Author Topic: Pennsylvania A3 Switcher (Kozo)  (Read 327694 times)

Online Kim

  • Global Moderator
  • Full Member
  • *****
  • Posts: 7862
  • Portland, Oregon, USA
Re: Pennsylvania A3 Switcher (Kozo)
« Reply #840 on: October 31, 2020, 11:32:21 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.

Thanks Per!
You're welcome to use my editor any time if you think you can trust him! :) :Jester:
Kim

Offline kvom

  • Full Member
  • *****
  • Posts: 2649
Re: Pennsylvania A3 Switcher (Kozo)
« Reply #841 on: October 31, 2020, 11:48:37 PM »
For me, 2-flute cutters are best for aluminum, but for steel and light cuts they work just fine.

Online Kim

  • Global Moderator
  • Full Member
  • *****
  • Posts: 7862
  • Portland, Oregon, USA
Re: Pennsylvania A3 Switcher (Kozo)
« Reply #842 on: November 01, 2020, 04:19:03 AM »
For me, 2-flute cutters are best for aluminum, but for steel and light cuts they work just fine.

Thanks Kvom,

Interesting.  I've heard other people say you should only use 2-flute cutters for slots, and if you can't use 2-flute, then definitely a cutter with an even number of flutes, never 3-flute or your slot may not end up straight (uneven cutting forces - or something like that).

I haven't heard that 4-flute is best on steel.  I've been using a mish-mash of 2-flute or 4-flute, depending on what I have on hand that is the size I want.

Kim

Offline john mills

  • Full Member
  • ****
  • Posts: 417
Re: Pennsylvania A3 Switcher (Kozo)
« Reply #843 on: November 01, 2020, 10:54:14 AM »
I have mainly used what ever tools available at the time   years ago end mills were made not cutting to the centre
and end mills were made to std size plus tolerance slots drills were size minus tolerance so to get a slot to size you needed to use a slot drill 2 or three flutes  a end mill would usually cut over size .the mean reason of avoiding
three tooth cutters i never had a three tooth measuring micrometer to check the size .similar 0ne inch end mills
often had 5 teeth did not have the 5 tooth measuring mic so after grinding could not measure the size ,on cnc machine using offsets you cannot put in the offset if you don't know the size the 5 tooth end mills cut all-right. i used what ever was there to use .  modern methods machining cutters from stock material cutters all seam to be more on the under size so old ideas don't apply the same.  John
slot drills are shorter so are stiffer and more likely to cut a better size.
« Last Edit: November 01, 2020, 11:01:14 AM by john mills »

Offline kvom

  • Full Member
  • *****
  • Posts: 2649
Re: Pennsylvania A3 Switcher (Kozo)
« Reply #844 on: November 01, 2020, 12:10:45 PM »
The more flutes the stronger the tool as the gullies are smaller are the core larger.  A 4-flute can be fed twice as fast as a 2-flute of the same diameter and composition.  Two flute end mills are best for aluminum in that there is more room to clear chips and avoid chip welding when you don't have coolant.

Online Kim

  • Global Moderator
  • Full Member
  • *****
  • Posts: 7862
  • Portland, Oregon, USA
Re: Pennsylvania A3 Switcher (Kozo)
« Reply #845 on: November 01, 2020, 05:24:56 PM »
Thank you John and Kvom for the additional info.

Things I never knew!  That's one of the many wonderful things about this forum! I learn something useful every day here :)

Kim

Online Kim

  • Global Moderator
  • Full Member
  • *****
  • Posts: 7862
  • Portland, Oregon, USA
Re: Pennsylvania A3 Switcher (Kozo)
« Reply #846 on: November 01, 2020, 11:04:34 PM »
Continued work on the front bumper and footplate today.

Drilled all the remaining holes in the footplate:


And in the front bumper.


To round off the ends of the front bumper, I centered up the rotary table, then used a close-fitting plug to hold the bumper centered, I clamped it down on the RT so it was centered exactly over the RT.


Then offsetting the X-axis, I slowly moved in and rounded off the corners to make a semi-circle.  Did this on each end.


Following that I did a ton of taping (various sizes) on both parts, and here’s where I ended up:


Though it looks similar to yesterday, the ends of the bumper are now rounded and all the required holes are drilled and tapped.

Next will be to connect these to the side frames. But that’s a story for another weekend.  And my big burst of speed here will come to an end.  I've been on vacation this week but will now be going back to being a weekend machinist!  If I don’t, they’ll stop paying me.  And while I’m quite ready to retire, I’m not ready to stop getting paid quite yet!

Thanks for taking a look!
Kim

Offline cnr6400

  • Full Member
  • *****
  • Posts: 2729
Re: Pennsylvania A3 Switcher (Kozo)
« Reply #847 on: November 02, 2020, 02:00:31 AM »
 :ThumbsUp: :ThumbsUp: :ThumbsUp: :popcorn: :popcorn: :popcorn:
"I've cut that stock three times, and it's still too short!"

Offline Roger B

  • Global Moderator
  • Full Member
  • *****
  • Posts: 6133
  • Switzerland
Re: Pennsylvania A3 Switcher (Kozo)
« Reply #848 on: November 07, 2020, 12:17:24 PM »
I'm still enjoying  :ThumbsUp:  :ThumbsUp:  :wine1:  I also mark complicated pieces with a marker pen so I know I am cutting away the right bits  :headscratch:
Best regards

Roger

Online Kim

  • Global Moderator
  • Full Member
  • *****
  • Posts: 7862
  • Portland, Oregon, USA
Re: Pennsylvania A3 Switcher (Kozo)
« Reply #849 on: November 08, 2020, 12:00:23 AM »
Thank you Roger!  :cheers:

Kim

Online Kim

  • Global Moderator
  • Full Member
  • *****
  • Posts: 7862
  • Portland, Oregon, USA
Re: Pennsylvania A3 Switcher (Kozo)
« Reply #850 on: November 08, 2020, 12:02:34 AM »
The first thing I did today was to drill and tap the 3-48 mounting holes in the side frames for the front bumper and the footplate.

Since the frames are so long, and the holes are in the end, I ended up drilling them with a hand drill using the bumper as a drilling guide.  I’d intentionally left these holes at the size for the 3-48 tap (not the through-hole), so this worked very well.  Here’s a shot of my clamping job for this drilling process:


And an end-on close-up – the ones circled in red are my ‘guide holes’ that, after this operation, will be drilled out to 3-48 through holes (#37).


With that complete and the holes tapped, I proceed to do as I said, and drilled those holes out to #37 and added a countersink.


After doing basically the same operation to the footplate, I screwed the parts together and it sprung into 3D! Here’s the basic frame complete:


Kim

Online Kim

  • Global Moderator
  • Full Member
  • *****
  • Posts: 7862
  • Portland, Oregon, USA
Re: Pennsylvania A3 Switcher (Kozo)
« Reply #851 on: November 08, 2020, 12:04:31 AM »
Chapter 10.6 – Crossties And Pins

The next parts up are what Kozo refers to as the Crossties and Pins.  These are two pieces that go across the frames to help tie them together. They go just before and just after the front axle block.  The pins will be inserted into the crossties to allow the front axle block to pivot a bit to allow for variations in track height.

The crossties are made from short lengths 1018  CRS.  I cut them, trimmed them to length, then drilled and reamed the hole for the pin.


After that, I drilled the 3-48 mounting holes on each side.


And tapped them.


The final step will be to add the pins.  But I ran out of steam at this point and decided it was time to call it for the day.

Thanks for following along!
Kim

Online Kim

  • Global Moderator
  • Full Member
  • *****
  • Posts: 7862
  • Portland, Oregon, USA
Re: Pennsylvania A3 Switcher (Kozo)
« Reply #852 on: November 15, 2020, 10:53:31 PM »
This weekend I finished off the Crossties and Pins.

There was not much left to do. I cut the pins from 3/16” 12L14 and Loctite’d them in place.


And here there are, mounted in the frame:


And that was it for these parts.
Off to the next!


Online Kim

  • Global Moderator
  • Full Member
  • *****
  • Posts: 7862
  • Portland, Oregon, USA
Re: Pennsylvania A3 Switcher (Kozo)
« Reply #853 on: November 15, 2020, 11:01:31 PM »
Chapter 10.7 – Front Coupler Pocket

And what’s next, but the Front Coupler Pocket, of course!  ;)

The attentive reader (or maybe the anal-retentive reader) might remember we made one of these for the tender, although it was called the Rear Coupler Pocket in that case.  Regardless of the name, the construction technique is pretty much the same.

I cut the various pieces from 0.090” sheet steel (I used 4130a), which is petty close to the 3/32” thickness specified by Kozo. This is what I could find. Couldn’t seem to find any 3/32” thick sheet (3/32”=0.093” for those of you used to the more sane metric system).


Then I squared the four smaller pieces and up trimmed them to a uniform size of 1/2” x 7/8”.


After trimming the backplate, I drilled the four mounting holes and two small 0-80 clearance holes for little screws to hold things in place during soldering.


With the smaller 1/2" parts, I cut two slots in each – this is the two horizontal pieces, ganged together while cutting the slots.


With the slots cut, I drilled a 0-80 hole for the solder-holder-screws in the horizontal pieces.


Then knocked the outer prongs down a bit.  This is to keep you from having to clean up a soldered piece right next to another vertical piece.  It’s a great little thing that Kozo does, that I’d never have thought of on my own, but it does make a big difference in clean up later.


Here's a shot of me tapping the 0-80 holes.  Have I mentioned that this is the BEST little tap handle ever?  If you don’t have one of these, do yourself a favor and spend a few bucks and get one! I got mine from Little Machine Shop*.
*No affiliation with LMS other than a satisfied customer. All standard disclaimers apply.


Here are all the parts for the coupler pocket, ready for assembly.


And here’s what they look like assembled:



Here it is, all fluxed-up and ready for the torch.


And after the torch ceremony – Yeah, I was a bit harsh with this one.  Maybe I had the oxygen too low/high? I sure got a lot of soot on it!


And here’s after some time in the pickle.  I think it could use more time, but I will milling a bit off each edge anyway.  And it looks like I got good penetration with the solder on each of the joints, which is good!


Next time I’ll take the Front Coupler Pocket to shape and finish it up.

Thanks for stopping by,
Kim

Offline cnr6400

  • Full Member
  • *****
  • Posts: 2729
Re: Pennsylvania A3 Switcher (Kozo)
« Reply #854 on: November 16, 2020, 12:09:44 AM »
You definitely got penetration / flow of silver solder on that assembly Kim!  :ThumbsUp: :ThumbsUp: :ThumbsUp: :popcorn: :popcorn: :popcorn:

That's a beefy coupler mount box! You'll be ready for the tractor pull with that!  :Lol:
"I've cut that stock three times, and it's still too short!"

 

SimplePortal 2.3.5 © 2008-2012, SimplePortal