Best Of New Brass EP-2 assembly & Mod clinic

[u18b]

Hi Roger,

Only a few of Kumata's locos were factory painted.

Unfortunately, the 1983 NJCB EP-2 was not one of them.

This new 2003 EP-2 was release factory painted in 3 paint schemes with about 11 units per scheme.

Unfortunately, I've never seen any offered anywhere except the single painted unit I bought from them.  It was the last one, and had problems.

[ChristianJDavis1]

When I inquired about replacement parts for my Train master a few months ago, Kumata offered to sell me one of these kits. The picture they sent me was of a decorated model. I assume this was a factory-painted model like Ron had previously discussed.

[u18b]

Hi Christian,

Yep.. That's it.  It runs on my layout now.... but only after a complete redesign.

[u18b]

I posted a movie on the previous page on the old EP-2 I was working on.

What I have not shown is the jumper situation between Cabs.

The stock configuration is absolute cr@p.    
I mean, it is a rivet through a plastic insulation (so it does not short to the shell).  So the manufacturer solders a jumper wire to the rivet BEFORE assembly and then presses the rivet parts together.  Done.  Sell it.  Make money.

Now you the user have a nightmare.

As I have said before, that wire from the rivet to the motor is GOING to break one day.
When it does, you get your soldering iron out and try to solder the wire back.
But the rivet gets hot (naturally) and the plastic insulator now MELTS!   

So once the wire breaks on your EP-2, you are in trouble.

Thus..... I just ripped the whole useless thing out.   
Going to install a new plug.



Next step was to take a motor tool with a stone and rough up the inside removing paint and exposing fresh brass.



I got to thinking.... how can I secure the socket better.  I didn't want to drill a NEW hole for a micro socket like I did several pages ago on the new EP-2.  That would make TWO holes.

Instead, I thought.... hey, why not use some of the circuit board I've been using for this project?

So here is a piece of board that is just a little wider than the hole shown above.
Also shown is not the micro, but the larger Mini plug and socket by TCS.
I held the board in place with my finger on the inside and used a permanent marker to mark the whole.
I then drill appropriate size holes for the pins (not wanting pins to touch the edge.).



Testing the socket pins in the little board.



Now I need to turn the board over and cut dividing lines to separate parts.
The hole on the right will go DOWN and will electrically touch the shell.
The hole in the "island" is for the pin that goes to the front truck and motor.



Testing placement.  I then apply a TINY amount of superglue to the board (away from the holes) to glue the board to the shell. (I can't hold it and solder it at the same time).



Here is the inside with the board glued in place.



The orientation of the shot is the bottom is the bottom (not a sideways shot).
First step was to flux and solder the outside edges at the far end.
The plug is inserted and the lower pin is soldered and the solder spills over and soldered to the shell
The other pin is soldered to the island.



Here is an outside view.  Plug is now FIRMLY soldered in place-- with proper continuity with the charged shell.



Now a jumper wire is soldered to the pin in the island (only!).
Hard to tell from this shot, but everything is good here.  No solder bridges.



Finally, I have a reliable plug that is tough and can take the rough normal use that is realistic.

[nkalanaga]

A half-millimeter diameter spring might work for trolley poles if anyone wants to try that in N scale.

[u18b]

That is an excellent suggestion.

My brain does not even think about trolleys.

As of now, I have not received the sample springs.  When I do, I will post.

[u18b]

The springs arrived today.

All I can say is.....



Tune in later for photos.

[peteski]

Nice!
Sounds like you might become our local TRW micro-springs pusher! 

[u18b]

Opened the envelope with the bag of springs .... and I confess, I was a little disappointed.
Some of the springs were fairly large.
The smallest ones actually looked a little bigger than the 1.5 mm NiTi springs I have.
Oh well.



Then I turned the bag over and .......

HOLY SURGICAL PROCEDURE BATMAN!!!!!!!!!!!!!!!!!!

Good grief!!!!!!!!!!!!!!!!!!!



As a comparison, the 1.5 mm OD (outside diameter) spring I'm already using is on the left.
Obviously, those long ones look like good candidates to experiment with.



Here is a closer comparison.
Left- 1.5 mm  NiTi spring.
Middle- #74 drill bit
right- my target.



I got my calliper and measured it more precisely.



Read it for yourself.  About  .0238 inches.



A handy internet conversion utility says....



So these new springs are slightly bigger than 1/3 the size of the old ones.
about  .6 mm

Time to get to work.

[u18b]

Wow.

I'm exhausted.   This was REALLY tedious work.

These springs appear to be made of steel.  That is actually helpful when trying to rescue them from the carpet gods.  Metal is also a little softer.

The other springs were Nickel Titanium.

OK.  I start by bending the end.  These are so tiny, it is really hard.





Looks like it will work OK.
In fact, it looks like I can cut this spring in half and have enough for the other side.




A mark in the middle – hahaha.  Look how huge the fine tip marker is.




Cut the spring with rail nippers.




Measure the spring..... and
Now try to pull out a loop for the other end.




The bottom spring worked best.
Body about 10.5 mm
Overall length with hooks  12 mm




Wow.  These new springs are much smaller.





When backed up and not so close, the spring almost blend in.



There is enough springiness that I think these would work with catenary.

[peteski]

Sweet!
I might also request a sample pack from that company. Lots of those springs look very useful for models. 

[nkalanaga]

Those do look good.

On my first attempt at a pantograph, back in the late 70s, I used elastic thread.  With nothing to start with, mine was built from wire, brass rod and tube, and plastic strips.  Surprisingly, the things worked quite well, although they weren't electrically live.  The appearance wasn't great, but as nothing even close was available, they served the purpose.  That thread was just about the same size.

[u18b]

Been doing a lot of experimenting.

I may lose my mind.

I decided to experiment with some of the smaller springs.

Just to give you an idea of what this company can do....
In this shot.... the big spring is the one I just used.  It is  .6 mm OD.
That smaller one stuck to it... is what, about .2 or .3 mm OD.
That wire in the foreground is a hair from my head.
Afterall, many of these smaller ones are heart stents.



One of the larger TINY springs measures out at about 5 mm long and about .3 or .4 mm OD.




I was thinking it might be cool to try and mount a tiny spring up top near the pantograph blade instead of the bigger springs down below.  That way, the spring action might be almost invisible.

But speaking of invisible..... I could barely see these things adequately to work with them.
Even with an optivisor, I was having trouble seeing.

And then, as I tried to pull a loop out so as to bend it into a hook....
The carpet gods got it.

After two offerings to the carpet gods.... I gave up.   

 

[nkalanaga]

Part of the reason the springs are so visible is that, on the prototype, the lower pivots are under the frame, rather than on top.  That allows the springs to sit barely above the frame.

[u18b]

Ok. After a lot of experimenting, I think I've hit upon some good solutions.

Here is where we last left the pantographs.
.6 mm micro-springs hooked on holes drilled in the side arms.
Looks much better than before.



But you can notice that the spring in the front right... the hole got drilled a little too high... so the spring is high on that end.
And actually, it was REALLY hard to drill those holes.
I broke a couple of #80 bits just drilling 4 holes (and I'm an experienced modeller).  I remember a thread a while back about the poor quality of small bits these days.  Very brittle-- man, yall weren't kidding.

So I came up with a new idea.  These springs are so small, that I could hook them on the little cross bars themselves.  And the hooks would be so small, that they would be barely noticeable.

here you can see an end view.  You can see the hooks are not that prominent.  And no more drilling holes (yay!!).



But I encountered a problem.
The force of the springs compressed the pantographs too much into an unrealistic contorted shape.
And don't think that I made them too tight.  You can see that the back spring is so loose it is about to come off.
What I would need is a counteracting force.



So after some experimenting, I found a spring under the bottom works out well.
The under-springs worked out well at about 8 mm with big long hooks.



The hooks simply hooked on the base bar.  Here is an underside shot.
And I only needed one spring for this opposing force.



Here is the pant with the under-spring installed.  It holds the pant at a better level (with no catenary.)



Here is the whole loco.



So I have a couple of flexible options.

1.  No catenary.  Run the rear up (3 springs) in middle position.  Front has no springs.  (most prototypical).
2.  No catenary.  Run both pants at mid level with 3 springs (pictured above).
3.  Catenary present.  Run one pant with two springs (no underspring).  The cat wire will keep it from contorting and raising too high.
4.  cat with both high.