Beam Engine Governor Gears
The bevel gears on the plans looked rather difficult to make. Finished gears were available from the castings supplier, but on ordering, no, they had not had them in stock for a long time, and even if they were available the cost would be $a254.
So, I tried another option which was successful.
I ordered some angle grinder gears from China, cost $5 per pair, machined new centre holes for brass inserts which fitted the shafts, used Loctite to glue the inserts, and broached the keyways into the brass inserts.
The photo shows the larger gear unmachined at top, and bored ready for the brass insert at bottom.
The gears were too hard to machine initially, so I put them through a couple of cycles of heat to red hot and slowly cooling, and then my carbide cutters worked…. just. I did not want to risk my expensive broaches however, and that was one reason for the brass inserts. The other reason was to remove some of the angle grinder features from my antique looking model.
The angle grinder bevel gears have curved teeth, which would not have appeared in 1880, but you can’t have everything. It does make them very silent.