Hello Builders We build a CNC based with vslot and some custom parts (mdf-table underneath , some custom milled metal plates/profiles for the axis). It took us ages but made us happy once it was running! Currently it's just operating with a cheap dremel to test, but results seemed pleasing. We are thinking of buying a Kress 1050 FM-1 as a spindle. I'm personally not sure on how to judge stats/noise. What do you think of it? http://www.kress-elektrik.com/Power-tools.71 M5a52714ab70.0.html?&tx_commerce_pi1[catUid]=17&tx_commerce_pi1[showUid]=1035 Other than that, does anyone know good resources to read about the calibration process? We went through the process rather quickly. We made a few things in PVC, XPS, MDF, thing plywood so far. They where good. But recently I found a huge imprecission when trying to mill some patterns that makes me scratch my head: When I carve the following objects as holes into a plate, the holes on the left are perfect, the ones on the right turn out too big. It happens in different materials and with different geometries. I though it would be either the geometry (drawing) or that the drill might be a little angled in the z-axis. Or the way the objects are carved out (spindle movement, somehow taking more material away on the right side). I checked the Gcode and the preview of how its gonna move, and its the same on both side -regarding how the spindle turns in direction and how its being moved around in X&Y. I also checked the drawings, they really are fine. All closed polylines, all the same distances etc. And it happens with a lot of other, similar files too. Also, I redjusted the z-axis for some hours thinking the spindle might not be straight, but the problem still persits (in the exact same scale regarding how many mm the milled objects are off, though I changed its alignment a little n the process). The right, is a mirrored geometry of the left, but turns out different when milled. Its supposed to be 3mm, but the left is ~ 3,5 mm in the end. When I mirror the geometry again horizontally, its the other way around: The left parts turn out bigger, the right ones are perfect. I don't get it! CAD files come from Rhino. Any help or links appreciated!