ive been playing with this for days and ive eliminated 99% possible hardware/gcode issues that i could research as being a possible issue. the last issues is software and ive seen some similar post but no real follow-ups. Im trying to cut a bracket with a small cricle in the middle of it. it starts to cut the circle on right side 3/4 down then cuts a straight line across then continues a circle on the opposite side and then does another straight line. ive tried multiple files with and without smoothing in gcode but cant cut a circle. anyone know a reason or fix for this?
Can you upload the gcode file for us to look at? Have you ran it in a gcode simulator to see if it looks like it should work? Here is a simple one online: NC Viewer // GCode Viewer and Machine Simulator Erase all the stuff where I circled and paste your gcode there.
this is just a simple circle i did up to see if it was my gfile but it also cuts the circle the same way as other file this one has smoothing (1 Operation (1 : 2D Profile1) ( Work Coordinate System : G54) ( Tool 2: Plasma Cutter Diam = 5mm) ( Machining time : 0h:0m:2s) G90 G94 G17 G21 (Plasma pierce height 3) (Plasma topHeight 1.5) (Operation 1 of 1 : 2D Profile1) G54 (Plasma cutting with GRBL.) (Using torch height probe and pierce delay.) (This relies on homing, see Search Results for Query: G53 fusion | OpenBuilds ) G53 G0 Z10 G0 X4.58 Y-4.85 F1600 G0 X4.58 Y-4.85 Z15 G38.2 Z-100 F150 G10 L20 Z-1.8 G0 X4.58 Y-4.85 ; force position after probe Z3 M3 S1000 G4 P0.6 G1 Z1.5 F1200 G1 X0.25 Y-7.35 G2 X-14.95 Y-7.35 I-7.6 J0 F1600 X0.25 Y-7.35 I7.6 J0 G1 X4.58 Y-9.85 F1200 M5 G0 Z15 M5 G0 X0 Y0 M30 this one without (1 Operation (1 : 2D Profile1) ( Work Coordinate System : G54) ( Tool 2: Plasma Cutter Diam = 10mm) ( Machining time : 0h:0m:6s) G90 G94 G17 G21 (Plasma pierce height 3) (Plasma topHeight 1.5) (Operation 1 of 1 : 2D Profile1) G54 (Plasma cutting with GRBL.) (Using torch height probe and pierce delay.) (This relies on homing, see Search Results for Query: G53 fusion | OpenBuilds ) G53 G0 Z10 G0 X-13.462 Y26.4 F1600 G0 X-13.462 Y26.4 Z15 G38.2 Z-100 F150 G10 L20 Z-1.8 G0 X-13.462 Y26.4 ; force position after probe Z3 M3 S1000 G4 P0.6 G1 Z1.5 F1200 G1 X-17.462 Y26.4 X-17.455 Y26.159 F1600 X-17.432 Y25.919 X-17.393 Y25.681 X-17.339 Y25.446 X-17.271 Y25.214 X-17.188 Y24.988 X-17.09 Y24.768 X-16.978 Y24.554 X-16.853 Y24.347 X-16.715 Y24.15 X-16.565 Y23.961 X-16.403 Y23.782 X-16.23 Y23.615 X-16.046 Y23.458 X-15.853 Y23.314 X-15.65 Y23.183 X-15.44 Y23.064 X-15.223 Y22.96 X-14.999 Y22.869 X-14.771 Y22.793 X-14.537 Y22.732 X-14.3 Y22.686 X-14.061 Y22.655 X-13.821 Y22.639 X-13.579 Y22.639 X-13.339 Y22.655 X-13.1 Y22.686 X-12.863 Y22.732 X-12.629 Y22.793 X-12.401 Y22.869 X-12.177 Y22.96 X-11.96 Y23.064 X-11.75 Y23.183 X-11.547 Y23.314 X-11.354 Y23.458 X-11.17 Y23.615 X-10.997 Y23.782 X-10.835 Y23.961 X-10.685 Y24.15 X-10.547 Y24.347 X-10.422 Y24.554 X-10.31 Y24.768 X-10.212 Y24.988 X-10.129 Y25.214 X-10.061 Y25.446 X-10.007 Y25.681 X-9.968 Y25.919 X-9.945 Y26.159 X-9.938 Y26.4 X-9.945 Y26.641 X-9.968 Y26.881 X-10.007 Y27.119 X-10.061 Y27.354 X-10.129 Y27.586 X-10.212 Y27.812 X-10.31 Y28.032 X-10.422 Y28.246 X-10.547 Y28.453 X-10.685 Y28.65 X-10.835 Y28.839 X-10.997 Y29.018 X-11.17 Y29.185 X-11.354 Y29.342 X-11.547 Y29.486 X-11.75 Y29.617 X-11.96 Y29.736 X-12.177 Y29.84 X-12.401 Y29.931 X-12.629 Y30.007 X-12.863 Y30.068 X-13.1 Y30.114 X-13.339 Y30.145 X-13.579 Y30.161 X-13.821 Y30.161 X-14.061 Y30.145 X-14.3 Y30.114 X-14.537 Y30.068 X-14.771 Y30.007 X-14.999 Y29.931 X-15.223 Y29.84 X-15.44 Y29.736 X-15.65 Y29.617 X-15.853 Y29.486 X-16.046 Y29.342 X-16.23 Y29.185 X-16.403 Y29.018 X-16.565 Y28.839 X-16.715 Y28.65 X-16.853 Y28.453 X-16.978 Y28.246 X-17.09 Y28.032 X-17.188 Y27.812 X-17.271 Y27.586 X-17.339 Y27.354 X-17.393 Y27.119 X-17.432 Y26.881 X-17.455 Y26.641 X-17.462 Y26.4 X-13.462 Y26.4 F1200 M5 G0 Z5 X-31.4 G38.2 Z-100 F150 G10 L20 Z-1.8 G0 X-31.4 Y26.4 ; force position after probe Z3 M3 G4 P0.6 G1 Z1.5 F1200 G1 X-27.4 Y26.4 X-27.4 Y33.778 F1600 X-27.393 Y34.007 X-27.37 Y34.234 X-27.334 Y34.46 X-27.282 Y34.683 X-27.217 Y34.902 X-27.137 Y35.116 X-27.044 Y35.325 X-26.937 Y35.527 X-26.818 Y35.723 X-26.686 Y35.909 X-26.543 Y36.088 X-26.388 Y36.256 X-26.223 Y36.414 X-26.047 Y36.561 X-25.863 Y36.697 X-25.671 Y36.82 X-25.47 Y36.93 G2 X-18.139 Y39.632 I13.913 J-26.461 X-7.025 Y39.031 I4.437 J-21.013 X-1.677 Y36.792 I-8.749 J-28.396 G1 X-1.49 Y36.667 X-1.311 Y36.53 X-1.141 Y36.383 X-0.981 Y36.225 X-0.831 Y36.057 X-0.692 Y35.88 X-0.564 Y35.695 X-0.449 Y35.502 X-0.346 Y35.302 X-0.255 Y35.096 X-0.178 Y34.884 X-0.115 Y34.669 X-0.065 Y34.449 X-0.029 Y34.227 X-0.007 Y34.003 X0 Y33.778 X0 Y3.54 X-0.008 Y3.308 X-0.03 Y3.078 X-0.068 Y2.849 X-0.121 Y2.624 X-0.188 Y2.402 X-0.269 Y2.185 X-0.365 Y1.974 X-0.474 Y1.77 X-0.597 Y1.573 X-0.732 Y1.385 X-0.878 Y1.206 X-1.037 Y1.037 X-1.206 Y0.878 X-1.385 Y0.732 X-1.573 Y0.597 X-1.77 Y0.474 X-1.974 Y0.365 X-2.185 Y0.269 X-2.402 Y0.188 X-2.624 Y0.121 X-2.849 Y0.068 X-3.078 Y0.03 X-3.308 Y0.008 X-3.54 Y0 X-23.86 Y0 X-24.092 Y0.008 X-24.322 Y0.03 X-24.551 Y0.068 X-24.776 Y0.121 X-24.998 Y0.188 X-25.215 Y0.269 X-25.426 Y0.365 X-25.63 Y0.474 X-25.827 Y0.597 X-26.015 Y0.732 X-26.194 Y0.878 X-26.363 Y1.037 X-26.522 Y1.206 X-26.668 Y1.385 X-26.803 Y1.573 X-26.926 Y1.77 X-27.035 Y1.974 X-27.131 Y2.185 X-27.212 Y2.402 X-27.279 Y2.624 X-27.332 Y2.849 X-27.37 Y3.078 X-27.392 Y3.308 X-27.4 Y3.54 X-27.4 Y26.4 X-31.4 Y26.4 F1200 M5 G0 Z15 M5 G0 X0 Y0 M30
nothing wrong with the gcode you posted. if the machine is not following the code then I believe it is getting stuck, either in X or Y, and cannot follow the arc. look for something stuck in a wheel, or V groove, sticky leadscrew, etc.
Loose setscrew on shafts coupler. Check grubscrews and make sure on is on the flat of the D-shape motor shaft, and properly tight
ok newest update. replaced all couplers from the spirals to the more solid ones with rubber cushion. cleaned every rail again. i have already taken bearing blocks apart and cleaned and regreased them a few days ago. they are to the point i can spin the ball screws extremely easy now. made a new circle and started the cut. it looks like the y axis slows down at those 2 points. it doesnt stop but it slows almost to a stop before starting to spin the other direction. then again before it gets to lead out.. instead i tried increasing the speed. reccomended speed is 1600 mmps for my settings and i thought holes should be cut slower. instead i set speed to 3200 and i got almost a perfect circle. y still slowed down but at that speed the difference in the left and right diagonal sides of the circle were only .35 mm instead of almost 2mm now. any idea what this could mean?
I am confused now (probably just failing to visualize what you said). To draw a circle X and Y must both slow down, stop, and spin the other direction, at different points, otherwise you dont get a circle. This is normal. To figure out if there is a problem , we need pictures and/or video please. Along with the pictures we need to know which direction the cut was done, clockwise or anticlockwise? and also which is X and which is Y you have calibrated X and Y, right? There is a wizard in OpenbuildsCONTROL.... if they are not moving the correct distances then circles will never be round.
Ok. X and y are perfectly calibrated. Only like .1 mm off. Cuts are clockwise. It will cut a perfect square. But when cutting a circle y slows down almost to a stop when changing directions. Yea I know it should slow down but y is visually alot slower than x. Here is a picture. It slows down so much slower in dysyncs itself.
looks like backlash in Y , or some freaky spring loading against resistance. make sure your GRBL settings are correct, in particular $1 Step idle delay, milliseconds must be set to 255
As @David the swarfer said, that looks like quite noticeable backlash on the Y axis. The first place I would look is the motor couplers - do you have a grub screw on the flat of the motor shaft. Assuming leadscrews, are they really secure in the motor coupler? - any movement within the coupler? Any signs of the gantry skewing slightly when this happens? - one side slowing more than the other? Alex
ill take a video later and check areas mentioned. ty. been trying to figure this out every day for the last 7 days at this point ive pretty much taken whole thing apart and put back together. cant find anything physically wrong.
The shape of the circle suggests backlash during direction change. Usually that's loose shaft coupler screws. What kind of machine is it? Pics?
Sorry for delay got caught up working. That was the most extreme case I cut. The slower I cut the worse it is. The faster I cut the better but don't think I should need to cut 2.5x faster that recommendation for a good circle. I'll try uploading the vids.
Looks like I had to make a yt to upload them as this sight doesn't allow direct uploads. On phone not able to link each one but this is the channel to the videos. It should have the. Uploaded soon. https://www.youtube.com/@user-zu4vw9ql2v
The z axis is only crappy part of build. In the process of converting mill to CNC then I'll build a better floating z. But for now it's stable and doesn't move around.
Probably flex in that 3D printed float. Put a marker on the Z axis (plate before the flimsy bit) and draw some shapes, see if the issue is carriage or torch Also, never underestimate the weight of that hose at it moves around it will tug on the torch. Lots of flop between cable tie up top and torch down there. * Flimsy bar, held in one little spot by printed clamp. Long reach down flimsy bar to torch. Heavy hose.
from the direction of cuts and orientation of the part there is definitely backlash in the X axis. why it is speed dependant is probably due to the dragging pipe, it is the only thing putting force on the head since there are no cutting forces. (point finger at 3d printed parts and says "start there" (-:
Ok attached a pen to frame but honestly I can't tell if good or bad. Did a number of circles in both directions spaced .5 inches apart.
