Märklin Mikado Update to NP Class W-3 Mike

Around 2004 I converted my first Marklin Mikado to DCC. It ran great at first, but after a short time I burnt out the decoder. Then I decided to make a tender that looked like the NP Shorty w/Doghouse, and convert to DCC. Shortly afterwards the decoder burnt out. I decided to modify another Marklin Mikado to look more like the NP Mike's, and I used a Lenz Gold Mini decoder and installed a Lenz Power One supercap in the tender. It looked decently NP and ran great... For a while, then the decoder burnt out. I installed some decoders in Marklin Pacific's and those too burn out. So I was done with Marklin and DCC from around 2006 on.



Well now Marklin has been using coreless can motors, and I want to give the Marklin Mikado's another chance. I always felt the 3 and 5 pole (Old Sparky) brushed motors Marklin used were the cause of the problems, because the brushes can move around, especially when changing directions. And I think the brushes flexing can cause voltage spikes that might be burning out H Bridges on decoders. Either way, I ordered 3 Marklin 275145 Motors and 3 Marklin 275123 Drive Gears to update the drives. Meanwhile, I want to make my Mikado's look more like NP Class W-3 Mikado's. Here is the NP Mike, Engineer's Side:


And here is the Fireman's side:




In order to do make my Marklin Mikes look like NP Mikes, the tender must be replaced and the loco shell detailed. I had done this to a long time ago, but I think I can do better now. Here is how my old NP Mike conversion looked. Yeah, the more I look at it the lumpier it gets!:



So I will need to identify and gain access to suitable Z Scale detail parts. This part may take a while, but here is what details I have identified on the Fireman's side:



Here is a Side view of the doghouse tender:


Here is a End view of the doghouse tender:

Here is the end that's attached to the locomotive:


And here is a whole bunch of doghouse tenders.. Who let the dogs out?

 

So I am starting with the tenders first, because I am waiting for the motor parts to arrive. First I looked for drawings so I could get actual measurements, and I found a drawing for a W-5 Class Mikado Tender. The end view matches up showing the offset of the doghouse as viewed from the Fireman in the cab:




After I drew up the side, I had to decide what material to use for the carside. I wanted to use brass, but I will take whatever comes out looking the best. I rastered 8 car sides to compare:


Then I painted them all with BBQ Black to see if paint would highlight or remove rivet details, the order is the same as above materials:


So the best two were the acrylic single pass 500ppi, and the 2 passes less power. Even though the 2 pass has more pronounced rivet detail, I thing I like the one on the left, as the 500ppi single pass will probably take decals easier:


Well that's it for today, stay tuned!

 

I made a little progress today. I laser cut a brass tender underframe to use for a "bottom heavy" weight.


I used trucks from an unpowered Rokuhan Shorty so I can have tender electrical pickup, and checked the height good. The contact wipers go through the floor nice.


There is plenty of room for swivel with the contact wiper cutouts.


I slapped together the tender sides and slid it over the brass underframe


And the drawbar is just right.


And here you can see where the decoder wires will pass through. It's the spot that the feed auger is in the prototype as in the photo in the previous post above.

 

I plan on having full lighting. I was thinking of wiring the headlight to always be on by using the blue decoder wire (positive) and tapping a ground off the decoder board somewhere, then use the F1 forward decoder output programed for firebox flicker orange LED and put it low in the cab between the motor and firebox , and just using the output 2 for the tender reverse light as normal. This trick should net me 3 effective functions.

 

With today's progress, I cut Mylar insulator sheets for the brass underframe of my doghouse tender:


I superglued on the insulators, and painted the underframe, them screwed on the Shorty Trucks. I also designed the more detailed doghouse, water hatch, and made a speaker grill for the coal bunker so sound can come out. I will put a piece of fabric there, and sprinkle on real crushed coal for the bunker, but sound should come out there and through the wire feed area too.


Test fit the tender shell over the tender chassis, fit's just fine. I still have a lot more detail design to do for the tender before I call it done, and move on to the locomotive:

 

Today I received some .003" Phosphor Bronze sheet I ordered months ago. Just in time to make some electrical wipers for my tender. The Fiber laser has no problems with this material, and quickly cut the strips I drew up. I also peeled off the Mylar because I could not glue anything to it, so I used peel and stick label acrylic, then I could glue more sign acrylic on to make the alignment slots for the contact strips:



I bent up the terminal ends of the strips then slid them in. You might be able to see the nubs from the trucks contacting the wipers here:



I tested continuity with a meter lead on each track rail, then dropped a dime on the contact strips and measured intermittent continuity, so I will look into that tomorrow. The meter read from 0 ohms to 1500 ohms, so something is dirty:

 

Yes Please... I need "Marklin E275145" motors. I need about 10 to start, but will take whatever I can get. Get them from local the local Modellbahn Geschäft or Spielzeugladen if they are out of stock at Marklin. Grab all you can find, as people will snap them up since they are sold out in the US.

 

Hi Tex, Welcome to Trainboard!

I do plan on fixing the trailing truck area too. In fact I have a zoomed in photo showing what it looks like on the NP Mikado's. What I plan on doing is make a firebox pan on .015" Polybak, then add layers of all the details seen here to cover the trailing trucks, but it will be attached to the Marklin shell. I found a place I can slice between the Marklin's naked firebox pan and Marklin cab, that I can attach my firebox pan updates.

Right now I am still working on the tender details. I finalized the electrical pickup from the tender, and I detailed the Rokuhan trucks to look like Mikado Doghouse Tender trucks, and made some other improvements, so I am ready to start cutting parts for my rev 3 Doghouse Tender. Here is Rev 2 as of last night.

Engineers Side:


Fireman's Side:

 

I finalized the electrical wiper design, and mounting inside the tenders today. There are folds just above the wipers that force better conductivity, and now I measure between 0 and 250 ohms as the underframe rolls. Still better than no electrical pickup in the tender:


I also finalized the Rokuhan to NP Tender Truck design today, with overlays that represent the trucks better. Also I moved the front truck .050" forward:


And I cut all the brass and phosphor bronze parts, and the insulator sheets for 9 more enders today: