TheRailwire
General Discussion => N and Z Scales => Topic started by: u18b on April 02, 2023, 10:29:56 AM
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(https://www.therailwire.net/forum/gallery/32/medium_1277-020423102758-329841017.jpeg)
I’ve spent a lot of time with N brass Kumata locomotives. In fact, some of you helped me in my research. Thank you. I’m still in the process of writing a “book” in pdf format. About 80 pages are written so far with more to come (including material from this thread). I got delayed because of the great EP-2 revised version I discovered and am slowly building (which is an extension of the Kumata project)
In the last year or two, I obtained a plated E3/6 set and an AT&SF E1 set (the better 2nd version). It’s time to fix these up with the goal of eventually selling them with the research accomplished for the book.
So in this project, we’re going to see how I improve these locomotives. In all, Kumata brass often gets mediocre reviews. In fact, Spookshow was not impressed- at first. But the simplicity of the design allows for improvements- if you know what to do. I demonstrated this to Mark and he raised his ratings a notch with improvements made.
These locomotives are about 30 almost 40 years old now. This thread concerns specifically the E units, of which there are 5 (well 6), though some of these techniques apply to other Kumata brass.
B&O E (this was the last E unit produced by Kumata)
AT&SF E1 first run (this was the first produced and came with a dummy B unit)
AT&SF E1 second run
E1 B unit revised chassis (to power the dummy B)
E5
E3/6
I’ve worked with everything on that list.
As with almost all Kumata brass, the biggest problem is correcting electrical shorts (which is also the problem with some Samhongsa brass as well).
The shorting is so bad, it’s a deal breaker. Forget DCC and especially sound. You often can’t even run some Kumata brass on anything other than perfectly level straight analog track. For example, the worst offender may be the Trainmaster.
The reason shorts are a problem is that the entire frame is usually electrically charged (not a rare thing in brass locos)- thus when an oppositely charged truck touches the frame you get a short. On the list of E units above, only the B&O EA/EB set does not have a charged frame.
There are a few other problems with these E units as well.
More to come over the next days and weeks.
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I'll be following. E units of all vintages are great, and anything E6 or earlier is especially attractive (see my avatar).
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This thread will not exhaustively cover every E unit, but I’ll show you a good bit. And besides, there are a lot of design similarities. The specific example I’m primarily working with is an AT&SF E1 second run set. I’ll be correcting problems and then adding sound. Since the designs are similar, these procedures could be used on others.
Let’s start with the chassis variations of all the E units.
E1 first run
(https://www.therailwire.net/forum/gallery/32/medium_1277-020423163146-329982003.jpeg)
The E1 first run is the poorest design of the lot and it shares the same design as the SD40-2. It uses a knock-out pin and the trucks are very difficult to disassemble from the chassis.
(https://www.therailwire.net/forum/gallery/32/medium_1277-020423163350-329991019.jpeg)
Furthermore, the gearbox halves only have two screws instead of 4- which allow them to come loose from the frame and each other.
(https://www.therailwire.net/forum/gallery/32/medium_1277-020423163048-329972366.jpeg)
Kumata also used plastic screws on one gearbox for insulation. The first things you should do after disassembly is:
--open up the frame a bit with a file so you can get the trucks out in the future without removing the knock-out pin.
--drill holes in the frame and gearboxes for additional screws.
The other problem is the dummy B unit. The A unit does not have enough traction to pull both the dummy B unit and a bunch of passenger cars. That’s why Kumata released the powered B unit chassis later.
Rebuilding one of these first run locos is a more challenging task and not specifically covered here.
The motor is offset and entirely supported by the nose gearbox.
(https://www.therailwire.net/forum/gallery/32/medium_1277-020423161914-329861858.jpeg)
One thing you can do is shim the motor to support it and take some of the stress off the worm bearings. Or you could make an L-angle mount and drill/screw it into the frame.
The front gearbox charges the frame and the frame charges the motor frame. Since one pole has no insulator, the motor can run.
Note: the motor is on the front end.
Because the motor is offset, there is a long worm shaft and weight. That long shaft is a prescription for loud noise because of wobble.
The E1 B power chassis
(https://www.therailwire.net/forum/gallery/32/medium_1277-020423162153-329912382.jpeg)
Even though it was not released next, the power chassis has a similar look with improvements.
The motor is still offset, but now has a support bracket. The long worm shaft also has a support added as well as employing a different u-joint (dogbone).
The motor is still on the forward end. And the trucks are retained by a headless screw- NOT a knockout pin.
Purchasing an ATSF E1 set
To be honest, the E1 first run set is not desirable. Do not purchase unless you get a look at the underside of the B unit. If it is a dummy, I’d stay away unless you can power it yourself.
If you see that the B unit is powered- how can you know that this is first run (with the power chassis installed) or second run?
The answer is the box. They have different labels.
The first run does NOT have a number. It also has the KMT logo.
(https://www.therailwire.net/forum/gallery/32/medium_1277-020423162017-32990904.jpeg)
The second run has #0249
(https://www.therailwire.net/forum/gallery/32/medium_1277-020423162728-32996165.jpeg)
E1 second run, E5 and E3/6 all share the same basic chassis design.
E1
(https://www.therailwire.net/forum/gallery/32/medium_1277-020423102758-329841017.jpeg)
E5
(https://www.therailwire.net/forum/gallery/33/medium_1277-020423165832-33002982.jpeg)
E3/6
(https://www.therailwire.net/forum/gallery/33/medium_1277-020423163710-330002103.jpeg)
The motor is now centered. There is one weight. Only one gearbox is insulated so the frame and shell are charged. And all trucks are retained by a headless screw.
(https://www.therailwire.net/forum/gallery/32/medium_1277-020423162250-329921301.jpeg)
I have tested two E5 sets, and both were amazingly quiet. It’s probably a co-incidence since I can’t see what would be different besides the closed frame motor.
The weight is in the rear.
The B&O E set is a bit different. The driveline is the same, but now two weights are used and both gearboxes are insulated. Consequently the frame and shell are NOT charged.
(https://www.therailwire.net/forum/gallery/33/medium_1277-020423163801-330011828.jpeg)
(https://www.therailwire.net/forum/gallery/32/medium_1277-020423162450-329951932.jpeg)
By now you may have noticed that the motor poles always go the front. This mostly matters when you are dealing with a B unit and forget which orientation it follows.
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Test Case: Improving an E1 A & B 2nd run
(https://www.therailwire.net/forum/gallery/32/medium_1277-020423163146-329982003.jpeg)
I first do a survey and see what I am facing. I pull the shell.
This set is not too bad. I have seen much, much worse.
Here are the problems with this set. These are fairly common problems with Kumata E units.
Trucks sometimes short on the shell or frame.
(https://www.therailwire.net/forum/gallery/33/medium_1277-020423171700-330031451.jpeg)
One of the worst offenders is the Kumata Trainmaster. Here is one crossing a turnout. In the process, the truck shorts on the frame.
The shorting makes DCC, and especially sound, impossible.
(https://www.therailwire.net/forum/gallery/33/medium_1277-030423180121-330332289.jpeg)
Out of 8 u-joint cups in the E1 A & B unit, 6 were cracked. This is average. I have never seen a Kumata E unit set with all u-joints in perfect shape.
(https://www.therailwire.net/forum/gallery/33/medium_1277-020423171734-330072246.jpeg)
Driveshaft alignment. This is mostly noted by the u-joint between the motor and the worm which are not perfectly aligned.
This set was slightly off, but here is what I found on another KMT (Kumata) loco.
(https://www.therailwire.net/forum/gallery/33/medium_1277-020423171838-33008360.jpeg)
When the shafts are not aligned well, the end result is a locomotive set that is loud and runs poorly.
You should always inspect the insulated gearbox and the shoulder washers.
At least one gearbox will be insulated from the frame. This is done in two ways.
First there is a clear acetate under the gearbox- as seen here.
(https://www.therailwire.net/forum/gallery/33/medium_1277-030423182147-330432105.jpeg)
Then, the screws are isolated from the gearbox by a plastic shoulder washer.
(https://www.therailwire.net/forum/gallery/33/medium_1277-030423180106-33031315.jpeg)
The insulated shoulder washers on the insulated gearbox may be damaged. Here is a good one and a damaged one from another KMT loco.
(https://www.therailwire.net/forum/gallery/33/medium_1277-020423171857-33009660.jpeg)
On this set, yep- there is a damaged washer which is close to failing and creating a short. The error people make is cranking down screws in the delicate plastic. They also don’t make SURE the parts are all centered correctly before torquing the screw down.
(https://www.therailwire.net/forum/gallery/33/medium_1277-030423180150-330341949.jpeg)
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While we are here, you should also inspect the gearbox metal, Sometimes there can be Zamac rot.
E units usually don’t suffer from this, but I would BEWARE ever buying an Alco where you cannot see the gearboxes and the truck frames. The metal in the Alcos was a BAD batch…. As seen in this RSD-4/5 truck frame.
(https://www.therailwire.net/forum/gallery/33/medium_1277-030423180912-33040602.jpeg)
And this RS-2.
(https://www.therailwire.net/forum/gallery/33/medium_1277-030423180810-33039722.jpeg)
When things have been really bad, I have created my own cast gearboxes. Thankfully, I don’t need them here. When a truck frame is seriously bad- the loco may become a shelf queen.
(https://www.therailwire.net/forum/gallery/33/medium_1277-030423181040-330412302.jpeg)
There can be corrosion on the screws- especially the one at the motor tab.
(https://www.therailwire.net/forum/gallery/33/medium_1277-030423180155-33035949.jpeg)
You can also have broken wires which have come loose from the motor or the gearbox tabs. This set had none, but I’ve seen it before. I assume it was a cold solder joint, or poor fluxing, or corrosion, or all three.
Like here:
(https://www.therailwire.net/forum/gallery/33/medium_1277-030423200618-330451392.jpeg)
Even if the joint is in tact, there can be so much corrosion, that the conductivity is greatly reduced. I had some clean-up to do.
(https://www.therailwire.net/forum/gallery/33/medium_1277-030423180229-33036622.jpeg)
Oh- that photo above also shows a mis-aligned u-joint can be side-to-side, and not just up and down.
You should also check the excess screw length on the gearboxes. In my E1 set, there was one screw that was longer and projected out a bit- but not excessively so.
(https://www.therailwire.net/forum/gallery/33/medium_1277-030423204339-330472213.jpeg)
Hopwever, look at these two EP-2s. This first one is a photo taken in Japan of a 2000 release. Follow the line down from the cab windows to the frame. Those black spots are the protrusions of absurdly long screws. While, in this case, these will not create a short, they are really ugly and could be a snagging problem.
(https://www.therailwire.net/forum/gallery/33/medium_1277-030423180559-33038786.jpeg)
But now look at this NJ EP-2. See on the far left….. that screw projecting upward from the truck? That is an absurdly long coupler screw. This is the insulated truck. So if there is uneven track or some other obstruction, if that screw goes up and touches the frame, there will be a short.
(https://www.therailwire.net/forum/gallery/33/medium_1277-030423182236-33044530.jpeg)
You should also check for a bent frame. I once had an RS-2 that would not run because the frame was bent and caused a bind in the drive train. In this set, the A unit had a slightly bent frame. I didn’t notice it at first, but when I saw the loco on the track, I could clearly see that the shell sat lower in the rear than in the front.
(https://www.therailwire.net/forum/gallery/32/medium_1277-020423102758-329841017.jpeg)
One other thing to check is the tightness of the gearbox bearings on the worm shaft. Excessive wear in the worm bearings is manifested by a worm shaft that wobbles a lot. The bearings don’t hold the shaft tightly. Mine were fairly tight because this was a lightly used set.
You can check in two ways. First, just grasp the worm shaft and see how much it wiggles. Second, with the u-joint straight, turn the motor with your finger (or run at very low speed if it’s possible) and watch the worm shaft. Is it true? Or is there eccentricity to it?
Mine were fairly true.
(https://www.therailwire.net/forum/gallery/33/medium_1277-030423205533-330481211.jpeg)
You will also want to remove the trucks and inspect the bottom surface of the frame- because it tells a story. If you see semi-circular wear spots, they can also be indications of shorts. In the next photo, you can see two arcs. The one near the fuel tank is the tip of the truck frame rubbing. Track work has to be pretty bad for that to hit. However, the inner arc is the wheel flanges hitting. If this is the insulated truck, then it will short on the frame.
(https://www.therailwire.net/forum/gallery/33/medium_1277-030423205549-330501451.jpeg)
This concludes our tour.
I will have to correct all these problems that I find in the E1 set- before we even think about adding sound.
The first priority is smooth, quiet reliable running.
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Ron - thanks for taking the time to prepare such a thorough presentation.
I know nothing about Kumata, and it is unlikely that I would ever acquire such a thing, but your tutorial was still of interest. Just curious - when were these brass models produced?
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Never mind - I see now that you mentioned that they are approximately 30 years old.
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Dwight,
Here is the specific info. All sets A and B unit except B power chassis
E1 1st run, AT&SF painted, Oriental, 11/1982 (B unit dummy)
E3/6 undec, brass or plated, Hallmark, 4/1984
E5, undec, plated, Hallmark, 4/1984
E1 2nd run, AT&SF painted, Oriental, 5/1984
E1B power chassis, Oriental, 6/1984
E B&O painted, Oriental, 10/1985
That list has lasted fairly well.
No one has even made an E1 (though BLI has made it in HO- maybe N one day).
BLI has made a nice E3/6. Atlas bought Life Like, so maybe they will make an E3/6 one day.
Kato makes a nice E5
And no one has even made an E for B&O.
Of course, I'm speaking of commercially produced complete locos. You might be able to find 3-d prints of some of these.
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The newest one will be 38 this Fall? Definitely old-tech!
I have some Hallmark diesels of similar age, and they all run very nicely.
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The newest one will be 38 this Fall? Definitely old-tech!
I have some Hallmark diesels of similar age, and they all run very nicely.
@nkalanaga haha. You are correct. These are almost 40 years old as a group.
I edited the first post.
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U-joint Repair
Before I get to electrical (I just ordered something and want it to come in)…
As stated above, cracked u-joints is a common problem for KMT locomotives.
(https://www.therailwire.net/forum/gallery/33/medium_1277-030423180307-33037398.jpeg)
Now, on this locomotive set, the cups were still holding, but usually there is a loss of grip. So they need to be replaced or repaired.
One way will be to add flywheels, which we will talk about in the future. But first let’s talk about no flywheels.
I have commonly cannibalized old locos- even vintage locos. While the motor from a 1970s loco may be crap, the u-joints may be useful. Here is a KMT loco where I installed a new u-joint from one of those old locos. Note the new joint on the right.
(https://www.therailwire.net/forum/gallery/33/medium_1277-050423194437-330781170.jpeg)
However, it is possible to repair those old KMT cups.
These u-joint cups just happen to to be about 5/32”. Therefore, K&S brass tubing of that size can be used to make a little band that goes on the outside. I got this idea from @peteski in a gear he salvaged a long time ago.
(https://www.therailwire.net/forum/gallery/33/medium_1277-050423192408-330511467.jpeg)
This is not a perfect solution because the shaft is spinning and if the band is not perfect, it can create some wobble and noise in the shaft. So it is important to make the finished band as straight as possible. People with a lathe have an advantage here. Here is a decent one with only a motor tool.
(https://www.therailwire.net/forum/gallery/33/medium_1277-050423192408-330512249.jpeg)
I press the band onto the cup. Then add just a little superglue to the back side of the band once in place. In fact, this band is a little wide and could have been made a bit narrower.
(https://www.therailwire.net/forum/gallery/33/medium_1277-050423192411-33063635.jpeg)
I have found so far that this is sufficient to cause the u-joint cup to hold onto the shaft sufficiently tight.
I had a good cup and a bad cup. Therefore, I placed the repaired cup with the band on the motor shaft to reduce the effect of any possible wobble.
(https://www.therailwire.net/forum/gallery/33/medium_1277-050423192411-33063698.jpeg)
We will look at other solutions in the future.
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Looks good Ron!
Thanks for the mention. The brass band fix works really well for me, and should permanently prevent the plastic part from cracking again in that high-stress area.
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I bought an E1 second run from Brass Trains a few years ago - the UJ had been replaced with a silicon tube - seems to work well. Its the shorting that is the problem! Looking forward to your solutions immensely. Apologies, it's packed away at the moment, so no photo. I'd be interested to know what you think about using these tubes.
Great stuff
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Silicone tubes, over the years, have been used in many models (especially brass ones). When they work, they work fine, and even provide a soft and quiet coupling. The problem can happen if either the tube is not tight enough on the shaft, or oil gets on the shaft. Either way the tube can start slipping causing drivability problems. But cracked universals will have the same problem. If in your case, if the tubing works well I would keep it.
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Flywheel and Worm Shaft Mods
I like to add flywheels to Kumata brass if possible. This not only smooths out performance a bit, but it also solves the U-joint problem. Furthermore, it can free up two u-joint cups per side.
For example, here is a flywheel added to a KMT Trainmaster- two different variations.
(https://www.therailwire.net/forum/gallery/33/medium_1277-100423191122-33197663.gif)
(https://www.therailwire.net/forum/gallery/33/medium_1277-100423191239-33198623.jpeg)
In the past, I have installed two flywheels in each E unit. This sometimes required trimming the lead weight- which is not a great loss since the flywheel adds weight back.
In this example, the weight was removed altogether.
(https://www.therailwire.net/forum/gallery/33/medium_1277-050423204701-330792022.jpeg)
Here is an example with the weight trimmed.
(https://www.therailwire.net/forum/gallery/33/medium_1277-050423204714-33080993.jpeg)
In this case however, since I plan to add a sound decoder in the E1A, I’ll only install one flywheel. Because the sound decoder is sizable, I’ll install a flywheel on the short side (with the motor support) leaving the larger side for the decoder. So in this photo, flywheel on the right and decoder on the left with the weight removed.
(https://www.therailwire.net/forum/gallery/32/medium_1277-020423162327-329931203.jpeg)
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Through the years, I’ve used flywheels from Atlas, Kato, or Life Like locomotives that have a hex hole. You might need to pull one off of a motor (as I have done before).
(https://www.therailwire.net/forum/gallery/33/medium_1277-100423190814-331961484.jpeg)
With a hex hole in the flywheel, you now have a couple of options.
You could use a u-joint from a Kato loco from a few years ago (like the old U30C/SD40/SD45 etc.). This has been one of my favorite solutions through the years. You used to be able to buy these easily from Kato.
(https://www.therailwire.net/forum/gallery/33/medium_1277-100423184704-33186904.jpeg)
The same green cup accepted a floating hex rod of differing lengths.
(https://www.therailwire.net/forum/gallery/33/medium_1277-100423184701-331732148.jpeg)
If you can’t find what you want from Kato, you could search ebay.
Atlas has also made a good u-joint. These also work well
(https://www.therailwire.net/forum/gallery/33/medium_1277-100423184705-331861672.jpeg)
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After installing the flywheel, you will probably need to cut the Kumata worm shaft to proper length.
However, my favorite procedure is to Beardenize this end of the loco. This is a term people have given for a procedure of mine for removing the inner bearing block from a wormshaft with no bending u-joint.
See my article: http://u18b.com/wp-content/uploads/2019/10/Bearingblock09.pdf
First, I pull the gearbox apart. This might be hard. Kumata learned that the bearings can be too loose, so they began using epoxy to hold it together. That was the case in this E1 set. I had to very very carefully use an Xacto #11 to pry the haves apart (and do it without cutting myself!)
This is a good time to note that the steel KMT uses in the worm shaft is VERY soft. I have had a u-joint cup that was stuck on. I would grasp the shaft with a pair pf pliers to pull the cup off- only to see that the pliers had damaged the shaft! Thus I have determined the best course is to simply replace the shaft with something just the correct length.
I very carefully drive out the old shaft. Chamfer (round) the end of the shaft before it gets near the worm so you don’t gouge out the worm getting it off.
For a replacement shaft, I found stainless steel tubing works well. I have some in the aprox 1.5mm shaft size.
My worm is not real tight on the shaft so I add some superglue on the end of the worm away from the outboard bearing.
Now we need a hex interface. With no inner bearing, you cannot use the floppy Kato joint described above.
But Atlas has made several variations through the years for several locos. Here is one- though sometimes you might need to remove some flashing (as seen here).
(https://www.therailwire.net/forum/gallery/33/medium_1277-100423184706-331881508.jpeg)
I place an Atlas hex nut on the end of the shaft. I then test fit and cut the shaft more if needed.
As described in my article, when the shaft just right length and all assembled, there should be a only tiny amount of lateral play in the worm shaft. No play and there is a bind. Too much play and there can be a rattling noise. The hex nut should almost bottom out in inside the flywheel.
Time to assemble everything again (with the weight). The loco should run smoother and quieter.
(https://www.therailwire.net/forum/gallery/33/medium_1277-100423184815-331911543.jpeg)
(https://www.therailwire.net/forum/gallery/33/medium_1277-100423184733-331901801.jpeg)
Beardenizing the loco like this greatly reduces noise. This is especially true in longer locos. If you have a long KMT commuter set (Silverliner, Washboards, etc), then you REALLY need to do this.
I added flywheels to both the A and the B unit.
(https://www.therailwire.net/forum/gallery/33/medium_1277-100423184859-33195999.jpeg)
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Electrical Issues
This portion is slow because I’m continuing to research sources of solutions.
For example, I’ve ordered some M1.4 Nylon screws coming from Japan. I don’t have high hopes, but you never know.
Also, I have contacted two firms to get bids on shoulder washers.
(https://www.therailwire.net/forum/gallery/33/medium_1277-120423163847-332002121.gif)
These are the measurements I submitted.
A Diameter of the top surface- 2.55mm
B Thickness of the lip .60mm
C Outside barrel 1.85 mm
D stock is .75mm
E inner hole for the screw 1.35mm
This is such a small job (tiny object- 100-500 run) that I’m not sure how interested they will be.
If anyone here wants to draw and produce these on Shapeways… or even make the file available for free to all here, please speak up.
@narrowminded graciously made some for me, one at a time on a lathe- but that does not seem feasible if there is a need for 100 or more. I think a commercial solution would be best. The material must be not too brittle and not too soft.
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Here is the file:
https://www.thingiverse.com/thing:5974763
Had to convert it to inches :P
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Wow Chris. That was fast. Thank you. :o
@chessie system fan (clearing throat)..... Dad could use a favor.... :trollface:
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So we will proceed- because there are a number of things you can do.
As explained before, the problem is shorting to the frame and shell since everything (except in the B&O E’s) is electrically charged.
Now, the real problem is generally the rear truck in the E units since the rear truck is electrically isolated from the frame and charged oppositely. If the front truck touches the frame, there is no problem.
However, the other problem is the wheel flanges.
So, on almost all Kumata brass, I find it beneficial to insulate the bottom surface of the main frame.
Begin by pulling the shell and remove the trucks. The trucks are retained by a headless screw. Be very gentle when removing. I also remove the screw for the weight if needed.
Clean the bottom surface of oil if needed.
You can see in this shot the tell-tale sign of wheel flanges scraping. The chrome plating is covered in clearcoat and you can see where the clear is rubbed off.
(https://www.therailwire.net/forum/gallery/33/medium_1277-160423183742-33246608.jpeg)
I then take plain old clear packing tape and stick it to the bottom. Starting at the fuel tank and excess forward.
(https://www.therailwire.net/forum/gallery/33/medium_1277-160423183742-33246613.jpeg)
Now, obviously we need to cut the tape for all pass-through parts. So here I am cutting the tape so the truck geartower will pass. I’m cutting at the frame.
(https://www.therailwire.net/forum/gallery/33/medium_1277-160423183746-33248161.jpeg)
I then have to cut out the holes for the screws which pass through to hold the shell. As well as the screw hole for the weight.
(https://www.therailwire.net/forum/gallery/33/medium_1277-160423183746-332482276.jpeg)
Just making this simple change improves many KMT locos.
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The next solution is simple and effective.
Shim the shell to raise it away from the trucks.
I use Micro-Trains washers. The edges often need to be trimmed. They're about .005" thick.
(https://www.therailwire.net/forum/gallery/33/medium_1277-160423225524-33256662.jpeg)
A little superglue hold them down.
(https://www.therailwire.net/forum/gallery/33/medium_1277-100423184839-331941014.jpeg)
If you have a KMT Trainmaster, you absolutely MUST do this since clearance is WAY too close on that loco.
(https://www.therailwire.net/forum/gallery/33/medium_1277-030423180121-330332289.jpeg)
Now, after doing this…. I noticed the gap was larger at the front truck than rear. If that ever happens, you should check to see that the clear acetate insulator is present under each gearbox- because without it, it changes the height of the shell. In my case, the insulators were present.
(https://www.therailwire.net/forum/gallery/32/medium_1277-020423102758-329841017.jpeg)
Closer examination revealed a slightly bent frame forward of the fuel tank. Since this is plated, I didn’t want to risk damaging the integrity of the plating- so I did not try to bend it straight. I simply removed the shim I had installed in the nose- which lowered the nose and the gap. Now all is good.
Unfortunately, while this helps many electrical issues, it does not solve them all. In my A unit, the rear stirrups are soldered just a hair too far forward. This means the rear truck can short near the fuel tank skirt or the stirrups.
(https://www.therailwire.net/forum/gallery/33/medium_1277-020423171700-330031451.jpeg)
Now, on an E unit, raising the shell gives you a few extra microns clearance because of the angle of the skirt.
But what about the stirrups?
Well, we have four sources of play which we can manipulate.
Shell
gearbox
truckframe
truck
Let’s look at each one. The first three are all similar in that the screw hole is a few microns bigger than the screw.
#1 So on my A unit, I loosen the three screws (not remove) and press the frame/mechanism forward toward the nose. Then tighten the shell screws. That helped. But not enough.
#2 So then I pulled the shell and loosened the screws on the rear gearbox. I then pushed the gearbox toward the nose (moving the rear truck forward) before tightening the screws. That did not gain me much on this loco because the gearbox had very little play. Of course I repeated #1.
#3. With loco assembled, I flipped it over and see two screws holding the rear truck sideframes. I loosen these screws and slide the sideframe toward the fuel tank before tightening.
So #1 + #3 + raising the shell did the trick. The A unit runs perfectly now with no shorting- even with the inherent unevenness of grades.
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Now, if you STILL have not gotten the movement you need, you have two more options.
You can take a motor tool and open up the holes to give you a little more play. The best candidates are the truck sideframes and the gearboxes. In my case, I did not want to break through the plating so opening up holes was not an option.
That meant #4 above. Addressing the truck play.
Now, I did not need the following since my shorting stopped, but I tested it to make sure it works- and it does.
The trucks themselves have some gap between the geartower and the gearbox sides. Thus, one solution is to place a barrier to remove some of that play.
In my example, I moved the mechanism into the shell farther. This helped the rear truck clearance, but now the front truck front edge can hit the curved skirting of the front plow at the nose.
This is not a crisis electrically since the truck and the shell are charged the same. But just for fun, let’s see if we can correct this.
You can see in this shot , you can see the frame hole is larger than the gearbox. I want to place something on that gearbox edge.
(https://www.therailwire.net/forum/gallery/33/medium_1277-160423183746-332482276.jpeg)
I found some styrene that was just under the thickness of the frame. I then trimmed and filed to get a good shape. The side toward the truck is curved a bit.
(https://www.therailwire.net/forum/gallery/33/medium_1277-160423195505-332502097.jpeg)
After test fitting and making adjustments, I superglued the styrene to the gearbox. Of course I did not use much- applying a tiny dot with a fine wire. You cannot see in this shot, but I also ran an Xacto blade and trimmed the edge about 45 degrees so that the gears will clear the styrene.
(https://www.therailwire.net/forum/gallery/33/medium_1277-160423195505-33250793.jpeg)
This procedure worked. It moved the truck rearward toward the fuel tank and it now clears the pilot skirt edge.
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The last electrical step to take right now is to clean up all connections and check solder joints.
All solder was strong on this loco, but I had some typical corrosion.
(https://www.therailwire.net/forum/gallery/33/medium_1277-030423180155-33035949.jpeg)
So all the screws and brass tabs were cleaned.
This loco set now runs perfectly with no shorting. Adding sound is in my future!
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So how many of the thingy's do you want? :)
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So how many of the thingy's do you want? :)
20 would be a good start!
:D
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This gives me hope. I had my eye on the B&O EA set for some time, but have hesitated based on the Spookshow review. I feel like it might have the best of the E unit drives now, and with a more robust motor and perhaps a flyweel, it could be a strong contender...
Lee
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This gives me hope. I had my eye on the B&O EA set for some time, but have hesitated based on the Spookshow review. I feel like it might have the best of the E unit drives now, and with a more robust motor and perhaps a flyweel, it could be a strong contender...
Lee
Hi Lee,
Yes, it is the best of the KMT E units. I'll be talking a bit more about the B&O EA set.
And bringing the E1 up to the EA standards will be where I'm going soon with this thread.
Waiting on a few parts to come in.
-
No word on anyone producing the shoulder washers yet.
So what can be done instead when you have some insulators that are damaged or destroyed? You must electrically isolate one of the gearboxes from the frame. I’ll cover 4 solutions and evaluate them.
1. First, I have used heat shrink. Not desirable since it is not strong enough.
(https://www.therailwire.net/forum/gallery/33/medium_1277-040523210129-33576178.jpeg)
2. I have used an awl and poked a hole in a business card. The awl pushes some paper thru the hole and sort of centers the screw in the hole and provides a little insulation.
Works- but not a good long term solution.
You can see the white card pieces in this shot of a Trainmaster.
(https://www.therailwire.net/forum/gallery/33/medium_1277-040523210138-33584942.jpeg)
3. M1.4 insulated screws are hard to come by. But 0-80 screws are common. This is a pretty good solution. It requires you to take a tap and thread the stock M1.4 screws to 0-80.
This was the same Trainmaster as above. This is a MUCH better solution than the imprecision of cards.
(https://www.therailwire.net/forum/gallery/33/medium_1277-040523210145-335852226.jpeg)
However, while this is a generally good solution, I did not want to do this on the AT&SF E1 set. This set is chrome plated. Tapping for 0-80 screws would cut through the plating- which can then lead the the plating peeling once broken through.
4. Thus I found a source for M1.4 insulated screws.
The company home office is in Japan. And they have an office in USA. They make a resin kind of screw. Much stronger than the old Delryn screws Kumata originally used in early locos. And stronger than Nylon.
This is a destroyed screw from a KMT SD40-2.
(https://www.therailwire.net/forum/gallery/33/medium_1277-040523230035-33594496.jpeg)
This is the screw I wanted- but they were out. It has the largest head.
https://solidspot.com/shop/index.php?main_page=product_info&cPath=143_380_216_220_330&products_id=2471
Model: RENYLM146
Reny is the screw.
LM is a large head.
M14 is size (M1.4mm)
and 6 is the length (6 mm).
I figured I’d cut off excess.
So rather then wait, I bought the screws with the smaller head.
https://solidspot.com/shop/index.php?main_page=product_info&cPath=143_380_216_219_327&products_id=2469
They are a little pricey but you get 100 (shipping is 10 bucks- but there is no extra charge if they have to get them from Japan).
(https://www.therailwire.net/forum/gallery/33/medium_1277-040523211454-33586772.jpeg)
These are great screws.
I did notice a problem. They are Phillip screws, but the center cut is not very deep. A typical pointed Phillips screwdriver will strip the head. So I found it is actually better to use a correctly sized flat screwdriver.
(https://www.therailwire.net/forum/gallery/33/medium_1277-040523211540-335871913.jpeg)
(https://www.therailwire.net/forum/gallery/33/medium_1277-040523211540-33587420.jpeg)
These screws are so tough that I could not easily cut them off without risking the X-acto knife jumping dangerously.
So I scored them….
(https://www.therailwire.net/forum/gallery/33/medium_1277-040523211543-33589736.jpeg)
Then broke them off. Any extra is easily removed now,
(https://www.therailwire.net/forum/gallery/33/medium_1277-040523211543-335891360.jpeg)
I admit- I’m very impressed with these screws. I can now use them as a method to replace the shoulder washers when damaged.
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Xuron flush-cutters and some light filing?
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Trucks Shorting to the Shell
Reading thus far, we’ve seen how to greatly reduce the chance of the trucks or wheels shorting to the frame or shell in Kumata E units.
But since the frame and shell are always charged on most KMT E units, there is always the risk of a short.
Well, that risk can be minimized even more. Enter the last E unit made: The B&O EA and EB set.
(https://www.therailwire.net/forum/gallery/33/medium_1277-090523214310-33664219.jpeg)
This set is superior because it is one of the few Kumata locomotives that does NOT have an electrically charged frame and shell. They accomplished this by isolating BOTH gearboxes from the frame.
In the other E units, the front gearbox is screwed directly to the frame (with no insulation for the screws). Therefore, the frame and shell are charged.
(https://www.therailwire.net/forum/gallery/33/medium_1277-040523211756-335927.jpeg)
The rear gearbox has those insulated shoulder washers.
(https://www.therailwire.net/forum/gallery/33/medium_1277-090523215631-3367968.jpeg)
The metal screw is screwed into the frame, but the screw never touches the gearbox because it passes through a plastic shoulder washer. So that gearbox is isolated from the frame.
(https://www.therailwire.net/forum/gallery/33/medium_1277-030423180110-330321982.jpeg)
So KMT isolated both gearboxes in the EA/EB set. As can be seen here. There are shoulder washers on all screws- along with jumper wires to both trucks.
(https://www.therailwire.net/forum/gallery/33/medium_1277-090523214344-33678136.jpeg)
So when it comes to other E units like our E1 set, why not do the same thing?
Now, I have a few extra shoulder washers, so I could have used those. But instead, I simply used the resin screws described above.
(https://www.therailwire.net/forum/gallery/33/medium_1277-040523211454-33586772.jpeg)
So by using resin screws on both gearboxes and using the jumper wire, the shell and frame are now insulated and with the other changes, electrical shorting is almost impossible.
(https://www.therailwire.net/forum/gallery/33/medium_1277-040523211815-33593479.jpeg)
(https://www.therailwire.net/forum/gallery/32/medium_1277-020423163146-329982003.jpeg)
By the way- remember all of this only works if the clear acetate is under both gearboxes. If a gearbox rests directly on the frame, the process is defeated.
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Although I sold my Santa Fe E1's years ago, I'm following this with interest (and a bit of fascination). Fabulous work.
So insulating both the frame and the shell solves the shorting problem potential, but how does the power get transferred to the motor? Picking up through the truck/gearbox on one side of each truck only? If so, perhaps wiring the A and B together, with a micro plug, would improve electrical pickup reliability on dead frogs etc? Perhaps you already thought of that...
A great write up, thank you.
Otto K.
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Otto, good questions.
The Kumata design is actually pretty simple (some would say primitive by modern standards). But once the shorting issues are corrected, it is actually a solid design.
It starts with the trucks. One side, the wheels are insulated, one side is solid metal. Since the truck frame is solid metal, the electricity charges the solid wheels, the axles, the entire truck and then the gearbox. So (bottom line) each gearbox is a different polarity. Electricity gets to the motor by jumper wire- or sometimes simply through the frame.
For example, if your E1 set was a first run, then one motor pole has no cardboard insulator. The brushcap touches the motor frame. The motor frame touches the motor mount- which is charged like all of the frame and shell. So an early E1 actually only uses one jumper wire. But all the rest (including my second run E1) have two jumper wires.
By totally insulating the gearboxes from the frame, then jumper wires are required to get the power to the motor.
Now, as you are observing, each 3-axle truck only picks up juice from 3 wheels. 3 are dead and wasted. Normally, this is OK on this loco. But you are correct, running jumper wires between the A and B unit would double the electrical contact. I'm already exploring this because of DCC sound.
In my next post I'll start working on installing sound.
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Thanks for the description, Ron, that's kind of what I figured. And yea, since the AB lashup will be operated mostly together, using both will virtually eliminate any power cutouts. I didn't realize you were eyeing DCC, than that's even more important!
Fun stuff!
OttoK.
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Installing Sound
I had a ESU Loksound Micro v5 on hand and used it. The Nano might work better because it is shorter, but right now there is a worldwide shortage of Nanos! Esu just released some more last week, but they are going FAST.
I first tested the v5 decoder with my Lokprogrammer sound tester to confirm it works.
(https://www.therailwire.net/forum/gallery/33/medium_1277-090523230349-33684970.jpeg)
I also used the LokProgrammer to install an early EMD sound file.
I navigated to the ESU site and searched in the Downloads/v 5 files.
I downloaded and installed a 1 gen EMD dual engine file.
S0583-LS5H0DCC-Diesel-Dual-EMD-12-567-V1-R1.esux
(currently in this list: http://projects.esu.eu/projectoverviews/search?cat=18&q=emd+dual )
Of course, I already had thought all of this through with lots of planning. In situations like this I spend a LOT of time thinking, imagining, drawing and making notes.
For example, I found the v5 Micro could NOT fit under the motor without sightly raising the motor and changing the worm shaft interface. Instead, it will fit where the weight normally resides. Further, the decoder will fit if it sits on the frame at a slight angle using it’s own internal components.
(https://www.therailwire.net/forum/gallery/33/medium_1277-100423184815-331911153.jpeg)
So with a workable plan, it’s now time to squeeze this thing in – and I mean squeeze.
There is a small amount of room for a speaker under the worm shaft and in front of the flywheel. But we need to get speaker wires to it. Rather than go up and over the motor, I went under.
So I removed the motor support bracket from the frame (motor still attached because of the flywheel)
(https://www.therailwire.net/forum/gallery/33/medium_1277-090523230301-336801679.jpeg)
I cut a groove in the motor support bracket. Of course, to protect the motor from debris, I taped everything up first. The bracket is made of brass, so no worry about particles attracted by magnets.
(https://www.therailwire.net/forum/gallery/33/medium_1277-090523230314-33681751.jpeg)
To isolate wires, I needed a circuit board. So I cut divisions into 4 quadrants for red/black/gray/orange wires.
(https://www.therailwire.net/forum/gallery/33/medium_1277-090523230314-33681836.jpeg)
This will rest on top of the motor and I cut it to fit. I left an opening for oil for the bearing on the non-commutator end. I folded the motor tabs and soldered them to the board. This held it in place.
(https://www.therailwire.net/forum/gallery/33/medium_1277-090523230337-336831068.jpeg)
Since this is an E unit, all I am going to need is a white-wire headlight. I therefore wanted to remove the purple, green and yellow wires to get them out of the way. Here you can see purple and green up top.
(https://www.therailwire.net/forum/gallery/33/medium_1277-090523230349-33684970.jpeg)
Rather than remove the shrinkwrap, I use a fresh Xacto blade to cut the wires through the wrap. Try to cut in such a way that you won’t damage any traces.
Look at this bare board. There is a trace which runs from the A2 pad at the bottom toward the letter S. We do not want to cut that trace. Notice there is a dead spot right where the white printing of “A2” resides. THAT is where I made my cut. I did the same for the green wire.
(https://www.therailwire.net/forum/gallery/33/medium_1277-090523230431-33686171.jpeg)
Wires safely removed.
(https://www.therailwire.net/forum/gallery/33/medium_1277-090523230445-33687750.jpeg)
On the other side, the yellow wire was easy to get off with a fine soldering iron.
(https://www.therailwire.net/forum/gallery/33/medium_1277-090523230419-33685878.jpeg)
The decoder is ready.
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Time to secure wires- since if not careful, the shell will pinch them when installed.
Holding the decoder as shown, I routed the Red wire in the little gap between the main board and the NEXT-18 board. I superglued the wire to the shrink wrap about halfway back. NOTE: ESU folks need a better buyer for wire. The “red” wire is really deep orange. The orange wire is pale orange. A little confusing at first.
I then routed the blue and white wire the same way on the opposite side.
(https://www.therailwire.net/forum/gallery/33/medium_1277-090523230507-336891871.jpeg)
Here is the reverse side for clarity.
(https://www.therailwire.net/forum/gallery/33/medium_1277-090523230525-336901350.jpeg)
I then positioned the remaining wires in the directions they will go. Gray and black to the left side of the motor, orange to the right side, and the brown speaker wires straight back (will go through the newly cut groove in the motor mount).
(https://www.therailwire.net/forum/gallery/33/medium_1277-090523230524-336901252.jpeg)
I then superglue the decoder to the locomotive frame.
(https://www.therailwire.net/forum/gallery/33/medium_1277-090523230527-33693711.jpeg)
The decoder cannot lay flat. But there is a natural angle that is supported by the current electronic components. See this side view.
(https://www.therailwire.net/forum/gallery/33/medium_1277-090523230526-336921257.jpeg)
I installed the gearbox to make sure there was no obstruction.
Red wire is soldered to the front gearbox tab. Orange wire to right motor tab. Gray wire to the left motor tab. Black wire to the back quadrant on the circuit board. And the brown speaker wires run through the motor mount.
(https://www.therailwire.net/forum/gallery/33/medium_1277-090523230604-336941809.jpeg)
(https://www.therailwire.net/forum/gallery/33/medium_1277-090523230604-336941060.jpeg)
(https://www.therailwire.net/forum/gallery/33/medium_1277-090523230719-33696774.jpeg)
Here is a close-up view showing that the decoder clears the worm shaft and u-joints.
(https://www.therailwire.net/forum/gallery/33/medium_1277-090523230839-337001968.jpeg)
A test run confirms all is working (at present, blue, white and brown wires are unattached).
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I then made a little circuit board divided in half for under the flywheel. I removed the motor to the side and ran the brown wires to that board. This board was because of disassembly or repair later.
I also placed some Kapton tape on the frame to keep the speaker solder points insulated.
(https://www.therailwire.net/forum/gallery/33/medium_1277-090523230743-33697568.jpeg)
The next step was to build a custom sound box for the little Soberton speaker. Styrene was too flexible when thin, so I used clear acetate window material. Looks I bit ugly, but I don’t care.
I place a piece of Kapton take on the frame to insulate and protect from the solder pads and the charged loco frame. The box had to sit under and clear the worm shaft. When the size and fit were good, I superglued the speaker box to the Kapton tape and then soldered the wires to the little circuit board.
(https://www.therailwire.net/forum/gallery/33/medium_1277-090523230806-336981930.jpeg)
Of course I constructed the speaker box with clearance from the wormshaft.
(https://www.therailwire.net/forum/gallery/33/medium_1277-090523230815-336991066.jpeg)
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Ron,
the speaker seems to be blocked on both sides. On one side it is sealed inside the enclosure, and it seems that the other side is glued to the loco's floor. The side of the speaker that is outside of the enclosure should be exposed to open air. Just like the speakers in your home WiFi.
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Hi Pete. Thanks.
Not quite as tight as it looks.
There is a gap at the bottom edge. The speaker has a solid metal frame that has air opening at the corners (down in my installation).
(https://www.therailwire.net/forum/gallery/33/medium_1277-090523230806-336981930.jpeg)
Though now that I have this working, I may open it up a bit along the bottom edge.
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Ah yes. The slots in the speaker housing's corners. I now see what you mean.
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Headlight LED
Time to install a headlight.
(https://www.therailwire.net/forum/gallery/33/medium_1277-140523145843-33758397.jpeg)
The inner headlight casing on this loco is a tube angled downward toward the bottom of the worm bearing so it was hard to know how to proceed. Of course this old brass loco came with no windows or headlight lens- I’m on my own.
(https://www.therailwire.net/forum/gallery/33/medium_1277-140523145850-33759576.jpeg)
I had an LED- which ALMOST fit. The lens barrel fit just right after trimming the wider base. But the problem was with the leads. They were too close to the tube edge and would cause a short.
(https://www.therailwire.net/forum/gallery/33/medium_1277-140523145913-337601396.jpeg)
Then I had an idea. Since the barrel was perfect, I milled out the guts of the LED so a 0402 mico LED could fit inside. I epoxied the LED inside the barrel lens.
(https://www.therailwire.net/forum/gallery/33/medium_1277-140523145920-33761438.jpeg)
I then had to make a circuit board and placed it on top of the forward gearbox. I used a TCS 4-pin micro plug/socket set. This will be a high stress point and the 2-pin sockets are too fragile. The socket had to be positioned at the back edge so that it would clear the nose.
(https://www.therailwire.net/forum/gallery/33/medium_1277-140523150015-337622438.jpeg)
You can see the blue wire runs straight to the socket. The white wire runs to a resistor and then the socket. Also note the silver sharpie mark for polarity so plug and socket will match.
(https://www.therailwire.net/forum/gallery/33/medium_1277-140523150037-33763674.jpeg)
Here is the whole chassis so far.
(https://www.therailwire.net/forum/gallery/33/medium_1277-140523150105-337641743.jpeg)
I then installed a plug. Pins 1 and 2 are soldered together and to a wire…. And 3 and 4 to the other wire. Note again the silver mark for polarity.
(https://www.therailwire.net/forum/gallery/33/medium_1277-140523150151-337661498.jpeg)
The LED barrel lens was pressed into the headlight tube.
(https://www.therailwire.net/forum/gallery/33/medium_1277-140523150145-33765735.jpeg)
Here is the headlight plugged in. Later I added some epoxy around the socket edge to give it a little more strength for when the plug is inserted and removed.
(https://www.therailwire.net/forum/gallery/33/medium_1277-140523150211-3376791.jpeg)
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Windows
Now time to install window glass. I cut pieces to fit and then used epoxy to hold in place.
Here is a trick. Sometimes it is hard to get the clear acetate to press up flat. So I found foam earplugs can help hold everything in place.
(https://www.therailwire.net/forum/gallery/33/medium_1277-140523150326-337682320.jpeg)
(https://www.therailwire.net/forum/gallery/33/medium_1277-140523150333-33769198.jpeg)
Another test run. The sound and lights work great.
(https://www.therailwire.net/forum/gallery/33/medium_1277-140523150339-337701731.jpeg)
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Great stuff, and the idea of using foam ear plugs to squeeze things together is genious!
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Well, I now have an AT&SF E1A with sound.
What about the B unit?
I saw about 3 possibilities.
1. Repeat the whole process installing a new decoder. To be honest, I didn’t want to spend well over 100 bucks to do this.
2. Drawbar and wire the A and B units together. That could be time consuming and tricky. Since the wires could be pinched, the shell would have to have notches cut.
3. Install a different decoder- non-sound.
Pursuing #3, I asked on the DCC board if it was possible to pair up an ESU LokSound v5 with a LokPilot v5.
https://www.therailwire.net/forum/index.php?topic=55753.0
Folks said it was possible but…..
The sound has a delay (prime mover revs up before the loco moves) and that delay must be accounted for. You would have to make the LokPilot act like a sound decoder.
(https://www.therailwire.net/forum/gallery/33/medium_1277-170523203641-337912148.jpeg)
OK. How do you do that? People assured it could be done…. But no one was absolutely specific about how to do it (change this variable to this, etc.).
So I decided not to do this. I’m not an advanced DCC guy like some of you (especially sound).
Thus, I chose option 2. Wire the B unit such that it sends rail power (black and red wires) forward to the decoder in the A unit, and then the decoder sends orange and gray wire power back to the motor in the B unit. Thus one decoder will run 2 locomotives. Since this LokSound v5 micro decoder can run a much larger HO scale locomotive, I assumed the amp draw of two N scale locos would not exceed its limits.
The down side is this requires semi-permanently coupling of the locos and the more complex wiring. Practical matters like storing them in a box becomes and issue.
The plus side is that I would double the electrical pick-up and make the decoder more reliable over uneven or slightly dirty track.
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So here is my A unit chassis.
(https://www.therailwire.net/forum/gallery/33/medium_1277-170523203712-338051172.jpeg)
My plan is to install a TCS 4-pin micro socket and plug. That way the B unit could be unplugged and the set does not have to be permanently drawbared together.
(https://www.therailwire.net/forum/gallery/33/medium_1277-170523203906-338061352.jpeg)
Since the wires have to go to the rear, I will mount the socket/plug in the rear over the gear box (left side of photo above). So I have to get electricity to that spot.
First I made a circuit board the width of the gearbox and cut traces to match the TCS micro socket. Notice I left room for the plug to the left (front of loco is right).
(https://www.therailwire.net/forum/gallery/33/medium_1277-170523203906-33806675.jpeg)
I then installed the socket. I used a multimeter to check for any shorts.
(https://www.therailwire.net/forum/gallery/33/medium_1277-170523203909-338081278.jpeg)
Then then did several things as shown in the next photo.
I superglued the board to the top of the gearbox. Notice a left a notch so I can get oil down to the worm bearing.
I had to get power from the motor circuit-board to the rear board- without obstructing the flywheel. So I jury-rigged some Atlas VO-1000 pick-ups. I had to keep the middle open on this E1 set because the exhaust manifold is recessed down in the roof and will be in the neighborhood. This is not an issue with the E3/6/5 sets.
I made the black and red track wires go through these VO-1000 strips to the outside edges. The orange and gray motor wires will go to the inside pins of the TCS socket.
(https://www.therailwire.net/forum/gallery/33/medium_1277-170523203909-33808343.jpeg)
Here is a view of the other side. The rear gearbox is powered by the left rail (DCC color black). So I made a short jumper wire to the board.
(https://www.therailwire.net/forum/gallery/33/medium_1277-170523203958-33811629.jpeg)
Here is a side view.
(https://www.therailwire.net/forum/gallery/33/medium_1277-170523204009-33812801.jpeg)
So now let’s move forward. The front gearbox is right rail powered (red wire). So I ran a red jumper wire from the tab to the motor pad
(https://www.therailwire.net/forum/gallery/33/medium_1277-170523204010-33812156.jpeg)
Next is gray and orange jumper wires back to the TCS socket. I placed the wires over the VO-1000 strips to keep them away from the flywheel.
(https://www.therailwire.net/forum/gallery/33/medium_1277-170523204011-338141178.jpeg)
So at this point, the A unit still runs the same. I’m now ready to work to transition to the B unit.
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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.
(https://www.therailwire.net/forum/gallery/33/medium_1277-180523154817-338151515.jpeg)
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.
(https://www.therailwire.net/forum/gallery/33/medium_1277-180523154817-33815447.jpeg)
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).
(https://www.therailwire.net/forum/gallery/33/medium_1277-180523154820-33826360.jpeg)
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.
(https://www.therailwire.net/forum/gallery/33/medium_1277-180523154820-338261204.jpeg)
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.
(https://www.therailwire.net/forum/gallery/33/medium_1277-180523154822-338282046.jpeg)
I then remove the B unit shell and place the chassis on the grid lines like before.
(https://www.therailwire.net/forum/gallery/33/medium_1277-180523154836-33829856.jpeg)
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.
(https://www.therailwire.net/forum/gallery/33/medium_1277-180523154839-338311195.jpeg)
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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.
(https://www.therailwire.net/forum/gallery/33/medium_1277-180523154856-338331643.jpeg)
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.
(https://www.therailwire.net/forum/gallery/33/medium_1277-180523154856-33833436.jpeg)
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.
(https://www.therailwire.net/forum/gallery/33/medium_1277-180523154900-338351196.jpeg)
I made a guess visually as to how long the wires needed to be. Imagining the shell installed.
(https://www.therailwire.net/forum/gallery/33/medium_1277-180523154911-338371699.jpeg)
I used a screwdriver to stretch out the wires to get them sort of even.
(https://www.therailwire.net/forum/gallery/33/medium_1277-180523154910-338371829.jpeg)
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.
(https://www.therailwire.net/forum/gallery/33/medium_1277-180523154914-33839408.jpeg)
Cut notches and solder notches on the B unit shell. Install the shell, and the drawbar. A little tricky with no foam cradle.
(https://www.therailwire.net/forum/gallery/33/medium_1277-180523154914-338392173.jpeg)
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.
(https://www.therailwire.net/forum/gallery/33/medium_1277-180523154916-338411930.jpeg)
Time for a test run!
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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.
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Ha! Imagine just two more wires would give you another speaker in the B :D
Nice job!
Otto
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Otto.... I might do that.
:tommann:
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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.
(https://www.therailwire.net/forum/gallery/33/medium_1277-200523110058-339601368.jpeg)
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.
(https://www.therailwire.net/forum/gallery/33/medium_1277-200523110058-33960123.jpeg)
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Ok Otto. I took you up on it.
:trollface:
I ran two more wires to the B unit and added a speaker.
The sound is much better.
(https://www.therailwire.net/forum/gallery/34/medium_1277-070623002411-34292230.jpeg)
(https://www.therailwire.net/forum/gallery/34/medium_1277-070623002411-342932089.jpeg)
I added a two pin socket and plug.
(https://www.therailwire.net/forum/gallery/34/medium_1277-070623002412-342941408.jpeg)
(https://www.therailwire.net/forum/gallery/34/medium_1277-070623002413-342951124.jpeg)
Here is the B unit.
(https://www.therailwire.net/forum/gallery/34/medium_1277-070623002414-342961222.jpeg)
(https://www.therailwire.net/forum/gallery/34/medium_1277-070623002415-342971445.jpeg)
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. :facepalm:
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!
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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.
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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....!
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Well, time to wrap up this project.
I decided to try the suggestion to add some American Limited vestibules.
I used part #8510
(https://www.therailwire.net/forum/gallery/35/medium_1277-050823171528-351461751.jpeg)
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.
(https://www.therailwire.net/forum/gallery/35/medium_1277-050823171529-35157144.jpeg)
On 15” curves there is a slight gap, but I can live with it.
(https://www.therailwire.net/forum/gallery/35/medium_1277-050823171530-35158842.jpeg)
My parts bag had one Kumata vestibule. So I installed it on the back of the B unit to complete the look.
(https://www.therailwire.net/forum/gallery/35/medium_1277-050823171528-351461718.jpeg)
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.
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👍👍
Otto
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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.
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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.
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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.
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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.
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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.
Thank you.
These are great locos when properly adjusted.