I have decided to build a second cnc router. The first one was made of wood and this one will be made out of metal. Using mostly simple shop tools. I am 17 years old and can use some of my highschool's metal working machines. I am posting this to give back a little to the site. I have learned from other people's machines and now can show other people my own as I build it. It should be done in about two to three weeks. Here are a few pictures, it looks rough right now but I have just finished painting. For the x - axis I used bearings inside of channels. This was my idea. Three bearings, the middle one is adjustable with eccentric bolts I made on the lathe. I can show a simpler method of making good eccentric bolts for bearing adjustment aswell. The Y - axis runs on v-wheels that I made on top of angle. Two on top, and the one underneath adjusts tension. Right now, both run very smoothly with basically no play. The Z-axis is still up in the air right now. I'm not sure how I am going to do it. As for controls, I already have everything I need from the last cnc router. Let me know what you think and if you have any suggestions or questions I can answer.
in the third picture, I can see the middle bearing riding and providing tension to push downward and hold the two outer bearings in the c channel, would it be better to have two one on each end, because you may get a little rocking forward and backwards.
So you mean, tension the two on each end up, against the middle bearing? Instead of the middle bearing pushing the two down? I never thought of that. But, it doesn't seem to be rocking for me right now, and to change it would mean to change that whole bracket. It would take a lot of force to rock that thing forwards and backwards. When I put the machine back together I will check this.
an eccentric bolt can be as simple as example in this case instead of having a circle hole where the bolt fits into you have an oblong vertical hole like this ( 0 ) not this ( o ) and when you place leverage to the bearing to ride against the top rail you lock down the bolt and washers in this possition to the actual bolt is in the upper portion of the hole. I think (maybe not sure) in the picture above he used an offset hole in a cap of some sort.
In post number 4, in the second picture mostly, you can see the offset in the bushing in the middle bearing. Instead of having the bearing mount in the center of this bushing, it is 1/8" offset from the center. This gives me 1/4" adjustment theoretically. I do not need this much adjustment, the reason it is so much is that it allows me to put the slide into the channel easier.
Thanks. I finished putting on the clear coat. I will probably put the x and y axis together tomorrow. It's amazing how much difference paint can make. It looks a lot better with the paint. I will post more pictures of the progress tomorrow.
Good job sir. You are a thinking man. This will be fun to watch come together.
Your triple bearing with a center eccentric looks great. I guess this will be a gantry style machine? If your gantry is strong enough, you may not need (or want) those horizontal bearings on both sides.
Some more close-up pics of your eccentric would be nice. Also the "simpler method" you eluded to.
Is that snow on the ground in the background of the pics in post #4?