Pennsylvania A3 Switcher (Kozo)

[cnr6400]

Like the towel bar idea, but a hot air dryer might be safer to dry parts- just had a mental pic of the towel going round and round the sander! 

Re the circus tent / cell phone thing - here's what happened: A few years ago my wife and I took our little nieces to a local mini circus / fair event. One tent had several donkeys from a local donkey shelter / rescue place. Outside the tent there was a BIG sign warning to keep cell phones in bags or pockets and turned off. Apparently one donkey had suffered some kind of trauma involving a ringing cell phone. It was quite clear on the sign that a ringing phone would be stressful / harmful to one of the donkeys.  Anyway we went inside the tent, and met the donkeys. The little girls just loved it. The donkeys loved to be patted and fussed over and the girls were given carrots to give as treats to the donkeys. Everyone was having a great time.  Next thing you know, we hear a cell phone ring, and a 20 something guy a few people ahead pulls it out of his pocket  . I just heard a loud "hee-yaw" from Dinah the donkey, and a small "clop" sound, and next thing I see is this goof's cell phone flying toward the tent "ceiling"   . It hit, dropped down to the floor of the pen, and got stomped by all 4 donkeys in the pen. Dinah calmed down and all was OK, except for "Mr Entitled Cell Phone" whining about his lost phone. Apart from the stress on poor Dinah the Donkey, and the fact someone could have been badly hurt, it was pretty funny. I don't think the guy with the phone realized he could have been very seriously hurt by any contact with a kick from Dinah. Apparently Dinah was an expert high precision kicker and probably hit the phone within a 1 inch margin of the goof's fingers!

So that's the story behind the comment! 

[crueby]

 

[Kim]

THAT is a great story, CNR!  Love it! Glad that everyone was OK!  Guess some people can't be bothered to read signs, eh? 

Kim

[Kim]

Chapter 19.6 – Arms

Next up is a series of arms used to open and close the drain cocks.  There are three different arms.  The one we’ll be focusing on today Kozo calls the ‘fork’ arm since it has a fork on one end that hooks over the pin on the drain cock valve and uses that to open and close the valve.

There are two of these little dinky things.  I made them both from a 1” piece of 1/4" square 12L14 – one on each end.  Making them together like this just gave me a little more to hold onto for machining.

After thinning one dimension down to 0.200” I further thinned the very end to 5/64”  - this will be the ‘fork’ end eventually.  (After this, I did the other side, of course.)


Then I drilled and reamed the 1/8” hole for the arm shaft.


And close to the end, I drilled a 5/64 hole and used a 5/64” mill to open a slot from the hole to the end of the part.  This is the fork that will capture the pin on the drain cock valve.


To make the sloping edges I used some angle blocks to stack up 7^o and took the corner off of each side of each end of the block.  Unfortunately, I forgot to take a picture of this.  I really thought I had, but I can’t find it, so I must not have.

Next, I used a slitting saw to separate the two pieces.  (You can see the sloping edges in this picture, so I really did do it!)


And I made a little jig to round the end of the arm on the belt sander.


It was at this point I realized I had intended to drill the cross hole (for pinning to the arm shaft) BEFORE I cut the part in half. Oops… so I figured out how to do that and did it later than I’d intended to.  And forgot to take a picture of it.

But I DID get a picture of me drilling and tapping a hole for a temporary 1-72 set screw in the end of the fork arm – in the WRONG place.   It should be centered, but I set the hole to be 0.100” from the edge.  That is the center for the OTHER direction.  This direction it’s actually 1/4" wide so the center would have been 0.125".  My hole was off by 0.025”.  Ah well... the temporary set screw will still work.  It just looks a little wonky.  But there won’t be a set screw there permanently, just while I’m setting the locations of the arms on the arm shaft.  It won’t be very noticeable so I’m not going to bother to re-do it.


And here are the two completed fork arms.


Then I put them in their place on the arm shaft. (I see one of the e-rings has popped off.  I didn’t even notice that till I was looking at this picture to type out my update! – or maybe it’s one of the ones that got away?  Guess we’ll see!).


Here’s a zoomed-out shot showing both fork arms on the arm shaft.  They seem to do their job – capturing the valve pin and moving it through the full required range of motion!


It was getting hot out in the shop and this seemed like a good time to call it a day.  There are more arms coming up in my future!

Thanks for looking in,
Kim

[cnr6400]

 

[crueby]

More clean crisp tiny parts!   
I like the little jig for rounding the piece on the sander, have to make that for mine next time!

 

[Kim]

Thanks CNR and Chris,

I like the little jig for rounding the piece on the sander, have to make that for mine next time!

It's just an aluminum scrap with a 1/8" hole and a pin stuck in it. Then I clamped it on the table at the correct distance from the belt.  I used a little pair of pliers to rotate the part, that way I didn't get my fingers in there too close to the belt! It worked surprisingly well and was quite easy to do.  A LOT easier than a filing button for sure. And setup was way easier than the rotary table

Kim

[Kim]

The next arm for this assembly is just a tad longer than the fork arms and also mounts onto the arm shaft.  It will impart the rotation to the arm shaft to make it do its job.

This arm was also made from 1/4" square 12L14 but only one was required.

The process was very similar to the previous arms just made.  I started by thinning the piece to 0.200” then drilling and reaming the two holes:


I drilled a cross hole for the pin and tapped a 1-72 hold in the big end.

I had something different I wanted to try on this arm though.  Rather than mill the angled sides I decided to make the tapered sides using the belt sander.  This is essentially connecting the two radiused ends and it seemed like that should be quite doable using the same rounding jig as I used before.  Now, I did have to update the jig with a 5/64” hole for the small end (and make the hole closer to the edge of the jig!).  But it seemed to work quite well.  Here I’ve rounded the big end but only one side of the small end – and one of the angled sides too.


Here’s a shot of the completed part:


And in place on the arm shaft.  Again, those brass screws will be removed after I add the pins – which I’ll do after the rest of the assembly is in place and I can verify the location and angles for all the arms.


That’s it for today’s update.
Kim

[cnr6400]

 

[Kim]

Thanks CNR! 


The last of the arms is a bell crank.  This “L” shaped arm doesn’t fit on the arm shaft but has its own spot above the arm shaft where it translates the horizontal motion of the lever to the vertical motion that will move the arm shaft.

This part was made from 1/4" x 5/8” 1018 CRS.   I started by thinning it down to 0.200” wide, then drilled and reamed 3 holes – the center hole (1/8”) is the pivot and the outer two holes (5/64”) perform the action.


Next, using the various holes as the datum I shaved off the edges of the part to help define the extent of the part.  This will make it easier to round the corners since I’ll know where they start.


Then I nibbled out the corner to make the “L” shape of the bell crank.


Holding the part at the prescribed angle, I notched out the fork on one of the arms.


Then back to my sanding jig to round the corners and taper the sides.


And here’s the final bell crank.  Looks like I need to blend that inside corner a bit better.  This is definitely a case where the camera macro picks up things I didn’t even see!


And this brings us to the end of the ‘arms’ section of the cylinder cocks subassembly.

Thanks for looking in!
Kim

[Kim]

Chapter 19.7 – Collar


Today’s little project was a collar.  This snugs up against one side of the chassis and helps keeps the arm shaft in position.

It was made from 1/4” round bar (12L14).  Very simple.  Here I’ve drilled and remade a 1/8” hole through the center on the lathe, then moved the part to a collet block to drill the pin hole and tap for a 1-72 set screw:


Back to the lathe to part the collar off the parent stock.


The completed collar:


You can see it mounted on the arm shaft on the right side in this photo, just on the outside of the chassis in front of the driver.


And that was it for today. It got hot early out in the shop today.  Tomorrow (and the rest of the week) is  supposed to be even worse, so I may not get a lot done.  We’ll see how it goes…

Thanks for stopping by on this hot day!
Kim

[Roger B]

Nearly there for that step     

What is the parting tool you are using? It seems to be wedge shaped or is that just the camera angle?

[Kim]

Thanks Roger!

What is the parting tool you are using? It seems to be wedge shaped or is that just the camera angle?

It's just a standard 3/32" wide parting tool.  I got it from Grizzly when I purchased the lathe: [URL]https://www.grizzly.com/products/grizzly-m2-hss-cut-off-blades-3-32-x-5-8-x-5/h4268[/url'

Yes, there is a bit of an angle on the cutting edge.  I assumed that was standard.  All the cut off tools I've owned have come with a little angle to them.  Not the Warner grooving tool - those inserts are flat on the end.  But any of the standard style cut-off tools like this seem to come with some amount of angle.  Maybe I'm wrong here and I need to sharpen it up and flatten it out.  I'm open to advise and recommendations on that!

Kim

[Kim]

Chapter 19.8 – Front Bracket

Today I made the Front Bracket.  There are two brackets that hold up the whole lever mechanism for opening and closing the cylinder cocks.  Kozo calls them the front bracket and the rear bracket.  This is the front bracket.  It will hold the bell crank that I made a few episodes back.

This was made from a chunk of 3/8” x 5/8” 1018 steel bar.  The first step was to square it up and trim to size, then drill and ream the 1/8” hole – this is the business part of this bracket.


Next, I cut a 3/32” deep channel on one side.  Not sure that this cut-out has a specific function other than to make it look less blocky.


Then flipping the part up on end, I drilled and tapped (3-48) the holes for mounting this on the underside of the running board.


Rotating the part again I nibbled out a large chunk of the block to leave just the necessary bits of the bracket.


And finally, rounded the end on the sander.


Here’s the completed front bracket.


Mounted in place on the front of the right under-side of the running board. Good place for a front bracket, wouldn't you say? 


It’ll be a few parts still before we can see the bracket holding anything, but this is where it will reside.

One part at a time… I’m getting there!  Thanks for checking in on me!
Kim

[Kim]

Chapter 19.9 – Rear Bracket

And what follows the front bracket?  The rear bracket of course!  The rear bracket will hold the lever used by the engineer to actuate the cylinder cocks.

This was made from 3/8” x 1” CRS (1018).  I cut a short piece, trimmed it up in the mill to the correct dimensions, then drilled and tapped holes in one end.  These are for mounting it to the underside of the running board, like the front bracket.


Then flipping the part onto its side, I drilled and reamed the 5/32” pivot hole for the lever.


Next was to create a short radius slot.  The lever has a pin that will fit in this slot to limit its range of motion.  I did this on the rotary table (as might be obvious).


Then, still on the rotary table, I set the angle for one of the tapered sides of the bracket and offset the mill appropriately, and milled one of the tapered sides.


Rotating the table (as one does with a rotary table) the opposite way, and REMEMBERING to offset the mill the opposite way too, I then tapered the other side.  So now the bracket is no longer rectangular, but a triangular shape.


And finally to the belt sander to round the end of the rear bracket.


And here’s the beauty shot of the rear bracket.   Unfortunately, I forgot to clean up the part before this shot and you can see one of my overly exuberant scribe lines.  Oops… I’ll have to fix that!


And here are both of the brackets attached to the underside of the running board.  The front bracket by the cylinders and the rear bracket located where the engineer can access the lever.


The next part will be the lever itself.

Thanks for stopping by for a look!

Kim