The belt grinder build continues. I'm finding this project to be a good match/challenge to my machining skills, I certainly have a lot to learn.
I had recently met another HM'er who lives about an hour away. Visited yesterday with a project in mind. I wanted to build the drive wheel for my belt grinder. Design calls for a 6" wheel, and I figured aluminum would be a good material to keep the rotating mass somewhat limited. I'm making the drive wheel a bit wider than the belt, 2.5", just to give a little extra width for belt tracking. Just turn that out on the lathe, right? So a chunk of 6" round by 3" long 6061 is how much? Onlinemetals wants $350+ for a 1' piece of 6" round. Hmm. McMaster wanted about $20 for a 3" long piece of 1/2" wall 6" aluminum tube, and about another $20 for a 5" diameter 1" thick aluminum disc. Well, I just need to join those together and I'll have a wheel.
The aluminum part is the light gray component above, the brownish center hub will be broached to match the motor key, and threaded to allow the backplate for the 9" disk sander to screw into it. I had initially thought about TIG brazing those two aluminum components, my TIG goes to about 200A with air cooled torches so I was skeptical that I'd be able to actually weld it. But
@Dan Krager offerred to let me try his MIG spool gun, which he had brand new still in the case. We messed around with some aluminum coupons until we got something that at least showed some strength under a vice and hammer test, basically cranking that MIG welder to its max output, and getting the technique down for the spray transfer weld. I wouldn't want to actually post a picture of what the welds looked like
But with a little cleanup in the lathe, I got something that doesn't look bad. I had chamfered the edge of the aluminum disc about 1/4" deep on each side before welding it to give some penetration. I am certain the weld doesn't go all the way through the 1" thick disc, but it filled the chamfer nicely. Pictured here is turning the first side as well as facing the center, then flipping it to work on the other side after drilling and boring the 1.75" center hole.
I'll need to drill and tap the 4 bolt holes on the mill. Then I'll make the center hub (brown part). When the hub is made up, I'm thinking I'll chuck the whole assembly back in the lathe and take a couple of finishing passes to true to whole assembly up as concentric as possible.
Here's a few extra pictures ('cuz we all love pictures). The aluminum wheel next to the heavy steel platten arm, and the whole thing so far.