Kato Mikado

[Dwight in Toronto]

Atta boy, Leon … thanks for posting. 

Not only is this LokSound install video a hugely instructive, insightful and revealing “how to” on disassembling Kato’s Mikado, but I found it to be engaging and relatable.  I really like Leon’s “man on the street” commentary.  His on-the-fly observations, doubts, cautions and “ooops” moments reflect the same sentiments that we all go through when dissecting an intricate and intimidating model for the first time.

He freely admits that some of the things that worked for him in this instance would/should be done differently by others.  For instance, not many would opt for a complete tear-down and rebuild, including the entire driver/piston/con-rods assembly (crazy, man!).  Regardless, the end result as evidenced in the closing minutes is impressive indeed.

@jdcolombo … is there a way to include dangerboy81/Leon’s video in the LokSound Installation Threads and Techniques section of TRW, please & thanks?

[jdcolombo]

Done.

John C.

[dangerboy81]

Thanks guys, I'm flattered. As for taking the locomotive apart so far, I didn't mean too, I think I was just trying to extract the frame so I could grind it, but the connecting rods and valve gear fell apart on me. I got it figured out after studying pictures.

[Dwight in Toronto]

I’ve made some progress with the Mikado.

As mentioned, I’m using an ESU 58731 decoder.  For those who may not be familiar with it, here’s what it looks like:




I think I mentioned in an earlier post that I’ve put 3 of these in N scale loco tenders. I like them because they are fairly thin, and they have 3 powered outputs - ideal for steamers, which usually only have a single headlight.  Before putting the decoder in the tender, I downloaded ESU’s heavy Mikado sound file, and verified proper motor, sound and LED operation with my tester.

I wanted to show the decoder above, simply because it all but disappears with how I’ve positioned it in the tender:




In the above pic, the decoder is lying flat on the tender floor.  Two sets of pin-&-socket connectors were then positioned directly on/above the decoder.  A 4-pin plug inserted in its socket can be seen immediately right of the speaker (red, yellow, black and blue leads), and a 3-pin plug is about to be inserted just to the right of that (orange, white and gray leads).  The latter 3 wires will exit the front of the tender and be run into the locomotive.  If the need ever arises, I can separate the connectors and remove the decoder/speaker assembly as a single modular package.

The blue & yellow wires are tucked out of the way; I was hoping to install a reversing lamp on the rear of the tender, but there isn’t enough space (maybe I’ll revisit this another time).


The speaker is one I’ve never used before - a 15x10mm unit made by Roco:




The Roco package contained two speakers for $14 (Cdn), which I thought was reasonable.  As illustrated by the speaker lying on its side, the enclosure is 9mm deep, so I had to cut out the top surface of the tender to ensure adequate clearance.  The coal load snaps back into place and covers it up nicely.

Next up - figuring out how best to run the orange, gray and white wires to their engine connections.

[Dwight in Toronto]

Spent time today exploring how to best run the orange, gray and white wires through the loco chassis and out the cab end, into the tender.

I settled on placing the white and gray wires on the fireman’s (left) side, using black tac to keep them tucked up and away from the drivers:




In the above pic, I had tried to string the two wires across the bottom face of the cab area, trying to recess as much of the wire as I could into the insulating gap that runs the length of the mechanism.  Despite keeping them as flat as possible, there was not enough clearance for the draw bar and the rear-most under-cab bogie.

I then focused on trying a different routing for the orange wire on the other (engineer’s) side of the loco.  In this trial, I simply ran the wire horizontally towards the rear, keeping it well above the drivers, and slipping into the cab interior at the bottom/right edge.  The plastic side piece slid in place, and the silver-coloured side plate of the ash pan concealed the wire adequately (I’ll camo the orange wire with black Sharpie later on):




I then re-routed the white & gray wires on the left side of the loco in a similar fashion, hiding them behind the ash pan piece, and entering the cab at the bottom/left floor area.

After slowly and carefully re-fitting all of the plastic shell pieces back together, I reconnected the drawbar and tender, soldered the white, gray & orange wires to their 3-pin connector, and inserted the plug into the socket in the tender.

It’s always a relief when LokProgrammer readily reads the decoder!  A quick check with Driver’s Cab verified that steam, bell and whistle were functional.  And although the loco would move when throttled up, there was an unusual deficiency.

Recall that I did not use a +5V blue wire on the loco light board.  In order to avoid a fourth wire, I opted to isolate the cathode side of the LED from the frame, soldered the white wire to this side of the light board, and relied on the anode side of the LED to conduct through the OEM pad via its friction-fit in the engineer’s side of the frame.  I had seen testimonials attesting to the validity of this approach (and yes, I do have Peteski’s simple diode circuit that improves on this “lazy man’s” technique). 

So here’s what’s happening.  First, toggling ‘Headlight’ did NOT operate the front LED.  Second, the LED apparently comes on intermittently.  Third, every time the headlight decides to illuminate, the loco stops moving.  If I jiggle the loco on the track, or tap the tender “just so”, I can sometimes get the LED to turn off, and the loco resumes movement.

I did, by the way, manage to construct a rear lamp in the tender, wired with decoder blue & yellow leads, and it works properly. 

I don’t think I’m going to troubleshoot the headlight.  I think I’ll just disassemble the shell yet again, run a blue wire to the headlight, and hope that the PROPER wiring technique works better.  I know … woulda/shoulda/coulda.  But hey, it was something I was curious about, so I scratched that itch, and the old dog continues to learn!  I’ll report back on how it goes.

[Dwight in Toronto]

I decided to strip out the decoder, and go back to square one. 

After a lot of continuity testing, I believe that the ‘springy’ contact wires on the draw bar exhibit good conductivity from the loco wheels.  However, it appeared that power pickup in the tender was hit and miss (gentle pressure on the top of the tender would consistently, but temporarily, restore decoder functionality).  This led me to think that the phosphor bronze strips located on the tender floor were making intermittent contact with the posts on the powered trucks.  If this was indeed the weak point, it would also explain why all of that additional pickup from the loco wheels wasn’t helping out.

So, I disassembled the trucks, used isopropyl alcohol to clean the wheels, polished the copper axle cones with a toothpick, and used 1200 grit abrasive to lightly buff the top of the pickup posts and the corresponding contact surfaces on the phosphor bronze strips. 

None of this made any difference … the herky-jerky operation due to sporadic track pickup remains.   If I lightly press down on the top of the tender, lights and sounds work as they should, and the loco drivers spin on the rails to beat the band.  When I let go, everything comes to a stop within anywhere from 1 to 10 seconds.

I’d like to hard-wire the track power leads to a reliable source, but there aren’t a lot of options on the Mikado since the contacts on the tender trucks and the draw bar have to be free to move.

I’m nudging up against a stalemate situation here!

[mmagliaro]

If you remove the plastic retainer over the bronze strips in the tender floor, you can examine the tender rolling on a piece of track, and make sure that both ends of both strips lay down as flat as possible to make solid contact with the truck "thumbs" coming up through the floor.  Rock the tender from side to side, and make sure you see the ends of the fingers pushing up and down as the truck thumbs gently push upand down through the floor as the truck rocks.  (You can put a dot of ACC at the centers of the brass strips to hold them in place while that retainer is off).
Adding weight to Kato tenders does help, because it puts more downward force on the wheels themselves, so they make better contact with the rails.  But in my experience, unless you can add significant weight, like 10g or more, it's not worth it.  Try temporarily taping a
weight to the top of the tender, like a chuck of lead or tungsten, and see if the whole thing just "works".   My guess is not.
It will work better, but I bet you still have some intermittent power hiccups.

I don't understand what you are saying about how if the tender floor strips are a weak point, that would explain why getting
power from all the drivers doesn't help.  If all the driver pickups are really working, they help a LOT. 

[Dwight in Toronto]

Max - thank you for following!

I have tried all of your suggestions, in one way or another (putting lead weights on top of the tender, using tiny bits of black-tac to retain the bronze floor strips, observing that the strips appear to be contacting the “thumbs”).  Intermittent power hiccups persist.

Let me try to better explain the “weak point” theory.  The 8 drivers SEEM to be doing a good job of conducting power to the two ‘stiff spring’ wires on the draw bar.  I can then assume that the tender-end of the draw bar wires are in good contact with the inner faces of the tender truck pickups.  But if the top thumbs on those pickups are not seeing good continuity with the floor strips, then all that nice driver pickup is for naught.

I have tried the tiniest of solder joints to connect the black & red leads to a) the rear-most tips of the floor strips, and b) the centre-most point of the floor strips.  For on-track testing, and using only the tender, I placed the decoder back in the tender, with only the speaker and rear LED assembly connected.  With the bell and LED activated, conductivity is ok as long as I’m gently pressing down on the tender.  If I let go, sometimes the bell and LED remain active.  When I give it a nudge, it doesn’t take long for a hiccup to kill the action.

Instead of trying to get track power from the tender pickups, I’m now leaning towards either:
a) carefully/lightly soldering the black & red to some spot on the draw bar wires (and thereby get the benefit of the 8 driver pickups)
b) running the black & red to the frame contact pads on the loco light board (major downside with this is having 6 wires between loco & tender)
c) putting the decoder on top of the loco boiler, abandoning the ‘pewter’ weight (or removing material so that at least some of it still fits), and running 4 wires to the tender (speaker, plus blue & yellow for the rear lamp).

I’m kinda surprised and dismayed to be experiencing conductivity problems with what is normally bullet-proof Kato design & engineering, especially when there is no clear and obvious deficiency (the ‘strips-&-thumbs’ SEEM to be in proper alignment and working order).

It’s a good thing that this is just a hobby - a past-time to, well, help pass the time, because THIS install is sure sucking up a lot of it!

[Dwight in Toronto]

As a “proof of concept”, I did a quick-&-dirty hookup of Option a) above.   That is, I soldered very thin black and red leads to each of the drawbar brass wires (this was left over material from some prewired 0204 LED’s; significantly finer than even ESU’s decoder wire).  I then hastily soldered them to the track power pads on the decoder.

Bypassing the tender trucks meant that I was sourcing track power solely from the 8 loco drivers.  I’m happy to report that the Mikado proceeded to complete its very first trouble-free loop around my 16’ test oval.

This confirms that I need to source track power from the loco, instead of the tender.  Doing so by way of the drawbar wires is not at all robust, so I am now going to investigate Option b) from my preceding post.  That is, investigate the feasibility of running 6 wires from the loco, back to the tender (black, red, orange, gray, white & blue).

[Dwight in Toronto]

As per Option b) described previously, I managed to fit the 6 wires into the loco, and run them out the back of the cab.  (I also determined that Option c) - fitting the decoder in place of the white-metal weight - is a non-starter … the 58731 is too wide for the space).

On the stock lightboard, I replaced the orange LED with a warm white, and severed the traces so as to isolate the LED solder pads from the friction-fit frame contact pads.  White wire to cathode side of the LED, blue wire on the anode side.  Black wire to the frame contact pad on the fireman’s side of the lightboard, red wire on the opposite pad, and squeezed the board back into its frame slots.

I then ran the white, black and gray wires on the top surface of the plastic running boards on the fireman’s side of the loco, pressing them as tight as possible into the bottom curve of the boiler, using tiny bits of Black-Tac to retain them.  Ditto for the blue, red and orange wires on the engineer’s side.

I was pleasantly surprised to find that the boiler shell and smokebox pieces went back into their respective positions, hiding the wires nicely.  I was expecting a sloppy fit, but I think it’s acceptable.

To get the wires into the cab, I removed the snap-in side windows, and filed a small slot, just wide enough to accommodate the 3 wires.  The routing of the red, blue and orange wires into the cab can be seen in the background of this pic:




After doing the same on the other side, here’s how the 6 wires exit the rear of the cab:




Next up, tying everything together in the tender

[peteski]

Your experience seems strange.

The tender pickups are designed the same way Kato does all the passenger truck pickups which (if kept clean) are very reliable.  I would not have used any sort of sandpaper for cleaning those strips. I would use metal polishing compound with a Dremel-mounted cloth polishing wheel to give them a mirror-like surface. Same for the sideframe pickup protrusions in the trucks which contact those strips.  Also take the trucks apart and make sure the cone axle bearings and the wheelset's pointy axle ends are very clean and lightly lubricated (on reassembly).  Those should all be dead reliable.  Also make sure the wheel treads are very clean. As you mentioned this mode spent a long time sitting unused in its box.

[Dwight in Toronto]

Thanks Peter - I always look forward to your guidance.  I couldn’t agree more that my disappointing experience with the tender pickup system is strange indeed. 

As mentioned, I tried cleaning/refreshing all those components and locations - wheel tread surfaces, axle points, copper axle cups and top-surface “thumbs”, as well as the under-floor-mounted conductive strips (next time I’ll use your Dremel buffing wheel on these).  An exorbitant amount of time was expended … persistent non-improvement persuaded me to throw in the towel.

Hopefully tapping track power from the frame contact pads on the loco light-board will be more successful.

[peteski]

Thanks Peter - I always look forward to your guidance.  I couldn’t agree more that my disappointing experience with the tender pickup system is strange indeed. 

As mentioned, I tried cleaning/refreshing all those components and locations - wheel tread surfaces, axle points, copper axle cups and top-surface “thumbs”, as well as the under-floor-mounted conductive strips (next time I’ll use your Dremel buffing wheel on these).  An exorbitant amount of time was expended … persistent non-improvement persuaded me to throw in the towel.

Hopefully tapping track power from the frame contact pads on the loco light-board will be more successful.

These locos have been around for several years. I do not recall ever seeing many online complaints about tender pickup issues. Something just doesn't add up. In  my experience the Mikado's tender pickups are more reliable than the pickups on the drivers of the loco. Combination of both should provide bulletproof electric pickup for this model. I will also echo the earlier recommendation to add some weight to the tender.

[Dwight in Toronto]

Peter, I couldn’t agree more that tender pickup problems should be nigh impossible, but this was indeed the major stumbling block in this project.  You have pretty good recollection of some of the oddball DCC experiences I’ve shared over the years; I’ve often wished you could witness them in person!

I’m happy to report that taking track power from the frame contact pads on the loco light board has made all the difference.   The Mikado has been doing loops on my 16’ test oval for over an hour, at varying speeds, with not one hint of a hiccup. 

The rear LED that I added works fine in reverse, but for some reason, the front headlight doesn’t toggle ‘on’.  I can try moving the white wire to the spare AUX output easily enough, but if that doesn’t work, I think I’ll leave well enough alone.  I’ve had my fill of accessing the inside of that loco for a while!

I progressively added cars until it was pulling all 11 of my colourful 40’ wood-sided reefers, plus a Rapido CP caboose.  It appears to be capable of hauling a few more, but it was the string of reefers that I bought it for, so this is a great result.

I still need to synchronize the chuffs, as well as add the baggie of detail parts.  After that, I’ll maybe post a short video, just because!

[Dwight in Toronto]

I wrapped up the Mikado sound install.  As promised, here’s a hastily shot 2 minute video, offered up as “proof of life”:

*(video was deleted, in favour of a slightly better clip, posted later in this thread)*

I managed to get the headlight to work.  After much head-scratching, test-moving decoder wires to alternate outputs etc., I traced it down to installer error … dufus me had the anode & cathode reversed on the LED.

Closing comment … adding the tiny detail parts included with the model was NUTS! 
A challenging install, to be sure, but rewarding, and a great way to have filled some time.