Why does my Shapeoko 3 XXL

Why does my shapeoko XXL keep losing zero

What is the context here?

The machine should home every time you turn it on — after that, things should be persistent until you shut it down, then the process starts again.

If that’s not the case, please describe in detail at each step:

  • what you did
  • what you expected to happen
  • what actually happened

I homed 1, 2 I zeroed X and y. then I zeroed Z. the I cut my pocket then I went to cut my Vcarver and it starts to loss zero

Probably the issue is happening between the pocket and the v-carve, right? Are those part of the same code file? What created the gcode file? When you change bits for the vcarve, what do you do exactly? Do you move the router?

And when you say “starts to lose” do you mean it starts out ok and then drifts (losing steps) or do you mean it starts in the wrong place?

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I homed the machine just as I do everytime before I a new job and everything went as it should. Then a loaded the job I was cutting and zeroed my X and Y then I zeroed my Z.

I was expecting the job to to run with out any issues but the z wasn’t working as it should it wasn’t moving to the set mark of the program and not it was going past its limits.

what happened is that it was stopping before it was reaching the set mark for the program

Step by step, include everything. So far we have:

  1. You homed the machine
  2. Set X zero, Y Zero, Z zero. (How?)
  3. Ran a job
  4. Stuff wasn’t expected

Was it a single job? Multiple Jobs? Did you change router bits between jobs? What software did you use to create the gcode?

What do you mean by moving to the set mark and not going past limits? Was it not cutting as deep as expected? Cutting too deep?

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It was a single job I did not change bits. When I st the program up I set it to cut to a depth of .200 in inchs and didn’t go to that depth. I had to stop the program and add another peace of sacrificial wood underneath the project to get it to cut to the death that I programmed

Is your router all the way down in its clamp?

something similar? Z-Axis loses zero

I’m wondering two things:

  1. Have you set your origin point correctly? You mention going past the machine’s limits and the cutter not jogging to the expected starting location for the job. What software are you using for CAM?

  2. You mention .2 inches, but Grbl is looking for millimeters. Feeding Grbl inches would result in extremely slow and smaller than expected moves. I’m not sensing this is part of the issue in your description but wanted to bring it up anyway.

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Yes router is all the way down in its clamp

1 I am using Vertric Aspire to draw and design and it has a a shapeoko c gode processor. So the parameters for the or the original parts for the machine are set correctly.

2 And I am drawing and design in inches not millimeters and using the post processor from vertric label shapeoko inches

There are a couple of other post-processors listed at: http://www.shapeoko.com/wiki/index.php/Commercial_Software#2.5D_CAM — might be that this behaviour is changed in one of them.

Unfortunately, since this is a commercial software program which I don’t have a license for, I really can’t help with it. I will note one valid testing technique from TeX/LaTeX, the “minimal working example”, where a complex task which exhibits a problem behaviour is broken down and simplified until only the aspects of it which are necessary to cause the problem are present.

Please, if we are to have any possibility of helping you, post this in excrutiating detail. Every menu name, every selection, every option. You might have better luck with a post title which mentions the commercial software name, or on the Vectric forums. I don’t know if Carbide 3D has a license, so that support can help you with it, but it might be worth packaging up the file(s) and a compleat description of your workflow and sending it in to support@carbide3d.com

If you’d like to try again in Carbide Create/Motion or some free / opensource workflow, it might be that we can work out what the difficulty is. Conceptually / fundamentally the machines are simple:

  • the machine is composed of rails, V-wheels, belts, pulleys, stepper motors, stepper drivers and a control board (as well as home/limit switches)
  • the control board has settings
  • Carbide Motion has preferences which interact with the settings on the control board
  • when it powers up, it sets an origin point, if the machine has switches enabled in settings (and preferences if using CM) it goes home to determine the origin
  • the machine then responds to the commands which are sent in, according to the settings (some software will parse and modify the commands before sending)

That’s it — (the complex stuff all happens in Grbl, which is what has made hobby-level CNC so affordable and reliable, if not directly, then by providing an MIT-licensed motion planner which was well-documented and an excellent model to follow) — please review your workflow, and try a write-up of it along the lines of detail which were used at: http://shapeoko.github.io/Docs/firstjob.html — include the descriptive text of why you think a particular operation is valid.

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Without any material mounted, can you jog your Z axis so that the end of the bit touches the the waste board - aka zero the Z at the top of the waste/spoil board.

If you cannot jog the bit to touch the waste board then you’re at the end of your Z travel where the bit stops. What happens when you try to continue to move the Z axis downward is the belt skip; you’ll hear a clicking type sound but the bit won’t move downward. The controller believes the bit has moved because it sent the signal to the servos, but due to physical limitations it won’t. When you attempt to go back to 0 it will move the bit higher than expected as the controller thought it was lower than the bit actually was.

Do you have a Makita of DeWalt router? the Makitas are a bit shorter and probably run into this issue.

Your options if you are at the end of travel are to add another piece of sacrificial wood under your piece, or extend the bit out of the collet more. I’d recommend adding another piece of sacrificial wood depending on bit size/length. More length out of the collet increases run-out and chance of breaking a bit.

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Use the GRBL (inch) (*.gcode) post processor. It should work great. I have been using it for a very long time and have not had any problems. The Shapeoko post processor sends my machine through calisthenics.and cartwheels.

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I have Vectric Vcarve Pro, and I do use the Shapeoko post but I had to modify it to get it to work. It was producing gcodes that GRBL doesn’t recognize. I don’t recall the details, but the main point is that just because the post name says “Shapeoko” doesn’t mean that it works right or was produced/supported by C3D.

The Vectric stuff is really great, though pricey. I use it in combination with Openscad.

Sorry if this was already mentioned, but simulating the toolpath can be really helpful if the probem is software/workflow related as opposed to electrical/mechanical. The Shapeoko wiki has a good list of free options, and simulation is built into Universal Gcode Sender (also free - think of it as an alternative to Carbide Motion).

If the problem is electrical/mechanical then none of this is helpful though.

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My XXL does not home when I turn it on, FYI. I have to issue a homing command.

I also lose zero sometimes for reasons I have not ascertained, but I use a touchplate in my workflow so it hasn’t really been an issue, for the kinds of projects I’ve done so far.

If you wish your machine to automatically home, please enable it in Grbl, and in Carbide Motion’s Preferences: http://www.shapeoko.com/wiki/index.php/Carbide_Motion_Machine_Control_Software#Enabling_Homing

Thanks, I do have homing enabled; though I generally use UGS not Carbide Motion. CM won’t allow you to jog until you’ve homed, but UGS doesn’t care. IOW automatic (or enforced, depending on how you want to look at it) homing appears to be a CM thing not something that grbl does on power-up.

In any event the workflow gives me no trouble, because I have an easy way to re-zero. I can imagine no end of frustration without easy re-zeroing.