Coupling and connecting rods

The rods were laser cut, so the rough profiling was done for me. I machined them down to have the appearance of having a thinner centre part. I also spent a lot of time cleaning up the visible edges so that they would look OK when painted or plated.

The bushes were made next. I obtained some 2" diameter phosphor bronze to make them with. I made these by:

Sawing off suitable thickness pieces

Machining them to the correct thickness

Sawing off the top part, leaving material to make the gib blocks with

Machining off the excess material to approximate the shape

Boring out the crankpin hole. This was done at a single lathe setting to ensure that they were all at exactly the same place

Milling out a jig (from 1"x0.5" steel) to ensure the sloping part was the same angle for each block

Milling out the slots etc. on each one

Then I fitted the rods to the flycranks. As detailed on the axles page, the quartering was wrong. Having corrected this, the rods were then offered up, and found to be correct size. At last ! The wheels rotated with the rods on !

The last stage was to drill and tap for the gib block retainers, and make the oil reservoir caps. This has completed the coupling rods.

The connecting rods need more work yet the rods themselves have been cleaned up, but the bushes will not be made until the cylinders are fitted to ensure that they fit properly.