Mlori Seiki SL-2 X-axis brake not holding -- adjust, or replace?

Hi guys,

My SL-2's X-axis brake is no longer holding. 1980, Yaskawa motors. After ~12 hours unpowered, the X-axis is all the way down and I have to jack it up. This happened gradually over ~1 month, so not something sudden, seems like a wear issue.

Has anyone been inside the X-axis brake and can offer some advise? Is it adjustable, or should I start looking for parts?

Thanks, and regards.

Mike

Is the brake in the motor? In the mean time I would fit a block of wood to hold it. Jacking it often my cause trouble.

ifixcnc said:

Is the brake in the motor? In the mean time I would fit a block of wood to hold it. Jacking it often my cause trouble.

Click to expand...

This. I remember working in a shop back in the 90's and they did this on a Hitachi while we were waiting for a replacement brake. Only difference was, the brake on our machine had completely failed. Made for some interesting power failures

Fixed it, I think/hope.

1. With power off, remove X-axis servo shrouding. See the brake motor behind the servo with a bushing and associated spring assembly on top
2. Loosen the 2 setscrews holding the bushing on the ~12mm shaft, probably will see the shaft slide up into the bushing a bit when the setscrews let go
3. Brake is engaged now, confirm by trying to wiggle the bushing assembly -- it should not move, being clamped tight
4. Power up the machine, and carefully go back to the X-axis servo and tighten the 2 setscrews
5. Confirm that with the machine powered, the bushing assembly is a bit loose (unclamped)
6. Depower the machine, verify the X-axis stays put

Basically, the bushing assembly mentioned above needs to be at a location on that ~12mm shaft where it's loose with power on, and tight with power off. I don't know that my steps 2-4 are the right way to do that, but it worked for me . However you do the adjustment, just make sure the bushing assembly isn't clamped when the machine is powered up.

Regards.

Mike