New brass Milwaukee Bipolar EP-2 clinic- part 2

[u18b]

After some distractions with work, Getting the Kumata Centipede finished, and vacation, I'm now ready to get back to it.

Now that the mechanisms run very well overall (even in analog, and also without the jumper wire between units)....

I made a huge list of what still needs to be done.

And when tinkering, I ran into a problem.   

Review:  When I built the first EP-2 .....
https://www.therailwire.net/forum/index.php?topic=31042.0

On page 21 of that fun adventure, I tried to address some of y'all's comments about the high-boy look of the model.
The old '80s EP-2 did not have so much of a problem, but since the new EP-2s use such finescale wheels with such lower flanges--- wow, there is a big gap under these locos.

So I thought to add an imitation frame.
In this old photo, you can see the high-boy side on the right, and a frame has been added to the left and the boiler room.




The ladder side was not a problem....
But that other side had the steam pipe running down it.



So (once again, in review) I found that if I used a motor tool to trim the BACKSIDE of the steam pipe, the new frame tubing would fit.



Worked out great.



I was very pleased with the end results.  With a black underframe and blacked wheels, that huge gap greatly disappeared.



The present
So, now it's time to get to the new ones and boy was I in for a shock.

The skinny:  The steam pipe was not bent nor soldered exactly the same consistently.

Here is what I encountered on E-4 that I'm building.

As you can see, the bottom unit is not far from what I had to deal with on E-3.
But dang!  Look at the top piece.



There is no way that new square tubing is going behind that steam pipe the way I did it before.



And the second one I'm building, E-5, is even worse!


So, I went back to looking at prototype photos.
Here, you can clearly see that the steam pipe is really running right behind the jacking pad.



So my conclusions are:
The Kumata folks bent that pipe far more than needed.
And that I need to now UN-solder it (at least partially), bend it out more, and re-solder it.

I'll keep you posted.

(wow am I ever glad I got that American Beauty resistance soldering outfit!  Time to put it to use.)

[u18b]

Glad I practiced with the resistance soldering unit.
https://www.therailwire.net/forum/index.php?topic=36318.0

I put it to good use.

First I heated the water pipe and got the end loose.



I then carefully bent the pipe outward.



I then had to bend it a little more to get the tubing in there.



I then went to soldering.
You can see that I tacked down the water pipe a little firmer.
And I tacked down the new square tubing frame.



Then I did the other side.
And added the front piece (Atlas VO-1000 jumper pickup.)



I then decided to go all brass.
So I removed the MT black plastic washers and then socked it in acetone to get all superglue off.  Especially around the height control nut.

I was then able to solder that nut down.  And then solder 4 0-80 washers for under the gearbox.



Now, three more to go!

[u18b]

OK.  I changed my mind.  Working on E4 and E5 at the same time is just too many parts.  Especially when the units are completely disassembled.
Remember, the EP-2 model is in essence 2 complete locomotives drawbarred together.

So I'm just going to focus on E4 right now.

I finished the underframe on the second portion.

I then made the secret screw covers for the back ends.

But based on my experience with building the E3 last year, it is VERY confusing where these screw covers go-- especially when all four are layiong on the table.

I needed an identification system.

ONE notch = the A cab.
TWO notches = the B cab.

When viewed from the BOTTOM....
LONG notches are Left
Short notches are Right

This is the A cab.  So we use ONE notch.
Long is Left, short is Right.



And here is the B cab with TWO notches.



Now I can keep them straight.


Oh!  There is one other thing I forgot to mention.
When I built the E3, one problem I encountered was the secret screw covers fit VERY snugly and were HARD to get out without risking tearing up the paint.

So this time I filed an angle on the back side of the square tubes.
When all assembled, this now gives me a spot to push against so I can get them out in the future.

[u18b]

For those of you that might be new to following this thread....

This has been the boring part.

The more fun stuff is yet to come.

[u18b]

Applied a very small but important detail tonight.

Jacking pads.

I figured out how to make them from etched roof walkways.
Unfortunately, they are REALLY tedious to make and then APPLY to the walkway.

Took me a good while to figure out how best to install them with the resistance soldering unit- especially since the tweezers are gigantic compared to these tiny details.

But I figured it out in the end.
E-5 will go a lot faster.





Glad this important step is over.

Grab iron and railing details still to go on the walkway.

[peteski]

Resistance-soldering is not a universal cure-all solution: sometimes it makes sense to actually use a conventional soldering iron.  Just like using various types of glues, depending on the specific need.  But it is good to know that you did figure out a way to resistance-solder these tiny parts.

Which electrodes do you use in your tweezers? Some of the available one are quite small and pointy.

[u18b]

Resistance-soldering is not a universal cure-all solution: sometimes it makes sense to actually use a conventional soldering iron.  Just like using various types of glues, depending on the specific need.  But it is good to know that you did figure out a way to resistance-solder these tiny parts.

Which electrodes do you use in your tweezers? Some of the available one are quite small and pointy.

The big fat hi amp tweezers came with my set.
These tweezers- note the big heat dissipating electrode holders.



It uses the double sided electrodes.



The "wire stripping" tweezers are what I hope to get one day.



The electrodes are much finer.

[peteski]

Yeah, I have the smaller tweezers.   I let my friend borrow my setup and he was using the small tweezers for soldering N scale rail-joints.  He did his entire 12 feet of N-Trak modules (not jut 3 tracks - his module set has an elaborate multi-level self-contained layout on it).

[u18b]

I'm interrupting my work to make a separate post about a tool.
I have to admit..... I was astounded.  Hence this post.

Time to add the railing that goes to the ladders.   The Kumata model has ladders, but no railing.

To do this, I need to make a small cut in the walkway on either side of the ladder.
In order for you to fully appreciate what you are about to see, let's review from the previous EP-2.

I had three wheels for doing this.
The left ceramic cut-off wheel measured at 40 mil.

The middle wheel measured at 21 mil.  Better.

The right wheel is a diamond dust impregnated steel wheel.
It measures 5.5 mil!!!!  Much better.



As I stated back then, the thin one had a problem.  It did not lay flat and thus wobbled when spun---thus making the cut larger than it needed to be.
My guess is that the packaging was part of the problem.
The way the cardboard holds the disc causes some flexing.



I did the best I could with as steady a hand as possible.
Not bad, but I wish it could have been better.
Solder filled in the gap when I installed the railing.





Well, recently, I was at Harbor Freight and picked up a package of these.
20.5 mil steal disc coated with diamond dust.  About the same size as the middle disc above, but that one is ceramic and breaks easily.

So these were bought for general modelling use.



Package came with 2 mandrills and 4 discs.   So...... I had two extra discs laying around.

And then the heavens parted, and a moment of brilliant inspiration hit me.



I wonder if I could place these extra rigid discs above and below the skinny disc and add extra support so it does not wobble so much.

And it worked.  In fact, the new discs were of a smaller diameter than my thin disc-- which was perfect.

I now had a thin cutting edge.



The difference in actual use was astounding.
Look at this first attempt with the new configuration (and compare with the old way above).



The actual disc is 5.5 mil.

The cut on the right is 10 mil.
The one on the left is a little more.

This is VASTLY better than my previous attempt.

On the previous thread, I just showed a photo with no further research on the product.
A widow who was married to a dentist gave me these.

The results are now so much better, I found more info if any of you are interested.

I did a internet search of simply   "x927-7".   The first hits were from these discs-- which are still sold for dentistry.

Here are three sources I found right off the bat (these links may not last a long time (like the Amazon link):

http://www.amazon.com/Premier-Diamond-Disc-X927-7-Mandrel/dp/B001EMIJ42

http://www.net32.com/ec/thin-flex-x927-7-0-15mm-45-d-88635

http://www.newarkdentalpemco.com/premier-diamond-disc/11425-ts-disc-x927-7-ds-2-pk.html

As you can see, they are pricey at 50 bucks for 2 discs.

That is a lot of money..... but the results for cutting brass were amazing.

[peteski]

Very creative solution Ron - thanks for sharing!

[Chris333]

I have been using Dedeco .009" wide cut off discs, they are about the same width as a Zona saw blade.

[u18b]

I think this one came out a little cleaner than the previous EP-2.

In fact, the cut slots were so tiny, I used 10 mill wire instead of 12.



After the resistance soldering and positioning was done, I went returned to the back side.  Added just a tiny amount of flux, and then a tiny amount more of solder.  This will give much more added strength, and since it is on the back side, it will not be noticed.

[u18b]

Completed some tedious work.

Walkways are now done for E-4.

Filed the heads of the screws thinner.  These are the screws at the cab.   They have to be flat so they can be hidden by the screw covers.




Completed all the frame and details on the walkway.




Now I am finally ready to start work on the shell.

[u18b]

With the main frame done, time to move to the shell.... and to correct a very glaring error (or omission) by Kumata.
Let me show you.

The NJ model is pretty good for 1919/1920 (as delivered).

This photo is probably the late 20s.  Notice sand boxes have been added to the nose.
Notice there is a big main handrail on our right that wraps around the nose.
On the opposite side on our left is a grab iron.




And that is EXACTLY the way Kumata modeled all of these new brass models.
So the model is PERFECT for about the late 20s.




But this version I'm working on shown above, you will notice has a welded plate over the door window.  That means this dates to somewhere in the 50s.

But when you look at a prototype photo from 1950-1953, this is typical of what you see.



Notice on the nose a change in the middle.   The railroad pulled the railing and grabs, and added two SHELVES.  I'm guessing these are little platforms for standing on for maintaining the headlight.

Almost every EP-2 had those shelves from the late black period to the streamlined rebuild.
The only main one missing them was the E-3 painted for the Railroad Fair (the one I already built.).

So in short, the model is wrong for having ommited this really big feature.

So, time to get to work (I'm a little nervous).
The rail on our right is cut and the support ring pulled.
The grab iron on our left is also removed.




So now I have to make a decision.  Technically, the shelf is a little HIGHER than the main rail level.
From there, a grabiron usually drops down.
But to do that correctly, I would have to FILL IN those holes and drill new holes.
So I decided to keep it at a straight level.




Studying photos, I aimed for the grabiron (and support brace) to stick out almost to the sand box.


 
Time to make a new tool for this project.  I wanted the grabirons to stick out the SAME.







Soldered in place on the inside of the shell.




I obviously had to drill one extra hole.




Trimmed some brass sheet.




I want to support the shelf with my wire, but a LITTLE needs to stick out for the grabiron.




Trimmed, with the edges bent up.
Soldered in place.




Soldered from the underside.




THIS is what Kumata missed.







Now to do the A shell.

[FlyGuyB]

Ron, I must say, that as a novice tinkerer, it is experts such as yourself, Victor M, Max M, Peteski et al that I begin to understand the process of how the thinking to attack a problem should go. It is from the excellent tutorials that you have all provided that help move the hobby forward for many of us. I send thanks to you all, and please keep up the good work and providing the insight that is needed. Now to start acquiring and learning to use the essential tools to begin! Please keep up the good work!