Okay, I took the sled off and cleaned the router body and collar with WD-40 (couldn’t find the beeswax). I think I have things operating smoothly now. I rotated the Z axis a little bit more and can now see visible air between the bracket and the router all the way down. The router still doesn’t move very nicely in the collar despite the WD. I’ve played with the clasp adjustment screw as @bar suggested and have it essentially just keeping the collar a uniform size but not really tightening it down (if I tighten it it pulls the z axis in toward the router to the point where it touches.
I think I have the z working reliably now, and am going to try some test cuts. It’s surprising how much bungee tension is required to keep the router sliding down. I’m hoping that some wax will help.
In our woodworking shop we use 3M spray silicone lube or TFE lube – dry, so don’t gum up with sawdust – For the chain, and lubricating the router motor to slide in the housing, I’ve been using “White Lightning” chain lubricant from a bike shop
I am having this same problem. I was doing some after calibration “fun cuts” and I cant set the depth to anything I want and router cant get through my half inch plywood. I need to take the sled off and play with it but, I have lubed the router, I have the bungee in place and I have loosened the clasp.
@arnoldcp, do you have a stock setup and are you using a linkage kit (if so, which one)? If you take the sled off the chains, leaving the z axis motor cables connected, can you get the bit to lower all the way using the manual z-axis command (the screen where you would define zero for the z-axis)?
Stock setup, with Logan’s linkage kit. I have a bungee up over the top and the base is clipped. The first thing I did was take the sled off and I lowered the bit all the way up and down maybe 10 times or so. The router is binding a little, so I do need to polish it up and put some paste wax on it. I am still seeing a discrepancy between what I am measuring and what I am telling it to move. Over a 1/2" movement I am losing about 3/64ths of depth.
What version for Ground Control and Firmaware pease? What OS are you on your computer? Can you upload a copy of your GroundControl.ini file from your user directory?
The symptoms are different but I also have had a problem with getting depth out of my setup and it turned out that because I twisted the z-axis away from the lower right pillar of the linkage kit, I created the slightest of interference between the z-axis motor mount (up top) and the top of the router. As the router lowered, it would just clip the motor bracket and get hung up. The arm on the lead screw would pop out of the tab in the router and continue to move down while the router wouldn’t. When I raised the bit, the arm on the lead screw would pop back into the tab on the router as it and everything moved back up together. Doesn’t seem like the issue you have, but check nevertheless.
And you can connect the Z axis cable and test it on your work bench before reconnecting the sled. It’s much easier to see where things are getting hung up when it’s on a flat surface, rather than hanging from the chains.
I ended up putting the bolt for the lower right pillar through the bottom of the z-axis motor bracket and installing the pillar on top of it. It works well enough.
I found your description of doing this while wading through the long Linkage thread and it totally saved me. I was really struggling with the Z axis vs. Linkage block placement until I saw it. Should probably be on the Linkage instructions wiki…
I will spend a little time tonight looking closer, I have moved my z axis a few times making sure it didn’t catch. I was expecting thats what was happening.
I may have solved what was making me lose the 3/64. The lock tab and the lead screw itself has so much play in it that if I push the router up and down I can gain or lose about that much. I think the bungee preload I had on it was far too much because I can actually see thread patterns cut into the side of the magnesium lock tab. This may be exacerbating the behavior I am seeing. I ordered a new lock tab and I am going to get some UHMW plastic washers to put at the bottom of the lead screw.
