Author Topic: Pennsylvania A3 Switcher (Kozo)  (Read 327644 times)

Offline Admiral_dk

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #1785 on: August 09, 2022, 09:05:12 PM »
Great result Kim   :ThumbsUp:  and thank you for showing the hanger detail - hope I will remember it next time I do some Powder Coating  :cheers:   :popcorn:

Per

Offline cnr6400

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #1786 on: August 09, 2022, 11:14:14 PM »
Great looking finish on the parts Kim!  :ThumbsUp: :ThumbsUp: :ThumbsUp: :popcorn: :popcorn: :popcorn:
"I've cut that stock three times, and it's still too short!"

Online Kim

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #1787 on: August 10, 2022, 01:56:17 AM »
Thanks Per and CNR!  :cheers:

Kim

Offline kvom

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #1788 on: August 10, 2022, 02:24:50 PM »
I use wire to hang the parts and connect the ground clip to the wire.  So coating the rack isn't an issue. But I can see where doing multiple small parts grounding the rack would be preferable.

Offline Baltic

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #1789 on: August 11, 2022, 02:49:21 AM »
looking better every day, the power coating looks fantastic, I will have to complete some research into this method :)
Well done Kim.

Gary

Offline ddmckee54

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #1790 on: August 11, 2022, 05:33:42 PM »
Do you guys plug the holes when you powder coat?  Or do you clean the plastic out of the holes and chase the threads after you've powder coated?

Don

Online Kim

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #1791 on: August 11, 2022, 09:07:25 PM »
Do you guys plug the holes when you powder coat?  Or do you clean the plastic out of the holes and chase the threads after you've powder coated?

Don

The first time I powder coated I filled every hole with something (those fancy rubber stoppers they sell) or with the appropriate machine screw, to keep the threads from getting coated.

But after I'd done it a few times I started to see how HARD it was to get the powder down in little holes like that.  This time, I only plugged large holes.  i put a few screws in place, but mainly as attachment points for wire to hang the part.  Most of the small screw holes I just left open and figured I'd clean them out with a tap if needed.  But as I'm reassembling things, I'm finding that most of the threaded holes just work, no chasing with a tap required.  A few needed a tap to make the screw go in well, but not many.

I'm saving a lot of screws this way! 

I have considered powder coating a bunch of screw heads, but I'm also considering just leaving them bright, as is.  We'll see.  I can also mark them up with a bit of regular paint or even a permanent marker if I choose to.  That looks pretty close to the black paint.

Kim

Online Kim

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #1792 on: August 14, 2022, 11:13:06 PM »
With the reassembly, I took my time and carefully made sure each part fit well before moving on to the next thing.  I believe this paid off because I think the engine runs better now than it did before!

One of the differences is that I found some better packing to use for the pistons.  Before, I used some generic graphite yarn from a hardware store.  This was OK, but was messy and had tendrils that stuck out everywhere.

However, on Amazon I found some much better packing – it is 1/8” braided PTFE.  It was more expensive than the other stuff but SO much better!  The lower blue bubble pack is the hardware store stuff that I used previously.  The roll above (with the big yellow box) is the braided PTFE.


I found the 1/8” PTFE a bit too large for the groove in my piston.  So, what I did was pull one of the strands out of the braid to make it a bit smaller.


This worked really well!  The packing fit and the braided PTFE didn’t come apart or fray or anything.  I was quite impressed!


With the pistons installed, it was time to put on the cylinder heads.  Following Kozo’s recommendation, I used the LocTite Gasket Eliminator. I also used the Loctite primer to prepare the surface prior to applying the thin layer of the Gasket Eliminator.


Now, I didn’t seal up ALL the parts of the cylinders yet.  I did the rear head (shown above) and between the cylinder and steam chest, but I just bolted the front head and steam chest covers in place.  I needed to remove them many times while attaching all the running gear and adjusting the valve timing.

After a lot of fussing about and getting things to where they ran quite well, I finally sealed up the steam chest cover and the front head.  ;D

It was then that I realized I’d forgotten to put on the beauty ring covers on the rear of the cylinders!  :wallbang:


While frustrating, it wasn’t totally unrecoverable.  I was able to detach the front drivers and flip them down out of the way, remove the crosshead rails, take off the piston rod and several parts of the valve gear, unscrew the crosshead itself, and then, finally slide the cylinder cover in place.

At least I was smart enough to mark things carefully with a felt tip pen so that I could get everything back in the correct orientation!  It took a lot of work to make up for my lack of foresight, but in the end, I finally got it all back together!  8)


And with that, I will leave you with one final video of the engine running.  It isn’t perfect, but it’s better than it was, and it makes me happy!  It leaks so much less than it used to and runs on a lot lower pressure.  I'm quite pleased!

<a href="https://www.youtube.com/watch?v=0L0sitX_HQM" target="_blank">http://www.youtube.com/watch?v=0L0sitX_HQM</a>

Thanks for looking in!
Kim
« Last Edit: December 06, 2022, 04:07:42 AM by Kim »

Offline cnr6400

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #1793 on: August 15, 2022, 12:51:28 AM »
 :ThumbsUp: :ThumbsUp: :ThumbsUp: :popcorn: :popcorn: :popcorn:
"I've cut that stock three times, and it's still too short!"

Offline RReid

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #1794 on: August 15, 2022, 01:32:47 AM »
Looks and runs great Kim. Treat yourself to your favorite treat! :ThumbsUp:
Regards,
Ron

Offline Don1966

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #1795 on: August 15, 2022, 01:57:28 AM »
Awwww music to my ears. Great job Kim she’s a runner and some very nice craftsmanship…….uh did I say I likeeeee……. :Love:


 :drinking-41:
Don

Online Kim

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #1796 on: August 15, 2022, 06:00:56 AM »
Thanks, CNR, Ron, and Don!    :cheers:


Kim

Offline Michael S.

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #1797 on: August 15, 2022, 06:50:09 PM »
Hi Kim,

I congratulate you on this successful phase of construction. 👍
What's next? The boiler?

Michael

Online Kim

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #1798 on: August 15, 2022, 09:16:38 PM »
Thanks Michael!

What's next?  Well, first there's a camping trip with my extended family.  That'll soak up a week or so.  But following that, I'll be building the water and oil pumps. Then I think next is the firebox grate and ash pan.  Then comes the boiler!  ;D

Kim

Online Kim

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #1799 on: August 25, 2022, 11:07:21 PM »
I’m back from a wonderful camping trip with my extended family.  We had a great time! The weather was good and the company was great! What more can you ask for? :)

Now it’s time to start on the feedwater pump.

Chapter 20.1 – Pump Body

The first part of the pump is the Pump Body.  This is a complex little fabricated part.  It’s made up of three pieces – a long rectangle block for the plunger and for mounting, a round rod to house the ball valves, and a smaller round part for the output connection.

The first thing I made was the output nipple.  It was made from 1/4" 360 brass rod.  A fairly simple turning operation.  Here I am cutting it off of the parent stock:


The next piece I tackled was the rod for the ball valves.  This was made from 7/16” 360 brass rod.  Here I’ve taken a short length down to 13/32” and drilled the lower ball chamber for the intake.


And now tapping it 1/4"-32 for the intake fitting, which will be made later.


After parting that off I held it by the 13/32” diameter end in a 5C collet holder and drilled a hole to receive the output nipple.


Then I silver soldered those two pieces together – the output nipple to the valve column.


Next, I took a length of 1/2" x 3/4" 360 brass bar and brought it down to the required size, which was a little over 5/8” wide.  Then I drilled a hole through it to receive the valve chamber column.


Then flipping on end and carefully placing at 90 degrees, I drilled the hole for the plunger and O-ring retainer.


With that, I silver soldered the valve chamber to the plunger chamber.  Kozo recommended dropping the solder down the plunger hole – that way it didn’t get the direct heat from the flame and could coat the entire joint.  That seemed to work quite well.  Though I also put a little piece of solder on the outside of the joint too, I don’t really think it was required.  And I probably just ended up using more silver solder than was really required.  Regardless, I am quite pleased with the penetration I got on this soldering exercise!


After some time in the pickle bath, I held the unit in a collet by the completed end of the valve chamber and proceeded to drill out the output valve side.  Here I’ve drilled out most of the stock with a #3 drill and now I’m taking it to final size with a D-bit.  This also created the reverse angle on the ball seat to help the ball seal well.


And, like the input side, the output side is tapped 1/4"-32 to accept the output plug fitting (which will also be made later).


Next, I opened up the rest of the plunger hole.  This got sealed off when we soldered in the valve chamber.  This operation connected the plunger chamber to the valve chambers.


And finally, I tapped several holes in the pump body.  These two side holes are tapped 3-48 for mounting holes. There’s another 3-48 hole to hold the O-ring retainer in place and one for a 1-72 screw to keep the ball in the input side from getting sucked up too high and cutting off water flow on the intake stroke.


And after a bit of cleanup, here’s the completed pump body.


Thanks for checking in on me and my build!  I appreciate it!
Kim

 

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