www.mikes-models.com blog

On one visit to my local scrap yard I was fortunate enough pick up a large diameter piece of scrapped brass. It had one problem, which I guess is why it was put into some factories scrap skip, a large cut on part of the bar, but fortunately it had enough unaffected to match the 2 ½” diameters needed for the flywheels.

Brass from my local scrap yard

The first task was to decide a machining procedure for the flywheels and after a little thought I decided that I would make a centre mark and scribe a 2 ½” diameter circle in the available space on the brass bar. This mark would be used to centre the brass  in the 4 jaw chuck by using a centre drill in the tailstock, using the pressure from the tail stock to hold the brass in position on the 4 jaw chuck.

Using the tailstock to centre the brass blank in the 4 jaw chuck

I will then face off the blank and turn the outside to a round shape before centre boring the cavity which forms the rear of the flywheel. Once this is done the blank will be removed and then use the 4 jaw chuck to hold onto the inside of the cavity, the front part of the flywheel will be turned and finished to shape. The final diameter however will not be completed until the flywheel is held on a mandrel running between centres as per Westbury’s suggestions, to get the flywheel turned accurate enough to eliminate wobble when used on the engine for real. Well that was/is the plan.

To save me some effort without producing mountains of swarf, I used the new bandsaw to cut away as much as was safe from the scrapped lump.  This blank was then taken to the 4 jaw and I decided it would be safer to reverse the jaws when holding the rough blank. They would be reversed again when the cavity is produced.

The blank was set up as per my machining plan and the first cuts made to the outside and this is where I decided that enough was enough. The next session will see the continuation of the turning of the outside until round before facing and then boring out the rear cavity of the flywheel. Look back and see the progress

Progress so far on turning the first of two flywheels for the Seal engine