I tried to use a drill press and some kind of sandpaper file (sandpaper cemented to steel plate) to true up wheels for model cars but I did terrible job. I don't have a lathe. The wheels are made from six pieces of plywood glued together. I'm not sure if I can use my CNC router as a lathe because I may not have enough Z-Axis travel. Any suggestions?
You must have a tiny CNC then? How thick are those wheels? When you say Z axis travel, do you mean the cutting bit does not have enough cutting edge length to get to the bottom of the wheel?
Hi @jeffmorris, I made a jig for jobs like that. My pillar drill has two slots in the table so bottom of jig has bolts protruding so it will slide in slots with wing nuts to lock it in place. Top has a dowel for the wheels axle hole, wheel overhangs edge of jig. Sanding drum in drill chuck. Slide until wheel touches sanding drum, rotate wheel on axle. Alex.
If you're just trying to level out the surface of the 6 pieces hold the sand paper in a U-shape around the wheel. This will give you 180 degrees of contact at once. Be careful of putting too much lateral pressure on the chuck as this can cause the whole spindle to drop out, flinging it wildly. (Drill presses lack a draw bar to hold the spindle in place). Conversely, just use your CNC system to do a finishing pass instead.
The wheels are made of six pieces of 1/8" thick plywood glued together. I have a Ridgit Oscillating Edge Belt / Spindle Sander but I don't have a jig for sanding circles. I'll have to search the Internet for plans for making the jig.
Why not glue up the six panels and then cut the wheels out with the CNC? They will be nice and round. If you need them rounded over you could use a 1/4 round bit in a router table. Or di you already cut them with the CNC and they are a little off? Pictures makes it easier for me to understand the question. That being said, you could just use the hole for the axle, if there is one, and bolt them to a board so the wheel barely overhangs one edge and slowly feed it into the belt until it just touches. Then, spin the wheel so it gets evenly sanded all the way around. I used to cut circles on a table saw in a similar manner, but now I have a CNC. Once you determine the perfect distance, you could put a tight fitting strip on the bottom of your jig so it slides in the slot on the sander so the distance is replicated every time. However, that is a lot of work if you only plan to do it once. I have this sander, is it the one you have?
Giarc, The problem is that two pieces have "spokes" and two pieces have "whitewalls". The "whitewall" pieces are glued on top of the "spokes" pieces. I have the same machine that you have.
Hi @jeffmorris, if you don't want to design a jig yourself I would be happy to help if you give me a dimensioned plan of your sander table, the wheel diameter(s), and let me know what cad/cam software you use. Alex.
If these are wheels with an axle hole, what's wrong with a piece of wood with a nail in it and a C-clamp?