Originally Posted by
ssutton
This may not seem crystal clear but if you study it a few minutes you will get the picture (No pun intended). The shaft coupler that I am using will NOT support a hanging load, it is the spiral split type, so I am using a thrust bearing to hold the router weight and cutting forces. I am also using a standard bearing in the mount plate to handle rotary loads and keep the acme rod centered on the thrust bearing. The bottom of the acme rod is just simply captured by a zero backlash acme nut from Dumpster CNC.
Hope that helps,
Scott
When your router bit is plunging into fairly hard materials like oak or aluminum there is upward pressure transmitted into the motor shaft and the internal motor bearing is taking the load forces. I would recommend installing another thrust bearing and shaft collar under the aluminum plate as well. The lower end of the Z ACME rod can still "float" but for accuracy reasons it needs to be constrained by at least a simple hole in a Delrin block, if not by a bearing block.
CarveOne
CarveOne
http://www.carveonecncwoodcraft.com