Pennsylvania A3 Switcher (Kozo)

[Kim]

Thanks Ron!
There's a lot of work in these guys for sure
Kim

[Don1966]

Looking awesome Kim……


 
Don

[joe d]

Those came out great Kim! 

Cheers, Joe

[Kim]

Thanks Don and Joe! 
Kim

[Kim]

Chapter 14.7 – Cylinder Head Covers

Today I tackled the Cylinder Head Covers.  These are somewhat decorative covers that go over each end of the cylinder.  I assume the purpose is the same as the Steam Chest Cover Casings – probably heat insulation?  But for me, they are mostly to make it look cool!

The cylinder head covers are made from the same 1.5” brass rod I’ve been using for the last few parts.  However, this time, I leave it at 1.5” diameter and hollow out one end so it will fit over the cylinder heads.

I stared with the rear end-covers.  So the first step was to bore out a hole to 0.830”, just big enough to slip over the o-ring holders in the rear cylinder covers.


Here’s the test fit:


Then I bored out to 1.441” (an easy sliding fit for the 1 7/16” cylinder size) to a depth of 15/64”.


And lastly, cut it from the parent stock.


I repeated this again for the other cylinder then did two more for the front end.  Those were even easier since they didn’t require the initial 0.830” bore, just a #3-48 clearance hole.

Next, I flipped one of the covers around in my small Taig 3” 4-jaw chuck. After centering it up, I faced off the top side where it was parted:


Then used the 3/32” round-over bit to put a nice corner on the cover.  You'll notice I was using the live center to provide more assurance that the part would stay in place while using that round-over bit as a form tool.  Unfortunately, I couldn't do that for the rear covers since they had a big hole in the center. But I took it slow and careful, using very light cuts, and everything held.


And here are all four of the covers completed.  The top two are the Front Cylinder Head Covers, and the lower two are the Rear Cylinder Head Covers.


And as I like to do, I’ll finish this post with the cylinder family shot, having added the front and rear covers to the cylinder assemblies.  In this picture, I have one facing forward and one facing back so you can see how the covers look on both ends.


And by this time I was melting into a puddle on the shop floor so it was time for me to ooze back into the air-conditioned house.

Thanks for taking a look!
Kim

[cnr6400]

 

Looking great Kim!

[Kim]

Thanks CNR! 
Kim

[RReid]

More Beautiness!

[joe d]

 

Fine looking assemblies!

Cheers Joe

[Kim]

Thank you Ron and Joe!
Kim

[Kim]

Chapter 14.8 – Piston Rod  Bushings and Valve Stem Bushings

OK, so I was calling them o-Ring retainers, but Kozo calls them bushings.  Regardless, that’s what I made today.

They were a simple turning exercise made from 3/8” nominal 932 bearing bronze. The bearing bronze comes about 50-60 thou oversize, so it really started at 0.425 rather than 0.375, but who’s counting.

Here’s one of Piston Rod Bushings being cut off after drilling and reaming.


And here I’ve flipped it around in a smaller collet to face off the end that was cut off.  For you observant folks out there, yes, this is a ‘postproduction’ shot.  I forgot to take the picture so I stuck one of the bushings back in the collet after I’d already stamped it. Oops


And here’s the cylinders to date with all the parts attached including the new bushings.


Thanks for looking in,
Kim

[Kim]

Chapter 14.9 – Bolts and Nuts

Now, THIS post finishes up the Cylinders.  In my previous list of what was left to do, I forgot to mention the nuts and bolts.  There are two tiny bolts that hold the front head covers in place, and there are two little nuts that secure the steam chest cover casings. This is what I made today.

The nuts and bolts were made from 5/32" hex brass.  Here's a shot of one of the bolts being cut off after threading:


And here’s a nut, just after threading, ready to be cut off.


And finally, here are all the nuts and bolts made today.  The larger 3/8” nut on the right is actually for the steam-T that will be coming up next.  So this is a bit of a teaser for upcoming episodes!


And finally, the traditional cylinder shot. This one is from the front end so you can see the snazzy new brass bolts that hold the front head cover in place.


I hope you're as excited as I am to get on to something besides the cylinders soon!

Thanks for checking in with me today!
Kim

[crueby]

Great looking parts!  Whats up next in the queue?

 

[Kim]

Great looking parts!  Whats up next in the queue?

 

The steam-T, which will connect the two cylinders while supplying steam and directing away the exhaust!

Kim

[Roger B]

So many little pieces     

What do you do for small threads? As I see it the USA threads go down to 0-80 which is around M1.6/12BA. George Britnell seems to move to metric threads for the small sizes.