More R2 progress! I needed a mental break today so I spent 8 hours standing at a manual milling machine. Some break, huh?
But first I dropped by Metals4You here in Austin and picked up about 9 feet of 3/4″ aluminum rod (6061). Alas, I’m about 12″ short. So unless I want to go spend another $20 (not a terrible amount), I’ll be looking for a remaindered piece but if I don’t find it I’ll make do.
I started off by cutting the rod in TechShop’s metalworker, a huge press that’ll cut through 3/8″ steel. Aluminum plate is not problem. I cut a few pieces from some bar stock then tried to cut the 3/4″ rod. It cut without a problem but mangled the end pretty badly. So I ended up cutting 15 pieces on the metal band saw. Awesome machine that made short work of it.
One of the benefits to being a TechShop member is that I can just walk in and use some pretty great machinery. I absolutely couldn’t do an aluminum R2 without being a member there. A wood frame wouldn’t be a problem in my own shop, but if yer gonna build a droid, ya gotta go aluminum.
Once all the pieces were cut I went off to the machine room and spent the next 8 hours slowly milling the pieces to exact (exact!) length– down to the thousandth of an inch. Metal is a cool to work in but, wow, do you have a different level of accuracy. I could have made these parts in wood in about an hour, and 1/16th accuracy would have been fine. But in metal, if you’re going to have two threaded holes lined up, you have to get the accuracy smack on. I’m learning a lot.
One of my good TechShop friends, Tim, saw me struggling with the crummy house bits. They’re used by everybody, abused, nicked, damaged, and not very good quality to begin with. About an hour later he walked in and surprised me with $160 in brand spanking new solid carbide bits. An amazing gesture. He basically said “they’re in my locker… use them like they’re yours”. Such a nice thing. And they were incredible to use. Like a hot knife through butter with a beautiful. near-mirror finish. I got 8 rods machined to length at 7.575″ long…. exactly.
I’m going to retake the lathe class tomorrow so I can start thinking about the tapping and drilling procedures for some of these parts. That scares me quite a bit since if I screw up there I’m basically back to square one remaking the parts. Hopefully I won’t break a tap off in a hole or drill in the wrong place. Pressure!
I’m already thinking ahead to the next phase of the frame. Won’t surprise you at all to know that I’ve decided to overcomplicate it. But it’ll add even more of a coolness factor. Stay tuned.
Pics should be coming along with these posts as soon as we get the camera/phone situation worked out.