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+--- Thread: A Small Milling Machine Repair (/thread-4020.html)
A Small Milling Machine Repair - the penguin - 04-01-2019
Apparently the Rockwell is notorious for cracks in the upper belt/motor housing, it’s a thin aluminum casing. Mine has been cracked at the motor pivot and tensioning bolts, since I got it. Last night, after a belt/speed change, the issue became painfully obvious, as I tightened the transmission assembly down.
I know numerous people who have either had them welded or welded them, themselves, but because of the aluminum quality and the casing thickness, they will recrack right next to the weld. I also found a few of the parts on the web, but they were almost what I paid for the mill.
So I decided to do a repair to the mill, to allow the mill be operational, without tearing the unit apart. So I did two straps, with slight bend, that straddle the pivot/tensioning bolts, while not pretty, they are functional.
RE: A Small Milling Machine Repair - TomG - 04-01-2019
It sucks when you have to re-engineer stuff to make it functional, but ti looks like you have it managed.
Tom
RE: A Small Milling Machine Repair - the penguin - 04-01-2019
Welp, I just could not leave it alone. I removed the transmission assembly looked over the housing, I don't believe the casting is going to split anymore, but damn it, as I said, I just couldn't leave it alone. The transmission sets on a aluminum ring built into the casting, thats 10" OD x 7-3/4" ID, so I cut out a matching steel ring from a piece of 3/16" plate. Then drilled for the pivot/tensioning bolts, then evenly spaced 8 mounting bolts, that were 6 mm x 16 mm flat head socket head cap screws, countersunk into the ring. The steel ring was clamped to the aluminum ring, then drilled and tapped and bolted together. this made a solid top ring that is bolted to the casting spanning the split, that still has the original repair straps, so the top of the casing is now very solid.
I'd post another picture, but it would only show a 3/16" thick layer between the casting and the transmission.