Hi, I am just getting to know my CNC and I am trying to surface my spoil board. To test it before doing the actual spoil board I have mounted a small piece of MDF to surface first. However, I get these stripes when surfacing (see attached image) IMG_2958.jpeg If they were saw toothed I could understand that the Z axis might not be square, but these are highs and lows like the Z axis is changing height when ever it turns to go the other way. like +0.5mm in the positive Y direction and -0.5mm in the negative Y direction. How does this kind of behavior happen? I have not been able to find anything on the forums or elsewhere on the internet... The setup I am running is an OpenLead 15x15 with extra Z height and an xPro V5 controller. The Spindle is a AMB Kraft 1050 and a 6mm flat end bit. (I know this will take for ever to surface the entire board with a 6mm bit, but this is just a test )
You sure get points for originality with this one. Just guessing but I’d say you’ve got an uphill/downhill issue due to too much flex in your system. One direction you’re climb milling, one direction you’re not. You’ll notice the little swerve at the end of each row as it digs in. As a suggestion try running a pattern 90 degrees opposite to see if the issue goes away. Also try tugging at tool head checking for weakness. Any motion will show up in your final work. If there is motion check for improperly tightened wheels or loose connections. Ultimately the only solution may be moving the lower rail down to stiffen the system if wheels aren’t the issue.
Can you confirm that it is not cutting a 6mm wide track in one direction then moving maybe 12mm on the X axis to start the next cut?
I will check this next time I am at the workshop. With my building skills, it might be some flex in the X/Z axis joint... I have modified the Z axis so the C channel is moving instead of the XL-Gantry plate. And I am always hunting for extra points
Even without the problem that you have it's not a good idea to have a 0% stepover. There are opinions galore of how much should be used but do yourself a favor and use at least 20%.
