# Roundhouse HOn3 recommendations?



## Shdwdrgn (Dec 23, 2014)

I've been watching for the Roundhouse #473 inside-frame 2-8-0 kit on ebay for awhile, and finally snagged one this week. While I'm waiting for shipment, I was wondering if there were any recommendations on these kits for improving how they run, or just general considerations to keep in mind while building the kit?

For my own purposes, I'll be using a custom computer control board and running on code-70 dual gauge track (there's a possibility of including some code-55 on some spurs). I'm mostly interested in mechanical upgrades, but would also be interested in easily-improved items for the visual aspect of the loco. Just anything I could/should look at while actually building it.


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## Harvey Kravitz (Feb 12, 2016)

*Roundhouse(MDC) HOn3 2-8-0*

I have one of these kits that I built years ago. To improve performance, Northwest Shortline sells a gear box and a can motor. I built this over 35 years ago. It runs smooth and slow. You can find this on ebay or a good hobby shop.
Harvey Kravitz


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## dinwitty (Oct 29, 2015)

just take each construction step slowly and carefully, test the free wheeling of the siderods before installing the motor. Have a file, HON3 NMRA gauge handy, they are great runners when done right. I lube the siderods and the cylinders.


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## Shdwdrgn (Dec 23, 2014)

I've found some motors on ebay with the 1.5mm shaft (so I can re-use the original worm) which have an output speed of only 1000rpm. The motor has its own internal gearing. At that speed, the loco would probably be rather slow, but it would be a beast for pulling power as long as the wheels maintained traction. I also previously found another motor with a dual-shaft output that I ordered a pack of... really cheap, but they run at 13,500rpm which would need some serious gearing down to be usable! Ideally I'd like to find something that runs about 3000rpm (based on some info that the original motor ran at about 5500rpm) so it has the pulling power for the mountain runs I intend to use it on, while still being able to maintain some speed.

The NS gear sets are interesting, but very high priced. For that kind of money, I'd rather stick with something like the above that has internal gearing.

I was having a lot of trouble with the wheels rolling freely until I did a temporary install of the siderods... made a huge improvement! At this point I think I have all the flashing cleaned up on the metal frame, so I want to pull it apart and paint it first before continuing with the build. There was a broken and a missing metal part in the kit, but I think I can build both of them from brass, then get everything painted at once.


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## Shdwdrgn (Dec 23, 2014)

Wow... 9 months since I posted this question, and I finally got around to actually making the modification...

The first problem I ran in to was that the original motor shaft was 2mm, not 1.5mm. I thought this would be fairly simple to correct since I have a nice lathe, but tiny parts can be rather fickle. After removing the worm gear from the original motor I drilled out the center a bit larger to fit a brass rod in to. Soldered that in place, then re-drilled a new hole for the 1.5mm shaft. OUT OF CENTER. Doh! Fine. Very carefully center the worm in the lathe, re-drill for the brass rod, solder and re-drill a new center hole. STILL WRONG! My best guess is that the worm itself is slightly out of round, but I'm left with a worm gear that is starting to see damage on the sides from trying to clamp it in the lathe.

Today I took the assembly to the hardware store and started comparing screw threads. No, they're not as deep as a worm, but I found that a regular 1/4-20 screw thread was nearly perfect. What I actually need is about an M7-1.25 metric thread, but I couldn't find that in stock. And the 1/4" screws are available in nylon, which means I can mesh it to my plastic gear without worrying about a lot of damage or wear.

Took the nylon screw home, chucked it in the lathe and cut a perfectly-centered hole on the first try. The hole is slightly undersized so I have to tap it onto the motor shaft, but at least it won't come loose.

To finish up, I needed to mount the new motor. Using some thin brass I made a faceplate and screwed it to the loco frame with a 2-56 screw. The face has a large enough hole for the worm gear to fit through, and there are two mounting screws. Good luck matching those tiny screws though, right? Turns out I have some really old 2.5" hard drives laying around, and the screw that holds the circuit board on them was the right thread AND length. What luck!










There is a ridge underneath the motor that allows it to rock. I made use of this and arranged for the back of the motor to be able to fit a shim under it. I bent a simple zig-zag into some heavier brass and curved the top to follow the curve of the motor body. Again a 2-56 screw hole was drilled and tapped to mount this piece in place, then I checked the fit of the new worm gear. Adding a 0.020" shim under the back of the motor allows the gears to mesh fairly closely, but I might go just a little thicker -- I'll wait until I have the wheels back on so I can test it on the track and see how it runs.










The motor is securely in place and doesn't rock or slide, although if anything vibrates loose I can add some lock-tite to the screws. The new motor fits inside the loco shell with room to spare, and the gap between the rear mounting clamp gives me room to solder on the wires. Also of note, the original motor was frame-grounded which will interfere with the electronics I plan to add. The new motor is isolated so I don't have to worry about that new.










I believe the original motor ran around 7500rpm. This new motor runs at 1000rpm and will be used on a steep mountain line. If it turns out this is too slow, they also make this motor in a 4000rpm version. Now back to nickel-plating the driver wheels so I can put it on the track and see how it runs!


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## Shdwdrgn (Dec 23, 2014)

Well, it rolls pretty good in reverse, but the gears keep jamming up in forward. There is supposed to be a cast piece that holds down the side pins of the gear that meshes with the worm, and I believe when trying to move forward, that gear is being pulled backwards by the worm and tries to climb up on the left side. I'm thinking I can make a suitable replacement with just a piece of brass rod (which of course I don't have on hand). Maybe I can pick up supplies this week and try to get it put together.


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## Shdwdrgn (Dec 23, 2014)

AH! Problem solved! One piece that was completely missing in this kit was a bracket that holds down the pins on that gear. I kinda thought that with close tolerance on the worm gear, the meshed gear would have no place to move to... but I was wrong, and that bracket really did serve a purpose.

I made up a piece out of 1/16" brass rod and now the loco runs great in both directions. Had to make some adjustments so there's just a minor gap between the brass and the gear, because originally I had some tension between the parts and it slowed down the motor quite a bit.









The only issue now is the height of the black screw holding this bracket and the yoke in place... the screw head hits the bottom of the boiler. It's really only about the thickness of that washer, but I think I really need that to hold the pieces together, so I'll just file down the thickness of the brass a bit to get the clearance.

Anyway, it seems to be running pretty smoothly considering there is no grease on the gears or wheel axles yet. However now that everything it working, I'll tear it apart and give the base frame a coat of paint, then I can finish it up and see how it runs on the track.


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## time warp (Apr 28, 2016)

Old school craftsmanship, very good to see and thanks for the step by step progress!


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## Shdwdrgn (Dec 23, 2014)

I ran into a small problem with the front coupler on this loco. I cut an HOn3 Kadee back to expose more of the coupler, but after mounting it I find that it's still too short. When moving up to the height gauge the hose hits the cow catcher just as the couplers start to touch.

I probably need a coupler shank of at least 1/16" more length to engage with regular cars, however Kadee doesn't make long-shank couplers in narrow gauge. Does anyone else make them? I'm not too concerned about brand or if it is metal, since this coupler will be rarely used.


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## Freightliner (Jul 30, 2016)

I'm using the same motor on mine. Decided to use the NWSL gear kit. I'm at a stand still. Boiler weight ate my tap!


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## Tranz4mr (Sep 3, 2013)

If anyone wants an HOn3 Roundhouse kit I have a bunch of each of model 477, 472, 473, and 474. $25 each plus shipping. I do have a few spare parts as well so send the part number from the instructions if you need any.


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## Shdwdrgn (Dec 23, 2014)

I'd be interested in that! I'm having trouble with Google providing decent pics though... I currently have the 473 with the inside frame, and am interested in that same style. It looks like some of the roundhouse kits are painted with the silver front for D&RGW? And some might even come with silver instead of brass wheels? Do you happen to have a kit with those features?


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## Tranz4mr (Sep 3, 2013)

I have one 477 complete kit partially assembled inside frame with factory silver smokebox. Wheels are black centers with brass rims or tires with 378 on cab and rio grande on tender. 
Also have four 473 inside frame kits. All have black wheels with brass tires or rims. The loco bodies are black unpainted plastic molded around a weighted metal core.


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## Tranz4mr (Sep 3, 2013)

I have a second 477 complete unassembled kit silver smokebox lettered rio grande 378


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## Shdwdrgn (Dec 23, 2014)

Ah bummer, I was really hoping some of the kits came with silver wheels. I had a hell of a time nickel-plating my wheels due to the cast metal centers on the drivers, but I still really like the looks of this kit. I assume the 473 kits are complete, as far as you know? I'm just up the road in Longmont, is there any chance we could meet up somewhere? You wouldn't happen to attend the Boulder model railroad club, would you?

I'm debating whether to get one or two kits from you... I'll have to think on that, but definitely interested!


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## Tranz4mr (Sep 3, 2013)

I went through each of a dozen kits checking parts against the list. Most are unassembled, some are partially assembled but they are complete. I'm in Littleton near W470 near Ken Caryl exit. Probably could meet somewhere maybe Saturday or Sunday. Email me.


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## Shdwdrgn (Dec 23, 2014)

I sent you an email, just wanted to make sure you got it?


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## Shdwdrgn (Dec 23, 2014)

Awesome, I actually have more HOn3 locos than HO locos now.  Thanks again, I should be pretty good at building these by the time I get done with all of them! And like I said, if you run across a 2-truck shay in that pile, let me know.


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## Tranz4mr (Sep 3, 2013)

I also have a Roundhouse 390 HOn3 3 truck shay kit undecorated for $35

I also have a Keystone Locomotive Works HOn3 all metal 2 truck shay kit #HO-105n included is a NWSL Keystone locomotive kit 1053 which provides brass wheels axles gears, motor, transfer gears etc to power the Keystone shay kit $65


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## Shdwdrgn (Dec 23, 2014)

Just a quick update as I'm nearing completion of the brass replacement pieces. AFter nickel-plating the slide rods a couple days ago, I got the pieces soldered together tonight. Just need to finish painting the brass, and it'll all be ready to screw in place...










Basically the black pieces are cast, and everything else there is brass pieces that I made.










I'm going to paint the yoke black, and snip off the back of the slide rods closer to the yoke. There's been a lot of time spent on getting all these pieces together, so it will be nice to finally see the entire drivetrain in action.


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## Shdwdrgn (Dec 23, 2014)

I've been busy with other things, but wanted to show a progress shot with the boiler and cab sitting in place. I need to work on the tension placed on the gear by the retainer as it is slipping in forward, but otherwise I'm pretty happy with how it is coming out. The connecting rods move smoothly by hand, hopefully they will continue to work well when powered by the motor.










I'm going for a traditional D&RGW black and silver scheme, and I think I'm going to number this loco as 315 (although I'm still trying to track down info about the locos that were in the 200's). I would like to go with the diamond stack on this loco as a way of showing a greater age although I'm not certain what other changes I might expect to see.

Hoping to be able to try it with the motor soon...


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## Shdwdrgn (Dec 23, 2014)

Well it took awhile to get back to it, but I finally got a chance to do a simple run test on the track by hooking up a pair of wires with alligator clips. Once I adjusted the tilt of the motor, there was no slippage of the gears, and nothing in the drivetrain had clearance issues. Overall it ran smoothly even when applying pressure to the wheels with my fingers.

It is definitely a slow-running motor. I think I would have preferred the ability to run faster, but since it is intended as a steep mountain train, slow and steady may just win the day. I'll still keep my eyes open for an alternate motor though -- basically I need something with a body thickness no more than 12mm (the overall width can be greater though), and either a 1.5 or 2mm shaft, and runs at about 2000-3000rpm.

I only have a single flat car in narrow gauge right now, so it's hard to get a sense of its pulling capability. However I was running without the boiler in place, which is a nearly solid piece of metal for weight, and just tugging on the power wire it still seemed to have decent traction. For now I think I'm going to leave it alone and get started on the boiler and cab...


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## ebtnut (Mar 9, 2017)

Top speed on those little iron ponies was only around 30 mph with those little drivers and lack of counterbalance space. So yes, slow and steady is the norm. Wish I could track down one of those tenders. I need it for a kitbash project trying to create East Broad Top No. 7 after its post-shop fire rebuilding.


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## Shdwdrgn (Dec 23, 2014)

Huh, I had no idea they were quite so limited in speed, but it certainly makes sense for the reasons you gave. So it looks like a scale speed of 30mph works out to about 6 inches per second, which seems remarkably close to how I remember it running. I'll have to try and get a measurement though just to see, because now I'm curious!


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## Shdwdrgn (Dec 23, 2014)

Been doing more research and more work. This model is actually almost identical in body style to the Baldwin prototype which D&RG numbered 228 through 295. Number 228 was originally numbered 22 and was D&RG's first 2-8-0 on the line. Classified as a C-16, it was renumbered in 1894. Number 268 was given the well-known bumblebee paint job and featured in the 1952 film "Denver & Rio Grande". Numbers 268 and 278 have both been restored and are currently part of museum displays in Colorado. The one major difference I see between these locos and the Roundhouse model is that the prototype had the connecting rod going to axle #2 while the model is going to axle #3, and the spacing between the four pair of driver wheels is different (and thus prevents me from modifying the connecting rod to go to the correct axle). Ah well, close enough for me... 

So I've been working on the boiler details and realized this kit is not fitted for working lights.  Well I've come this far, lets see what else I can do to it! I've decided to go with a diamond stack and an electric light for this loco, and the mounting platform for the light doesn't match the prototype, so I decided to just rebuild a whole new light from scratch. Whew that took some work! I found some 3/16" tubing that allows a 3mm LED to fit loosely, but it wasn't quite large enough diameter so I wrapped it with a layer of 0.010" styrene and then added the shroud. On the back side of the tubing, I drilled a shallow ledge a little larger to fit the base of the LED so it now sits flush to the back of the new light. Then I cut some wedges for the number panels and filed everything smooth.










This morning I started the hard part... I needed four very tiny legs for the light to stand on. These are made from 0.030" square styrene and are barely the size of the tip of my tweezers. After several tries I finally got all four in place, and after drying all day I filed them off even so the light sits square. I bent the LED legs at 90 degrees and will snip the length once the LED is glued in place (after painting). I have a bag of these LEDs which put out a nice warm white color and should be fairly appropriate for the period.










So with that done, the next step is the platform. This should be pretty easy, just a piece of 0.020 x 0.25 styrene cut to length, with legs running the full length of either side. When that's all glued together it will be painted black to stand out against the silver of the boiler. Finally I have to drill a hole through the metal boiler casting that I can feed the wires through. The wires will just be a pair of 34awg magnet wires, so the visible hole in the boiler can be pretty tiny.

I'll also be fitting a light in the cab, and once the drilling is done I should be just about ready to start painting the boiler. Still waiting on that new motor to arrive, though...


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## Shdwdrgn (Dec 23, 2014)

I finished off the new light last night, except for paint. Unfortunately no new pics yet.

Received one of the new motors in the mail today... OK I was not expecting it to be so small! My criteria was for a 12V 2000RPM motor with a body size of 12mm. On the new motor, the height is 12mm and the width is only 10mm, quite a bit smaller than the previous 12x15mm motor. However the unit has metal gears for taking down the speed, and when applying 12V to the leads it actually feels as strong as the larger, slower motor. Since I currently only have a single flatcar in narrow gauge, I think I'll set my test track on a slope and see how well each motor performs. I just have to make a new mounting bracket and worm gear for the new motor first...

What could be interesting is that due to the smaller size of the new motor, it frees up quite a bit of space inside the loco body where I could possibly mount some of the electronics. I'll have to see how that plays out after I test both motors.


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## ebtnut (Mar 9, 2017)

Re: The main rod location - It appears that a number of locos from that era got re-shopped to put a new main rod on the third axle. This occurred with EBT No. 7, which was built to the same blueprints as the D&RG C-19's. This rod relocation was supposed to help improve the riding characteristics of the engine. EBT 7 was sold to the Ohio River and Western in 1913 and made the last run on that road in 1931.


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## Shdwdrgn (Dec 23, 2014)

Ah that's interesting, I don't suppose you've found any info on what years this change was taking place? It could explain why it's so hard for my to find photos of any prototypes that fully match the model.


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## jlc41 (Feb 16, 2016)

Very interesting build and nice workmanship.


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## Shdwdrgn (Dec 23, 2014)

Thanks, I haven't had much time to work on it lately, and I've been reconsidering my paint scheme. I ran across some material talking about the heavy use of Russia Iron in the 1800's which looks pretty interesting. My concept is for a railroad at the beginning of the 1900's which still runs narrow-gauge, but those lines are being replaced and the narrow gauge locos are expected to be decommissioned in the coming years. As such these locos may have older paint and should be fairly weathered, so I think still having them in the russia iron scheme could be appropriate (and would make them stand out nicely against the standard-gauge locos).

Oh course *finding* this color in a spray paint appears impossible, so it may be time to actually start working with the air brush -- in which case I have a lot of learning to do before I can proceed with the loco assembly.


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## Shdwdrgn (Dec 23, 2014)

I finally got around to drilling the holes through the boiler for the wires today. That was entertaining, the white metal really gums up the drill bit! Got it drilled for a pair of 30awg wires to fit through, now I just have to clean up the piece and get it painted.

Starting into unknown territory here... I picked up some model-quality paints for the air brush today and I'm going to make a go at the Russia Iron color. It looks like a good scheme is to paint the boiler jacket russian iron, then the front of the boiler and everything else in black. That leaves a good base to make the brass trim really pop out. Or so I hope...


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## Shdwdrgn (Dec 23, 2014)

Well that's not going as expected... Tried working with the air brush today. The first thing I realized was that nothing was coming out. Tried pulling it apart and it was gummed up. Turns out the paint from the last time I messed with the air brush (last year) did not get cleaned out completely! I got everything apart and let it soak in alcohol for a few hours, seem to have to cleaned out and flowing well now. I put plain water in the jar to finish clearing it out and I get a nice even spray, but the output is pulsing. Erg! OK did some reading on that, and the most likely culprit is the nylon O-ring behind the head. Apparently this will compress over time...

Hmm I've had this air brush sitting in a box for, what, about 25 years now? Would that be enough time for the O-ring to compress? 

Yeah ok, so I'll make another trip to the hobby store tomorrow and see if they carry replacement parts, otherwise I'll find some online.

In other news, expecting to be able to work immediately the first thing I did was combine my new paints, add some thinner, and shake it together to try and make the Russian iron color. In the jar it looks pretty decent, although I don't like the formula I was expecting to work with. That formula called for 1cc gunmetal, 2cc white, and a drop of blue. I have twice as much gunmetal as white, and it still looks too light. However I AM happy with my tint. I found a color simply called "blue green" and it seemed to just add that hint of color without being overpowering like some of the pictures I've seen. Once I get the new O-ring I'll spray a sample of what I have, see how it dries, and make adjustments from there, but many examples of what I've found for the Russian iron seem to indicate it was more on the dark side. And I'm not quite sure how to get the mirror finish it was supposed to have, I guess the best I can do is try to get a nice gloss finish -- although since I plan to weather it, the finish doesn't need to be quite so perfect.

I also got the new headlight glued to the boiler last night. I think my plan will be to simply paint the front of the boiler in black, then solder the leads to the LED and hand-paint the back side of the LED and the wires black. Sounds simple enough, but there's going to be a lot of masking and painting sections before I ever get to that LED...


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## Shdwdrgn (Dec 23, 2014)

I got a chance to work with the air brush again today. Still some problems, but definitely making progress. I thinned the paint a little more as I know it should be close to milk, but still had some clogging issues. I did manage to get a crap plastic frame painted though, and I think the color came out very close to my goal, so I'm happy with that.

By itself, the color seems fairly silver-ish, so I placed some actual silver paint next to it so you can see the difference. Remember this is supposed to represent Russian iron, so it should have just a touch of blue or green tint to it (I went with the blue).










While mixing the colors, initially I thought it as too dark with the gunmetal, but adding white just seemed to wash it out instead of making the color richer. I ended up adding some plain silver, which with this brand is giving the paint a metal-flake quality. Overall it turned out to be a very interesting color carrying the depth of the gunmetal but the shine of silver. Add a gloss coat over the top and I think I'll have a model to be proud of. It's a real shame that I lost count of just how much of each paint I added, but I suspect I can reproduce it again. I may add another drop of white or silver to lighten it up one more shade, but really I think I'd still be happy with it exactly as it is.

I went through pages of Google images searching for other models to reference for my color. Most were way too solid of blue for my taste, but the one below stood out to me. There are no color photos available of what the locos actually looked like with the Russian iron jacket, but from reading it seems the theory is that the blue or green tint came from the high polish of the metal reflecting grass or sky. That's why I wanted to keep my color tint subtle and not overpower the paint scheme.










It's possible that because my paint bottle has sat for a couple weeks, there are some 'strings' of paint in the bottom that clogged the air brush. I think when I'm ready to paint my model I will strain the paint into a clean bottle and hopefully avoid that problem again.


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## Shdwdrgn (Dec 23, 2014)

I see I haven't updated this thread in quite some time, but I AM still working on this loco! I've considered a number of different options, and even bought some brass castings to change out the domes for an older C16 style.

Lately I've been working on the electronics. Got DCC++ running on my test track, and last weekend I picked up a decoder for this loco to get it running on the track. Yeah, after all this time the loco still hadn't had a proper run. Well wiring up the decoder was simply enough, and the loco responded right away when I put it on the track. The gears weren't exactly smooth though, so I let it run for awhile to try to work out the kinks. Unfortunately after awhile the loco completely locked up and started tripping the DCC protection circuit. I took the boiler off to see what was happening, and the motor was too hot to touch! Not good! I let it cool down for awhile then checked the lubrication and clearance on the worm gear. Everything looked good so I put it back on the track. After running for about 5-10 minutes I checked the motor again, and once again it was too hot to touch.

This motor is supposed to be rated for 12VDC, but I get the feeling it isn't really. Also it's a slow motor, running at 1000rpm. It runs at a nice speed for general use, but I think it should have the ability to go a bit faster. So now I need to find a new motor that is actually rated at 12V, runs at 1500-2000rpm, has a 1.5mm shaft, and fits into the loco frame. Yeah that may be a challenge.

I also need to try something different for the gears. When going backwards there is a definite *chunk* in the drivetrain, making me think one of the gears is damaged (although I haven't seen anything yet). There is a company that makes brass gears for this loco, though. Expensive, but maybe worth the money to get a smooth-running drivetrain.

It IS nice to see both standard and narrow gauge locos on my test track now though. There weren't any problems with the hand-laid turnouts, which I feel pretty proud of since the three on the test loop were the first dual-gauge turnouts I ever made. Now I just need to get the loco running right, and then get some cars for it to pull.


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