Chiron VMC X axis going the wrong way

We have a Chiron VMC that was giving torque alarms on Z. Figured the brake was sticking because we also had an issue with it dropping a bit when the access door was opened and the servos were dropped.

Of course, while the machine was locked out awaiting our attention, the cooling fan in the X Y servo amp packed it in so when we fired it up we had one more problem.

No problem, X Y amp pulled, fan replaced, machine erroring out saying it needed to be homed. No big deal other than it is dogless.

Z was easy, picked a spot near ot limit switch and did the 1815 bit 4 toggle thing.

Operator can touch off the tools to deal with that.

X Y seemed simple enough. Jog over to the collet chuck, indicate spindle to be on center with a bore of a finished part. Look at fixture offset numbers, move that much more in X and Y. Should be home, reference position, machines zero, take your pick.

Do the 1815 bit 4 toggle thing.

Life should have been good but I'm getting an overtravel on X.

MDI a G54 to load that sides fixture offset and a Y0 puts you at part Y0.

A X0 has the axis wanting to go 13 inches the wrong way.

The fixture offsets look legit. All negative numbers which match what I wrote down the last time I worked on this machine.

When I look at the keybad, no MPG (cheap bastards), axis move directions seem to match keypad layout.

Any ideas?

Thanks,

Wes

Reply to
clutch
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This is a known problem with this machine. No, it isn't a problem that you, as an end user, can resolve unless you have gasoline and a match. You have gotten exactly what you paid for.

Reply to
John R. Carroll

Details?

I know it is a POS but I didn't buy it. I just gotta keep it running. I have a feeling we will scrap it before our ancient Mori MV40. Sure wish the Mori had faster rapids.

Wes

Reply to
clutch

Well Jon, First, if you thought what I posted was, Ah - "Hasty"?, I apologize. These things remind me a little of Sharnoa's bed mill. Great in many respects but they don't run well enough to do much more than put a small company out of business. It isn't a model specific issue. It's a get it out the door and on he floor looking good issue.

Reply to
John R. Carroll

The chips are weak and the software doesn't error trap lost bits. You can't really fix that. Believe me, if I had a magic bullet for you I'd pass it on. This really is a MatchLight machine and unless you guys want to try and undo sunk cost fallacy thinking,e getting rid of the thing sooner is better than later. Plus, you'll save on the Emperin III's or IV's. I wouldn't kid you on this. Especially not in a public forum.

Reply to
John R. Carroll

I thought Chiron was a decent brand. Is that problem specific to that model machine, or do Chirons have problems in general?

Jon (the other one)

Reply to
Jon Anderson

No, I didn't think you hasty at all, I was just curious. Though a garage shop, I still look to the day I can buy a machining center, and it will likely be a used machine. I just try to stay aware of which machines have issues, the sort of issues garage shops don't need... I have seen a Chiron on ebay now and then go for what I thought was a low price, maybe this explains why.

Thanks,

Jon

Reply to
Jon Anderson

The brake on the axis is probably dragging. Also, check the thrust bearing. You could also look at the counterbalance road wheels if it has a mechanical counterbalance. The bearings go out and that loads up the axis. Sometimes a machine with this set up will "klunk" when you rapid the axis full stroke. The noise is caused by the counterweight banging against the column as it swings due to the uneven load as the chain bearings stick. Hydraulic or air cylinder systems won't do this. On those, the proportioning valves go out but on your Chiron the gain parameters in the control might be scrambled.

This is the wrong machine tool to E-stop and then power off so if you guys are doing that - stop doing it. Just turn the thing off. Everyone does it but E-stopping a machine when you shut it down is hard on the electronics and it's also not required except on certain very specific configurations.

Have fun.

Reply to
John R. Carroll

was sticking

was opened and

there tends to

can unlatch

lock release.

down a bit

the morning.

it rapid in

Wes, Mine has a Siemens 810 control and references using limit switches to tell the control to look for the zero pulse from the encoder.The travels are entered as parameters but you also have to enter the working area as parameters. This uses Siemens servos also and thinking back I once had a fault where the Z would alarm out causing a servo shutdown.It turned out that on that axis the Heidenhain encoder is inside the servo motor and coolant had got in and corroded the wires.It may have been the Y axis but I`m sure it was the Z. I also,not long after buying the machine had overcurrent alarms on the X axis.This was due to the previous owner machining plastics and never cleaning under the bed covers.The dust had jammed the ballscrew bearings solid.A strip and clean cured that for good. I find the machine ok but the service from Chiron UK is crap although not as bad as Mazak. Mark.

Reply to
mark

What are you machining on it?

To the machines credit it has been facing cast iron semi truck pulleys for a few years followed by drilling and tapping ops. It is still alive.

Today, I felt like an idiot. Pulled out the Z ballscrew, saw it was a 20 mm pitch screw. New one shows up. I see ball ways 10 mm apart. Call chiron. Parts guy said it was right, don't worry. Got number to engineer there that was irritated with me that I didn't remember name of parts guy and kept telling me that he was leaving to go back to Germany, like that is my problem. He said he would call me back. Never did.

Find I need more parts, get another parts guy that seems like he has it going on. After getting my order put together I ask about the screw, he tells me, it works.

Then I find the machine isn't critical like it was the days before. Last one to know about that.

Call tech support and ask, guy tells me that isn't right, tells me he will check and get back to me. Calls back later and says it is right. I ask how, he said he will call Germany on Monday. I'm still thinking if it is right, I should get a list of parameters to change to make it work.

I was talking to the guys on the next shift and said the only way this screw could work if it was a two start. Damn, hours later the brain finally kicks in.

Yes, it is. I called the tech back, told him what I learned and thanked him for his time and to tell the parts guys about it.

Sometimes things are over my head ;)

Cheers,

Wes

Reply to
clutch

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