Some newbie questions at remotoring an old Mantua 0-4-0 I got on ebay. Trying to learn how to remotor/dcc-convert so this is my first foray into the zone:
What motor would be a good fit for this? Existing open frame motor is about 40 mm long. How to attach new motor to frame?
Do I use existing worm or get a new one and an entirely new gearbox? Where to get worm and gearbox?
If I use existing worm, how do I get it off that existing shaft and put it on a new one, or do I cut existing shaft and somehow link to shaft of new motor?
Brush isolation: If I wanted to convert this loco to DCC with existing motor, I know I have to isolate the brushes, correct? I see one is already isolated, and the second one is not. As you can see there is a wire under tension holding the brush in place that is connected to frame. How would I isolate that brush and keep it in place like it currently is?
The simple way is to slide a piece of wire insulation onto the spring pushing on the brush.
You should probably do the same for the other spring, to keep brush pressure the same.
I can’t figure out, from the photo, the physical construction of the brush area. So I don’t know if there’s another way to isolate that brush–like cutting or removing a metal piece. But the insulation trick should work.
Try to use a “sturdy but thin” type of insulation.
And, of course, solder the new wire onto the brush BEFORE installing the insulation.
Hi there. I remotored a very similar model, the 2-6-2, which is pretty much the same model in terms of motor and gear.
Here is my two-cents worth:
1. What motor would be a good fit for this? Existing open frame motor is about 40 mm long. How to attach new motor to frame?
Generally speaking, any can motor that fits would work (check ALL dimensions, including shaft). Now to be honest, some can motors are better than others. You can’t go wrong if you order from NWSL or MicroMark tools, but you can also get good motors from China. Make sure they are 12V, and I would recommend a motor that runs less than 9000 RPM. I have preference for motors with flywheels, but its debatable apparently. You will get a much smoother running loco if you change the motor. Try to find one with a shaft that matches your gear (see below). Using caulk, with a small plastic support to compensate for angle, is the best way IMHO. You might have to try a few times to get it right.
2. Do I use existing worm or get a new one and an entirely new gearbox? Where to get worm and gearbox?
Mantua’s worms were very good. Durable and quiet. You can keep the original.
3. If I use existing worm, how do I get it off that existing shaft and put it on a new one, or do I cut existing shaft and somehow link to shaft of new motor?
You should remove the gear and install on the new motor shaft. The best way is to use a gear puller. NWSL sells one. NWSL also sells sleeves to adapt the gear to the motor shaft, if necessary. You might be able to get someone at a local hobby shop to do it for you.
4. Brush isolation: If I wanted to convert this loco to DCC with existing motor, I know I have to isolate the brushes, correct? I see one is already isolated, and the second one is not. As you can see there is a wire under tension holding the brush in place that is connected to frame. How would I isolate that brush and keep it in place like it curren
Hi Simon,
Thanks for the detailed reply. I very much appreciate it. The main reason I’m doing this is to learn some new skills, so that I may be able to do something similar with a nicer model or a brass loco in the future. If I make mistakes with this model, it won’t be a big financial loss. The journey is the destination here
I would add a “keep alive” and probably not bother with adding more pickups on the tender. Not that they’re a bad idea, but in my experience they’re unnecessary.
I have a brass gas-electric that has the traditional four wheel pickup (just like the Tyco, by the way). It wouldn’t go more than an inch without stalling. I added a “keep alive” and it’s never stalled since.
can’t say i’ve done this, but you might find this helpful
the newer Mantua yard goat uses a can motor. it sits on a wedge shaped piece of plastic which it is attached to (forget how) and is attached to the frame using the same mount as the open frame motor
i doubt you’ll find a newer motor with the same shaft size. if you do, however, that plastic worm can be pulled off. Northwest Short Line sells worm/gearbox sets.
if there is a wire between the frame and brush, that type of motor is isolated from the frame, that’s why there needs to be that wire.
presumably you want to isolate the motor from the frame to install a DCC decoder.
Any recommendations on what decoder/configuration to use if I wanted to convert this to DCC with sound? Obviously very small boiler for 0-4-0.
Assuming I would need to put decoder and speaker in tender. I would want to be able to decouple engine and tender (not hardwire), so assuming plugs needed?
Yes, both in the tender. If you keep the original motor, check the amps so that it won’t exceed the capacity of the decoder.
And yes, the wire between the motor and the tender needs to be removed. If you don’t install extra wipers on the tender, you will need to get power from the frame of the loco, so through a new wire. I drilled and tapped a hole in the frame of the engine.
Any specific sound decoder recommendations for this type of model?
The tender’s left wheels pick up the current, right wheels are insulated. If I wanted the tender to do all of the power pickup, how would I be able to make this happen? Would I not have to replaces the axles and/or trucks in tender to pick up left and right rails? That would make it easier to get power to the decoder from only the tender but difficult to set up?
If I were to put the decoder in the tender, it looks like I would need to feed at least 3 wires to the boiler: 2 for motor, 1 for electrical pickup to go from boiler to the tender and feed into decoder’s + terminal for power (assuming no headlight). Engine picks up current from right rail, tender from left.
Would a 3 pin JST connector make sense in this case? I think I have seen other types of “plugs” that people use to connect the tender to the engine that are not JST but are same size as NRMA pins?
It also looks like I would need to drill a hole in the tender to feed the wires to whatever plug I use between it and the boiler? And another set of holes in tender floor for speaker sound. Is this a typical solution?
Mel and Wayne use plugs - hopefully they will chime in. I hardwire and permanently connect the engine and tender.
About the wiring, if you go with all wheel pickup on the tender, you don’t need extra pickups from the engine. So 2 wires are enough, unless you install a headlight.
I found the Athearn 100 ton and 70 ton trucks w/ electrical pickup. So the idea is that I get all of the power from the tender using these, and I would feed 2 wires to the boiler/motor, with brushes isolated? This makes things much easier.
On the old Mantua engines, the tender floor / underbody was metal. The trucks on the tender touched the metal where they connected, and a wire from the tender floor was connected to one connection on the motor.
You could insulate the tender trucks from the floor (and each other) I guess, and just use that for power pickup, but it’s a small tender so you’re going to probably have pickup problems unless you add some type of “keep alive” to the decoder…and if you’re going to do that, you might as well just keep the factory set up with the tender picking up on one side and the engine on the other.
It would mean running wires between the two for power pickup (1) lights (2) and motor (2), but most engines do that anyway. You can run the wires through a short piece of tubing to bundle them together.
I have a pair of MDC 0-6-0 switchers that both have the original open frame motor. Locked rotor is pretty high at 1.4 amps but I haven’t had any problems with either locomotive running Digitrax decoder.
I use the standard NMRA type connectors on all of my steam locomotives. I make my own Mel version from mini header strips, much cheaper at about 2¢ per pin.
Both locomotives are wired identical with the original slope back tenders, I did buy a Vandy tender that I can swap around and wired it the same way.
I also swap the decoder to the Vandy when I want that version for running.
I buy the header strips off eBay for around 2¢ per pin in both 40 pin single row and 80 pin double row.
You can make any connector configuration using the header strips.
The Athearn truck that you ordered will be insulated, so that is not an issue. You just need to drill holes (two per truck, just above where the wires stick out) to get the wires through. I use a pin vise, starting with a small bit, then enlarge it with a larger bit. Some folks put a drop of oil as a lubricant - but it’s not really necessary, these metals are in fact quite soft. Take your time, don’t apply too much pressure, and wear safety glasses (to protect you if you break a bit). Just turn in the opposite direction from time to time to clear the hole as you drill down.
Just make sure your wheels don’t short by hitting the bottom of your tender. In some cases, I’ve glued thin strips of plastic on the belly of the tender, directly over the wheels to prevent that…
Mel’s work is impressive, is it not? I prefer to keep everything together, they are just easier to handle when all is permanently connected. But Mel’s workmanship is admirable.
