Got a tricky machining requirement:
A brush-less motor with a 8.4mm shaft must be supported by a flange bearing with an ID of 12mm
what is needed is a bushing of approx. 25 long.
Seems simple enough to bore out some stock to suit the shaft, and then turn it down to 12mm.
BUT. Getting the bush to be 100% concentric is not as easy as it sounds. The motor cannot be easily disassembled, and the shaft does not have a center indent on the end of the shaft.
A solution that comes to mind:
The shaft has a threaded tip (M8) about 12mm long.
1. Bore out the stock to be a light press-fit on the shaft. The OD is made oversize and say 13mm.
2. Loctite the bushing to the shaft.
3. Make an adapter to screw onto the threaded end of the shaft. Mount it on another shaft with a M8 thread and proper centre, insert this into the lathe and machine the outside of the adapter to be 100 concentric to the M8 internal thread.
4. Remove the adapter from the shaft and fit it to the motor shaft. Now we have a way of gripping the end of the motor shaft on the lathe chuck.
5. The shaft on the other side of the motor sticks out just enough to locate it in a rotating-center with a conical depression, or maybe it will be possible to drill a small center in this end and use a conventional support.
6. With the motor accurately centered and secured in the lathe, the bush on the shaft can be turned down to 12mm.
If I had the tools and skills to to do this, I'd give it a shot, but I don't.
Anyone here up to the job, or know someone in the Cape Town area that is willing to give it a go?
A brush-less motor with a 8.4mm shaft must be supported by a flange bearing with an ID of 12mm
what is needed is a bushing of approx. 25 long.
Seems simple enough to bore out some stock to suit the shaft, and then turn it down to 12mm.
BUT. Getting the bush to be 100% concentric is not as easy as it sounds. The motor cannot be easily disassembled, and the shaft does not have a center indent on the end of the shaft.
A solution that comes to mind:
The shaft has a threaded tip (M8) about 12mm long.
1. Bore out the stock to be a light press-fit on the shaft. The OD is made oversize and say 13mm.
2. Loctite the bushing to the shaft.
3. Make an adapter to screw onto the threaded end of the shaft. Mount it on another shaft with a M8 thread and proper centre, insert this into the lathe and machine the outside of the adapter to be 100 concentric to the M8 internal thread.
4. Remove the adapter from the shaft and fit it to the motor shaft. Now we have a way of gripping the end of the motor shaft on the lathe chuck.
5. The shaft on the other side of the motor sticks out just enough to locate it in a rotating-center with a conical depression, or maybe it will be possible to drill a small center in this end and use a conventional support.
6. With the motor accurately centered and secured in the lathe, the bush on the shaft can be turned down to 12mm.
If I had the tools and skills to to do this, I'd give it a shot, but I don't.
Anyone here up to the job, or know someone in the Cape Town area that is willing to give it a go?
