Cylinder caps

[harve202]

Have bored 1/2" x 1" cylinder casting and machined both ends  P&P as designed. The two cast brass disks are next, then boring of the valve assy.  PRM was source of castings.
Question: Rather than solder, machine one face, unsolder,resolder then do other face on lathe, can you use a 3/32 piece of sheetbrass for the dead end cover?  I don't see much of a shortcut for the packing valve cover.  Is there a better way than soldering to a mandrel in the latter case?
I am returning to lathe , first time since 10th grade and its a lot like a bicycle so far. My first steam engine. Sprung for brass and CI castings. Be gentle with me.   :roll:

[harve202]

Excuse my omission. Engine is horizontal type. Sorry.

[Eddy Matthews]

Well knowing very little about steam engines and there manufacture, I didn't even understand the question!

Sorry Harve, hopefully someone with a bit more knowledge than me can help?

[Bill Hudson]

I'm taking a wild guess here as I really am not sure just what your are talking about.  I am assuming you are asking how to machine the cylinder covers.  To machine these I make a split ring bushing (collet) to hold them.

If you are lucky you can find an old bushing a bit larger in diameter than the cap. I have also used a piece of old pipe or from aluminum round bar.   Chuck a half inch thick or so section of this in your three jaw chuck. Then true up the face. Flip it over and face it again. Now mark #1 chuck jaw location on the fixture. Bore it out under size to  the  cap diameter. Then turn a recess in the inside of the fixture just so it is a nice push fit to the casting. The depth of  recess should be about half the thickness of the casting.  Remove the fixture and saw a slit across one side of the fixture to make a split ring. I like to make a slight cut into the other side to allow flexibility. Now press the casting into the fixture and  mount in the lathe aligning the mark with the #1 jaw.  Tighten the chuck until it clamps the ring around the casting.  Lightly tap the cover in to seat it.   Take a very light facing cut on the casting and flip it over in the ring. Now finish facing off the casting.  Most caps have a slight raised area in the center. This is to be turned to a nice fit to the bore and will help hold the cap in alignment the cylinder.  Do not finish off the outside of the caps until they are drilled.  I like to locate the screw holes in my caps first then transfer to the cylinder. I then mount my caps to the cylinder and turn the outside edges to  flush with the cylinder flanges.

Hope this more clear than mud and what your were asking about.

Bill

[harve202]

:bow  Thanks, Gracias, and Ville Danke ! ! ! :lol:

[harve202]

Actually, it was much easier done that expectations predicted. Have finished project and am now ready to run on air. Will also begin pricing boiler kits.  PRM vertical looks best right now. Merry Christmas and  Best for 2007 !!!