G'day Chris here, and welcome back to Clickspring.
My 1" belt sander has a broken drive pulley,
so in this video, I make a replacement pulley to get it running again.
Of course a replacement pulley can be purchased quite cheaply, but I figured it was a good excuse for another video, so here we go.
The broken pulley appears to be a zamac or pot metal casting.
It's an original part, so it's had a fairly long service life,
and I've got no complaints about it letting go. Taking dimensions from the original, this is what I'm going to make,
and it has a few key features that are going to dictate how I make it.
The first is this keyway.
I don't have an arbor press, so I'm going to do this on the lathe.
The second is the v-groove for the belt. It's has a 30 degree included angle, and not very deep,
so I'll form that with the lathe compound. And lastly, there's the set screw hole, which I'll do on the mill.
If you'd like to know the dimensions, I've put a link to some free drawings in the description box below.
These are the materials I'll be using for the job. I've got this excellent little piece
of aluminium that's a left over from another project, although it's a bit too short for chucking,
so I'm going to turn it between centers to form the features.
So that means I need an arbor, and I've have this nice length of silver steel for that.
I'll fix the work on the arbor using super glue, and break the bond with heat when I'm done.
And this little scrap of high carbon steel will eventually become my keyway cutter, so I can cut the keyway on the lathe.
So let's get started.
The arbor needs centers on each end, so Iset it to run true in a 4 jaw chuck, and then faced and center drilled the ends.
Next I drilled and then reamed the slug of aluminium to match the outside diameter of the arbor.
The work is a nice close fit on the arbor, so a small amount of the glue is enough to hold it firmly in place for the rest of the job
provided I don't let the heat from the cutting, build up too much.
I formed a temporary center from some hex stock, and then set up the lathe for turning between centers.
A quick facing cut, followed by a clean up of the outside diameter, and the work is ready for marking out.
Next I formed the basic profile of the part. I'd like a nice generous fillet in the corner for strength,
so I've ground quite a large radius on the cutting tool.
a lot of cutter contact when it's right in the corner, but a shallow depth of cut It means there's made the chatter quite manageable.
So now it's starting to take shape, I marked out the inner groove,
and got to work roughing out the rest of the profile.
I started with a parting tool to open it up.
Then I set the compound over to 15 degrees to cut the flanks of the groove.
I've ground this narrow, blunt nosed cutting tool to do the cutting.
It can cut on both sides of the tool, which is going to be handy in this case,
to get a matching surface at the bottom of the pulley groove.
The size of the stock I started with didn't really give me any other option, but I think
this is the big advantage of making this part between centers; each side of the v-groove
can be formed from the one compound setting, just by reversing the work.
A light chamfer on each of the corners, and the profile of the part is complete.
A bit of heat from the propane torch softens the glue bond, and I'm wearing breathing protection here because of those fumes.
The facing cuts didn't quite get to the arbor,
so there's a small burr at each end of the hole to take care of.
I used this hand held countersink to knock them off.
So with the profile complete, it's time to sort out the keyway.
Now I made this cutter specifically for the job, in a separate video, so click on the link if you'd like to see that.
Once it was complete, I set the cutter on center, loaded the pulley in the chuck, and
then I took the first cut to form the keyway
I started by feeding in 2 thousandths with each pass to begin with, but as the cut became more established,
I had to reduce that to a half thou per cut, and make 3 passes at each depth.
I found that any more than that put too much strain on the carriage wheel.
The cutting action is not unlike that of a shaper; it makes similar looking chips.
And it generates quite a clean cut.
So with the keyway finished, the pulley is almost complete;
It just needs a quick trip to the mill to drill and tap a hole for a set screw.
And it's done, so let's put it to work.
Thanks for watching, I'll see you later.
If you enjoyed this video, then here's 2 more that I think you might like.
And I do appreciate it when you give the video a thumbs up, and leave me a comment.
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Thanks again for watching, I'll catch you on the next video.