Hi my name is Dave, I am building my second CNC router, which is of my own design. I based the design on my original cnc router, that I built from some plans bought from the internet. I am trying to improve accuracy and useability by buildin a heavier duty machine than the original
I have started building the z axis components and am having trouble boring the holes for the z axis rails accurately enough.
Here is a picture of the z axis so far
The curved component, which I am calling the motor housing holds the spindle motor (brushless DC) and is designed to move up and down on 2 parallel rails, which will pass through the rectangular z axis component and through bushes pressed into the back of the spindle housing.
I have tried to bore these holes in the mill once already, by clamping all of the parts together in a stack and drilling a pilot hole, then boring straight through.
The problem I encountered was 2 fold, caused I think by deflection of the boring bar, due to the long distance and small diameter of the holes. The bottom holes were slightly smaller than the top holes, which I fixed with a reamer and the holes were slightly out of parallel, which I couldn't fix and caused the spindle housing to be very stiff on it's rails.
I could have loosened the bushes a bit to overcome this, but I was concerned that the spindle would no longer be perfectly parallel and that I might introduce play, which I am trying to minimize.
I am hoping that someone will give me some tips about boring longish small diameter parallel holes
Here's a picture of my workshop