Z-Axis stops short

How To
1

My kit is a standard XXL bought early 2018
I upgraded my Z-Axis with one from CNC4Newbie to fit a 2,2kw spindle and the ability to use a variety of bits with an ER 20 collet system and I am very happy with it.
However one problem I cannot yet get fixed, is that with soft-limit grbl code $132 set at 150 mm, it only goes to 95mm and then stops. (It is exactly 100 mm including the 5 mm of $27 (homing pull-off))
I have changed $102 to 200 and that gives me the correct span: it moves 100 mm when the indication shows 100 mm.
To ensure that there is no physical limit or something mechanically stopping it but that it is clear and the travel is possible, I changed it to 300, it moved 150 mm but then moves 1,5 mm for each 1 mm indicated. Thus not acceptable.
It is as if some other soft mechanism is preventing it from moving the full 150 mm.
Anyone with similar problems or suggestion where I can start to look further?

2

What gcode sender are you using? CM4 has axis limits pre-set. If using something like UGCS, then disregard.

Dan

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3

As @DanoInTx says, CM4 doesn’t respect the GRBL settings here like CM3 did. CM4 and any difference in axis extent “just doesn’t work” - you need a different sender. UGS and CNCjs are both pretty popular.

4

Thanks Dan, using CM4.
So there is no way to access the axis limits pre-set’s?
Regards Herman

5

Nope :-1:

Part of the reason I still have my new Z slider sitting on my workbench a year after I bought it. CM4 is working so well for me, it’s stupid simple, and my stock belt driven Z works ok, so I’m a little apprehensive about pulling my machine apart and then having to switch senders. I actually ordered the latest upgrade plate from CNC4Newbies a few weeks ago too, just can’t bring myself to do it…that and I’ve had other non-CNC projects keeping me busy. I’ll get around to it, and keep crossing my fingers that this limit will eventually be changed.

Dan

6

Thanks everyone, all sorted.
I chose CNCjs app and it is working pretty well - much smoother than CM3or4 on the HMI interface.
Regards Herman

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