Frage Keep hitting softlimits, not sure why

Hey all,

SC2 840. Using UCCNC with the 840 profile. Working on a piece thats 24"x12" or so, so it fits well within the machine limits.

Trying to do a hole dead center. I have measured and found center, and in the Aspire file and Mach3 MM output I have the toolpath starting at center.

1. I load up UCCNC 840.
2. Home the machine
3. Manually jog to center of piece, and zero it out.
4. Load file.
5. Start Cycle.

That's when I get the "this job outside of software limits message.

I have tried restarting the app, the computer, the machine, re-homing, etc. The toolpath literally is asking it to drill a hole 1.25" deep at center, where it's already zeroed, so I cannot for the life of me imagine why it's saying it's outside its limits.

I have ensured I am exporting as the right format (the one I always use Mach 2/3 MM).

Any help is appreciated. I'd like to avoid disabling software limits if possible, unless there is something inherently broken with them.

Thanks all!

As it is standing the answer could be four topics below yours: https://www.stepcraft-systems.com/en/service-and-support/stepcraft-forum-uk/software2/2404-uccnc-stepcraft-300-problem . Hope it helps.

as per Tikkas link... just turn them off (button below the XZY readouts on front screen)... could be something funny with Z limits...

but again - turn them off and check manually its the best way. you still need to check the depth of collet at full depth and at the max/min X and Y to make sure you have no crash situation.

soft limits are only 1 line of defence.

Software limits are almost incompatible with manually zeroing the machine.

Suppose you set your X limit to -10mm once homed.

Now you manually move the machine to X=300 and Y=300 that is where your piece is. Now you zero the machine.

Your new coordinates are now X=0 and Y=0.

If the machine tries to move to X=-10 (relative) your soft limit will be triggered even when your machine is really at X=290 (absolute) and no danger of crashing is there.

Soft limits are relative, that's the issue. I don't use them at all. But I suppose there are people that use the machine in Absolute coordinates all the time and Soft limits work well for them.

Mike is correct - the soft limits are set relative to the homeing routine and are always the same. You cannot change the machine co-ordinates. Only homing the machine and setting these can change them.

The soft limits are then relative to the positions set when the machine is homes.


the workpiece co-ordinates do not effect softlimits.

it could be that you soft limits are not setup correctly?


>> home machine


>> then move to all extents of travel and check that they are working correctly.