Weekly Update on the 1 by 1 - part 15

It has been a week with too much unwanted adulting, it's the annual insurance renewal time after all, but I did complete the mounting plate I talked about last time.  

Top view:  

and bottom view:

As you've probably noticed, there are excessive machining marks on the top, and that's kind of sitting on a background processor in my head to try to come up with ways around that.  I'm watching a few forum threads by really master machinists and they tend to finish parts before they put the engine together.  One guy in particular is building a model of the Ford 300 cubic inch in-line six cylinder engine at about 1/4 scale and his work is so beautiful it blows my mind.  He has a bead blaster, another tool I don't have, and every part that will be seen is bead blasted and painted.  It makes raw machined parts like this look ugly in comparison.  I always thought of them as pretty.

I have some powder coating experience but even though it tends to come out thicker than other finishes, powder coating relies on having the metal itself smoothed and preferably shiny.  

The other activity was picking what part to make next.  The answer is the next important group of parts: the cylinder, piston, connecting rod, and wrist pin, but probably not in that order.  The conventional advise is to make the cylinder as close to perfectly sized as you can determine, then make the piston to fit it.  In other words, the cylinder is supposed to be 1.000" inside diameter, but if I make it a little too big or too small, it's still usable if the piston is custom fit to the cylinder.  The engine is designed for a polymer piston ring in contrast with the cast iron rings I bought for the Webster last year.  The connecting rod has to fit the journal on the crankshaft I just built and it can be sized to that bearing in the same sort of way: the journal size is what it is and I just make the connecting rod to fit.  

The cylinder will be made from cast iron, and the finished outside diameter is to be 1.750".  My stock is a square bar that's sold as 2" on a side, but is closer to 2-1/16".  I plan to cut that down to a slightly oversized square bar, perhaps .050" over on a side, and then mill away some of the protruding corners so that it's easier on the lathe than turning the rectangular crankshaft bar was.  Every revolution of the bar as the lathe spun whacked the cutting tools loudly.  

I should probably have the connecting rod made before I try to fit the piston into the cylinder.  I'm going to need a handle and that's its job in the engine. 

Meanwhile, though, it's what we used to call the short week.  There will be a couple of days of holidaying so no telling what I'll be able to do.  SpaceX has no road closures until next Monday the 29th - and those slip all the time.  It figures to be a slow week in everything.