Installing Digitrax DN163K1D in Kato DE10

[KenS]

I know there are decoders available from Japan that don't require modifying the weight, but I chose to go with the Digitrax DN163K1D (the GG1 decoder, readily available in the U.S.), which does require a small bit of filing-down of the weight.  Here's my procedure:

 

Caution: there are several places where you can easily break things (I broke a drive shaft, and bent a brass contact strip, both likely due to being a bit impatient). Work carefully, and if you aren't willing to take the risk, you shouldn't be doing this.

 

Step 1: pull the body off, it should slide off easily.

 

photo 1: DE10 with original lightboard

 

If you want to add a figure to the cab, do that before adding the number boards (removing the cab top will pop the side number boards loose).  Do it now, and let the glue set while you work on the decoder.

 

Step 2 (photo 2): lift the walkway assembly away from the undercarriage (small bumps on the weight tend to hold it in place, so a mild amount of prying is required, but it comes off easily).

 

Step 3 (photo 3): take off the trucks. This is done by gripping one firmly by the sides (very firm, or you’ll just pull the truck apart, which is a nuisance to put back together and you might lose a gear) and twisting, while holding the weight firmly in the other hand.  Be careful not to lose the driveshafts (white part). The coupler assembly may get knocked off (as the one on the right did) in the process.

 

You can try fitting the decoder at this point, and you'll see how the brown component on the underside causes the end to stick up (photo 4). You need to file down the weight (just a few mm of it need to be made level with the end section; I filed a bit more than necessary).

 

Step 4 (photo 5): take the undercarriage off (pry the gas tank away from the frame). This is all that holds the two halves of the weight together, and they may fall apart now.

 

When the frame comes apart, note how the plastic tabs on the top side of the motor stick into holes in the weight (photo 6). You’ll need to put them back there when reassembling, and it’s not obvious. 

 

Also note how the motor is essentially suspended inside the weight. You don’t need to add any insulation here, as no part of it that’s conductive touches the weight.

 

Step 5: remove the brass strip from each side (be very careful not to bend it), but first take note of where it fits into the weight, and where the ends go (as shown on the top one above); they should just overlap the point where the metal frame curves down at each end.

 

File the weight down to make room for the resistor, then clean it well to remove the filings.  I clamped the weight lightly in a vise (not too hard, or the weight will bend; if it does, you can gently bend it back, but too much of that and it could break) and filed the end down with a metal file. A Dremel with a grinding wheel would have been faster, I prefer to take my time and be careful.  After that, I washed the weight and my hands with soap to remove the filings, then dried both throughly. Then I let the weights sit on a paper towel for a couple of hours to remove any remaining moisture (blasting them dry with compressed air also works).

 

Step 6 (photo 7): filed down weight (note: make sure the two halves are both straight when you’re done, as if they’ve bent, they could short together once the model is reassembled).

 

Step 7: reassemble the weight, motor, brass strips, undercarriage and walkway (reverse of disassembly)

 

to be continued...

[KenS]

Step 8 (photo 1): insulate. It’s possible the circles that look like conductive metal on the underside of the decoder are varnished and won’t short against the motor, but even if they are this could rub off. I added Kapton tape liberally to insulate the weight. Note that the far left then needs to be bare where the decoder slips under the metal tabs to make contact (that’s the power pick-up for the decoder).  

 

Note the tape above the circular contact on the motor. I bent this down over the sides, but only be about 1 mm, as you need to leave most of that side open to contact the brass tab you’ll attach to the decoder.

 

Step 9 (photo 2): Install the decoder. Note that the left end is at a sharp angle. This is because the decoder, unlike the lightboard, rests atop the two metal bumps on the top of the weight, rather than snapping down to the left of them (compare lightboard photo at the top of this page).

 

Step 10 (photo 3, 4): insulate the brass contact sides and back (but not the inside face!), insert into frame side so that the motor tab is touching the uninsulated inside face. Note that the edges of the brass clip need tape wrapped around them, as they WILL touch the weight.

 

Step 11: Snap the trucks back on. Make sure you insert the white driveshaft into the truck first if it fell out, that place its other end into the hold on the flywheel. Make sure it goes in smoothly; if you force it, it can snap (I broke one, so one of my three DE10’s presently only has one driven truck)

 

With the trucks back on, put it on the track with a DCC command station set to address 3, and test it. One of the two LEDs should be lit, and they should change when the direction is changed, even if the throttle is at zero. Run the locomotive back and forth a bit, and make sure it sounds normal.  If not, or if it’s not working, you’ll need to figure out if there’s a short somewhere (most likely cause of it not working) or some other problem.

 

Before you can put the hood back on, the long-hood light-pipe needs to be shortened radically. But to do that you need to take the light assembly out of the hood, and that’s hard to do. I managed to break one of the two lenses in the process, but only slightly and the resulting assembly still worked pretty well once reassembled. The trick seems to be a combination of pushing from the outside (using a paper clip) and prying on the inside (with a jeweler’s flat-bladed screwdriver)

 

Step 12 (photo 5): remove the light pipe (note the lens on the top right, and the missing (broken off) lens on the lower right).

 

The two angled parts should be cut off (flush-cutters used to take model parts off a sprue work well) and then  the bar shape needs to be filed down to about half its original thickness, otherwise it will hit the decoder when the hood is reattached, and cause it to make poor electrical connection with the weight.

 

Even if you break the light-pipe, don’t despair. The LED actually works fairly well with no light-pipe at all, although you get a brighter, more focused beam if it’s undamaged.

 

Step 13: snap the light pipe back into the hood (it may only loosely fit, if so just rest it in place and let gravity keep it there while you slide the weight into the hood.  Make sure the hood snaps down all the way (it should rest against the walkway piece, without any of the weight showing.

 

Photo 6: DE10 disassembled

 

A slightly longer write-up appears on the DE10 page on my website.

[CaptOblivious]

Nice job! This sounds frightfully complex. Until and unless the US market makes a new form factor decoder, it looks like new Kato locos have lost their one real advantage over the competition...ease of conversion.

[Bernard]

Ken - Great install and good to know how complicated the install is for a Kato DE10. (And I only thought only most of Tomix trains were complicate!) Though your thread I now know to pass on this train.

[KenS]

Well, it's certainly not a "plug-in replacement". On the other hand, aside from manual dexterity it doesn't require any special skills to do.

 

There are a bunch of steps, but for the most part they're all relatively easy except for extracting the light-pipe.  Even the broken drive shaft was probably me trying to force the truck on when the shaft hadn't been seated into the flywheel (usually Kato drive shafts slid into the flywheels easily but these were very stiff and took some fiddling to get in; if you don't do that, the truck can't go in without bending the shaft, and these are too short to bend safely).

 

Although I will note that the coupler assemblies do seem to want to leap off the frame, and not go back.  Poor design by Kato's usual standards.

 

All of these problems are down to the decoder, and mostly to having to take the motor/weight/truck assembly apart.

 

If Kato had only milled the weight to allow the resistor to fit (as they did on the DD51, which this decoder also fits), and made the lens/light-pipe assembly easier to remove, this would be a drop-in decoder.  Or, if Digitrax had made a shorter one without the misplaced resistor.

 

So I guess I'm agreeing with you. 

[Guest Closed Account 1]

Nice thread.

 

Is the DE10 a modern replacement for the NW2 type yard switchers?  I could use a yard switcher.  4-4 is best for any tight places. Even cleaning trolley tracks.

[KenS]

The DE10 was introduced in the late 60's as a replacement for lightweight steam engines in both yard and branchline service.  The original series included a steam generator for coach heating, although those were removed once coaches upgraded to electric heat. They're still in widespread use today in yards (and some freight duties, apparently), and some "joyful trains" normally used on electrified lines were pulled by DE10s on non-electrified lines (I'm not sure if any of those are still in use). The newest is getting close to the typical 40-year retirement age, and JR's new Hybrid is likely going to replace them in a few years.

 

It's similar to the NW2 (slightly more horsepower), but I'm not aware of the NW2 being used in Japan, or the DE10 elsewhere, so you can't really call it a replacement. However, I'd call the DE10 a "road-switcher" (a locomotive suited to either role), so in a sense it's more like a GP7 or similar small loco that could be found pulling small freights, as well as working a yard. That may also be true of the NW2 (I'm not all that familiar with early diesels but I think of the NW2 as an industrial loco or switcher, rather than a road-switcher).

[Guest Closed Account 1]

Oh sorry. Didn't know my RR history. 2 different animals on two different continents. 

 

I'll look for a NW2 since I want a small 4-4.  Thanks Ken.

[Darklighter]

Would a TCS K1D4-NC be a better fit? 

[KenS]

Would a TCS K1D4-NC be a better fit? 

 

I can't find a photo that shows the underside, and all of the U.S.-prototype loco's they show it installed in have a notch where the underside resistor might be, so it might have the same problems as the Digitrax. Otherwise it looks like it would work, but I've never tried one.

[Darklighter]

According to this photo from this guide there is nothing on the underside. Maybe I should give it a shot...

[Darklighter]

I gave it a shot and it worked out well, no modification (and disassembly) of the frame necessary.