I could use the forum’s expertise in helping me troubleshoot this issue. I carved this in a vertical orientation, so it looks like the X axis is off, but it’s really the Y axis. My Primo has dual end-stops, and they are solid. I perform an x/y/z home after the tool change. But, for some reason, the Y axis is off by about a quarter inch. I’m hogging this sign-out with a 1/8" up-cut bit, then doing the carving with a 45 degree V-bit. I’m using Estlcam 11.245_A_64.
G91 ; Relative positioning, just in case
G92 X0 Y0 Z0 ; Set Current position to 0, all axes
G00 Z5.0000 F500 ; Raise Z 5mm at 8.3mm/s to clear clamps and screws
G28 X Y Z ; Home in order, w/zprobe
G92 Z1.19 ; Account for probe thickness (set your thickness)
G00 Z5.000 F500 ; Raise Z probe off of surface
M00 ; pause for LCD button press
M03 S<s> ; PID, set spindle speed
G90 ; Absolute positioning, just in case
Here is my Tool change code:
M05 ; PID, Stop spindle
M00 Shutdown Spindle
G0 Z60 F400 ; Raise Z axis 40mm
M84 X Y; Disable X Y steppers
M00 Change Tool ; Wait for LCD button press
;Change tool: <n>
G28 X Y Z ; Home in order, w/zprobe
G92 Z1.19 ; Account for probe thickness (set your thickness)
G00 Z5.0000 F500 ; Raise Z probe off of surface
M00 Start Spindle ; pause for LCD button press
M03 S<s> ; PID, set spindle speed
Is your stock mounted at the machine 0,0? If not, can you upload the full g-code file? Even if you are mounting at 0,0, it might be helpful to see the first part of the g-code file.
There are some things you’ve done in this code that are a bit strange, but I don’t see anything that would cause a 1/4" Y axis slip. Personally, I don’t disengage the steppers when I change tools.
One troubleshooting step would be to run the script again with the router turned off and the bit in the air to see if the problem reoccurs when not cutting. Use a nail or other pointed object to mark the original origin before bit change.
Home is 0,0,0. @Philipp , I’m not sure what you mean by “after homing, it might not know where home is”. The point of homing is to ensure that “home” is always in the same place. I home it at the job start, and then I home it after the tool change.
@robertbu , I’ll add my g-code file a bit later today when I go back to my shop. The purpose of the stepper disengage is for tool changes, where my stock is a bit too thick. My Z range is pretty short. The disengaged steppers allow me to move the gantry to an area without stock for the tool change. Since there’s an X/Y/Z home after the change, this shouldn’t affect the cut.
Yes, your “machine home” is always at the same place, but “workpiece home” might be somewhere else. So basically the question about absolute and relative coordinates.
Let’s say you square the machine and then drive 2 inches to the workpiece and set X to 0. After the toolchange, running your squaring/homing again, did you maybe forget to drive it those two inches again?
Almost all MPNC users do not mount their stock at the machine origin. In fact, you are the only second person on this forum that I remember mentioning mounting the stock at the machine origin (as a standard practice). Most of the rest of us mount the stock wherever we want, move the router to the origin of the job relative to that stock, and execute a G92. From the firmware’s (Marlin’s) point of view, this set the machine origin to the point you specify.
There is nothing wrong with mounting your stock at the machine origin, but if it was further in, you would have some space to move the router off the stock for a bit change while the steppers are engaged.
But this has nothing to do with the actual problem you posted. So far, I don’t see anything in the g-code you posted to account for the 1/4" slip. It is possible this is a mechanical or electrical issue. If this is a mechanical issue, you should have heard an unmistakable grinding sound. Note that the grinding sound is non-destructive.
While you are using the machine home to continue cuts when the steppers have been disengaged, the primary purpose of homing is to square the machine.
Assuming your stock is typically smaller than the work area, you could do a rapid move to near max X or max Y as part of your bit change routine. This would allow you to continue your current mounting position but allow space (while the steppers are engaged) to change the bit.
I am using the dual end-stops and home it to 0,0 every time. I haven’t used the user-origin ever since I installed the dual end-stops. I place my material on the cutting bed and clamp it down in the lower-left (origin). Unfortunately, Estlcam does not accommodate switching between absolute origin and user-origin very well, having only one set of gcode texts for project start and tool change.
@robertbu
There is no grinding or tooth-skipping going-on. Over the years, I’ve experienced that, and that would have been a pretty obvious call-out. In this case, the tool change goes without a hitch. I don’t move the gantry during the tool change on this project. It simply carves in the wrong spot every time. I built this Primo about 3 years ago. I’ve done dozens of projects with tool changes without much trouble. However, I can’t remember when I last ran a project that required a tool change. As a result, it’s tough to pinpoint WHEN this issue started happening. When I head to the shop, I’ll also check the SKR Pro firmware and update if-needed.
I’ll head to the shop shortly and get that gcode. I appreciate the help.
I uploaded it to NCViewer and it looks fine.
Firmware on the machine just updated from 2.0.9 to 2.1.1. I don’t see any related fixes in the change log, but I’ll run this again to be sure.
Are you able to change your tool without disabling steppers? that way x/y stay where they are and you will not have a chance of setting your 0 wrong. When I do tool changes, I raised, changed, probed and resumed.
I’ll give it a shot. I also suspect something is up with my end stops. I’ll go through the instructions here again to be sure everything is still working properly.
Interestingly, when I updated the SKR Pro firmware to 2.1.1, the CF card reader stopped working. It wouldn’t detect the card when I inserted it. Downgrading back to 2.0.9 fixed that. @Ryan, have you seen this before?
I changed my config to NOT disable the XYZ steppers, and I eliminated the XY home and left the Z home after the tool change. Additionally, the SKR Pro firmware is updated and so is the TFT firmware. Thanks to Ryan for reminding me that this has a touch interface, I’m getting used to that now.
The carve is now clean after the tool change that I attribute to the locked XY steppers. But, the HOME XYZ should have solved that. I haven’t gone through the dual end-stop set-up and troubleshooting yet. I’ll do that later when I have more time.
Thanks for you input and suggestions. I know where the issue is now, and have some clues to move forward.
