Mazak - SQT10MS

Hello,

I have a 94 Mazak SQT10MS. She is a grandma, but makes great parts when she is running.

As shown in the model number, this lathe has a rear spindle with live tooling.

Yesterday, the timing belt that drives the rear spindle back and forth on the gibbs (z) snapped..OUCH!

Of course it broke during a transfer.

Upon quickly looking under the back of the machine with a flash light, I thought it was going to be an easy belt swap out, but looking at it a little closer today, it appears it may be more of a challenge than I originally anticipated.

I still need to pull the coolant reservoir so it is out of the way and I have easier access.

I have already purchased a new timing belt which is a # 270L150.

The belt pulleys will be sitting right in front of me. The one toward the back side of the machine is completely open
and easy to slip the belt over. But, the pulley that is attached to the end of the ball screw has a 'cage' which allows the 'end coder' to be mounted outside of it at the end of the shaft.

I am wondering if any has changed this belt or one similar before. I am going to crawl under the machine shortly and was hoping someone has some insight about how to install the belt on the pulley/endcoder end?

I have not look close enough yet, but I do not see any bolts that hold the cage in place and thus the end coder in place.

The cage/end coder need to come off I believe. Is there a timing issue if I move or rotate the end-coder? Or, not because there are limit switches for travel?

Any hints or suggestions would be helpful.

Thanks much!
Mike

I have no real clue because I haven't seen this machine in particular
but
it would be mazaks style to locate from a home switch system, this would imply that "timing" of encoder to screw is not necessary.
a call to mazak would tell the tale for sure

Thanks for the review.

Yes, this is what I believe it is also.

Just for documentation purposes/

I removed the back and end cover of the machine. Pulled back the way cover to expose the ball screw. Not sure I had to even do this, but it was helpful in turning the coupler in order to have access to the coupler set screws.

Removed the belt/pulley cover. There is a helical coupler that connects the end coder to the end of the ball screw. Turned the ball screw to a position so that I could get at the (2) 3mm allen set screws in the coupler. Loosened set screws. Removed (3) 5mm allen bolts that hold the end-coder 'housing' to the machine. I did not remove the end coder from the housing. After some work and successfully separating the end coder/housing from the end of the ball screw, I did not move/rotate the ball screw or the end coder shaft. I did this so I did not screw up the timing from where it was when I started. It may not matter as this machine has a homing switch. I cleaned both gear pulleys with soft cloth and solvent. Loosen (3) 10mm allen bolts on rear pully mouting plate for belt tension and slide plate forward so I could get the new belt over the pulleys. Installed new belt over pulleys. Make sure teeth of the belt are engaged in pulleys correctly and alignment looks good. Slide tension plate back by hand and then adjust belt tension screws so the belt tension is firm, but still can pinch together a bit. It might need to be re-adjusted as a result of stretching after we run for a few hours. Lock the slide plate bolts back down. I used a scotchbrite pad to polish the end of the end coder shaft without rotating it to remove any burrs from the set screws. Put a little lite oil on the shaft. Re-installed end-coder/housing to machine with 3 bolts and tighten. Made sure end coder shaft flats are aligned with the coupler set screws just the way it was when I took it apart. Make sure the end coder shaft is fully engaged into the coupler. Tighten coupler set screws on the coupler. Re-installed the pulley cover with (3) bolts. Fired up machine and tested movement a small amount in both directions. Now working on cleaning all the chips that have been buried in the back of this machine before putting covers back on and moving head back to where it should be. All looks fine.

Hope this helps someone else in the future.

thx
Mike