I finally completed the hubs for my robot. It felt great. It took a lot of time, wasted aluminum and burnt off flesh, but they were done. Unfortunately, they’re not straight…
When I spins the sprocket, there’s a distinct wobble. That wobble will decrease when I reduce the lengths of each shaft significantly, but I don’t think that it will be enough. The problem is that the hub needs to go inside a set of bearing so they need to spin true. The bearings need to support the stress of the tracks. It’s not a huge amount of stress, but enough to wreck the motors if the motor shaft attempts to support the load.
What I need is a metal lathe. Unfortunately a right-sized one costs about $600. So I’m going to check out my options with machinists and see what turns out.
robot
(No Ratings Yet)
Loading ...
2 responses so far ↓
1 mike // Sep 2, 2007 at 11:41 pm
Many tasks for which you need a lathe can actually be done decently well using a drill. You need a drill with a wide speed range, like a 0-1500 rpm (the slow speeds are more important).
I find that the portable battery powered drills have better speed ranges. We used a portable 18V DeWalt drill, it’s very nice. Of course, an $80 mastercraft will work just as well.
Insert your metal rod as if it were a drill bit, steady the drill by whatever means necessary, and let it roll at a low low speed. Instant lathe.
The catch is that this really only works when fastening things to circular rods and similar tasks - actually fashioning a rod with appropriate weight and balance does require a real-life lathe.
2 Marc // Sep 3, 2007 at 2:40 pm
I had thought of doing that before, but wasn’t sure if it was a good idea or not. I’ve got a drill press so that will work, but my round aluminum stock is 5/8″, likely way too big for the chuck.
I appreciate the suggestion though. In the meantime I’ve put in a query with one machinist to see what he would charge to do this.