Does anyone here know of, or use, a bushing for the slots found on the C-beam and V-slot plates? I am in the process of making a build, and it would be very useful, and cut down on a lot of unnecessary parts if I was able to simply hard mount some bushings or pins, that could be secured behind the plate, and then to my top plate, that would hold the top plate at a fixed distance yet at the same time allow it slide back and forth along the slot. I would like it to be rigid with no side to side slop or front to back, just simply hold the plate a fixed distance, and allow it to freely slide along the slot. I have a mini lathe and can make the parts if necessary, but I'm just wondering if anyone here uses those slots as actual slots or simply just uses them to offset bolt patterns. I can't find any part similar to what I need in this regard in the parts store.
I appreciate the reply, however what I am referring to are the slots in the actual mounting plates, not the v-slots themselves. Circled in red.
In all the years I've been watching the forum I don't recall anyone ever using those slots. That being said, what you seek is not that difficult. A flat head screw, a threaded fender washer, a couple of slip sheets and a bit of red loctite should do the trick. If you need resistance to axial rotation you'll also want to drill in an M5 setscrew into the fender washer adjacent to the main screw.
Thank you for the response. I am in the process of replacing the Z axis head for my manufactured CNC Plasma table. I plan to use a C-beam linear actuator and simply add limit switches to the top and bottom, and then 3D print a torch holder that will bolt to the plate. Here is the issue. The torch head has automatic torch height control, meaning the bottom limit switch, is actually on the floating head, so when the Z is lowered, if the torch hits something, such as a thicker piece of material or a piece of square tubing, it will push the floating head plate up and engage the lower limit switch. This allows the machine to believe it has bottomed out, while on top of a much thicker piece of material. If I were to just use a limit switch at the top and bottom of travel, the actuator would not quit until it reach the physical bottom limit of travel, which would break it. So an idea I had, was to see if I could utilize those slots, mount another plate directly in front of the gantry plate thats connected to the lead screw, using a solid mount between the two plates in those slots, and just mount the torch holder to the outer plate. Then I would mount the limit switch right above the "floating" plate, and when lowered if the nozzle touches something it will push it up, sliding within the slots, until it triggers the limit switch, stopping motion. The only other way to do this would be to add additional rollers and another piece of v-slot rail, essentially in the same fashion, with the torch mounted to that plate, limit switch above it, and it would push up just the same. However this would add around a pound or so in weight and around 2-3 inches in thickness, not to mention cost of additional materials. Working the system dynamics for the gantry of my table, less moving mass translates to less overrun and better circular interpolation for holes and circles.
Sorry but the slots won't work for this. By the time you have tightened the connections up enough to prevent flopping you will have induced too much friction in the joint for it to move freely. You truly need a roller bearing here. Best suggestion would be to take a look at the Z-axis on the 5 X 5 Plasma SIMPLE Build. This is pretty much the ideal method for accomplishing what you seek by the slimmest means allowable. (You could potentially cut another 20mm out but I'm not sure it's worth the effort.)
