Y Axis accuracy issue

Troubleshooting
1

Hi all,

Started cutting for the first time today. Setup my machine using the calibration video and all seems ok. Went to cut a test piece of a 200mm disk and ran into an issue. The x axis measures fine however the y axis is 210mm. Using Fusion to create my Gcode with the default MaslowCNC preset in fusion. It looks like it is stretched when it is inputed into the M4 GUI. Anyone able to assist?

Thanks

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Will only let me upload one photo at a time.

4

I had something similar with the first test I did a couple of days ago - I also had only done the minimal callibration and knew it was slightly off from my measured frame size.

I don’t suppose you have the calibration log? Or alternatively, have you dowloaded the maslow.yaml file from the board and checked the value against what your frame actually is?

I suspect that’s the first thing to rule out.

5

Hi Dave,

Thanks for the info. I did a calibration 800 x800, 7x7.

How can I download the yaml file to check?

Should I do another calibration?

Thanks

6

(I’m new to Maslows so this is just what i’ve learnt - but hopefully it’ll help):

When connected to the device, on the FluidNC tab there is a file system tab, and from there you can download the maslow.yaml file.

I would think another calibration is needed if the dimensions of the frame that the maslow.yaml file has don’t match your own measurements (it’s where it saves it all after calibration).

If you do calibrate again - there is a ‘Save Serial’ button at the bottom of the controls - it would be good to save the logs from the calibration.

7

Thanks Dave.

I have downloaded the yaml file. Sorry to ask the obvious but what parameters are the frame dimensions?

Tried doing a new calibration size 1000x1000, 9x9 grid. It tried for 2hrs but couldn’t calibrate so I had to abort. Will try again tomorrow with the original 800x800 but with 9x9.

8

This is pulled from an early attempt by me:

Maslow_vertical: **false**
Maslow_calibration_grid_width_mm_X: 500.000000
Maslow_calibration_grid_height_mm_Y: 500.000000
Maslow_calibration_grid_size: 3
Maslow_tlX: 2.400000
Maslow_tlY: 2234.199951
Maslow_trX: 2957.000000
Maslow_trY: 2220.699951
Maslow_blX: 0.000000
Maslow_blY: 0.000000
Maslow_brX: 2968.699951
Maslow_brY: 0.000000
Maslow_tlZ: 0.000000
Maslow_trZ: 0.000000
Maslow_blZ: 0.000000
Maslow_brZ: 0.000000
Maslow_Retract_Current_Threshold: 900
Maslow_Calibration_Current_Threshold: 900
Maslow_Acceptable_Calibration_Threshold: 0.450000
Maslow_Extend_Dist: 1700.000000
Maslow_beltEndExtension: 30.000000
Maslow_armLength: 123.400002
Maslow_Scale_X: 1.000000
Maslow_Scale_Y: 1.000000

So the values for the fram it calculated are:

Maslow_tlX: 2.400000
Maslow_tlY: 2234.199951
Maslow_trX: 2957.000000
Maslow_trY: 2220.699951
Maslow_blX: 0.000000
Maslow_blY: 0.000000
Maslow_brX: 2968.699951
Maslow_brY: 0.000000

For top-left-x, top-left-y, top-right-x, etc, etc.

AFAIK it takes bottom left as zero and bottom-left, bottom-right as a baseline (and it’s assuming the side with the vacuum port / power cable is pointing towards that).

Did you try again and did you manage to capture the log of the calibration? That and the yaml it creates might help track things down if you post some details.

9

Are you using offset anchors (i.e. they are different heights) to match the stacking order of the arms in your M4? If not, then these values are wrong, and fixing them, and then rerunning calibration will yield you better calibration and ultimately more accurate cuts.

10

Yep, this was from an early attempt where I had the anchors set to match the height of the arms - after trying that I have a bit of height difference now because I was seeing some tipping towards the edges.