Reamer

[Cross Slide]

(01-10-2021, 10:40 AM)Ok TomG Wrote: Boring would be the prefered method for a cylinder bore, over reaming. The hole will be more consistent, and should have a better surface finish. Get yourself the type of bar that uses square HSS tool bits and grind the bit just as you would grind it for turning. Get the biggest bar you can for rigidity, probably 3/4' for a 1" bore, and take some practice runs to get the technique down. My guess is you were probably using pre-ground carbide boring bars, which are tough to get a good finish with. Also make sure you aren't using low carbon steel for the cylinder. You'll never get a good finish with that.

Tom

Tom. 
These are what I have for boring bars. They are just cheap ones. 
   

The plans call for the Cylinder to be machined out of Cold Rolled Steel Bar Stock
I have a piece of Cold Rolled Steel. But I’m not sure if it is 1018 or 1045. I’m leaning towards 1018. 
In the plans it says “Use one size under, drill to the correct depth for the cylinder bore, and finish off with a 1 inch reamer. Polish the boar using scotch pad and a hand drill motor.”
A Brake Cylinder Hone should work fine for that as well, and I have one of those. 
The plans call for the piston to be machined out of Brass. They say “Machine the piston slightly oversized. Polish the piston until it fits down the cylinder bore. 

Trevor