Author Topic: Pennsylvania A3 Switcher (Kozo)  (Read 29083 times)

Offline crueby

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #315 on: May 12, 2019, 10:07:49 PM »
Well Kim, the fact that you are moving along at a human pace, does not make it less enjoyable for the rest of us to follow  :ThumbsUp:   :cheers:    :popcorn:

And on a side note about Chris and his elves - since he is more or less one himself - you might consider them his family  ;)
Absolutely!  We all worked for the big guy up north till the, um, incident. I am not really any bigger than them, its just camera angles!   :Jester:

Offline Kim

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #316 on: May 19, 2019, 05:34:05 PM »
First order of business for today is to silver solder the back onto the Front Step assembly.

I started by filing the bottom side of the step frames flat, to make sure we had good solid contact with the back across the whole assembly. (Sorry, no pic.)

Then, after a good cleaning, I fluxed the parts up and placed the bits of silver solder around.  I put them on the inside so I could apply the heat on the outside.  This worked for all edges except the middle step. And for that, I put the solder in the little section above so I could apply the flame in the larger hole.  I made a gap underneath the part so I could apply some heat there if needed.


This actually worked out a lot better than I’d feared.  This is the most soldering I’ve done in a single operation – five separate edges, and several of them fairly long.  I did some preheating along the bottom, but most heating was done up top, right at the corner line between the back and the edges of the stair frame.  I’m fairly pleased with the results!  (Though it looks a little chard here, it's not really as bad as the photo makes it seem).


After soldering the other one, I left them both in the pickle solution for a while and worked on a tool I will need shortly.  I have to make an 82o countersink for the mounting screws.  These holes are at the bottom of a 1/2" deep hole and very close to the edge.  So I need a small countersink to fit down there.  Rather than go looking for something to purchase I decided I’d make one. Seems like a fairly simple tool to do.

I took some 1/4" W-1 that I had on hand, and cut an 82o cone on the end, then brought about 5/8” length of it down to 3/16” diameter.
 

Then I moved to the mill and made a single cutting edge.


Then I heat-treated and tempered it. Here’s the end result.  Now I’m all ready when I need to use it!


Out of the pickle and washed off (no other clean up done yet) here are the two front steps:

(Also, here you can see the two mounting holes on that drawing between the top and middle steps – the reason I made the countersink tool.)

Next, we need to cut off all the excess metal – the part that was used to hold things together during fabrication but really isn’t needed as part of the steps. Kozo says to cut it off with a fret saw, but I chose to mill most of it off.  Seemed easier to me.  I started with the flat sides:


Then moved to the complex angled sides:


Since it would make less filing later, I turned the parts at an angle and cleaned up the diagonal edge too.


And finally, I cut down the width of the top two steps to 5/16”.


The rest of the shaping was done by hand filing – cleaning up the final bit of the outside edges and then creating the rounded part between the middle and bottom steps. Here’s the first step completed, to shape:


Here’s a before & after shot, well, a not-done vs. done shot :)


Next time I’ll finish shaping the other front step assembly.

Thanks for following along on my progress.
Kim

Offline b.lindsey

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #317 on: May 19, 2019, 05:40:06 PM »
Nicely done Kim. Lots of work in those little detail parts!

Bill

Offline crueby

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #318 on: May 19, 2019, 09:51:46 PM »
Steps came out great! Got to remember the trick with the weighted arm for soldering....

Offline Dave Otto

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #319 on: May 19, 2019, 11:47:12 PM »
Nice work on the steps Kim!

Dave

Offline J.L.

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #320 on: May 20, 2019, 01:39:29 AM »
Hi Kim,
I really do appreciate the amount of work you have put into making each part. Here I am, reaching into a plastic vaccuum formed tray and pulling out a part that has taken you hours to fabricate from scratch.

You should be very proud of the each and every part that goes into this engine.

Very skillful work.

Cheers...John

Offline Kim

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #321 on: May 20, 2019, 05:37:19 AM »
Thank you Bill, Chis, Dave and John,
Appreciate the comments! 
And thanks to everyone who stops by to check out the build, comment or not!  :)

John,
I'm thoroughly enjoying your D51-200 2-8-2 build.  Yes, they are different types of building, and yours is quite interesting and I'm learning a lot by following along.

Thanks,
KIm

Offline Kim

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #322 on: May 27, 2019, 11:04:13 PM »
This weekend, I finished up the front steps for the tender.

After shaving off the extra parts of the second set of steps, I used my new fancy 82o countersink.  It worked OK.  Not great, but for the few holes I need it for, I’ll deal.  I tried to sharpen it several times, then I tried to grind some relief on it. That helped more than anything.  But it still pushed metal out of the way more than cut it. You can see a healthy mound around the edge of the countersink there.


It was very hard to clean up the edge around the countersink since it was so deep in the hole.  I ended up clamping it in the mill and using a little mill bit to take off that edge.  And here are the two completed steps.


That completed the steps themselves.

Offline Kim

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #323 on: May 27, 2019, 11:07:50 PM »
Chapter 4.6 – Step Bracket

Next, I made the brackets to connect the steps to the tender frame.

The bracket is a little piece of 1/2"x1/8” angle.

I made it from a piece of 1/2" square bar (12L14).  I put a short length in the mill and cut out the excess to make the angle.


Then using a chamfer bit, I cut a 45o along one edge of the angle.


And cut the angle in half to make two brackets.


After cleaning up the ends, I drilled and tapped #2-56 holes for mounting the steps.


Then I drilled and countersunk the holes for mounting to the tender frame.  Again, you can see the marginal ‘cutting’ job that my countersink bit did here. But in this case, it was easy to file the little mound of metal away.


And here’s the completed Step Brackets.


Then I screwed the steps onto the brackets:


And mounted the brackets onto the frames.
Here’s the family shot, of the tender to date:


Thanks,
Kim

Offline cnr6400

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #324 on: May 28, 2019, 12:52:06 AM »
Looking great Kim! top notch work.  :ThumbsUp: :ThumbsUp: :ThumbsUp: :popcorn: :popcorn: :popcorn:

Offline b.lindsey

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #325 on: May 28, 2019, 01:02:47 AM »
Very nice Kim. Was the countersink bit an import?

Bill



Offline Kim

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #326 on: May 28, 2019, 05:48:00 AM »
Thanks CNR and Bill,

Was the countersink bit an import?

Bill, the countersink bit was one I made.  You can see more about it in pictures 3 to 5 in post #316.  So I have no one to blame but myself and my own inexperience.  But I learned a lot from this exercise!  I think a straight D bit would have been better.  Or at least make more relief on the rest of the cutter.  Maybe if  I'd made 2 or 4 flutes it would have been better than the single?  Just thoughts for next time.  It worked well enough, and I'm past that part now :)

Thanks,
Kim

Offline b.lindsey

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #327 on: May 28, 2019, 02:43:59 PM »
Sorry Kim, somehow I had missed that. As you say though, past that point now and it all turned out well in the end.

Bill

Offline Kim

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #328 on: May 29, 2019, 06:17:14 AM »
Nothing to worry about there, Bill!  I'm happy to have people comment for any reason :)  There are a lot of builds going on here at MEM (which is wonderful!) and its hard to keep track of all of them all the time.  No reason to be sorry!

Thanks for the comments and for following along!
Kim

Offline Kim

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #329 on: June 02, 2019, 02:40:22 AM »
Chapter 4.7 – Rear Coupler Pocket

Today I started on the Rear Coupler Pocket.  This will go on the back of the tender to hold the coupler.

This part is another fabrication job, very similar to the front steps.

The Rear Coupler Pocket is supposed to be made from 3/32” brass.  But I substituted steel for most of the brass, and I couldn’t find 3/32” steel sheet.  So I ended up using 0.090” 4130A sheet steel.  It's pretty close to 0.09375 (3/32”).  Here I’m cutting out the pieces for the coupler pocket from the 0.090” sheet using my HF saw in vertical mode.


Then I cut all the pieces to the correct width. I did four at a time here since they are all the same width.  These are being cut to 0.50” wide.


This is the back plate for the rear coupler being milled to size.


And a family shot of all six pieces that will make up the coupler pocket.  I’ve laid-out the locations for the slots and holes and marked where they are in black pen.


Back to the mill to cut the 3/32” slots.  Now, this slitting saw is brand new.  But its way out of round.  Like way out.  It only cuts with one tooth I think.  And It goes ‘Thunk, Thunk, Thunk’ as it turns since only one tooth hits metal.  Many of my slitting saws are a little out of round, but this one is WAY off.  I guess it worked in the end though.


Here are all the parts after cutting the slits.


And with the four pieces that make the pocket slid together.


Next time I’ll silver solder the pocket together, then solder it to the back.

Thanks for taking a look,
Kim