This project had a simple goal, create a custom steel pulley for my friends Barber Colman no. 3 gear-hobbing machine.
- Manual Machining
This projects aim is to create a custom pulley out of steel for my friends ‘new’ Barber Coleman No. 3 gear-hobbing machine. I will go through a general machining operations order in this summary. The material used was a piece of round-stock of mild steel.
(Face-off both sides) – This was my first operation, generally used to clean up the work piece before doing any other operations. The work piece is still the wrong length, on purpose.
(Drill an initial hole) – This is to allow us to use a live-center tail-stock to give extra support to the material to reduce potential chatter in the piece when turning the outside diameter to the proper diameter.
(Turn the outside diameter) – This operation was to achieve the proper final outside diameter.
(Drill and Bore the Hole) – This hole was 1″ in diameter, and 3″ deep in the back end of the stock.
(Face-off to right length) – This operation is to bring the work piece to the proper length dimension.
(Re-clamp work-piece closer to the work area)
(Precisely turn the center of the grooves) – This operation was the operation with the most chattering, primarily due to plunging the tool into the material (specifically used a carbide insert cutoff tool for this operation).
(Turn the slopes of each pulley grove, Right side slopes first of each groove, then left.) – This operation requires you to adjust the angle of your compound slide.
(Use high grit sandpaper and sand out any imperfections or roughness in the piece) – I wanted to make sure that the work piece wouldn’t accidentally damage the V belts over time due to surface roughness or imperfections. But you must remember that you don’t want to make the grooves a mirror finish either!
(Optional – Buff the finished working surface) you could in theory buff the non-grooved parts of this piece to make it even more reflective. I opted out of doing this because it will eventually wind up on the back end of a machine where no one will see it often.