Author Topic: Pennsylvania A3 Switcher (Kozo)  (Read 21426 times)

Offline joe d

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #180 on: January 06, 2019, 12:36:30 PM »
Hi Kim

Following along, and enjoying it.  I've got the book, and even got around to drawing up a BOM a few years ago...
Maybe seeing you progress will get me off my behind...

Cheers, Joe

Offline Kim

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #181 on: January 06, 2019, 05:46:04 PM »
Thanks for following along Rich and Thomas!

For temporary soft jaws for your vise, just mill some aluminum in the form of "angle iron" that sits on top of the steel jaws.
I'll probably do that) though this is working at the moment :)

I was hoping to be able to screw in some soft jaws. I've heard that if you clamp things only in the top part of the jaws, the ones held by magnets can flip up, if that makes sense.

Thanks,
Kim

Offline Kim

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #182 on: January 06, 2019, 05:52:01 PM »
Hi Kim

Following along, and enjoying it.  I've got the book, and even got around to drawing up a BOM a few years ago...
Maybe seeing you progress will get me off my behind...

Cheers, Joe

Yes! you should definately start this project! While it does challenge me, Kozo breaks everything up into manageable steps. I've found it quite rewarding, so far!

It'd be grea to have a couple of A3 builds going at once :)

Kim
« Last Edit: January 06, 2019, 11:41:23 PM by Kim »

Offline Steve17

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #183 on: January 06, 2019, 07:47:40 PM »
You are making great progress Kim. The good thing about the Kozo trains is that you can make so many sub assemblies and get a feel good factor. There are so many hints and tips in the book even if you don't or can't follow them you can certainly get the general idea.

Over the years I have tried to make short cuts with holding jobs for a one off and fallen fowl. Now I just make soft jaws and fix them in. At work I purchased a length of ally and pre made a pile of them to fit the vices.

 :facepalm:owe yes the w word! Back in tomorrow  :toilet_claw:

Steve.

Offline Dave Otto

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #184 on: January 07, 2019, 12:49:11 AM »
Hi Kim

Lots of nice work going on here, won't be too long and you will have some assemblies that you can push around on the bench. :Lol:
I had missed the post about the soft jaws, after seeing some comments I had to go back and look for it.
You should be able to drill the head off of the screw then after the jaw is removed there should be enough of the screw sticking out that you could grab it with some vise grips.
If you use a left hand drill bit, lots of time the screw will back out as you are drilling.

Don't know if you remember this thread or not. Might be good for some ideas. :)
http://www.modelenginemaker.com/index.php/topic,6105.msg121984.html#msg121984

I have been using some sheet aluminum covers on my 6" vise that are way beyond their useful life. An engine collector friend gave me some nice copper bars the other day so I can make a decent set of jaws for this vise too.

Everything is looking great!
Dave



Offline Kim

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #185 on: January 07, 2019, 05:47:48 AM »
Thanks Steve and Dave,

Yes, I do remember that thread, Dave! Are those jaws still just as pristine looking today?  :LittleDevil:
Yeah, that's probably what I'll do, is drill the heads off the screws.  Just a bit frustrating.  Why would they put the screws on so tightly for removable jaws?   Doesn't make sense to me.  Maybe they put Loctite on them, which even makes LESS sense.  But since I got 2 of them out, I doubt that's the case.

Anyway, I'll deal with it some day.  And I'll make some really pretty soft jaws like you have Dave!  :ThumbsUp:

Thanks!
Kim

Offline Kim

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #186 on: January 12, 2019, 11:56:46 PM »
Last shop session, I’d left off having cut and stress-relieved the bolster blanks, and them made the 3o jig that will be used in fabricating the bolsters.

First, I took the bolster blanks and milled them all to length (which was 5 3/16”, just in case  you care).


The two upper bolsters need to be 19/32” thick, and the material I have is 5/8” thick , so I need to loose 1/32”.  My plan was to shave a bit off each side, to decrease the chance of the part going all banana on me. I started in using a 1/2" carbide 4-flute end mill.  This took too passes which produced the familiar line down the middle of the part.  Not a biggie.


But then I remembered that I had a cool new tool that I got when I purchased the Grizzly mill – a 2 1/2" face mill!  Figured I should give that a try! Wouldn’t want any of my tools to feel left out, would we?
It worked quite well!  And I could do the 3/4” wide piece in a single pass.  And gave a very nice finish too!


After shaving the upper bolsters to width, it was time to cut the grooves that the columns will slide into. These grooves will be at a 3o angle, which is where that cool jig comes in. Now, I didn’t show it very well in this picture, but the bolster is clamped between those two parts with the 3o faces.  It worked amazingly well!
I made 3 passes with a 1/4" HSS end mill to cut the 0.315” wide angled groove (one down the center, then one along each edge to get the proper width).  0.315" is just a few thou over 5/16”, which is the width of the columns (just in case you don’t remember – cause I never would if it wasn’t my build).


I had to cut 4 of these – two on each side of the upper bolsters.  The trick was remembering to make the 3o angle face the correct direction (narrower at the top).  Luckily, I was able to maintain my attention the whole time and did them all correctly.  You can see in the next picture that I’d labeled one side of the bolsters as ‘Top’ to help ensure the angle was sloping the correct way.


With the column slid in place, you can see how the angle will give the truck some wiggle room and allow it to move a bit as it goes over the track.



That’s where I ended the day.  I’ll need to cut similar groves in the lower bolsters, then drill some holes to retain the springs that provide the suspension for the trucks.

Thanks for checking in,
Kim

Offline crueby

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #187 on: January 13, 2019, 12:19:57 AM »
Very well done, watching along with great interest!


 :popcorn: :popcorn: :popcorn:

Offline Kim

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #188 on: January 13, 2019, 05:59:54 AM »
Thanks Chris :)
Kim

Offline 10KPete

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #189 on: January 13, 2019, 06:34:49 AM »
That wiggle room is evident many places in his designs. It shows the complete nature of his understanding of how things work.

It's the first thing that grabbed me when I first saw his book. Then had to buy it. :whoohoo:

Pete
Craftsman, Tinkerer, Curious Person.
Retired, finally!
SB 10K lathe, Benchmaster mill. And stuff.

Offline Steve17

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #190 on: January 13, 2019, 06:53:42 PM »
Getting to the stage when you can start bolting thins together. It's amazing how w :censored: gets in the way and we are reduced to weekends.

Looking really good and can't wait  :popcorn: :popcorn:

Steve.

Offline Kim

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #191 on: January 14, 2019, 02:28:10 AM »
Thanks Pete and Steve!
Kim

Offline Kim

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #192 on: January 14, 2019, 02:30:41 AM »
Today I focused on the lower bolsters, cutting the slots in those.

First cuts were identical to the upper bolsters – ~5/16” wide slots sloped at 3o on each side.  This was tricky because the BOTTOM was narrower for the lower bolsters (opposite of the upper bolsters).  I got that all right!

Then, I needed to cut a similar 3o angled slot across the bottom of these parts – connecting the side slots.  First I did one side, like so:


Then flipped it around (and the angle jig too) and did the other side.
The peak of this one didn’t come out ‘exactly’ on center, which means one side raised up a bit when I tightened the vise. But I figure it can’t make THAT much difference to have this shallow peak off center by a fraction of an inch.
 

Here’s a better one:


And here they are all mock assembled with the upper bolster and the columns:


Unfortunately, as I was fitting them together, I realized that I’d cut the connecting slots of one of the lower bolsters on the TOP instead of the bottom.  But I didn’t really notice it till some time during the fitting.  And as it turns out, I can’t really tell a difference in the movement of the ‘right side up’ one and the ‘upside down’ one. Which makes sense, as there really isn’t much difference in height a 3o slope over 1/4".

Anyway, I’m currently planning on not worrying about that blunder.  I don’t think its going to make a noticeable difference in how the tender moves.  If I change my mind as I’m going along, I can always re-make that lower bolster.  But as I said, I don’t notice any appreciable movement difference between them when assembled.  Maybe it will look different when I get the springs in place?  We’ll see.

Just one moment of inattention caused this dilemma. I’m sure it was that I was hurrying to get this step done before I went in.  Hurrying is always a bad idea.

Kim

Offline Kim

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #193 on: January 20, 2019, 12:04:30 AM »
Today I completed the bolsters.  Last session I'd just I’d screwed up one of the lower bolsters by milling the slots on the wrong side. My plan was to ignore it and go on.  However, that bothered me.  And even though it didn’t act ‘much’ different, I could still tell the difference in how the bolster moved inside the columns.  So, I decided to remake that part.  I’m sure, in the end it wouldn’t have made any real difference, especially for the amount of time I plan to actually run this on a track.  But it bothered me and so I remade the part.

Here’s the new part – the one on the bottom is new, the one on the top, with the X’s is the bad one.  It’s hard to see the difference in this shot, but it’s the direction of the 3o side slope in the grooves on the ends of bolsters.  The new one is brighter than the old ones because I didn't bother to stress relieve the new one.  I only did the original ones because I had to do it for the upper bolsters, so why not?  But I didn't think it was really required for the lower bolsters, and I believe I was right.


After remaking that part, I drilled the holes that will retain the suspension springs.  I set it up for one of the holes, then did ONE hole on each end of the upper and lower bolsers.


Then I moved the position of the mill and did the matching hole on each end of all bolsters.


The upper bolster had several holes that needed to be drilled.  The center hole for the pivot pin, and threaded holes where the side bearings will attach. Here’ after the holes are drilled and I’m tapping the side bearing holes:


And to finish off the update, here’s a picture showing one set of bolsters stacked on the columns (no suspension springs yet) and the other set spread out for display.


Thanks for taking a look,
Kim

Offline b.lindsey

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #194 on: January 20, 2019, 12:42:32 AM »
Things are looking good Kim. Great to see a new update on your progress.

Bill