|Project by JoelK||posted 03-08-2012 02:15 AM||3502 views||14 times favorited||15 comments|
My first attempt making a CNC router was an interesting voyage into the unknown. I had no idea how a cnc machine worked or how it was controlled and started out with an idea which never made it to paper this was built all from my head. Not a great way to build anything but I knew what I wanted and putting it on paper seemed to be a waste of time. I started by doing quite a bit of research then decided on the materials mostly wood except for the rails which also acted as a partial frame. The bottom is an egg crate design(torsion box) using plywood the angle iron is bolted through the first layer of plywood. the size of the machine is 3’ x 4’ enough room to do a relatively large project if I so desired. The original gantry is 1 1/2” oak the side of the gantry are 7/8” oak and the z axis is a combination of oak and birch plywood. The torsion box is a mixture of 3/4” plywood and chip board. The machine is quite heavy more than I expected but that is OK, it makes it quite sturdy. This design gave me some problems the biggest was the plywood z axis, I should have used oak. The plywood was much too soft to handle the stress on the bearings. I used V grove bearing which allows everything to run on the edges of the angle iron, much less expensive than using other types of bearing designs. Probably not the most precise as far as the angle iron but it appears to be withing 1/32” over the 4 foot travel which isn’t too bad. The bearings don’t seem to have any problems traveling the length of the table and I don’t seem to have any play form one end to the other. I did use a flat file to bring the angle iron into an acceptable tolerance from one end to the other. I upgraded the gantry and the z axis to extruded aluminum so I now have a hybrid and it appears to be working quite well. Only time and more projects will tell. Stay tuned for the upgrade to the beast.