Author Topic: Pennsylvania A3 Switcher (Kozo)  (Read 368904 times)

Online Kim

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #4005 on: May 05, 2024, 04:38:46 PM »
Thanks Tom!  :cheers:
Kim

Offline Prowler901

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #4006 on: May 05, 2024, 05:14:09 PM »
Wow!  That's looking really spiffy, Kim!

Todd

Online Kim

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #4007 on: May 05, 2024, 06:20:39 PM »
Wow!  That's looking really spiffy, Kim!

Todd
Thanks Todd!  ;D
Kim

Online Kim

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #4008 on: May 06, 2024, 10:17:09 PM »
First thing was to get curves on the ends of the sills.  I scribed 1/8” radius corners on the parts and used the belt grinder to freehand the radius.  Kozo doesn’t specify this radius so I just made up something.  If you find where he did specify something, please let me know. I couldn’t find it anywhere on the drawings.  So I just did what looked goodish.


Then I cleaned the parts, fluxed things up, and proceeded to soft solder all the pieces together.  There are a lot of edges that need soldering, so it took a while. I used a smaller burner this time and I think that made the whole thing go a lot better.  The heat was more controlled, and I didn’t have so much of it to throw around. Still plenty though!  I used the 3940 burner (17mm).  It throws off about half the heat of the next one up (3941 – 22mm) that I’d been using.  And has a much smaller, more controlled flame too. Soft soldering just doesn’t take as much heat as silver soldering!


Then there was the cleanup.  The soft solder flux is just a lot more greasy and harder to clean up than the silver solder flux.  But I got there.  And I removed the heads (and tails) of the hold-down screws.    Then put the whole thing together again.
Looks about the same as yesterday, but things are soldered together and there’s no brass screw heads sticking out.  Oh yeah, and the ends of the sills are artfully rounded :)


Next will be to make some brackets and link to hold the roof open.
Kim

Offline crueby

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #4009 on: May 06, 2024, 10:30:53 PM »
Even more excellence!   :popcorn:

Offline Admiral_dk

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #4010 on: May 07, 2024, 06:38:17 AM »
Looks Great Kim  :ThumbsUp:   :ThumbsUp:

Per    :cheers:

Offline cnr6400

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #4011 on: May 07, 2024, 12:50:08 PM »
 :ThumbsUp: :ThumbsUp: :ThumbsUp: :popcorn: :popcorn: :popcorn: Where'd you find that special Artful Rounding cutter?  :Lol:  Just kidding, the cab looks excellent. :cheers:
"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 #4012 on: May 07, 2024, 09:51:18 PM »
Thanks Chris, Per, and Jeff!  :cheers:

Where'd you find that special Artful Rounding cutter?  :Lol:
Those Aftrul Rounding cutters are pricy bits of kit, but well worth it for the final effect, don't you think?  :ROFL:

Kim

Offline cnr6400

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #4013 on: May 07, 2024, 11:00:51 PM »
Worth every penny, by the look of the results!  :cheers:
"I've cut that stock three times, and it's still too short!"

Offline Prowler901

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #4014 on: May 08, 2024, 02:59:08 PM »
Excellent cab you have there, Kim.

Todd

Online Kim

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #4015 on: May 08, 2024, 04:02:51 PM »
Thank you Todd!  :cheers:
Kim

Online Kim

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #4016 on: May 10, 2024, 11:26:00 PM »
Chapter 32.5 – Link Brackets and Link

For most of this week, I’ve been focusing on the link and brackets that hold up the cab roof.  The roof is hinged so it can tilt up, but if you don’t support it by the link and brackets, it will slam back down as soon as you let go of it.

I started with the link. This was made from 1/8” x 1/4" 1018 CRS.  I started by drilling the endpoint holes.  I just accidentally started to put one of the holes in the wrong place… ooops. :embarassed: Luckily, I’ll be skimming ~23 thou off both sides of this to bring it to the desired width of 5/64” which should cover up my sin.  It’s nice to get out of a stupid mistake that easily!


Next, I rounded the ends of the link on the belt sander.


Then thinned the part to size.   And now that misplaced spot is completely gone!  Nobody will ever know!  O:-)


Finally, I cut the slot in one end of the link using a 1/16” end mill.   I made a center slot then widened it till it matched the diameter of the termination holes (0.100”).


Then I started the links.  These were made from 5/16” x 3/4" CRS.  I’m making two links back to back here.  Then I’ll cut them apart toward the end.  First I took a notch out of the ends. This makes the L shape for the brackets.


With the basic shape of the brackets complete,  I drilled the pivot holes. (Note, the brackets aren’t identical – one is a bit longer than the other one).


Now to the belt sander to round off the pivot ends.


And back to the mill to cut a slit just wide enough for the link.  I made a couple of passes with a 0.040” slitting saw, which seemed to mostly work.


Next, I widened one side of the holes to be #3 clearance and then tapped the other side #3-48.


At this point, I separated the two brackets by sawing down the center using the bandsaw.  I put the parts on the mill and cleaned up the end taking it to the specified 5/32” width.  Then drilled the mounting holes and tapped them 3-48.


Here are all the parts made for this assembly.


Now, to mount it between the cab front and the roof.  To make the roof stay in place, you have to tighten the #3 screw in the link bracket on the cab roof which clamps the link between the forks of the bracket.  But it takes quite a bit of force to tighten it enough to get it to hold.  Unfortunately, the fit between my link and the forks of the bracket was a little too loose for this to work well. So my solution was to make a brass shim washer and place it between the link and the bracket.  You can just barely see it if you look below the link and above the roof bracket fork (the one on the right).  Maybe not the prettiest, but it works. However, it still takes a pretty good amount of force to clamp the link enough to hold the roof open.


At this point, with the cab secured in place on the engine, I finally felt it possible to accurately(ish) mark the location of the two handrails that are on the boiler.  These have to pass into the cab just a bit.  So I did my best to mark them, like so:


I drilled the holes where I’d marked and it came out pretty well.  I used slightly oversized holes of 1/8”, rather than the actual diameter of 3/32” and that seemed to work out pretty well for me.


Now here are a couple of shots from the inside of the cab with the roof lifted up.




That’s it for the cab. Next, I’ll be working on the air reservoir (i.e. batter holder.)

Sorry for the length of this update.  I probably should have done it in a couple of installments, but I just didn’t get around to it.  So here it is, all at once.  ;D

Thanks for looking in!
Kim

Offline crueby

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #4017 on: May 10, 2024, 11:34:04 PM »
Wow.




The cab turned out great, and it really changes the look of the engine!!




Wow!

Offline cnr6400

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #4018 on: May 11, 2024, 02:39:04 AM »
 :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 #4019 on: May 11, 2024, 05:38:32 AM »
Thanks guys!  Yes, it really does change the look  ;D

Kim

 

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