How to update the offset param on a acramatic 850SX

94 Cinci Sabre 750 acramatic 850sx. I installed a new thrust bearing in X axis but afterwards I get a 15191 alignment failure in X a couple times before it will reference. It always references after a few tries but Id like to fix it. I know theres a procedure to get into SYSCOM and reset the reference offsets but its not in my manuals.

I see talk of a few people who have fixed this online over the years but of course no one bothers to explain what they did.
Anyone know how?

Ok, I just figured out the non factory approved method of fixing this problem. (This is only applicable if your machine IS NOT moving away from the reference point. If its doing that, the switch is probably stuck).

Remove the left way cover. Move machine to align position in X. There are two limit switches mounted to the lower machine frame. Above them is a single metal plate with the two offset ramps for the X axis limit switches. Loosen the two allen screws. Note position, easy as theres crud in there.

I moved the plate about .005" to the left. (first moved to the right but same error). That fixed it. Aligned 5 times in a row so Ill call it fixed. The new thrust bearing stack was a little shorter.

markp said:

94 Cinci Sabre 750 acramatic 850sx. I installed a new thrust bearing in X axis but afterwards I get a 15191 alignment failure in X a couple times before it will reference. It always references after a few tries but Id like to fix it. I know theres a procedure to get into SYSCOM and reset the reference offsets but its not in my manuals.

I see talk of a few people who have fixed this online over the years but of course no one bothers to explain what they did.
Anyone know how?

Click to expand...

.
many machines also have a grid shift adjustment. that is after machine zero returned a position is measured like table center XY or table side X and center Y and table top Z and if dimension is off the grid shift is fine adjusted in parameters. that is if you want center of table and table top to be at expected position. usually grid shift adjusted only .001 to .004"
.
i have been out of range before and after machine would not zero return. sometimes limit switch mechanically adjusted to center in the tolerance range. once the Y grid shift parameter was +1500 and i accidentally put in -1500 and was out of range on next zero return
.
same with tool change position. if too far out it wouldnt tool change. not sure if that was mechanical or electronically fixed. all i know is maintenance guy centered something so after zero return and grid shift it would be centered at the proper tool change position. i believe he went to a screen that showed whether limit switch was on or off correctly and adjusted it til is was correct