I've got an Omni 1530 that I've had since 2018. Just recently it started cutting out of square. I'm confused on how to fix this. It's got proximity sensors on both Y rails, which makes me think one is Master and one is Slave and to get the machine back into square I would simply need to adjust the stops for proximity sensors. However, there is no adjustment for the proximity stops. They are just metal clips held on by 2 screws. Additionally, when I remove the Slave side clip, nothing seems to happen as if there isn't any calibration between the two sides when the machine Homes.

The manufacturer sent me a document that describes squaring the machine by loosening up the bolts that hold the gantry in place and then just whacking the gantry in the needed direction. Maybe I need to hit it harder, but it doesn't appear to be moving no matter how hard I hit it. Also, I can't tell because I haven't been able to move the gantry, but it doesn't appear that the bolt holes for the gantry have any adjustment to them. So if I do succeed in moving the gantry, I won't be able to reattach the bolts.

The omni is built similar to an old MultiCam.
Loosen the bolts a few turns (finger tight) that are holding the gantry to the uprights on both sides. Home or zero the machine, send (rapid or park) it to its opposite end of the machine then (rapid or go to home) bring it back to the home area and rehome. You may want to do this a coupe of times. Tighten the bolts, cut a square and check corner to corer for square with a tape measure. This should allow the gantry to re-center itself.

Thanks for the advice Jim, I'll give that a try.

It is recommended to apply force carefully to try to move the gantry and recalibrate the sensors for precise positioning. If the issue persists, it is best to seek professional help to ensure the normal operation of the CNC machine.

Also remember that when you measure the number has to be divided by 2 to get how much it is out

Got it figured out. The instructions from Omni were correct, it's just that the documentation was kind of lacking. I was under the impression that I needed to loosen up the bolts on one side of the gantry and move it in the desired direction. Turns out I needed to loosen up both sides because the gantry essentially needed to twist back into alignment.

I'm still confused as to the purpose of the Y-axis proximity sensors on my machine. I don't think they have anything to do with squaring the machine. The one of the "left" side is the one that triggers when homing. The one on the "right" side never triggers. If I take it off completely, nothing really changes that I can tell. Perhaps it's just a fail safe if the other one dies?

Are the axis belt driven? If so check to be certain that one of the belts has not broken. If they are direct drive check the tightness of the coupler between the gear box and motor. If neither of these situations apply follow the directions given to you by Anderson.

Rob,
For the sake of posting correct information in case someone with an Omni 1530 / 1325 CNC is reading this thread, your advice is incorrect as far as my machine and my experience is concerned.

The manufacturer documentation is correct. Loosen the gantry bolts on both sides. Tap on one side of the gantry. In theory, you move the gantry half the distance that your diagonal is off by. But with these machines, I see no way to be precise about it. I just used a measuring tape to measure from one end of the machine to the gantry. I used a bar clamp to hold one side of the gantry in place while I used a metal mallet to tap on the other side of the gantry. Once they were roughly equal, I tightened the bolts back up and ran my diagonal test program. The process worked for me.

I'm a little surprised there isn't a more precise way to adjust the gantry position, but I guess that's just how it is when you pay $20k for a CNC from China. Small price to pay however. Machine has been running like a champ for 6 years and paid for itself many times over.

We have a Morbidelli X200 that calibrates it's self if the axes' are with in 1mm. After we tried to change a tool with a tool holder in the unload slot already we had to calibrate it. Loosened all the bolts on bots side except one so that the gantry can pivot on that bolt. Used a knife to mark the current position of the gantry and a mellet to move it. Very simple process.

Our onsrud will get out of square ocassionally, but we figured out that if we loosen the gantry bolts, and give it a good pull forward until it hits the solid metal overtravel stop blocks, and then tighten everything back down, it's back to square. This method seems to be quicker and relies less on someone measuring and marking and malleting the machine.