Kumata brass E/E1/E5/E3/E6 Rebuild Project w/ DCC & Sound KMT

[u18b]

If wires come off the A unit  rear gearbox and come out.. they will be pinched between the shell and loco frame.   So I need to cut notches on that shelf where the drawbar post is located.



With notches cut, the chrome plating is now broken and could peel one day.  So after I smoothed everything off, I then added flux and solder over the exposed areas to keep the plating sealed.



I then built my plug with strands of thin black wire.  They are DCC color coded in my mind- but obviously want black as visible.  DCC colors nearest to far are:  red, orange, gray, black.  (rails to the outside and motor wires to the inside).



I then replaced the shell on the A unit and the wires came through their notches perfectly.  The wires are paired.  Black and gray on one side.  Red and orange on the other.



Now I encounter a challenge.  How long do I make my wires?  I decided to put shells on both locos and drawbar them together.  Now I can measure the final distance.   I notice in this photo that when using the grid on my mat,  the axles closest to each other almost fall on a line.  THAT is my reference.



I then remove the B unit shell and place the chassis on the grid lines like before.



With the A unit shell on, I realized I could not be certain which wire was which.   So I pulled the shell and marked the tip of the rail wires (red and black) with a silver marker.

[u18b]

I then made two circuit boards for the B unit.  Lets start at the back.
The rear gearbox is powered to the left rail.  So the jumper wire goes forward to the motor board.



The board over the motor is connected to the motor tabs.  I then have an island in the middle for that black wire.  More VO-1000 strips, but these do not have to go over a flywheel.




Then there is a board over the forward gearbox.   The front (right) side is divided into four lines to match the A unit.   From near to far:  red right rail, orange motor, gray motor, black left rail.   On the rear side of the board, I made the orange and gray traces larger for pads for the VO-1000 strips.  A second black jumper wire goes from the island over the motor to the far side.  A short jumper comes up from the gearbox on the near side.

Also seen in this shot are two wires temporarily soldered from the A unit.  Axles (almost!) on the grid lines.




I made a guess visually as to how long the wires needed to be.  Imagining the shell installed.



I used a screwdriver to stretch out the wires to get them sort of even.



Then, with the basic length determined, I stretched the locos out.   NOW I could make all wires the same exact length.  Notice that there is not plug and socket here.   The wires are just soldered on.   



Cut notches and solder notches on the B unit shell.    Install the shell, and the drawbar.  A little tricky with no foam cradle.



And now it looks good.  A little far (as is most N scale) but looks good otherwise.  The wire drape is just right.   A little dip- but loose enough for curves.  And if I feel they ARE too tight for some curves, then I just need to move the wires on the pad of the B unit for more slack.



Time for a test run!

[u18b]

I have to admit I'm a bit neutral on sound generally speaking.  I have mixed feelings.

However....... WOW, this dual prime mover non-turbocharged sound is amazing!

Volume is a little soft at first and then picks up around the horn blast.

[Cajonpassfan]

Ha! Imagine just two more wires would give you another speaker in the B
Nice job!
Otto

[u18b]

Otto.... I might do that.

 

[u18b]

So the B unit is a stand alone analog chassis. 
If I wanted to do some testing or troubleshooting in analog, I could take another TCS  4-pin micro socket, solder pins 1&2 together and then pins 3&4 together.   This would form a jumper when pushed onto the plug.




To install, I have to pull the shell on the A unit.   Insert the B unit plug.  Put the A unit shell in place.
Roll the set over.  Install the A shell screws.
The install the drawbar screw on the B unit.

[u18b]

Ok Otto.   I took you up on it.

 

I ran two more wires to the B unit and added a speaker.

The sound is much better.





I added a two pin socket and plug.





Here is the B unit.





I used a marker to mark polarity since the two speakers are supposed to be wired the same.

https://www.therailwire.net/forum/gallery/34/medium_1277-070623002416-342982035.jpeg

Made a new video.
Sorry about the crappy tripod.  Need to get one with ball bearings.   

The project is completed.
This is a pretty amazing piece of equipment.

Going to make it a lot harder to sell it.
I'm starting to like it!

[u18b]

So I rebuilt and perfected an EMD E1 set made by KMT.

However, these techniques apply to almost all of the E units.
So maybe this thread will help some others improve their brass Kumata E units.

[Dirk Jan Blikkendaal]

Thats a nice story........ perfect ending!
Years ago (Tsunami was the only option then) I did basically the same to my set ...... also ATSF.
Only difference: I opted to apply American Limited diaphragms between the A and B and couple them a bit closer.
Had to grind of the make believe doors and drill a hole in both bulkheads to let all wires go from A to B.....
Result: a fine running, good looking and sounding engine....!

[u18b]

Well, time to wrap up this project.

I decided to try the suggestion to add some American Limited vestibules.

I used part #8510



It turned out that the draw bar was not long enough for two vestibules.
So I installed one on the A unit.

As it is, the one vestibule touched the B unit when on a straight. 



On 15” curves there is a slight gap, but I can live with it.



My parts bag had one Kumata vestibule.  So I installed it on the back of the B unit to complete the look.



This is a great model and has been a great project.

Now I will have to repeat it some day on my B&O EA/EB set.

Remember, the purpose of this thread was broader in showing how you can improve almost any Kumata brass E set.  Some short so badly that they can barely run.  But I have shown that not only can you get them to run well and reliably, but I also installed sound.

The only caveat is that best results are on level track.  If you have grades, that’s a bit tougher.

[Cajonpassfan]

👍👍
Otto

[daniel_leavitt2000]

Ron, I love these types of threads and I'm sorry I missed this until now.

I see several tips that would also work with Samhongsa engines that I have given up on because of shorts. Now I just need to find proper replacement gears for them.

One idea that I use a lot... I try not to use super glue if at all possible. I use a lot of 3M double sided adhesive used in electronics. For example, you could use it to attach the PC boards to the worm towers. It would also be ideal to anchor the sound decoder to the frame. The adhesive is very thin and insulating - so it could even be used to insulate the worm towers from the frame AND reduce strain on the plastic screws. It also would not mar the plating.

[freescopesdad]

Beautiful... I'm still learning this hobby, and trying to figure out the best way to add DCC/Sound to a DC E6/E8/E9 Illinois Central pair. But your thread provides hope. Thanks.

[u18b]

Ron, I love these types of threads and I'm sorry I missed this until now.

I see several tips that would also work with Samhongsa engines that I have given up on because of shorts. Now I just need to find proper replacement gears for them.

One idea that I use a lot... I try not to use super glue if at all possible. I use a lot of 3M double sided adhesive used in electronics. For example, you could use it to attach the PC boards to the worm towers. It would also be ideal to anchor the sound decoder to the frame. The adhesive is very thin and insulating - so it could even be used to insulate the worm towers from the frame AND reduce strain on the plastic screws. It also would not mar the plating.

Daniel, I see that I was traveling last month and missed this comment.    Thanks.
Yes, you are correct... and this is one reason I posted this thread.  Several of these techniques will work with other Kumata brass locos (like placing tape on the bottom of the frame to reduce shorting).

On the tape idea, thanks.  If you mean the foam tape, that would work for the circuit board on the worm.  However, clearance for the decoder is pretty tight.   Not sure it would work there.

But I have a lot of that tape around for handing stuff.  Good idea.

[u18b]

Ron, I love these types of threads and I'm sorry I missed this until now.

I see several tips that would also work with Samhongsa engines that I have given up on because of shorts. Now I just need to find proper replacement gears for them.

One idea that I use a lot... I try not to use super glue if at all possible. I use a lot of 3M double sided adhesive used in electronics. For example, you could use it to attach the PC boards to the worm towers. It would also be ideal to anchor the sound decoder to the frame. The adhesive is very thin and insulating - so it could even be used to insulate the worm towers from the frame AND reduce strain on the plastic screws. It also would not mar the plating.

Oh...  And @daniel_leavitt2000 , what gear are you talking about?    The main drive gear in the gear tower?  Often called the worm gear because it interfaces with the worm.

If that is the one you mean, there is an option.