Is There Such a Thing as a Good Running 0-4-0 Steam Loco?

[randgust]

The ancient Rapido 0-6-0 is really an 0-4-0 mechanically as the middle driver rolls along for the ride, no gears, no rods, no pickups in the stock tender.

Wheel wipers on the first and third axles, and stock has no tender pickups.

I rebuilt one of those with a Kato 5-pole 11-103 motor and Kato caboose trucks for 8x8 pickup under the tender and that is just an outstanding little locomotive, mine has the old Kadee lead truck on it to make it a 2-6-0, but it enforces the 'it's all about pickup' mantra.   That's the locomotive that runs nearly nonstop on the Hickory Valley portable layout at train shows, and it's the original Woodsman's Axe, 3 different motors, 2 different rebuilt tenders, and been running since 1975.

You can also go full desperation mode for pickup as I went in two other ones, first my Trackmobile where I linked it to a scale test car with Kato pickup wheels under it to get a 'tender' for pickup, and also my Burro crane (smallest moving thing I've ever built) by marrying it to a 40' flatcar with Kato caboose trucks under it for pickup, and it's pretty flawless in performance.    That gets around the bugaboo of short wheelbase and only 4 points of electrical contact.

[peteski]

Thanks everyone.  I'll be checking out your recommendations.  Poor pickup really isn't the issue; I can fix that.  It is having to crank up the voltage just to start the old ones (I can hear the hum, so it is getting power) and have to run it fast to keep it going.  I'd like to slow down the movement with a better runner.

Well, poor pickup (where wheels sit on insulating debris) will not be resolved by cranking the voltage (unless you get into voltages much higher than 12V to arc across the debris.

But if the motor is humming then as you mentioned, the electrical connection is there.  Assuming the model has a typical permanent motor magnet used in the N scale models since the beginning of N scale, I recommend to re-motor it using a coreless motor.  Those are very efficient and have more torque than those old-style motors. They will be able to run even a high-friction mechanism much smoother and with lower voltages.

[wm3798]

There is another critical question...  Does the suitcase layout need turnouts?  If it's a novelty display with a short train chasing its tail, there's not operational need for turnouts, which introduce insulated/dead frogs that are the bane of these little guys' existence. 

If you find a new/old stock Rivarossi (Atlas) 0-4-0 with the sloped back tender, the two-rail (but not all wheel) pick ups will help maintain pretty good contact if there's no interruption to the track continuity.  Then you just have to deal with wonky Rivarossi motor with its rubber magnet and 3 poles.


Even with the old motor, they run remarkably well, but as has been described upstream of this post, it can be improved.

If turnouts are a must, use Peco short radius switches, which have a pretty short frog and spring contact at the points, which helps keep things moving as well.

Lee

[ajkochevar]

Thanks for the tips wm3798.  I do have one turnout with a plastic frog and it did have issues with the 4 wheeled engine.  I was able to solve this with a bit of electrically conductive paint on the right areas of the frog and overlapping a bit on the rails to get power.  It needs redone once and a while but so far is working to "power" the frog.

[Another modeler]

This may sound odd but if your willing to put in a good bit of work the new bachmann percy runs very well and has been used since its release with HOn30(and its UK equivilant) with good results, bare in mind it will require lots of rebuilding to make it US suitable

[u18b]

I made 2 Atlas 0-4-0 with extra pick up.
I'll post when I can.

[u18b]

Here are my 2 Atlas Rivarossi  0-4-0

The plastic frames do crack.   So years ago I brought a brand new frame from Con Cor- and Chessie system fan made a mold and castings for me.

Here is a mostly stock unit.



On the stock tender, I replaced the trucks with Bachmann trucks.   This required metal grinding for the pickups on the frame of the tender.



I was able to use the stock drawbar interface, but as you can see, I had to thin the lead axle for clearance.



On this one, I simply replaced the whole tender with a Bachmann shorty tender.   This also allowed me to easily add a DCC decoder.



Using Bachmann trucks (either version) increases the electricity from 1 axle to 5- a very dramatic improvement.



However, kitbashing the drawbar (electrical connection) was tricky.



The Bachmann tender is a little too big for this loco when compared side by side.
But it's acceptable to me.

[timwatson]

I know I talk a lot about 3d printing and design and this will not be any different. I have been working on an 0-4-0 steam loco design for the past year. I plan to open source it along with the software to create the gears. It is very very possible to create a well running small wheelbase locomotive.

This is 9mm or n scale or Hon30. Feel free to ask questions.

Here is the 3d version of the mechanism.

[chessie system fan]

I like it, though I wonder what could be done to hide that big gear where the steam chest should go.  Can you share your wheel source and wheel size for the design? I'm on the lookout for 42" steam engine wheels on a 1mm shaft.

[timwatson]

I like it, though I wonder what could be done to hide that big gear where the steam chest should go.  Can you share your wheel source and wheel size for the design? I'm on the lookout for 42" steam engine wheels on a 1mm shaft.

Yeh that’s a good point @chessie system fan I had a version like that I made in the beginning and this version was better because the cab was smaller but for most that may not be the case.

The wheels are Intermountain 28” ho scale wheels. They’re 8mm ish. So too large for your use case but I’ll go measure the ho Athearn wheels I have to see their diameter. These are 1.5mm shafts I don’t see any 1mm shafts for wheels in the stash I have.

[randgust]

That's basically the Toma approach, and I'll certainly agree that it works.   Chris333 and I have both had success with that approach.  If there was a problematic issue, it has been pickup.   Chris experimented with fixed wires at the top of the axle bearings in Nn3.   In N, I put in .008 phosphor bronze wires touching the inside split axles, and it took a LOT of tinkering to get that tension just right.  It 'sort of' gave the wheels some springing, but not really functional until sufficient body weight was added.   Pickup, pickup, pickup, pickup. 

The real secret sauce here I hope somebody does is imitating that GENIUS feature on the Kato 11-109 chassis.   One side of the four wheels frame is fixed with an end-axle pickup.  The other side is set up like a rocker, so it is a three point suspension.  The other side axles are SLIGHTLY allowed to flex up and down. so all four wheels stay in constant rail contact.  Then it is perfect.

It's so amazing, between the coreless motor and that pickup system.  I've overcome the issues with the Toma/Showcase drives by figuring out, by hook or crook, to get another pickup truck working (my 0-6-4 truck is hot, and both Shays the lead truck is hot).  But if you ONLY have four wheels, then that Kato equalization stunt is required.

There's some pretty good photos here of how they pulled this off.   The difference is in the frame halves, one side allows movement and the other is fixed.   The first time I tested one of these I was simply floored by performance and pickup in particular.   Nothing else like it.

https://tramfabriek.co.uk/kato-take-a-part.html

For steam (no end axle pickup) you need to move that rocker side inboard on one side only to split axles, but that's the principle.   First time I saw this attempted was on Nigel Lawton mine locomotive mechanism, it worked, the fail on that was the rubber washer drive instead of a spur gear.   In my shop, it got christened the "Nigel Nightmare" but it was the first tiny critter mechanism I ever experimented with.  But he got it on one count, one side of the four-wheel mechanism had to be lever-equalized. https://www.nigellawton009.com/TwoOandKRL1cChassis50.jpg

I still have it, but any attempt to make it equal to performance for anything has failed.  I succeeded in replacing the rubber drive with gears, but still...

There's a certain validity to doing DCC where you can overcome a fixed four-point frame with a keep alive, that should work, if you have enough space to pull it off.   NONE of the tiny critters I've worked on have any space for a decoder, or a tiny keep alive, lucky if I can find space for wires.

Veteran of about 10 attempts to make a truly functional GE 25-tonner.... finally got it, and the mechanism looks very much like that, spur to gear to double worm, good wheels, and all the weight you can stand.  Used an ARU 4007.  ARU makes a similar 0-4-0 drive with basic side rods at least.  The 'compromise' was that the CENTER spur gear and the wider motor barely fit in a 25-ton printed cab, took some widening, but it runs reliably.

Oh, and I tried several of these Tsugawa without side rods, and can reliably state they have no torque, 3v motors, and are rockets.  I transplanted Kato 11-105 motors as an expiriment, almost worked, but direct worm to axle will never beat the double reduction.