After months of planning and designing, I've begun construction of a small, Desktop CNC router. It will be a fixed gantry for the X-Axis and a moving table for the Y-Axis. Work envelope will be about 12" x 9" x 3" for the X, Y, & Z respectively. The X & Y axes will be 5/8" diameter hardened steel shafting with the moving parts attached with bronze bushings. The X axis rods are 16" long and the Y axis rods are 18" long. The main frame construction will probably be MDF although that may change. The inspiration for my design comes from Microcarve's MV2 and BBox routers with a lot of my own changes. Here is a picture of the assembled Y Axis:
The end plates 1/2" thick aluminum, 8" long. Spacing between centers of the shafts is 7". The back piece of aluminim is 1.25" high and the front is 1" high. The back will have some of height cut away to make room for the Y axis stepper which will be inside the frame (maybe). Other parts of the router will be made largely from items and materials already on hand. The X & Y axes will use 16mm ball screws, pretty beefy, I know, but I already have them. The spindle will be a 400 watt, 12,000 RPM DC model with integral ER11 collet chuck. Stepper motors will be older, NEMA 23 which I already have on hand, although I may have to upgrade these to something a little newer and stronger. The Z Axis will be a dovetail setup which I made from aluminum. I have the good fortune of having a small machine shop so am able to custom make a lot of the parts for this router. Don't know how fast this build will go, since I'm still designing as I go, so stay tuned.
Chuck