Trunnion Rings Completed.

by John

Today I turned the trunnions.

1. The centres were measured, marked and drilled. The squared end was held in a 4 jaw chuck and the end to be turned was held in the tailstock. Turned to 20mm dia with a “Diamond” tool holder and HSS 1/4″ cutter from Eccentric Engineering.

2. Then the turned end was held in an ER40 collet chuck to avoid marring the surface, and the tailstock end was turned.

3. One finished, one end to go.

4. Then I used the undersized laser cut parts to turn another “coil” (solid steel in the model, not a wound coil as in the full size cannon), also to be heat shrunk to the barrel.

Next step will be to turn the barrel diameter down to about 0.06-0.07mm bigger than the internal diameters of these parts. I will try to take some photos of the heat shrinking process for the next post.