Machining the pulley
by, 06-19-2011 at 02:39 PM (6587 Views)
I have finishing turning the pulley from one side, inclusing the bore and drive key slot. I use the lathes old top slide for shaping slots.
A pivot is bolted to the end of the slide, and an anchor pivot bolted to the cross slide t-slots, behind the shaper slide.
To lock the spindle, I just use a bolt wit nuts as a machinist's jack.
The casting has come out really crappy, with a lot of voids. This alloy has turned out to be pretty abrasive, and dirty. I it not very nice to machine, and is differcult to get a decent surface finish with.
It came from die cast industrial transformer covers, and had a thick strong paint on it. This Alloy is a mix of about 65% which had already been skimmed and made into ingots, and 35% which was still painted. I skimmed a lot, and used soda, then salt, but still need to improve my technique in this area a lot.
The mill motor I will use is only 1/2 HP, so I doubt the defects will cause a failure, but if it does frature, the next will be better
Now I just need to turn it around and remount it to so the 100mm pulley step. For this I regret not having the 2 speed gears in my lathe. The slowest speed is currently 250 rpm, and I have to turn faster than that to get enough torque to avoid stalling, but then get edge buildup on the cut off tool used to make the pulley grooves.