Hi, I finally had time to assemble the unit and start the calibration.
position: horizontal
anchors in concrete, can’t move
dimensions 417x312 cm to be able to cut 250x125 cm sheets.
firmware 1.20
calibration without any router bit, z axis bottomed out
first calibration starts from the center, each belt is around 5 cm longer than needs to be.
finding anchors on a larger area gets quite low fitness. I’ve tried to mess with the calibration grid in maslow.yaml and edit values of anchors but nothing really helped…
I’ve read that early 4.1 units had tighter spool fitment so I’ll try to address it later, but I wonder if the measured data could show a hint where possibly can be an issue. I saw sometimes you recommend checking the data on Maslow CNC Calibration Simulation but I don’t know what to look for.
Also, when the calibration stops, maslow is usually pretty far from center. Does it mean that re-running calibration doesn’t need to retract/extend belts again? (this step was not totally clear to me)
Looking at the logs I’m not seeing anything that looks catastrophically wrong, it’s very very close to working.
It seems like maybe in the bottom left and top right corners something is a little off so it could be good to keep an eye on the machine when it’s there.
The first thing that I would try changing is to mess with the “Work Area” settings. The measurements will all be taken in that area and it seems like you are getting good measurements towards the center and worse out at the edges so starting off with a smaller work area should get you up and running and then you can grow it from there.
thank you…, so I need to verify the dots in the calibration simulation…they should ideally overlap, got it.
You’re right, I was able to calibrate it successfully with a smaller area (1200x900 mm), with fitness 0,612.
My problem is, I don’t know what else to do to improve accuracy on a larger area. I’ve tried messing around with the calibration grid and manually overriding measurements in the maslow.yaml but with no luck of getting better results.
Do I need to actually modify these calibration grid settings?
Maslow_calibration_grid_width_mm_X: 1200.000000
Maslow_calibration_grid_height_mm_Y: 900.000000
Maslow_calibration_grid_size: 9
I’ve read in another thread that the vacuum attachment may touch the belts in certain position so I’ll double check what’s going on near those top right and bottom left areas. I think those two have belts in the lowest position. My spoil board is 21 mm. Maybe when cutting anything, the anchors are just a bit too "deep - flush with the floor…)
I’m 100% sure the frame can’t flex, and there’s not much to check. I’ll try to verify if the spools aren’t too tightly clamped but that’s all I could think of.
Could you share what accuracy are you able to get from your machine? is it within +/-1 mm when you compare digital vs. real cut? or more?
thank you…, so I need to verify the dots in the calibration simulation…they should ideally overlap, got it.
You’re right, I was able to calibrate it successfully with a smaller area (1200x900 mm), with fitness 0,612.
My problem is, I don’t know what else to do to improve accuracy on a larger
area. I’ve tried messing around with the calibration grid and manually
overriding measurements in the maslow.yaml but with no luck of getting better
results.
Do I need to actually modify these calibration grid settings?
Maslow_calibration_grid_width_mm_X: 1200.000000
Maslow_calibration_grid_height_mm_Y: 900.000000
Maslow_calibration_grid_size: 9
I don’t think those are used any longer, several versions ago we went from
having people manually set the grid to having it automatically set the the grid
the wider the area that it measures, the better
post v1.21, Bar has introduced new calibration calculation math. I created a web
page to let me see the accuracy it produces and to let me throw out measurement
points that are too far off
copy the largest array of points from a find anchors run log and this will run
the new algorithm, tell you it’s estimate of accuracy, and let you adjust the
threshold for what points it should throw out for being outliers (including a
historgram to show the number of points in each error category and where on the
sheet they are)
another approach you can take is to measure all 6 distances between anchors and
enter the results into a manual calibration tool. I have one at
I would suggest doing this just as a sanity check against the automated methods.
The default now is to have the grid width and height set to 0 and 0 and then the machine will automatically calculate the best grid to use for your setup. That might be worth giving a try.
I’m in the process of making some big changes to how the math works which will require some accuracy testing so I’ll post some good measurements soon. Mine is all over the place because I am always deleting my .yaml file and starting over, but I have for sure had it within 1mm many times. Generally I think what happens is that people keep messing with things until they get a good set of settings and then they stop messing with it…but where we want to get to is you can press “locate anchors” once and it will give you good results the first time every time in every setup. We’re not there yet, but we’re getting closer steadily.
