I am still having some issues with the accuracy of my c-beam cnc machine. It is off by roughly .02'' on cuts. I calibrated the machine using the openbuilds software (x,y,and z) and that did not seem to help. All of the parts of the machine seem mostly really sturdy. I am confused on why I am still not getting within the precision it says on the website. Any suggestions?
1) make sure to caliper your endmills actual flute diameter and CAM accordingly - most are undersized a bit 2) make use of roughing+finishing pass strategy (a light finish pass puts less loads on machine resulting in better finish and accuracy) 3) check tramming, wheel adjustment and other mechanical setups
When you calibrated, what distance did you use to calibrate? 2", 5", 10" or even bigger. The bigger the distance the more accurate your calibration will be. I use the whole 47" of my machine travel.
I did 150 (roughly 6 inches) mm for x and y and did 60 mm for z. I knew that the bigger the distance the less room for error. I don't think this is the issue because I doubled checked all of them and after I fixed it they seemed to be right on the dot.
Once. a Leadscrew cannot change its pitch - if your calibration constantly changes - something is loose
Okay, thanks. I think I am going to buy a bit to try tramming it. I am a beginner CNCer so I do not know a lot about this stuff haha.
No bits required. Tramming = making sure the machine is perfectly square XY plane = perfectly flat (no corner of the Y rails higher or lower than the others) Z uprights perfectly perpendicular to the XY plane X gantry rail perfectly parallel to the XY plane X gantry rail not rolled forward or backward, pitching the z axis away from being perfectly perpendicular to the XY plane Z axis moving perfectly vertically in all directions - not mounted leaning a little left or right, and x rail it's mounted to not causing it to lean forward or back finally, Router mounted perfectly inline with the Z axis
The more accurate you build the machine, the more accurate work it can deliver. Up to you with how exactl you want to go. A standard Square gets you quite fary See Tramming: A generic guideline for more info
Do you have a longer measuring stick than 6 inches? I would do as @JustinTime said and calibrate over as long of a distance as you can. You will be able to see the error much easier. Especially if you use a pointy V bit.
