Linear Rails

Now that finals are over I got a chance to do a little more. I made some nice linear rails for one axis of my machine. I CNC'd them from MDF and painted them with epoxy to seal them. They worked reasonably well but ultimately I decided not to use them because they used twice the bearings they needed and were hard to adjust correctly. The hardware also weighed it down a bit. At least I learned a little about working with epoxy.
Now you probably think I'm crazy, and your entitled to your opinion even if you are wrong, but here is where I started over. This time I'm going with a traditional skate bearings and angle stock solution I see all over home made designs. I started by drilling holes for four 8mm bolts to hold my bearings I bought from buildyourcnc.com. The other two holes were drilled from the inside of the angle for mounting to a block. I also used a little blue threadlocker on every nut to prevent the vibrations from loosening them. I'm not sure if that was necessary but it doesn't hurt to be careful.
And here you can see them all finished. It didn't take long to make them and I only needed a drill press, a hack saw, and a few wrenches for the whole thing. Anyone whose worked with aluminum will know how easy it is to scratch so if your fanatical like me, a little steel wool will hide them pretty well and give it a brushed look. Just make sure to rub in circles across the entirety. It's also worth noting the finer the wool is, the finer the finish will be. I used coarse wool to hide the scratches then very fine to get a nice finish. It only took about 7-10 minutes to do all six pieces.

I have a few days before summer classes start so hopefully I can finish at least a few of the axes by tuesday. I have some almost finished blocks for mounting these rails to, then I should be about half way there. So far I like these much better than the first set. I'll have some more pictures soon.

Pictures!!

Here's some pictures of what I have finished...

(Below) A closeup of the front bolt on rail holder. The pipes were threaded so I just screwed them in this end.

A closeup of the rear rail holder. I added some set screws on this end to hold the rails secure. Both the rail holders were carved on the first machine so their almost perfect.Linear slides I made from mdf(also cnc'd) and soaked in epoxy. They turned out pretty well but I might remake these out of oak when I'm done. While I got the first few oak pieces cnc'd I couldn't get these made quite right.
another shot of the assembly.
I have one more cross piece drying at the moment that connects the two slides and holds the nut for the leadscrew. Then the table top just bolts on top with some barrel nuts to hold it all square. I also plan on replacing the X-axis rods with black pipe. They bend way too much with any signifigant cuts which is why I've been having so much trouble making new parts. With any luck I'll be finished in a few weeks.

Chuck's CNC Rebuild: Part 2

So I haven't posted in a Loooooong time. Being busy with school and all I didn't do much lately accept start part two of my rebuild, the bottom half of my new machine. I have to admit, I have more fun working on it than using it. Doesn't that seem backwards?
I built this part mostly out of oak just like before with 1/2in. black pipe for my linear rails and a few temporary parts that will later be properly made when I get it all together. While I liked the adjustment blocks I used for the X-axis I'm trying something new for the Y-axis. Instead of holes or rail supports on the frame I just added some bolt holes and the actual support pieces were made on my machine and bolted on.
Since I'm having rigidity problems I made some of the smaller parts from MDF instead of oak and soaked them in some 2 part epoxy. Now they don't swell with the humidity and don't mushroom when I drop them. I'm going to remake these later after I fix the rigidity problems (reason for my rebuild). I'll have some pictures up hopefully tomorrow.