Author Topic: Pennsylvania A3 Switcher (Kozo)  (Read 327987 times)

Offline Dave Otto

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #825 on: October 28, 2020, 11:31:43 PM »
Looks good Kim, nice save!
I also have one of the laser center tools, and like you have found limited use for it. What I have found that it excels at, is picking up scribe lines and center punch marks. Actually if you are picking up scribe lines there really is no need to center punch too.

Dave

Online Kim

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #826 on: October 29, 2020, 12:25:46 AM »
Thanks Dave!

Interesting that you've had the same experience as me on the laser center. I attributed its lack of use to my inexperience.  I've used it some, but it just isn't as repeatable as a standard offset edge finder.  But your right, it does work well for picking up scribe lines!  Not sure it was worth the price for just that, but since I have it, I use it from time to time :)

Kim

Offline pmerritt

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #827 on: October 29, 2020, 04:54:24 AM »
Hi Kim,

Really wonderful work here. What impresses me even more are you’re detailed progress reports and photos. I don’t have the discipline to take notes much less photos and write ups we all benefit from! I also appreciate how you show us all how you work through the mistakes. Inspirational. Kudos!!

Peter


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Offline kvom

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #828 on: October 29, 2020, 12:52:42 PM »
Good job.  I had forgotten that the large version uses different axle boxes and I didn't recognize that part.

Online Kim

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #829 on: October 29, 2020, 05:19:50 PM »
Thank you Peter!

Kvom,
So you made the 1.5" scale version?  I didn't realize that!  This one is going to be plenty big and heavy.  I can't imagine doing the 1.5".  It must weigh several hundred pounds!  :o

Kim

Offline kvom

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #830 on: October 29, 2020, 06:54:27 PM »
I had steel boiler made (not copper), bought 2 injectors vs. axle pump, and purchased oiler, blowdown valves, sight glass, etc.  Purchased a tender body (not the slant back).  Horn made from a kit.  Tender trucks and couplers from Tom Bee.

Driver and cylinder castings from Friends.  Loco weighs about 150 lbs.

Online Kim

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #831 on: October 29, 2020, 10:32:36 PM »
I had steel boiler made (not copper), bought 2 injectors vs. axle pump, and purchased oiler, blowdown valves, sight glass, etc.  Purchased a tender body (not the slant back).  Horn made from a kit.  Tender trucks and couplers from Tom Bee.

Driver and cylinder castings from Friends.  Loco weighs about 150 lbs.

Wow, that's really cool!  Have you shared a picture of it on the forum here?  I don't remember seeing it and I'd love to see your engine!

Kim

Online Kim

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #832 on: October 29, 2020, 10:35:08 PM »
With the pedestal base and rear axle box parts complete, I’m back to working on the side frames themselves.  My goal for today was to finish up anything I need to do with the side frames still connected together.  Basically, any symmetric feature.

As it turns out, I've discovered that I'm doing things out of from what Kozo shows.  No biggie, but if you're following along by the numbers, you'll see that this one is definitely out of order :)

Chapter 10.5 – Remaining Work for Side Frames

There were a few tapped holes on the top and bottom (these are the ones on the top and will be used to eventually attach the crosshead support).


Next, I finally cleaned up the rear cutout.  This one USED to have one of the screws that held the two sides together, which is why I left it till last.  The sides are still double-sticky taped together, but I wanted to leave the screw as a fail-safe as long as I could.  But with this operation, I’m down to two screws (and the sticky tape).


This final operation was to take off the excess on the bottom front of the frame.  This section housed another one of the screws. So now I’m down to just one (plus the sticky tape).  But there appears to be no sign of anything moving, which is good.


And here are the side frames, with all symmetrical features present.  Oh yeah, I also made a countersink around some of the through-holes on both sides.  I wanted to do that now since the countersink is supposed to be on the outside of the frames, and this helped make sure I know which side is the outside!  Now there is DEFINITELY a left and a right frame! :)


Tomorrow will be continuing the frames, but doing the asymmetrical work.  Can’t wait to be done with these side frames.  There’s a lot of work in these puppies!

Thanks for stopping by,
Kim
« Last Edit: October 30, 2020, 11:24:04 PM by Kim »

Offline cnr6400

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #833 on: October 29, 2020, 10:51:47 PM »
 :ThumbsUp: :ThumbsUp: :ThumbsUp: :popcorn: :popcorn: :popcorn:
"I've cut that stock three times, and it's still too short!"

Offline kvom

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #834 on: October 30, 2020, 12:04:13 PM »
My build thread is on the "other" site starting 10 years ago.

https://www.homemodelenginemachinist.com/threads/kozo-a3-in-1-5-scale.10775/

Online Kim

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #835 on: October 30, 2020, 08:20:18 PM »
My build thread is on the "other" site starting 10 years ago.

https://www.homemodelenginemachinist.com/threads/kozo-a3-in-1-5-scale.10775/

I spent some time looking around your thread there, Wow!  That's quite a beefy machine you made there!
I'll have to read more of it. Thanks for the link, KVOM.
Kim

Online Kim

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #836 on: October 30, 2020, 11:20:52 PM »
There isn’t too much left on the side frames – just a few tapped holes and opening up the window in the frame to view the oil level in the oil pump.

I went with the oil level viewing port first, since it was the most detailed.  I started by drilling out the corners of the viewing port with a 1/4" drill.


Then used a 1/4" flat end mill to carve out the rest of it.  I accidentally overshot one of the corners (as one does ::)) so I opened up the viewing port an additional 10-15 thou wider than specified in the plan.  I figured this wouldn’t affect the operation at all and would be far less noticeable in overall appearance than leaving the ding on one of the corners :)


After drilling out the few remaining holes, I tapped them (3-48).


And here’s the family shot to date.


Tomorrow I’ll be starting on the front and rear parts of the frame.
Kim

Online Kim

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #837 on: October 30, 2020, 11:49:06 PM »
Well, a post or two back I made something I called the "Pedestal Base". Turns out that is really the "Pedestal Brace".  Funny how I read that word many times and always read it 'base' not 'brace'.  Anyway, I noticed this just now as I was updating my build index (see the original post for this build if you care what that is http://www.modelenginemaker.com/index.php?topic=8552.msg185965#msg185965) and realized my error.  So now I've updated that post (#818) with the correct term in order to be less confusing to any future readers.  I apologize for any inconvenience you experienced due to my error and my editor takes full responsibility for the mistake.  :)

Pedestal Brace makes more sense, as it is bracing the Pedestal.  Though 'base' isn't totally bonkers is it?  Anyway, you live, you learn!

Thanks,
Kim

Offline Admiral_dk

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #838 on: October 31, 2020, 06:56:09 PM »
Quote
I apologize for any inconvenience you experienced due to my error and my editor takes full responsibility for the mistake.

 :ROFL:    :lolb:    I would love to use that one myself .... if I can remember to do so ....

Nice progress Kim.

Online Kim

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #839 on: October 31, 2020, 11:30:32 PM »
Chapter 10.4 – Front Bumper And Footplate


Today I started the Front Bumper and the Footplate.  The Front Bumper goes in the front of the frame, of course, and the Footplate goes at the rear of the frame. They both started from lengths of 12L14 square stock; the Front Bumper is 3/4" square and the Footplate is 5/8” square.

Starting with the front bumper, I squared up and trimmed the part to length, then, since it was indicated in, drilled all the required holes on one side of it:


And did the same to the footplate. They look similar, but they are different sizes with different hole patterns.


Both of these parts have 1/4" dados to fit the side frames.  (Can you use the term dado in metalworking? Well, I did, cause to me, that’s what it seems these are!).  But they are different depth.  One is 7/32” deep (the front bumper) and the other only 3/16” (footplate).  To further complicate things, the parts have different dimensions.  Regardless, Kozo recommends to cut the dados in these parts as a single operation. I assume that is so they are exactly the same width, which will keep the side frames parallel.

So this is how I did it.  I stacked up some things to use for a 3/32” spacer below the smaller part and used some 3/16” spacers on either side of the shorter piece so that it would be centered on the larger part.  Then I clamped them together to guarantee center and clamped them in the mill vise to hold them in place vertically.  This is with the vise open so you can see my packing job.


After tightening down the mill vice, the clamp I was using to keep things horizontally spaced was removed.  You can also see that I marked up the parts so I could keep the orientation straight!  Would hate to do this carving on the wrong side!


And I’m ready for my first cut! Looks like all my measuring was right because the groove comes out centered nicely on the holes (as it should).  The final cut will be 1/4" wide, but I started with a 7/32” mill and worked up to it.


All the bits I used, up to the 1/4”, were two flute bits.  Unfortunately, my 1/4" 2 flute cutter was several thou undersized and the frames wouldn’t fit in.  So I ended up doing the final cut with a 4-flute mill that is exactly 0.250”.  While I know it's best to stick to 2-flute cutters when doing slots, I figured it would be OK since it was only shaving a few thou off either side.  It seemed to work just fine and now things fit as expected.


And here’s my progress for the day.  The top one (smaller) is the footplate, and the lower one is the front bumper.  Neither part is complete yet, still more ops to do on them.


Thanks for stopping by!
Kim

 

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