Quite early on, I decided to have all appropriate parts laser cut. I decided to do this because:
A selection of laser cut parts for the project. Resting on the frames (L to R) are: the reversing stand and quadrant, coupling and connecting rods, brake lever and motion plates
The first batch of parts was:
In general, this was successful. However, the fly cranks, cut from 20mm steel, were not. I had never had material as thick as 20mm cut before. At this thickness, there is some appreciable marking due to where the laser starts/stops the cut. The idea here was to have the keyways accurately (and simply) cut. As produced, they are not useable: the keyways were just not accurate enough. In the end, I decided to use the castings for these. I could have got some new cranks (without the keyways) laser cut, but I felt that it would be easier to cut an internal keyway in a cast iron crank than a steel one.
The second batch of parts was:
This batch should complete the cutting for the loco.