Issues with x and y axis going beyond material

Hello all! A little history:

About 4 to 5 years ago I built a CNC router using my own design gleaned from several others, and the parts from OpenBuilds Parts Store. I used an xPro V3 controller. I have checked calibration, and 10 mm moves each access exactly 10 mm.

After all this time of struggling with graphics programs and CAM software, I finally broke down and purchased a copy of Vectric VCarve Desktop. Things go perfectly right up to putting a gcode file into the controller and making it carve wood.

For whatever reason, I am apparently very dense in that I am somehow getting the x and y axis screwed up. The z axis appears to be working fine, but the x and y end up going off the edge of the material by a considerable amount. It's almost as if there is a unit conversion issue somewhere.

For transparency, I am using inches within the program to draw the image, and then when I write it to a gcode file, I am using the mm. Maybe that is where I am failing, but I haven't found any documentation that states it will or won't do the conversion. Do I need to put my controller into inches mode and write the gcode in inches instead?

Any and all help is appreciated. Call me stupid, because that's probably my problem. However, if the conversion from inches to mm is the issue, then I will need some info on how to access the registers on the xPro V3 to convert it to inches. I did try that, but it never seems to keep the setting and always reverts back to mm on power cycle.

 

Thank you for that info. I am using grblpanel right now. Was originally using UGS 2.0.9, but for some reason it has stopped working as of tonight. Not sure what is going on with that.

First 4 lines of the gcode file in quesiton are:

T1
G17
G21
G90

So given that, I have no idea what else to check at this point. I will say that I flashed the xPro V3 with the latest GRBL hex code. It was originally on 0.90, but nothing would work with that code and the version of java I had on my laptop, so I researched updating and am now running GRBL 1.1h. Wondering if the controller is just too old at this point, but would think the latest GRBL code should work.

 

So I am using VCarve Desktop and using the GRBL post processor. Is there a difference between that and the OpenBuilds post processor?

Sorry, yes I am using the GRBL, not the OpenBuilds GRBL. I will change, as I was not aware there was a difference. I did do a gcode output using the OpenBuilds GRBL, and there was 1 additional line in the file, but otherwise it was identical. Material size is 5.5 inches high by 12 inches wide. GCode is attached. The Ryan-Stitch.gcode is with the standard GRBL post, the Ryan-Stitch1.GCODE is with the OpenBuilds GRBL post. Pic from VCarve showing what it is saying will come out is also attached

 

Considerable amount is 2 to 4 inches before I stop the machine for fear of going too far to the end of the axis. I always zero to lower left corner of the material and then immediately run the program, so program is already loaded and ready to go. It's almost like it's scaling up the size of the drawing as it's running. I have all the settings from my controller, and they always look the same between power cycles.

At this point, I am at a total loss, as this is the first time this has done this. I was able to create a 4 letter name, and it stayed on material, but that was running the gcode using ESTLcam. UGS and grblpanel seem to have issues for some odd reason. I'll try the OpenBuilds control software and see if I can get it to work. It will be this evening before I can do that, but I'll report back as soon as I can.

 

i'll run all this again to see what happens. just to add further information, i've also tried ugs 2.0.9, both the 32 bit and 64 bit. for some reason it worked a couple of days ago, and then stopped working, so i switched to grblpanel. i'll try it again with the openbuilds control software. ultimate goal is to eventually replace all my electronics with the kit that openbuilds sells along with the control panel so i don't have to keep taking my laptop out to the garage, i can just run it with a usb drive at the machine.

 

So I have attempted several calibrations and have been only partially successful. The y and z axes seem fairly close but the x is giving me issues

The attached video demonstrates a noise that I have not been able to correct. All axes spin easily by hand when power is removed from the controller.

Wondering if there is a binding somewhere that is causing my calibration to be thrown off

The x axis I use 400mm for calibration, yi used 500 and z I used 50

Thank you all for your help thus far!

 

To add more info, when I quickly turn the couplers at the end of the lead screw it seems like it's moving too fast for the blocks. I am using the anti-backlash blocks, in case that matters. I've tried adjusting the tension on it, but that doesn't seem to have any effect on the issue.

 

I appreciate that. I do disconnect them. At this point, however, I'm so frustrated that I'm just about ready to just haul it off to the trash. Never had completion of any project escape me so thoroughly! Quite disgusted with this. I designed and built this over 4 years ago, thinking that within 5 to 10 years I could be making some decent side money. However, this has become the biggest waste of money and time I have ever started out trying.

 

how is it a wiring issue? the axes move, and in the correct direction. everything functions, just not accurately.

 

sorry, missed the second part of your reponse. here are my grbl settings. every time i attempt to calibrate my x axis at this point, i get a different measurement. i am attempting to calibrate at 500mm, and it will move anywhere from 490 to 512 mm, depending on what the last calibration was. closest i've ever gotten was 502mm

$0=10 ; Step pulse time, microseconds
$1=255 ; Step idle delay, milliseconds
$2=0 ; Step pulse invert, mask
$3=4 ; Step direction invert, mask
$4=1 ; Invert step enable pin, boolean
$5=0 ; Invert limit pins, boolean
$6=0 ; Invert probe pin, boolean
$10=2 ; Status report options, mask
$11=0.020 ; Junction deviation, millimeters
$12=0.002 ; Arc tolerance, millimeters
$13=0 ; Report in inches, boolean
$20=0 ; Soft limits enable, boolean
$21=0 ; Hard limits enable, boolean
$22=0 ; Homing cycle enable, boolean
$23=1 ; Homing direction invert, mask
$24=2000.000 ; Homing locate feed rate, mm/min
$25=1000.000 ; Homing search seek rate, mm/min
$26=250 ; Homing switch debounce delay, milliseconds
$27=5.000 ; Homing switch pull-off distance, millimeters
$30=1000 ; Maximum spindle speed, RPM
$31=0 ; Minimum spindle speed, RPM
$32=0 ; Laser-mode enable, boolean
$100=200.000 ; X-axis steps per millimeter
$101=197.920 ; Y-axis steps per millimeter
$102=191.520 ; Z-axis steps per millimeter
$110=1000.000 ; X-axis maximum rate, mm/min
$111=1000.000 ; Y-axis maximum rate, mm/min
$112=1000.000 ; Z-axis maximum rate, mm/min
$120=100.000 ; X-axis acceleration, mm/sec^2
$121=100.000 ; Y-axis acceleration, mm/sec^2
$122=100.000 ; Z-axis acceleration, mm/sec^2
$130=270.000 ; X-axis maximum travel, millimeters
$131=270.000 ; Y-axis maximum travel, millimeters
$132=80.000 ; Z-axis maximum travel, millimeters
$I=cbeam

 

i don't think so, but that's an easy one to double check all the couplers. it's very frustrating.

i've got an issue somewhere, maybe in the anti backlash blocks? other than a controller or stepper motors that just aren't fucntioning correctly. i should be able to completely disconnect the couplers and run the motors and rule those and the controller out, correct? in other words, if disconnecting the couplers and running the controller and motors as if they were connected still causes the chattering, then it's a controller or all 4 steppers are bad, otherwise, it's got to be in the lead screw/anti backlash connection.

i will say that this machine sat for almost 4 years doing nothing because i gave up on it for a while. i am at the point now where i either get this up and running, or i go find some financing for a complete factory built router.

 

i'll answer in order:

i believe the motor coils are paired properly. i was very diligent in making sure of that, as that is one thing i read was critical while i was researching before i ever ordered any parts.
no loose wires that i can find. i'll check motor coil pairing again, as well as all connections made.
all the screws, couplers, and plates are openbuilds parts. the only things that did not come directly from openbuilds was the xpro v3 controller, the stepper motors and power supply. the motors and power supply came from omc-stepperonline.com, which was a link referenced in other builds, and the controller came directly from spark concepts.
yes, the problem is on all 3 axes.
yes i am still using the xpro v3 board. i have updated the grbl code to 1.1h.
current was adjusted at the time of build. i'll confirm that as well.
motors are nema 23 motors.
i appreciate all the help that has been given thus far, and thank you in advance for further input.

the wiring had come up earlier, and i was confused as to the question, but confirming the coil pairing does make sense now that it was specifically mentioned. thank you for that, and thank you to @sharmstr for your input as well. i re-read my reply, and apologize if it sounded dismissive, but wasn't thinking in terms of coil pairing and such.

i will go through this list and report any findings.

 

just checked the x axis and both coils are correctly paired, as well as correct polarity according to the wiring for that controller. will check the y and z axes as well as current adjustment sometime in the afternoon and report back

 

My next steps will be to disconnect the coupler and jog x axis. That should rule in or out the overcurrent since wiring is good and I was very careful to wire all axes identically. I'll work on that this afternoon

 

well, that's good information. i'll see what we can do.

 

just confirmed that the xpro v3 does have the drv8825 drivers. i've been keeping tabs on the heat sinks on those chips, and they never really got that hot. they were warm to the touch, and the stepper motors i have are rated at 2.8 amps vs the 2.5 amp max of the driver. i guess that's a little detail that i missed at the time. that could explain a lot of the problems i've had!