At age 75, I’ve just gotten into the hobby a few years ago. One of my interests is scratch building, and in particular working with brass. I’m currently building a '50s era flatcar in brass, working on a Pennsy N5C cabin car kit in brass, and…building out a brass Prairie 2-6-2 kit.
My railroad is a hypothetical midwestern regional line, the Ottawa & Northen, set in 1954, (roughly analogous to the Chicago Great Western).
This post is about my newly acquired MDC/Roundhosue 2-6-2 Prairie locomotive kit. To help me understand how brass locomotives work and come together, I recently bought this kit on eBay (MCD model number 6L1). It’s party assembled (boiler and large cast body parts plus motor screwed onto the frame, drivers and trucks installed, nothing further.) The kit box has a price sticker of $32.00 dated 5-6-62, from “Stickler’s Hobby and Tobacco Shop”. (first two letters of the name are missing but I am guessing that’s what it is.) Although this kit is “undecorated,” and thus its prototype railroad is unknown, it appears to be based on the Santa Fe Prairies, including being equipped with an oil fuel tender rather than coal tender.
I’m planning to replace the open frame motor in the kit with a can motor and flywheel, and adding DCC with sound; I’ll be installing the speaker in the tender. I have a number of questions:
Existing 63" driver wheels look to be black plastic with Nickel Silver rims. Should I replace with Greenway or similar wheels? If so, would “medium” or “light” wheels be more appropriate for a Prairie? Should I stick with the kit’s 63" wheel size or go a bit larger (given that Santa Fe, Great Northern and other lines ran Prairies with 69" drivers on the main line).
Leading and trailing trucks are both sorta cheesy, and the trailing truck in particular looks undersize
You could try 69" drivers, but I would be afraid they won’t fit. You could cut some cardboard circles that are a scale 69" + flange height, and place them on the drivers, and see what kind of clearance you have.
You could replace them, but the mounting position may be different. For sizes, I’d check Steamlocomotive.com, if they have that info.
Archbars were still used for tenders in the '50s:
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4. What’s the best way to install power pickups on the locomotive and tender?
You can watch it run for awhile, and also study the “look” of it.
Any mechanical/electrical improvements that you want to make can be combined with detail modifications.
Your questions about detailing are a matter of taste. For every addition that YOU want to make, you’ll find someone who doesn’t want to. Everything you propose sounds like a potential improvement, though.
Of course, with MY first steam locomotive kit, when I bought it at my not-that-local hobby shop, I spent more on Kemtron parts than I did on the locomotive.
I agree with Ed, built it as is first. The older MDC/Roundhouse kits run very good, I have several that are great runners. As for changing the motor I have two MDC 0-6-0s with the original motors operating with Digitrax SHD166 DCC decoders and they run and sound great.
The MDC drivers work very good, many years ago I built a 2-8-8-4 Yellowstone using a pair of MDC 0-8-0 frames and drivers. The 63” drivers run great!
Depends what you are doing to mount the rods, if you want a small screw, the metal centers might be good. Measure the distance between axle slots, that’s the absolute maximum for wheel diameter. If its less than the diameter of the wheels over the flanges then larger diameter wheels won’t work.
I would use the arch bar trucks and use new wheel sets. I would add wipers on all the tender wheels. Use phosphor bronze wire or unfold the spring “ears” of a Kadee #5 coupler box spring to make wheel wipers.
You can add a lost wax casting or use the existing headlight. Get a very small surface mount LED (its a very tiny device). Get a MV products lens for the ight, use a ball cutter in a motor tool to make a small depression in the back of the lens (use masking tape to hold it while cutting) and glue the LED into the hole.
Yes.
[quote user=“LewPhelps”]
7. Setting aside questions about super-detailing and paint/
I built several MDC kits. It is what I enjoy the most in this hobby… If I were you, I would start by changing the brass tender wheels. If the drivers are nickel plated, I would not change them.
For the headlight, you can drill a hole in the boiler and get the wire through there. It is a tedious job, but having an operating headlight will greatly improve the appearance of the loco. It’s up to you (or the prototype you are modelling) whether you want to change the headlight or not. If it is compatible with your prototype, why change it?
Motor: the original open-frame motors were very good, but if you go DCC with sound, you might want to change it. NWSL is a great place to get motors and other parts. It will run smoother with a new can-style motor. If you think that you will stick with DC, then try the original one and see what you think. Given how old it is, you might want to add a drop of oil on the shafts before running it.
Details: that can wait for later. As others have said, build the engine first, see how it runs, and judge whether you want to add more details. I removed the molded details on mine and added new pipe fitings, etc. Results can be very convincing. But see if you like the running abilities of yours before going further.
If you only run your locomotive during the day previous to about 1952, you don’t need a working headlight or backup light, because they ran dark back then.
I’ve got a gas-electric that I’m running under those circumstances, and I expect I’ll pass up the work it takes to light up the headlights. Plus I don’t have to have “big” wires out of the back of the headlight.
Since the Ottawa & Northern layout is DCC, is it possible to install DCC in the locomotive without replacing the OEM motor? My understanding is that open frame motors are not competely isolated from the frame, and thus cannot be used with DCC. Mel, your experience seems to indicate that it can be done. I will replace the wheelsets on the tender, but keep the OEM bogies.
Y’alll have convinced me to keep the existing drivers, and at least for now the leading and trailing trucks.
I have several options available with respect to the headlight, which I will ponder.
I’ll stay in touch to let everyone know how the project progresses.
I am not sure I understand how working with a MDC/Roundhouse cast metal kit is helpful to understanding brass locomotives. It certainly won’t tell you much about how to build with and fabricate pieces from brass, because no cutting of metal and no soldering is involved with the MDC. The old MDC engines had brass driver tires and brass wheels if I recall correctly but that is about it.
I don’t know if Bowser still stocks Pittman Motor parts but I bought the brush isolating kits to isolate the motor from the frame. I think this fiber brush holder is correct.
“It certainly won’t tell you much about how to build with and fabricate pieces from brass…”
True enough, but my interest is more in how to deal with DCC-ifying a metal locomotive model, how the running gear goes together, etc. Maybe I should have said “metal model locomotive” to clarify my knowledge gaps. I have some experience at fabricating fairly small sheet metal parts from other hobbies, and less about steam locomotives more generally and HO-scale practices in modeling steam locomotives.
I’ve got some old catalog sheets from Pittman. There’s photos of their motors. It looks like most of them had brushes naturally isolated from the motor frame. Those would be DC-71B, DC-91, DC-60, DC-81 and various double-shaft motors.
The exception is the DC-70. It has a metal tab under the brush mounting screw that “grounds” the end of one brush tensioning spring. I expect the tab is easily removed.
I am not recognizing a “brass brush holder”, as they all look like they’re made of fiber/plastic. Thus making it easy to isolate the brushes. Something a metal brush holder has trouble doing.
You can isolate the motor by removing the attaching screw and attaching the motor to the frame using silicone. It will also quiet down the motor. It will work with DCC in these conditions, but you will need a 1 amp decoder.
I think it would be easier to isolate the brushes. If it turns out they aren’t already isolated. And if you wish to keep the old motor.
Perhaps the silicone does lessen motor noise. I would think it would. You could also put a neoprene pad under the motor to do the same think. Then you could still easily remove the motor if it were necessary.
I’ve built two of the MDC 2-6-2 Santa Fe type kits (later versions with can motors and N/S wheels). The supplied can motors were single shaft so I replaced them with double-shaft motors and added a flywheel to one shaft. I also added NWSL 72:1 re-gearing kits, all-wheel electrical pick-ups on the tender, and operating headlight/reverse lights. If you try drilling out the existing headlight casting, go VERY slowly and lubricate the drill bit often. The biggest danger is breaking off a drill bit with it stuck in the hole! On the 2-6-2 Harriman style kit I built, I used magnet wire to simulate conduit to the headlight and powered it that way. The tender wheel pickups are simply lengths of phosphor bronze wire set in holes drilled horizontally through the center truck bolster with the ends rubbing against the axles for the uninsulated wheels or against the back sides of the insulated wheels. I was also concerned with how spartan the kit details appear, especially under the cab and around the trailing truck. However, searching the internet for prototype photos showed that the Santa Fe Praries were indeed rather spartan (see Gary’s photo). I added DCC sound decoders in all three kits and painted/weathered them for my Santa Ana & Newport themed layout. It did take a little tweaking to get them to run as smoothly as I desired and to get the leading and trailing trucks tracking well but they are now some of the nicest locos I own. Best of all, I can point to them and say, “I built that!”
Thank you, Hornblower! A very useful and thoughtful reply. I have a few additional questions:
I am assuming that conversion to the NWSL 72:1 kit requires pulling the driver’s off the center axle and replacing the gear. Correct? If so, will I need the NWSL Puller or similar tool?
The motor is the older open frame version, and while it seems to work well is fairly noisy, so I am thinking to replace it. It appears that a 15mm flat width x 20 mm x 32 mm can motor (NWSL 2032D-9) is the largest that will fit. However, it has a 1.75 amp stall current, and thus would requrie a 2 amp DCC controller. Would one of the slightly smaller NWSL motors (well under 1 amp) be sufficiently strong to power the locomotive? ( I don’t anticipate more than a dozen or so cars behind it at any time, facing maximum 2% grades.)
Someone on this forum suggested reaming out the headlight with a small deburring tool on a Dremel tool, rather than using a drill. You’ve done this procedure; does the deburring tool seem like a good alternative to a “fragile” drill bit?
Thanks for all your help,
Lew
[quote user=“hornblower”]
I’ve built two of the MDC 2-6-2 Santa Fe type kits (later versions with can motors and N/S wheels). The supplied can motors were single shaft so I replaced them with double-shaft motors and added a flywheel to one shaft. I also added NWSL 72:1 re-gearing kits, all-wheel electrical pick-ups on the tender, and operating headlight/reverse lights. If you try drilling out the existing headlight casting, go VERY slowly and lubricate the drill bit often. The biggest danger is breaking off a drill bit with it stuck in the hole! On the 2-6-2 Harriman style kit I built, I used magnet wire to simulate conduit to the headlight and powered it that way. The tender wheel pickups are simply lengths of phosphor bronze wire set in holes drilled horizontally through the center truc
When drilling in zamak (zinc alloy), a lubricant REALLY helps lessen drill breakage problems. Practically anything will do, from kerosene to heavy oil. A light oil like 3 in 1 would be my choice.
It’s even more important when tapping.
Cleaning the cutting oil off later is irksome, which causes some people to try dry cutting. That’s taking a chance.
Most open frame motors at this point in thier age have a weak field magnet, if your going to isolate the brushes and use the motor, I highly recommend replacing the field magnet. You can get small super Neo magnets from Micro-Mark and stack them where the old magnet was. You have to complete the “circuit” between the upper and lower motor frame, so if you have a small space between the magnets and the frame, a small piece of metal or a metal washer is needed to complete the magnetic “circuit”. Its amazing how well one of these motors can run with a good, strong magnet in place. It lowers the amp draw, the motor will run cooler and it stores the low speed torque, enabling better crawling speeds. Mike the Aspie
Brilliant idea! I couldn’t find neodymium magnets anywhere on the Micromark web site, but they are availalable at low cost in a number of sizes and shapes from www.allelectronics.com. In fact, I already have some, which I had ordered for another purpose. Thanks!
I’ve purchased engines with can motors that were connected to the frame and need to be isolated for DCC conversion. Open-frame motors and can motors both have to be isolated from the frame for DCC. Can motors started to be used in ‘ready to run’ engines about the time manufacturers started to isolate the motor from the frame to make DCC conversions easier, but it’s just a coincidence of timing.
