not spin freely and has a certain amount of resistance that prevents it from freewheeling.

So, that's good enough for me. It's all back together, and I've been waiting since then for this upcoming weekend. I'm going to get the garage nice and warm, and give it a whirl this weekend with the feedrate turned down to 70%. After a while, I will turn it up gradually until I reach 100% or another DAU-limit reached error, whichever comes first.

Actually, I 'm thinking of piping in one of the furnace ducts into the garage to keep it at a higher overall temperature from now on, rather than heating it up when needed with the electric heater. I think the constant warmth will only improve the longevity of the machinery, and can only help improve the performance of the motors (i.e. heating up the grease in the bearings in the motor can't hurt.)

So... thanks for the support. You were supposed to call me this Thursday to discuss our mutual exchange of parts. Incidentally, I've been looking at 11.25" stroke pneumatic cylinders and want to use a 3-position 5-way valve with open neutral so that I can command the sliding door open or closed, but have the door float while the value is neutral so I can manually slide the door open or closed. I'll probably re-use the part chute command unless the CHNC1 provides for an automatic part door - I think it might. That part chute is practically useless anyway.

Anyway, give me a call.

Torin...
--
www.walker-tech.com

[mike^3]

Hey Torin, sorry I missed your call, give me a call back.

I spoke with my friend and he had mentioned that he does not have any spare motors.

Ill try to call you shortly

Mike