I am in process of building a Jan Ridders Glass Cylinder engine and it requires T2.5 timing pulleys. I am not fond of spending money (it is a hereditary thing I think) so I intend to make my own pulleys. Originally I was going to use the fly cutter technique but with the tiny tip size I am concerned that the tool will not last cutting 3 pulleys. Continue reading
The next few parts on the Glass Engine are brass. For that I need to grind some cutting tools, the geometry for brass cutting is quite different. While I have a Quick Change Toolpost, every cutter more or less needs its own holder. This gets pricey at CA$20 each. Plus the growing collection needs a storage solution.
On YouTube I had seen an interesting solution while browsing for tool grinder videos. Luis Ally uses round tool bits for his machining. Well worth a watch. Basically you make a holder for round tool steel, and replace the ‘inserts’ as needed. Since I have a Tool & Cutter Grinder and I have 6 and 8mm round tool steel, it was just the solution.
I used some .5” square stock, drilled a 5.5mm hole and reamed it out to 6mm. Then using a slitting saw I cut a groove on one side. This allows the clamping force of the tightening screws to lock the tool bit in place.
The work head on my antique grinder is in need of some remedial work. When I measure the run-out (wobble) it is 0.006”. Might not seem like much but when you need to grind a shaft down to some size it would be great if the result were actually round!
Time for some heavy metal! The flywheel is 100mm diameter and 25mm thick. I had an ugly lump of steel that was just right for this.
The lump was setup in a 4 jaw chuck and centered as best as possible. With light cuts to avoid the thing flying out I surfaced the outer diameter to correct size.
The pulleys and shafts are fairly straight forward although there is some close tolerance required on the shafts.