I have purchased a low rider cnc kit and I had a few questions that I hope someone could answer.
First what provides stability in the x axis? Do the z rails actually rub along the table, it’s hard from the pictures to tell what’s actually keeping the gantry aligned with the table?
Second is why the recommendation of under 4 inches. on table thickness, I have some larger 3x6 extrusion that was given to me from work that I am going to use to make the table, I was originally going to have the 6" dimension be the thickness of the table, will this cause interference at all?
The wheels driving on the table keep it straight. Most of us keep about a 16th of an inch of space between the table and the tubes, for just in case it actually slips. I’ve not had mine slip. The 4" spacing is because one of the Z parts stick out towards the table, it’s about 4 inches down from the top, so we have a 4" limit on the table thickness. I got around this by using some metal unistrut as rails. My table is around 8 inches thick.
If you push on the lr from the side, the wheels can slip, but the router isn’t really going to pull on it that hard. If it does then either your Cam isn’t quite right (for this type of machine) or what you really need is an expensive hotrod cnc. If it turns out to be an issue, you can follow some people who have put angle on the table to keep the wheels from moving. Like Barry, though, most of us don’t have a problem with it.