Monday, 25 November 2013
another odd one (part 2)
The barrel turned out OK. I did discover a problem with the live centre. The centre deflects a lot when you apply any sideways pressure to the workpiece. Not good at all. It looks like it may have been ill-used by the previous owner.
The deflection resulted in excessive chattering and forced me to take very fine cuts at very slow feeds. A bit of a pain on a 5" workpiece that needed .100" taken off the narrow end. At least it's good practice for technique.
The breech end was flared using a file, and the chatter marks were removed using the same method. The application of a fine waterpaper under rotation gave a matte finish to the workpiece. I was able to re-use the muzzle brake portion of the casting and simply slipped it over the cylinder I turned at the narrow end. This is held in place using Zap-a-Gap thin ACC.
I'm going to have to make a new live centre. Luckily I recently purchased "The Amateur's Lathe" by L.H. Sparey; which has a suitable drawing of a live centre with two hefty ball races. I may have to scale it a bit, as I believe it was intended for a Myford 7 or 10.