Author Topic: Pennsylvania A3 Switcher (Kozo)  (Read 45759 times)

Offline Plani

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #675 on: June 08, 2020, 09:15:35 PM »
Very nice parts, Kim  :ThumbsUp: :ThumbsUp: :ThumbsUp:

It's almost always worthwhile to go the extra mile (ask me how I know that one  ;))

Keep up the good work. I enjoy your build log a lot  :popcorn: It's inspiring!

Plani

Offline zeeprogrammer

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #676 on: June 08, 2020, 11:18:09 PM »
Nice job!

Can you tell me more details about hardening and tempering that cutter?

(That raises another question for me...and hopefully I'm not hijacking things...)

I recently modified an HSS cutter. All I did was grind, file, and sharpen. No hardening or tempering.
Anything wrong with that?

Did you harden and temper because you used tool steel? (And I'm not sure what the difference is between HSS and tool steel.)
Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
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Offline Kim

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #677 on: June 09, 2020, 12:06:18 AM »
Thanks, Chris, Plani, and Zee!  :cheers:

Can you tell me more details about hardening and tempering that cutter?
I don't have a heat treating oven, so I just use my torch.  I heat the part up till it's a nice cherry red (or more) and hold it there for a few min, then douse it in water.   I use water because I'm using W-1, which is water hardening tool steel. (O-1 would be oil hardening.)

After drying the part, I polish it up a bit to get the soot and black off the part, then heat it up slowly and carefully till it just starts to turn a titch brown (people say "Straw Color").  Then stop QUICKLY.  And I try to be careful to stay away from the tool tip with the flame.  The tips can get hot fast, and if you do that, you can lose the hardening you did in the first step.

My understanding is that the tempering helps to make the steel less brittle, without losing the hardness you gained by heat treating.

(That raises another question for me...and hopefully I'm not hijacking things...)

I recently modified an HSS cutter. All I did was grind, file, and sharpen. No hardening or tempering.
Anything wrong with that?
Definitely not hijacking the thread!  This is good stuff!

Nope, nothing wrong with that.  Your HSS was already heat treated.  As long as you don't get the tip too hot, I think this is the correct way to do it. You don't need to harden it again unless you anneal it for some reason.  The tool should be hardened all the way through.

Did you harden and temper because you used tool steel? (And I'm not sure what the difference is between HSS and tool steel.)
Yup, just what you said.  I think tool steel is just high carbon steel that hasn't been hardened yet so you can still work it easily.  HSS is probably a little more fancy than just W-1 tool steel, but I don't know the specific difference. Smarter people on this board probably do though, and hopefully they'll answer.

Kim

Offline zeeprogrammer

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #678 on: June 09, 2020, 01:13:44 AM »
Thanks Kim!

I've been following closely. As I said before...your thread is a reference for me.
Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
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Offline Kim

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #679 on: June 14, 2020, 05:29:38 PM »
A lot done in the shop today, but not many pictures to show for it.  I made the remaining 3 vertical handholds. Here they are together:


And put 2 of them on the rear of the tender, in their final resting place.


Next up will be the hand pump.

Kim


Offline zeeprogrammer

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #680 on: June 15, 2020, 12:17:06 AM »
Loving the progress.

Question...what are you doing for lighting when you take pictures? I've really struggled getting decent pics.
Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
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Offline Dave Otto

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #681 on: June 15, 2020, 12:27:38 AM »
The handles turned out real nice Kim!

Dave

Offline Kim

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #682 on: June 15, 2020, 05:43:16 AM »
Thanks Zee and Dave! :)

Question...what are you doing for lighting when you take pictures? I've really struggled getting decent pics.
I turn off all my task lighting and just use the ambient shot light, which is still pretty bright, but it doesn't glare nearly as bad as the task lights do.  I use a tripod and take long exposures, probably f-stop of 13 to 32 and an exposure of 2-6 seconds (sometimes up to 10s, but usually not that long).

I do a little post processing - white balance and cropping, sometimes some exposure adjustment.  But usually not too much.  I use Picasa, but I'm not sure Google has it available anymore.  Which is too bad.  I've found it to be a great image management program.  We've got 20 years worth of pictures all in Picasa.

Kim
« Last Edit: June 21, 2020, 05:56:05 PM by Kim »

Offline Kim

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #683 on: June 21, 2020, 05:58:41 PM »
Chapter 8.1 Pump Body

Next, I started on the hand pump.  The hand pump will be inside the tender.  The handle will be detachable, but when attached will stick out through the manhole and allow you to pump water from the tender into the boiler.

The first part of the hand pump is the pump body.  This is a complex little fabrication job with six different pieces used to make up the whole thing.  The first piece I made was the discharge nozzle.  This was made from 5/16 round brass and threaded 5/16-24.

I drilled the hole in it (no picture) then threaded it:


Then brought the connection point down to 0.200 and cut it off the rod.


The discharge nozzle will fit into the column, which is made from 7/16 brass rod.  Here Im drilling a #20 hole half way through the rod to accept the discharge nozzle.


I then proceeded to silver solder the nozzle into the column. Heres the completed subassembly.


The main part of the pump body is made from a length of 5/8x3/4 360 brass bar.  This part is drilled and reamed 7/16 for the column to be silver soldered into.


Then I milled a 1/8 groove in the top of the body for the handle attachment lug,


and in the bottom for the stand lug.


And here are all the pump body parts we have so far, and where I left off for the day.


Thanks for stopping by for a look!
Kim

Offline Kim

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #684 on: June 28, 2020, 05:31:17 PM »
Continuing on with the body of the hand pump.

The next thing I needed to do was to make the two lugs (one for the stand, and one for the pump handle), then silver solder the pieces together.

The stand lug is just a length of 1/8 brass stock.  The handle lug isnt much more complicated, but it does have a hole in it and a bit of a shape.  So I drilled the hole:


And filed to shape.


However, when I went to solder it in place, I had a little mishap.  I was using a weight to hold the lug in place, but the material that went around the hole was so thin, that when I was heating the assembly up to soldering temperature the weight caused the brass to warp and smush the hole. :(  So, I made a second lug and chose to leave the hole, and final shaping till AFTER it was soldered in place.  You can see the smushed one on the brick in the lower-left corner.  This is after I soldered the new one in place. I actually soldered the pieces on one at a time.  The handle lug was the last one I did since it was small and I was worried that it could get overheated while I was messing around with all the other parts.  Seems my fear wasnt misplaced!


After a nice pickle bath it looks much better:


Im following Kozos steps for this part exactly as he shows them.  Left to myself, Id have probably used the mill for all this drilling.  But he used the lathe.  So, I followed his process, learning some new methods and techniques in the process!  The column was intentionally left long just for this operation.  Clamping the long column in the 3 jaw I faced off the other end to the correct length:


Then proceeded to drill a series of holes in the end.  This shows using a D-bit to create a good seat for the outlet check-ball.



Next was tapping the hole 1/4"-32 and then opening up the end a few thou just larger than the threads. Not exactly sure what this is for, but it looks nice!


After completing the top side (the outlet) ball chest, it was time to remove the excess length on the column, which I did on the bandsaw.


Then it was back to the lathe. Unfortunately, I couldnt get the part to fit in my 3 jaw there were just too many small protrusions on the pump body.  My solution was to use the Taig 3-jaw chuck.  For some past project, I had created a mandrel to hold the Taig chucks mounted in my collet chuck on the big lathe.  It seems to work pretty well.

With the holding problem solved, I faced off the bottom end to length and proceeded to do a similar series of operations to this opposite side.  No ball seat on this side though.  The ball seat will screw into the threads.  Here Im tapping the bottom with the same 1/4"-32 tap.


And this is the state of play where I left.  The main pump body has been fabricated and Ive created the ball seat for the outlet check-ball and the ball chest for the inlet ball.


And just to prove that the hole really goes all the way through:


Next time Ill drill the hole for the plunger and hopefully finish up the hand pump body.

Thanks for taking a look!
Kim

Offline cnr6400

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #685 on: June 28, 2020, 05:35:46 PM »
 :ThumbsUp: :ThumbsUp: :ThumbsUp: :popcorn: :popcorn: :popcorn:

Offline samc88

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #686 on: June 29, 2020, 10:02:32 PM »
Great work Kim

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Online crueby

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #687 on: June 29, 2020, 10:47:48 PM »
Nice work on the pump!  As I recall, that counterbore above the threads is for an o-ring to seat in, to seal up the top plug piece.

 :popcorn: :popcorn: :popcorn:

Offline Kim

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #688 on: June 30, 2020, 06:15:18 PM »
Thanks CNR, Samc, and Chris  :cheers:

Nice work on the pump!  As I recall, that counterbore above the threads is for an o-ring to seat in, to seal up the top plug piece.

Interesting.  I don't remember there being o-rings there, but maybe so.  Their is an o-ring around the plunger, but I thought the outlet was sealed by the threads.  But an O-ring could be a good idea.

Kim

Online crueby

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #689 on: June 30, 2020, 07:10:36 PM »
Rechecked the Shay book, no o ring there, my bad memory.