Probe crash, broken bit and Y zero stop trouble?

Hey Everyone,

First I have to tell you how much I am loving my X-Carve. I started out with the MPCNC and moved to X-Carve when my MPCNC gave me soo much trouble that I retired it.

The X-Carve has been so much more reliable and generally trouble free.

Unfortunately it has not been completely without issue. Last week I had an 1/8" mill chucked up and started a carve. I set the Z probe up for zero and it failed to stop when the mill hit the Z probe puck. It continued down, broke the mill and, in the process, forced the carriage towards the front of the machine. When this happened it moved the Y zero stop forward a bit over 1/4".

Now my zero is off. I need to move the Y zero stop back to it’s original position or re-mark my waste board to reflect the new zero. I prefer to return the previous zero.

I am a bit stumped as to how to do this. Any suggestions?

Also, any tips on preventing future Z crashes would be appreciated.



the only reason I can think off on why it did that is because something was not plugged in on the probe

what program was you using to Z-Probe with? Easel or something different like UGS, Bcnc, Chillipeppr? if Easel did it make contact before sending the probe command? if not Easel how do you know that contact was made? that is why Easel has the check for contact before you send the probe feed down, if no contact is detected then don’t send the probe as it will not stop until it hits it limit which is usually far below the waste board.

I would check my wiring for loose connections as it would seem that you lost contact and never triggered the probe.

Thank you for all of the replies.

I am using Easel and it did pass the “contact” test then failed to detect contact with the puck when I continued.

I am now poising my hand over the kill switch when I zero.

I did measure and input the exact thickness of my puck but I missed the the max seek distance setting. That said, I am having trouble seeing how that will save me in the future unless I limit myself to a fixed material (workpiece) thickness. What am I missing?

And finally, Jeff: I can figure out moving the screw but, what is the “correct position”?

I “ballparked” it and I have it close enough for rough work but if I want precision I need to fix it… And, while typing this response, I got an idea! EVERYBODY DUCK!!

I will report back.

:slight_smile: Coming from MPCNC, my first probe (using Triqueta) ended up with a broken bit as well. Too late to hit that e-Stop. Learned a hard lesson

dont worry you will break alot more tools in your cnc adventure lol I have broken many

the ones that hurt are when you first take it out of the package load it up in the machine and then 2 seconds later it breaks there goes 50 bucks!!

If you are talking about the homing switch contact screw then there isn’t a “correct position”, put it where you want it to be within the limits of moving the machine.

Obviously, you don’t want your machine to run into anything before contacting the homing switch, but keeping that it mind put it where you want it.

On my 500mm machine I line up the home position over the left front corner of the wasteboard graphic.

Moving it is easy. The challenge is trying to get it back as close to exactly where it was before.

What I wound up doing was:
Homed the machine
Dropped the Z down until the tip of a Vee bit was almost touching the waste board
Jogged the Y to the right a couple of inches
Checked the gap between the zero switch and the stop with feeler gauges.
Used feller gauge to adjust a couple thousandths
Zeroed again and repeated the above process until the tip of the Vee bit centered (almost…) on the Y0 registration mark.

Fortunately the broken bit was a $3 mill not one of my spendy ones.

I noticed that the connection to my z-probe is flaky. With the probe plugged in to the female jack, I can rotate the male probe plug within the jack and can feel the resistance to my rotating the plug change – at the point of least resistance the probe isn’t making contact properly and will fail the z-probe test. Fortunately Easel has you check this prior to probing and the flaky probe connection has yet to cause a Z axis crash. I should note that simply rotating the plug a bit (until it resists rotation) will restore connection. I’m probably going to switch to a different style probe plug or seek out parts made to a more exacting standard and replace the plug ends…

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Boy am I confused…

I thought the zero spot on the waste board was a reference point for placing my workpiece. Without it how would I know where Zero is and where on the waste board to place my work???

The wasteboard graphic is pretty, but it doesn’t necessarily become a useful item.

What you do is to place your work piece in the work area and then move the spindle to where you want to start your work and you then establish work zero at that location.

Once that’s done you can carve your design based on the location where you placed the material.


Thank you for the video’s.

As I posted above, I did manage to restore the previous setup using feeler gauges to measure and move the stop until I corrected the issue.

Well… there are no graphics and that is not how I do it.

There are lines that I scribed in the waste board along X0 and Y0. Where they meet is, obviously, X0,Y0. That is the point where I locate my workpiece zero. Then I home the machine and then set the Z axis using the probe.

I prefer the consistency that I get using the machine home. When I was running the MPCNC machine I did not have limit switches so I did “eyeball” the start location and found that I could not manage adequate repeatability or accuracy.

On mine, I used a Vee bit to mark zero. I homed the machine then manually jogged the router down to mark zero. Then marked lines along X0 and Y0.

I use these marks to place my workpiece.

Thank you.

I checked mine and it is similar. I may follow your lead and look towards a more robust connection.

Ok, I must have mis-read your post.

I haven’t heard anyone else use this procedure.

What is the purpose of homing your machine after you set work zero?

I don’t.

home=work zero

So, this statement is incorrect?

Thanks to those who offered constructive advice.
Much appreciated.