Spindle Orientation Fault - Spindle Hunting

Hi all,
Have an 08VF2D. Yesterday spindle was hunting clockwise and counterclockwise and then eventually found its spot and tool change occurred. Sometimes it couldn't within set parameter time and generated Spindle Orientation Fault. Here is some background:

Drawbar changed by HFO along with belts for spindle and encoder. This fault is first time ever in the three years I've had machine and only two start-ups since drawbar changed. Note I had 1500 to 1650 lb drawbar force and I think all that was wrong was the spiralock holding drawbar in was bell shaped. Now have 1800 to 1850lb with new drawbar. Oh well..Reason for changing drawbar was that a toolholder with tap in it was pulled out of taper on slow retraction. That was first time ever too. Form tap. HFO thought tap must have rotated in tool holder losing synch during rigid tapping. But it was on retraction and nearly out.

Diagnosis so far:

Have taken cover off. Spindle encoder belt fine. Encoder and spindle cogs turning. Can see spindle encoder data going up and down in raw data screen in debug mode - can make it go up and down in one count increments by hand turning spindle. No apparent number skipping.

On pressing Spindle Orientation button, spindle dogs eventually line up after hunting, but on opening door and testing how 'located' the dogs are in that position, it takes only slight finger force to set the spindle going left and right again. I thought on pressing spindle orientation it was supposed to stay solid! Maybe I'm confusing that with M19 as I have that function on my machine.

Tested spindle at 500rpm CW. Spindle pauses slightly before running. Goes up and down in speed as I direct, but can't slow down to zero as starts hunting again.

Spindle Orientation Offset Parameter set at -233 by HFO after belt changes. Pressed Spindle orientation button on control and eventually settled at -2233 in raw data screen in debug mode.

Tried tool changes while in debug mode. Tool changes occurred at 1852, 3754, -2238!!

Any help appreciated. Could it be the encoder itself? Encoder is Haas 60-1813 Rev E. Sancon Part # 2Q2000-649815

Any help appreciated. Thanks.

I would suspect a dirty spindle encoder, assuming yours is an optical encoder.

It sounds like the servo deviation error is not being generated. That makes for a spongy servo like you are seeing and also makes settling time to home difficult and long.

The dirt on the encoder in essence covers multiple lines and makes the encoder appear to the servo drive as being much coarser than it actually is.

This problem usually starts out as only on rare occasions and eventually gets worse over time to the point of almost won't function.

If you were doing rigid typing this would really show up.

Is there any way of cleaning the encoder, I do I have to change it. Can't tell if it's optical. Pic attached.

..or do I have to change it, I meant.

It is completely sealed.

I would suggest to replace it.

You can open some up to clean and some you can't and then cleaning is dicey anyway. The etchings are very fine and it is difficult to actually get them clean. If you scratch them you can make matters worse.

Then there is also the issue of sometimes failing electronics in them get flakey and behave the same way.

Yes I have been doing rigid tapping without a problem up until this fault. Being vector drive there is no locking pin on this model, and no gearbox. So no other proximity sensors to check etc. It was strange that I could get the encoder data in the raw data screen in debug mode to go up in very small increments when moving the spindle by hand. Could go up one pulse at a time if careful. But maybe it's different at speed an dI certainly didn't do that for 2000 pulses. Also I did notice that while the encoder belt has just been replaced, and the small pulley on the motor looks good, the pulley on the encoder looks like it has been working as it is aluminium and the teeth are rough to touch. Looked ok under a magnifying glass in terms of still having tooth depth but definitely could do with a replacement. I doubt that's causing belt slipping at all though.

I noted comments from Haastech that one should look out for that.

Well, today HFO came and was excellent. But we still haven't found the issue. Changed encoder to new magnetic style with new gear. Belt was already new. Changed Vector Drive to new one. Then tried new MOCON. All to no avail. Only leaves the one thing we were missing. The spindle encoder cable to try. Ordered.

PSRP said:

Well, today HFO came and was excellent. But we still haven't found the issue. Changed encoder to new magnetic style with new gear. Belt was already new. Changed Vector Drive to new one. Then tried new MOCON. All to no avail. Only leaves the one thing we were missing. The spindle encoder cable to try. Ordered.

Click to expand...

This is odd, I have never seen a spindle hunt CW and CCW with the end result generate a spindle orientation fault alarm. I have only seen that motion generate some type of gear change fault, however you do not have a gear box.

If the cable does not fix anything, have the tech try another MOCON, encoder, and spindle drive different from the ones he tested with already.

I had one job years ago that I was suspecting a bad MOCON to be the issue. My 4th MOCON fixed it.

Good luck and keep us updated.

Thank you for the reply Haastec. Much appreciated. I am awaiting that new cable from the current optical encoder to the current MOCON to try. When the new magnetic encoder and adaptor cable went in, it was left in when the new Vector Drive went in, and likewise when the new MOCON went in (V17 something). Mine is V12 MOCON. Software is V15. All 3 new items and still the problem. I noticed the 257 parameter is a negative number (-233) and read somewhere it should be positive. That's the way the HFO set it after the drawbar change but the machine worked fine for tool changes with that. I continue the pursuit of a resolution to get my favourite machine back up and running.Will report back findings to close the loop for all. But first I need to close the loop!! Cheers.

Problem Solved!

HFO came out again today. Tried the new encoder to MOCON cable - same problem. So that meant we have tried new encoder, gear, belt, MOCON and Vector Drive - everything that the error says could cause the fault - and problem still the same.

But then tried new contactors and problem fixed (all my other original parts put back in). One of the contactors (Wye I think) looked slightly depressed when it shouldn't have been. On closer inspection once replaced, it appears one of the connections was slightly melted and causing the contactor not to return to its normal off position.

I also noticed that the spindle acceleration sounds quicker/smoother now. Spindle load while free spinning (without cutting) also now 4% throughout whole range whereas I noticed with the bad contactor it was 4% at low rpm, getting to about 10% at 5000rpm and 25% at 10,000rpm.

Wanted to close the loop. Maybe helps others.

Thank you.

Thank you.

PSRP said:

Problem Solved!

HFO came out again today. Tried the new encoder to MOCON cable - same problem. So that meant we have tried new encoder, gear, belt, MOCON and Vector Drive - everything that the error says could cause the fault - and problem still the same.

But then tried new contactors and problem fixed (all my other original parts put back in). One of the contactors (Wye I think) looked slightly depressed when it shouldn't have been. On closer inspection once replaced, it appears one of the connections was slightly melted and causing the contactor not to return to its normal off position.

I also noticed that the spindle acceleration sounds quicker/smoother now. Spindle load while free spinning (without cutting) also now 4% throughout whole range whereas I noticed with the bad contactor it was 4% at low rpm, getting to about 10% at 5000rpm and 25% at 10,000rpm.

Wanted to close the loop. Maybe helps others.

Thank you.

Thank you.

Click to expand...

Thanks for the follow up and glad you are back in business!

Just wondering what contactor exactly was the problem and location my machine is doing the same thing thanks

TonkaToyz84 said:

Just wondering what contactor exactly was the problem and location my machine is doing the same thing thanks

Click to expand...

Told you that you might find some help, here. Hope it works out for you.

It was one of the two contactors that sit side by side - for the wye-delta switching of the spindle motor. They sit on the left hand side of the Vector drive on my 08VF2 and are without a cover. Later machines (some) have a metal cover plate. Look up 'Wye-Delta Contactors on Haas' in Google. It comes up with the Haas DIY page for this so it shows you what they look like physically.

Thanks for the reply

So.. I looked for the contactor and my machine doesn't seem to have them wonder if that's the problem

I see what you mean. sorry about delayed response. Looks like you have a 3 phase circuit breaker and not the wye-delta contactor system. Suggest you look at the electrical manual for your model machine, which should explain things. Others would have more experience with your machine.

By the way, for the information of others, I noticed that in cutting parts, my spindle load meter is only going at about 1/3 load now - and hence I have upped the feed rates and spindle speed and it is cutting faster and with less load. That stuck contactor must have been creating a magnetic load on spindle.

I had a Haas tech come out and they did a full diagnosis on my machine and finally found that my mocon board was shot replaced and all issues solved thanks for the guidance my spindle load was also 35% at free spin now is almost 0 symptoms were spindle resonating x,y,z axis chattering accuracy was out 1 thou over 10 thou and spindle would not orientate all the time causing code 143 spindle not locked fault unable to do tool changes

PSRP said:

. That stuck contactor must have been creating a magnetic load on spindle.

Click to expand...

Or was it possibly sending only two legs to the vector drive? That might explain the high current at no load?