Pennsylvania A3 Switcher (Kozo)

[Admiral_dk]

Congratulations Kim - Great News 

Happy to see it move again and that your problem turned out just to be bad memory and not structural 

Per     

[fumopuc]

Hi Kim,
there are so much little and tiny parts at this detailed model.
Congratulations, that another mile stones is archived.

[Kim]

Thanks Per and Achim! 

Kim

[Michael S.]

Hello Kim,

Nobody believes how much work goes into these many small parts. But you did it and took another big step forward.
It looks good and everything works.

Greetings Michael   

[Kim]

Thanks Michael! 

Nobody believes how much work goes into these many small parts.

Ain't that the truth!

Kim

[Kim]

Not a lot of progress today, but I had a nice zen time in my shop.  I spent most of the day recovering from my brilliant ‘dunk it in water’ idea that I had yesterday.  While that helped me solve my problem, it also caused many of the unfinished steel parts to rust overnight.  Doh…

It wasn’t terrible, but it wasn’t good.  And I’d gotten water everywhere!  All the painted parts were fine.  But the unfinished parts that got water on them had a good amount of rust in many places.  The ash pan & rails, the battery holder, the non-Kozo wire shield part that I made, the reversing handle, etc.

So, I spent a good chunk of time taking things apart and cleaning off the rust.

And, while things were apart, I took the opportunity to mill a hole in the bottom of the wire shield.  I’d meant to do that when I made it, but apparently forgot.


Here are the parts all back together, but less rusty. And with a hole in the bottom of the wire shield so I’ll be able to get the wires up from the battery.


That was my progress today. All in all, a good day, though not screaming toward the finish line, progress, nevertheless.

Kim

[Don1966]

Awesome results Kim glad you found you leak. The switcher is looking great your work is outstanding.


 
Don

[Kim]

Thanks, Don! 

Kim

[Kim]

Today I ran the pipe for the tender hand pump water feed.

This was made from 5/32” copper tube.  I thought to start at one end, with a connection, then make all the bends required to get the shape, then attach the connection at the other end.  It seemed like a plausible methodology.  However, as I was making the third bend, I got it in the wrong place.  So I unbent it, and rebent it.  It was still wrong, so I tried again.  I just couldn’t get it right. Even with annealing it.  The bend kept going back in the same place. And after a few attempts to correct things, the thin wall tube broke. How unfortunate.  This isn’t the actual break – the break was very ragged and out of round, so I couldn’t get the union nut off.  I had to cut the tube to get back to where it wasn’t squished out of round so I could remove the union nut.  Actually, I had to cut it a couple of times because I didn’t cut far enough back on the tube the first time.


I decided not to try and salvage the nipple.  It was easier to remake that part than to try and unsolder it and hope it was in good enough shape to still be used.

For my next attempt, I decided to bend the tube into shape and THEN solder the end connectors in place.  This was clearly a much better method since it worked. 

Here’s my bending jig.  I’ve gotten past the bend that caused me the trouble the first time.


And here it is, held in place with two pieces of blue tape.  The third piece of tape (leftmost blue) marks the location of the front end of the cab.  The tube is supposed to bend before it gets to the cab (edge of the tape).  Here I’m marking the length of the tube before I make the final cut.


After cutting to length, I soldered the ends on.  I’m using the little spring clip to hold the Union nut up out of the way of the soldering.  I’ve done this many times.  Unfortunately, this time, the clip was too close to the flame and the little red plastic handle gizmos went up in flames.  No biggie, though it made for a little more excitement during soldering than I'm used to.  And it was kinda stinky. But now I've got a clip where I don't have to worry about those cheap plastic handles! 


And here’s the completed water tube with both ends in place. And I even remembered to put on the bracket – in the correct orientation! (That took some focus from my pea-brain to make that happen!)


And here we are, with the tender pump feed water line fully in place.


Now my worry is this little guy – the bracket.  Kozo says you don’t need to solder it in place, and I can understand that.  It would be challenging to make it stay in the proper location and orientation during the soldering process.  However, I’m worried about powder coating it.  Powder coat is a bit thicker than a standard coat of paint.  And if I get it all painted in the wrong orientation (or location) I’ll have to break the powder coat to get it to move to the correct spot.


So here’s my current possible solution.  I’m adding a bit of wicking grade Loctite 290 to the joint. My plan is that it will hold it in place during the powder coating process enough that I can get through the painting process.  It might work.  Or it might not.  The Loctite 290’s upper temperature is only 300F.   And powder coating happens around 400F.  But the 300F is probably the max for the full strength and I don’t need full strength.  I only need it to hold enough for the bracket not to flop around while the paint cures.  Guess we’ll see if it works or not, eh?



That’s it for today, thanks for looking in!
Kim

[crueby]

Thats quite a complex tube!  Great result in the end.   

[Roger B]

As Chris said that's a complicated tube       

[Kim]

Thanks Chris and Roger! 

Yeah, this one is messy, but almost simple compared to the axle pump water infeed tube! That one is very squirrelly!

Kim

[Kim]

Today I started on the axle water pump feed lines, which are quite complex.  It is made up of four different lengths of tube and is where the bulk of those fittings that I previously made will end up being used.

I decided to start with the low-pressure main feedline from the tender to the axle pump, as this supports the back end of the other tubes that make up the high-pressure water line and the feed water return loop.

The idea here is that the axle pump will pump water into the boiler any time the engine is moving.  But at some point, the boiler will be full of water and you don’t want to add any more.  When this happens, the operator can open the bypass valve which connects the output of the axle pump back to the input side of the pump.  It’s still connected to the boiler inlet check valve too, but since the pressure in the boiler is higher than the pressure in the supply line (which of course is the pressure in the tender tank, so quite low), the pump ends up just circulating water around in a loop.  When you need more water in the boiler, the operator will close the bypass valve, cutting off that low-pressure return loop, so the pump water is forced into the water feed check valve into the boiler.  Pretty ingenious!

This main feedline is made from 3/16” copper tube.  I started by bending the tube into shape.  I put the infeed donut (the suction ring) in place on the axle pump, and working from that, made the necessary bends to get the tube to the back of the engine where it needs to go.  Here’s a shot of the tube, after it is bent, and just sitting in place.


Next, I soldered one of the T-joints in place on the tube.  This will be part of the return loop.  The junction on the end of the tube will be the connection to the tender.  That junction is just placed there temporarily as I do one last measurement to make sure I’m getting the T-joint soldered in about the correct spot. I don’t think it’s too critical exactly where it is, but I wanted it to be close to right.  The most important thing is that the T-joint faces the correct direction after it’s soldered.  So this setup is intended to accomplish that.  (I took that end junction off before soldering.)


After soldering the T-joint in place, I drilled the hole through the top of the tube to complete the T junction.


After soldering the tender junction in place (and remembering to get the bracket on in the correct orientation!) I then soldered the donut (suction ring) in place on the pump end of the tube.  The orientation of the donut was very important!  It had to be oriented correctly in order to fit on the pump input.  Normally I like to be able to supply heat to the bottom of a part being soldered too, but for these solder joints, holding them flat against the fire brick was part of what was helping me keep their orientation.  So I didn’t have that luxury this time.


After a pickle and cleanup, here’s the completed pump feed tube.  Again, the bracket is not attached.  It can slide back and forth and rotate around at this point.  Once it is mounted though, it will be held in one specific location.


Here it is, having been put in place, looking at it from the bottom of the loco.  The pump holds the donut end in place, and the bracket holds the other end.


And here’s from the side.  I used the wicking Loctite to glue the bracket in place on the tube, just like I did for the other side.


That completes the main axle pump feed water tube.

Kim

[Dave Otto]

Nice work Kim!

Dave

[crueby]

Excellent.  As usual!