The photo above shows the solution. The problem that I had, was that I needed a way to quarter the axles, as the locomotive was to have rods and cranks outside of the frames.

I decided that axles are to be of a common size, for this and other locomotive constructions (such as the future projects, such as the outside framed Porter, or the Pechot Bourdon), so that I can use one fixture for each projects.

The fixture has a .125” through hole and a 10-32 set screw for securing the axle during the machining process.

The fixture block from the locking set screw view

In this photo, it shows the fixture block from the locking set screw view, as you can just see, the 10-32 hole is straight through the block. This was done in order for the 10-32 tap to have clearance, the chips clears out, and the threads goes into the bore.

The decision to go with a 10-32 was decided upon what I thought was best for locating and securing the axle in a correct 90
degrees reference from the opposite throw.

Sounds like gibberish right?

The next photo shows what I am trying to describe.

A completed axle and fixture

The completed and assembled axle above the fixture shows the machined flats that the cranks will be mounted on, are 90
degrees apart from one another. The fixture shows the set screw in place, securing the axle, so the other flat can be machined.

The whole process is pretty quick. Insert axle, secure set screw, place fixture in milling vise with set screw >UP<.

Machine the flat (in my example, .020” depth), take the fixture out, loosen set screw and remove the axle, flipped end for end, re-insert axle in fixture, and set the screw on the newly machined flat. Place the fixture back in the milling vise, with the set screw >FACING AWAY<, machine the second flat, operation complete.

Keep an eye on the ‘Challenge’ forum, the completed VB creation will show the machined cranks and siderods, 90 degrees apart from the left and right side of the locomotive.

A completed axle