Machining Simplex smokebox saddle

Hello,

I have set up my saddle on the vertical mill for fly cutting the 5" diameter. However I am having trouble. I think I may need a boring head. any recommendations?

All the best,

Stirling.

A boring head is the easiest way to do it. I used a 2" Soba boring head but any one should do.

If you haven't seen the site have a look at the Simplex build pictures here although he doesn't show that operation there is lots of good info. there.

Russell.

Hi Stirling,

It is the devil's own job to set a flycutter accurately to a diameter, as you don't have two opposite points to measure across.. A boring head allows you to make incremental changes and 'creep up' on the right size, and also as it is graduated you can see how big a change you are making.

That said, if you can set the flycutter somehow, the actual mechanics of the cutting are probably more rigid. If you start sightly off-centre with the fly cutter, you can move the work across once the diameter is right.

Neil

Many thanks for all the info.

All the best,

Stirling

it is quite an easy casting to file to size using the smokebox material as a gauge. to machine it you will need quite a complicated set up and clamping arrangement IMHO - in the time taken to set it all up and make the clamps you could file it to size. much easier to fabricate out of 6 pieces of brass.

cheers,

julian