First, I was succesful and cut out the fold flat chair. I rounded over all edges and screwed in the hinges. Works really nice! The chair has only 2/3 of the normal size.
Because I reduced the size of the chair, the slots were too small for the 6mm cutting bit. So I told the CAM Software (KrabzCAM) that I only use a 4mm bit. Nevertheless it made all cuts in two passes for the inner and outer edge. Because of that the cutting bit was only touching the wood on the second pass. That pushed the maslow out of track. You can see clearly that in the y-axis this is more severe than in the x direction. Maybe I also had the DeWalt running to slow.
It is really important to fully support maslow with the right height. I screwed some scrap wood. around the workpiece but around 3mm thinner then the workpiece. That was enough to tilt maslow a lot and probably add a lot of friction.
When the cutting bit is plunged into the wood I often got some inaccuracies. This is extreme on the round holes. I don’t understand this.
not all bits are good for plunging, some have cutting surfaces over the entire
bottom edge, some have cutting surfaces on part of the bottom, and some only
have cutting surfaces on the outside edge. The latter type won’t do direct
plunge cuts at all, the middle tier will work if you do a helical feed, but not
well if you plunge straight down.
When I cut this circle, I lowered the z-axis in a ramping movement. After every tab was cut, the z axis was lowered and the sled moved back and forth. This movement during lowering also pushed the bit/sled into the workpiece. It is obvious, that the belts can’t be as stiff as a full metal gantry, but what could be done to make it better?
. By far the nicest one of those that I’ve seen.