Cast Iron

[tel]

Here in Oz the sash weights are more as the Bogmeister describes, I've used a good number of 'em over the years and only came across 1 (one) that was a bit crook.

The flywheels for my current project (Kerzel H&M) were hogged out of a big old roller from a baker's dough rolling machine - now that is one tough bit of ci, but workable just the same.

 

[compspecial]

I bought some large cast iron blocks from my local scrap merchant, not knowing what they were, it was much later a friend identified them as being from off-peak electric storage heaters. Good stuff but a lot of hard work to saw into manageable pieces for the four-jaw.
I too have tried sash weights, and found it best to grind them all over before trying to machine them.
Stew

 

[Peter.]

Just thought I'd follow this up with my findings today. I think I've pretty-much hit both ends of the scale with my freebie sash weights. I picked up two large and two smaller weights, the larger being approx 1.75" dia and 16" long. The larger two pictured here cut nicely with my bandsaw and when I put one on my mill for a trial it really did machine like a dream. The smaller pair had a far inferior finish, with cavities on the surface and a much less even profile, these were all but impossible to machine, taking the edge off my home-made carbide tipped cutter almost right away and giving an un-even shiny finish with much knocking and grumbling from my mill. Those two are going right in the scrap.

Looks like I've had a pretty good score with the larger weights I probably have enough material there to machine at least a dozen cylinders, I'm actually thinking of making a complete working engine from one sash weight, cylinder, crank, rod and piston, just to see if I can.