What's new
What's new

T42 Zero Return/1006 Torque Limiter Issue

msoden

Plastic
Joined
Aug 26, 2019
I have a new to me Hardinge T42 lathe that I am having issues with the zero return procedure. I am hoping to get some help with an issue I am having.

I am able to get the machine to move to the "stop on its own" position but when I hit X+ button to send it to the switch to set zero it stops immediately with a 1006 x/z lmtr/tlstk breakway. Looking in the parameters indicates a X axis fault. I jog the machine's x-axis until the bit goes from 0 to 1 indicating the clutch re-engagement. There is no audible clunk when it re-engages like the manual and the posts indicate there should be. Once cleared I can jog around a bit but when I go to set the x-limit I have the 1006 error again.

It seems to be the clutch is not re-engaging or the switch is not functioning (possibly switch alignment). Thoughts on this? Trouble shooting procedures? I haven't tried the 2x4 as that was specifically called out in the manual for the Z axis.

As far as I can tell the machine hasn't been crashed, or rather the x/z turret surfaces are in alignment (within .0005")

I referenced this previous post as it seemed relevant.
https://www.practicalmachinist.com/vb/cnc-machining/hardinge-t42sp-z-torque-limiter-reset-216318/

Matt
 
First off, w/o a PM, I wasn't going to see this thread in this board.
I am sure that a few CNC questions pop up in here, but this board is mostly a manual machine board.


Anyhow - what you are saying doesn't make sense to me...

If it was tripped, I wouldn't expect it to start the HOME procedure, but apparently it is.

Then you say that just by jogging X that you can git the param to change.
What param specifically?
Are you in 1815? (I'm guessing not if you have a HOMEing routine.

I guess that since you seem to have a ghost, maybe the best place to start would be to pull back the way covers and get an eyeball on the clutch.
Is it tripped? (may be hard to tell)
Or maybe does it just have a little pc of schidt on it that the prox is picking up?
Or maybe even just the prox got bumped somehow before you got it?
(someone changed X axis thrusts just before puting it for sale?)

You can manually trip it on porpoise.
Use the block if you like - but just go push agginst the spindle, or maybe a 1.5" bar in the collet, or ???
Just use the MPG to push on it.

If it is already tripped, and you dial in slowly, you can (should) hear it pop in.
However - if it is NOT already tripped, you will not only hear it, but will likely see the axis jump back a bit.
You will then need to keep MPGing it down until you hear it latch in aggin.
If you are handwheeling it too fast, you will blow right on through the clutch and re-trip it before you get stopped.
It could be up to a full revolution (of the axis screw) before it trips back in aggin tho.

After you go through that - if you tripped the clutch at all, you will likely need to tell the control to forget where it is.
Turn off the power to the control. (not the whole case)
Hold down the letter P and CAN keys, and boot up.
Keep keys held down until it is all booted up.
Then HOME it.

Let me know outcome - I will now see this thread since I have replied to it now.


-------------------

Think Snow Eh!
Ox
 
Thanks for the info Ox. Sorry if I put the thread in the wrong sub-forum. I thought this was the one for Hardinge lathe's like the T42. Is there a more appropriate location I should have this moved to?

I am speaking of is the diagnostic parameter x10 Bit 3 (XTQLM). The maintenance manual describes to watch it while slowly rotating the MPG.

After getting that (x10 bit 3) to reset from 0 to 1, I would trying the homeing procedure as described in the manual but I couldn't get past the step where I was to press zero reset and +x to move the axis to the home position. It would typically trip the 1006 alarm again. I haven't tried with the cancel and p trick, I will try that after I figure the clutch bit out.

Couple questions on this, does it stop automatically at the home position during the re-home procedure? When is it necessary to re-home? After every 1006 trip error?

I was in the process of removing the sheet metal around the x-axis (needs to be cleaned up anyway) and seeing if I could see if the sensor is out of alignment or maybe some chips got in there during transit . It looks like its up near the x axis motor.

Just a note, I can only work on the lathe when I am out at the shop on the weekends so it will be a few days before I can test this.

Thanks for the help!!

Matt
 
You should easily be able to hear the clutch trip in/out, even in a noisy shop.
If it is actually tripping easy enough not to make much noise, then maybe it needs replaced?


If the machine needs HOMEd at all, it will need homed every time that you reboot the control.

Yes, the axis should stop at the HOME position on it's own.


Typically this thread would be in the "CNC" section.


----------------

Think Snow Eh!
Ox
 
Last edited:
Hi Matt, you are correct about the location of the torque limiter. You will need to remove the cover under the servo motor and the lube block package (a couple bolts and let it hang) to access the prox switch and see the torque limiter. I have had to replace the torque limiters as they do wear out as Ox said. It could also be run-out on the tripped torque limiter making and breaking the prox (X10.3). When this happens there is a clicking sound but it's not near as loud as when the limiter snaps back in unless the limiter is wore out. On x-axis you usually don't need the 2x4 due to the weight of the turret. It should snap back in when hand wheeling in the positive direction with the smallest increment selected.

The Hardinge torque limiters only move out about .060" and they snap back in with a full revolution as suggested above. I also don't believe in ghosts. :)
 
Thank you for all the help, I haven't been able to work on it as much as I would like, out of town for work then on vacation.

I pulled the sensor back and the axis would not move. Basically the coupler would break free and immediately open again. I got my brother out and we were able to get a video of it.


That video was shot moving at .010 in intrest of video length it was the same at .001"/pulse. You can see it engage and disengage twice.

Unless someone thinks otherwise I would say that is a failed torque limiter.

Any tips or tricks for replacing?

I think the Steps would be something like (feedback welcome:))

1. Block X-Axis off of something, perhaps the sub-spindle somewhere
2. Power down machine
3. Loosen pinch/clamping bolts on torque limiter
4. Remove X-Axis (electrical connectors and large SHCS)
5. Remove and Replace torque limiting coupler
6. Replace axis
7. Re-zero x axis per zeroing procedure

Anything I'm off base on?

Matt
 
Ass_u_ming that "axis" in your scenario actually means "servo motor" - then sure.


I didn't hear the clutch in the vid - were you able to hear it?

Just for grins - I would try to turn the screw by hand - although with the turret hanging on it - it will turn hard.

... ????

But then that leads me to ??? your comment about "blocking the turret".

I would fully expect that the turret is bottomed out agginst the sub or crashed into the spindle, or ??? at this point.
No?

If it is NOT bottomed out, and the clutch won't hold it - how are you expecting to job to a block point?

If the X is not fully bottomed out on sumpthing, then maybe the screw or trucks are bound up?
The clutch may be shot, but maybe it is the result, and not the cause?

I have one clutch like that that lives at the bottom of a lower turret that I have to replace semi-frequently (???) but the rest that are clean and dry don't typically wear out.

???



---------------------

Think Snow Eh!
Ox
 
Last edited:
Yeah you are correct I should have said X-Axis Servo motor. Sorry.

The clutch doesn't really make any noise when engaging and releasing. I thought it could be a result of being worn out? It seemed like it was making more noise earlier but I could be wrong just seems to make a bit of a click now.

By block I ment put a piece of wood to support the turret from freewheeling down into the sub-spindle. I planned to put the biggest wood block I could fit, probably only a couple inches at this point just to keep it from damaging anything. Might be un-necessary just seemed like a good idea.

I was going to jog down until it rested on the wood. On that note I seem to be able to jog down but not up. When I jog up it pops out, but when I go down it does ok. I though it may be the weight of the turret on the axis making it a bit harder to drive up than down.

Interesting idea on turning by hand, I will give that a go when I get back to my shop this weekend.

An observation is that the holding power seems to be decreasing rapidly (or binding to your point). When I worked with the machine service techs, we were able to get the machine to home but it did pop out on one attempt. Got it back engaged and worked for a couple more hours. Came back to it a couple days later and it wouldn't home but I could jog around as desired, presumably inertial loading of rapid motion was too much. Now I can only jog x down towards the sub spindle.

I guess I will get a replacement clutch ordered up, hopefully nothing else is damaged.

Matt
 
Just thought I would post a follow up on this. The issue was indeed the torque limiter. I was able to de-couple it by hand on the work bench when I removed it.

Couple notes on some issues I ran into, first the control thought that my x-position was way out of range due to the x axis decoupling when tying to lift the carriage. There is probably an easier way to do it but I put the turret 3" off the and unwound the x-axis until it read 3" and re-connected it. i found it easier than always doing the cancel P over ride.

Second is the factory manual indicates a homing operation that did not work for me. It said to move the axis .1" off the home switch and hit the home button. I had to go with the standard move 2" z then x and stop on its own routine.

Thanks to OX and OB for the advice.

Regards,
Matt
 
For your issue of the X being way off when you hooked it up - you need to learn a classic Fanuc routine to cancel that issue.

With the control off, push and hold down the P and the Cancel buttons and boot the control up.
Hold them down until fully booted up.
Then you should be able to run your HOME routine.


---------------------

Think Snow Eh!
Ox
 








 
Back
Top