Issues with Z Zero

So I just upgraded my CNC control computer. When I did I switched from an older version of Carbide Motion without the changes to tool probing to the latest. I also leveled my CNC, trammed my spindle with a tramming jig, and used a flattening bit on my waste board so it should be as flat as I can get it. When I design parts in Carbide Create I set the Zero Height to “Bottom”. I also make my toolpaths so that they leave a 0.2mm onion skin on the bottom. I zero Z on my waste board surface using the paper method. When done I can just barely see light under neither the tool. After making the change to the latest CM I keep cutting into my waste board and there is no onion skin on my parts.

Just now I was setting up for a new job and I went to set Z zero using the paper method. I move Z till the paper felt tight and then loosened it till it could just barely move. I hit the button to set Z zero. The tool was probed and went back to the same X , Y position it was in before. I then used the Rapid Position buttons to go back to Z zero. It pierced the paper. I had to raise Z 0.2mm before I could move the paper again. I re-zeroed Z and repeated the same steps and it again pierced through the paper. I had to raise Z again 0.2mm before I could move the paper again.

At this point I am not sure what is going on.

In the machine setup did you select Z or HDZ? I’m not the professional on this but it has been a “high” hit item when upgrading versions of CC/CM. Search the form for this, The HDZ has more steps pre inch I believe and can cause symptoms like this.

1 Like

I chose S5 Pro and it did not prompt me for the type of Z.

1 Like

Sorry you have reached my useful knowledge on the subject. I would contact C3D support if you have not already.

Rapid your z up and down and make sure you aren’t loosing steps.

Do you have a gas strut?

1 Like

I am using the Carbide Router so no gas strut needed. I’ll check if I am losing steps, but I am not sure how.

Set your z zero. The bring the spindle to the front and move th z axis up and down to both limits several times at the fastest speed it allows. Pay attention to grinding or clicking sounds.

If nothing stands out return to you zero point and check your z zero again.

I just got my S5 Pro set up and I am having the same issue with the Carbide 3D Compact Router. I can zero X and Y but Z maxes out high side and goes to BitSetter and sets the max Z as zero. I have been trying to watch and re-watch ever video hoping i can get past this issue but 5 hours down that rabbit hole without luck.

If you are having such a problem with an SO5 Pro, contact support and we will work through this with you.

So I am starting to suspect something is wrong with my BitSetter. I wanted to test its accuracy so I opened the Debug console in Carbide Motion. I then moved the tool over top of the BitSetter and issued:

G38.2Z-136.0500F200.0

in the MDI. I then raised Z and did it again. Raised Z and did it again. Raised Z and did it again. …

Here are the probe results:

[PRB:-2.000,-1218.200,-87.988:1]
[PRB:-2.000,-1218.200,-87.975:1]
[PRB:-2.000,-1218.200,-87.969:1]
[PRB:-2.000,-1218.200,-87.956:1]
[PRB:-2.000,-1218.200,-87.950:1]
[PRB:-2.000,-1218.200,-87.938:1]
[PRB:-2.000,-1218.200,-87.925:1]
[PRB:-2.000,-1218.200,-87.888:1]
[PRB:-2.000,-1218.200,-87.769:1]

I never moved in X or Y. I only raised Z before probing again. The attached file has the full console output.

PROBE.NC (2.8 KB)

What I am noticing is that the Z results keep going down and over the course of that many probes went down by more than 0,2mm. Now I am by no means an expert on GRBL or Gcode but I do not think G38.2 actually applies any offset on its own so I would expect this to be reasonably consistent.

Maybe the bit tip isn’t making a good electrical connection with the BitSetter & it’s digging into the aluminum casing with each probing operation.
I often clean the bit I’m using for probing with alcohol to ensure electrical contact.

BitSetter does not use electricity through the bit. It is a precision mechanical switch. I think you are thinking of BitZero.

Ah, that’s right, I was!

One issue I had with a Bitsetter ages ago was that it suddenly stayed always ON. I took it apart & discovered that the nut or something on the end of the spring plunger had unthreaded. So it caused the Hall effect sensor to always be activated due to resting right atop/beside it. I don’t recall if I had noticed it reading the zero point gradually differently at the time - but I think it must have. This was on my SO3XXL with the belt driven Z-axis which didn’t have the precision of the HDZ or Z-plus.

A random evil thought. Axial play in the router shaft? Bearings?

I have noticed that the high up I go before probing the worse the change in Z is. I am also confident that I am not losing steps.

[PRB:-1.013,-1217.000,-87.463:1] Probe from 10mm
[PRB:-1.013,-1217.000,-87.444:1] Probe from 10mm
[PRB:-1.013,-1217.000,-87.444:1] Probe from 10mm
[PRB:-1.013,-1217.000,-87.444:1] Probe from 10mm
[PRB:-1.013,-1217.000,-87.444:1] Probe from 10mm
[PRB:-1.013,-1217.000,-87.438:1] Probe from 20mm
[PRB:-1.013,-1217.000,-87.444:1] Probe from 20mm
[PRB:-1.013,-1217.000,-87.438:1] Probe from 20mm
[PRB:-1.013,-1217.000,-87.431:1] Probe from 20mm
[PRB:-1.013,-1217.000,-87.425:1] Probe from 20mm
[PRB:-1.013,-1217.000,-87.419:1] Probe from 30mm
[PRB:-1.013,-1217.000,-87.400:1] Probe from 30mm
[PRB:-1.013,-1217.000,-87.375:1] Probe from 30mm
[PRB:-1.013,-1217.000,-87.350:1] Probe from 30mm
[PRB:-1.013,-1217.000,-87.319:1] Probe from 30mm
[PRB:-1.013,-1217.000,-87.288:1] Probe from 40mm
[PRB:-1.013,-1217.000,-87.250:1] Probe from 40mm
[PRB:-1.013,-1217.000,-87.231:1] Probe from 40mm
[PRB:-1.013,-1217.000,-87.225:1] Probe from 40mm
[PRB:-1.013,-1217.000,-87.219:1] Probe from 40mm
[PRB:-1.013,-1217.000,-87.200:1] Probe from 10mm

I am pretty sure that the issue you are having is why when Carbide Motion probes it does not do so once, but repeats the probe a second time at a slower speed — add that to the testing?

I have the feed rate set to 200 which is pretty slow.

Updated my GCode. I am raising to 40mm above BitSetter then probing at 200 feedrate. I am then raising to 2mm above BitSetter and then probing at 20 feedrate. Repeated that 5 times. Here are the results:

[PRB:-2.000,-1219.838,-87.438:1] Probe from 40mm above BS at 200 FR
[PRB:-2.000,-1219.838,-87.419:1] Probe from 2mm above BS at 20 FR
[PRB:-2.000,-1219.838,-87.431:1] Probe from 40mm above BS at 200 FR
[PRB:-2.000,-1219.838,-87.406:1] Probe from 2mm above BS at 20 FR
[PRB:-2.000,-1219.838,-87.419:1] Probe from 40mm above BS at 200 FR
[PRB:-2.000,-1219.838,-87.394:1] Probe from 2mm above BS at 20 FR
[PRB:-2.000,-1219.838,-87.400:1] Probe from 40mm above BS at 200 FR
[PRB:-2.000,-1219.838,-87.381:1] Probe from 2mm above BS at 20 FR
[PRB:-2.000,-1219.838,-87.388:1] Probe from 40mm above BS at 200 FR
[PRB:-2.000,-1219.838,-87.363:1] Probe from 2mm above BS at 20 FR

The probed values are still going down.

Here is my Gcode that I am making into a Quick Action:

G91
G38.2 Z-136 F200.0
G1 Z40 F200.0
G38.2 Z-136 F200.0
G1 Z2
G38.2 Z-136 F20.0
G1 Z40 F200.0
G38.2 Z-136 F200.0
G1 Z2
G38.2 Z-136 F20.0
G1 Z40 F200.0
G38.2 Z-136 F200.0
G1 Z2
G38.2 Z-136 F20.0
G1 Z40 F200.0
G38.2 Z-136 F200.0
G1 Z2
G38.2 Z-136 F20.0
G1 Z40 F200.0
G38.2 Z-136 F200.0
G1 Z2
G38.2 Z-136 F20.0
G1 Z40 F200.0

I am manually centering the cutter over my BitSetter then triggering the Quick Action. The first probe is just to find the top of BitSetter and is ignored.

After some back and forth with Carbide3D’s amazing support. We figured out that the capture nut on the Z ball screw was loose as well as the clamping screw on the Z motor coupler. After the blue Loctite on the capture nut to dry I am going to run some tests soon to verify that fixed everything, but I think that was the issue.

3 Likes