Conversion of K Line Hudson to 12v DC

The motor can be powered by straight DC, certainly, and polarity-reversed. The smoke unit probably could be.

At this point - bypassing all the existing electronics - you just have a 3RO DC-powered blank-slate loco, and anything done to one of those made by anyone should work in yours. I have no DCC experience, but you could use all that equipment, available sound and otherwise, I would think. 

It’s a very imposing model, but the sound isn’t great and I can’t get any answer what would happen if I attempted to run it on 12v DC, which would be a useful thing to know under the circumstances. 

Rockershovel posted:

It’s a very imposing model, but the sound isn’t great and I can’t get any answer what would happen if I attempted to run it on 12v DC, which would be a useful thing to know under the circumstances. 

 

Well, as I stated, if you bypass the existing electronics you have a DC can-motor loco, so using DC would be fine.

But, if your question was "can I run it on DC as it sits?" (maybe I misunderstood) - the answer is definitely no, as the electronics expect AC input, and would probably be damaged if you put DC through them. I think that some loco boxes/instructions mention this. 

I believe that some of the newer Lionel/MTH/etc locos can handle either A/C or D/C as input current (they sense it and handle it appropriately), but don't quote me. I don't buy much new product (I'm full!).

@Rockershovel, as you have been told many times in many of your inquiries - almost all American O Gauge like Lionel, K-Line, MTH etc is designed for the century old low voltage AC standard. The exception is most LionChief, LionChief+ and LionChief+ 2.0 can optionally be operated on low voltage DC (but not in command mode as command control requires Low Voltage AC at 60Hz).

For a rule of thumb, if you want to modify your locomotives to run on the bizzare and non-standard conforming low voltage DC of your club, it must be equipped with a DC or Universal Motor. You must remove all electronics and bring the power leads direct from the track to the motor. Note that this makes running them on AC impossible (with out destroying the motor) unless you add a high amperage bridge rectifier. Since your fellow club members seem to have success with this setup, they would be the ones with the most experience in such modifications.

If you are serious about operating a fleet of American O Gauge locomotives, it would be much simpler to convert a single power source setup to provide Low Voltage AC than to keep modifying locomotive after locomotive...

I’d be interested to know a little more about the club the OP belongs to.......so let me get this straight.....it’s a 3 rail railroad but all on DC??...that just seems odd .....like BMORAN4 says.....it’s kinda bizarre....tell us more about it please.........Pat

I’ve replied to this before, but it’s quite simple. 

I’m a member of a club (well, an informal group, really) which meets periodically to hold running days for their locos and rolling stock. 20v AC power supply has long been extinct in the U.K., apart from a small number of Lionel and older Märklin and Hornby locos which are still in use. There are a number of minor O Gauge suppliers like Daersted and Dapol, and quite a few BL locos. 3 rail generally is very much a minority interest here. 

Nobody apart from a small number of Lionel specialists uses the TMCC systems, which simply aren’t available here except by private import. 

There is a general practice of running 20v AC locos on 12v DC. I took along an old Scout, and a modern Polar Express Berkshire and experienced no problems at all. There were at least two Lionel Halls (Hogwarts Express), the day I was there. For running days, the issue of reversing from the transformer isn’t a problem, because the main purpose is to have some running time on a big track; as long as the loco will run forwards, that’s enough. Tender whistles are just disconnected. 

The K Line loco caused much comment, because no one had seen one before. The wire tether caused much comment. I don’t know how it came to be in the U.K.; I bought it for under $100 equivalent in eBay on its second re-listing. 

As far as I can understand, because electronics isn’t my field, it ought to run without difficulty on 12v DC - but I can’t seem to confirm this. (The literature says the Berkshire won’t accept 12v, but this is clearly not the case - I can only assume that this is a case of manufacturers literature rejecting anything outside their own system, not uncommon). The whistle can be isolated by disconnecting the pickups from the tender rollers. AFAIK, it doesn’t have TMCC or equivalent. 

I’d like to give this rather fine model, a good run out with a 4 or 5 car train of full length stock, which I have no opportunity to do at home. I think it would be well received at a running day. However I’m reluctant to take unnecessary risks, and I’m reluctant to spend £300 or so on a full conversion which would have little, if any resale value. 

Ahhhhhhhh.....ok...that makes sense now....I somehow completely missed the whole U.K. thing somewhere......Pat

I strongly suspect that if I had a tether cable cut short, with the wires to and from the rectifier linked together and any other wires isolated, the loco would run quite happily without a tender, on 12v DC, with no other changes. 

I could then pair it with the “dumb” tender I’ve already produced for the Berkshire (because that came to me with the roller connections already incomplete, for the same reason, I’ve just tidied them up) and I’d be off and running for running days. 

My own test loop and just-begun small O27 layout use entirely conventional Lionel KW transformer running from a 240v/110v stepdown transformer. 

It sounds like you might want to run this on DC at the club and AC at home?

If so, I would place double pole switches in the engine and tender.

The switch in the engine would transfer motor power from the motor driver board (blue, yellow wires) to the track (red, black wires). Using a recitifier would prevent the engine from going in reverse. Powered directly from the track it would operate just like any other DC engine.

Similarly the tender switch would turn off power to its electronics when running on DC. If there was room you could put a sound decoder in there and use the switch to transfer power from Railsounds to DCC.

If you have no intention of using AC power then just gut the engine and tender and install DCC.

Pete

That’s exactly right, thanks. 

The general format at club running days, is that you sign in for timed 20-minute running slots, through the day. With 7 or 8 loops, about 50 members present and about 70 locos and various trains, you need a quick turn-round. It doesn’t work QUITE that smoothly but everyone seemed happy enough at the all-day session. Monthly sessions are smaller and shorter, but the same principle.

”basement empire” type layouts are rare in U.K. and few clubs can achieve full-time occupancy of the premises, so the opportunity to run long trains is the attraction. 

So, in a spirit of enquiry, I connected the 12v DC supply and turned the knob. 

Loco seems to run fine. Reverses from the transformer, too - cycles through the N-F-N-R cycle as the power is turned off and on again. 

Whistle sounds non-stop, but I expected that. 

There are NO tender rollers, unlike Lionel tenders. 

I’ve spoken to a local chap who advertises DCC conversions, RC for garden railways and what-not. Seems he has seen Lionel Hogwarts locos converted to run on DC. He recommends a DPDT switch under the loco, as described above - switching between traction current direct to the motor for DC, and traction current to the tether for AC. He also pointed out that as the tender has no rollers, leaving the tether disconnected will isolate the tender and hence, isolate the rectifier and reverser and silence the whistle. 

All sounds good to me. Press on!