Hello everyone, I have an interesting question to ask. I would like to use Marklin 3 rail trains for an On30 type narrow gauge layout. On30 (O-16.5 in Europe) is using HO gauge track, locomotive mechanisms, freight car wheels and couplers, to model narrow gauge trains in O scale. I know that most people generally use regular 2 rail HO scale trains, modifying the bodies, to look nice as O scale narrow gauge. Or buying trains already designed as On30 trains, such as the Bachmann On30 lineup, which is quite popular here in the United States. And I'm certainly aware that Marklin produced the Minex On30 equipment from 1970 to 1972. But I want to build my own custom locomotive bodies, and freight cars. I would start with the regular Marklin model (such as the Marklin 3000 steam 0-6-0 locomotive) and modify the bodies, or scratch build some custom bodies for the narrow gauge trains. I'm on a tight budget, living in an apartment. Same with freight cars, using inexpensive freight car wagons, modified or with my own custom bodies. To look correct as On30 models.

Minex is rather limited in the amount of locomotives, freight cars and passenger cars available. I don't currently own any of the Marklin Minex trains, perhaps I will find some of them at a reasonable price to purchase. Generally the Minex are very expensive when I see them anywhere, and can be hard to find. I see a few available on eBay, but they are a lot of money. I'm on a tight budget.


Basically speaking, I want to use regular HO scale 3 rail Marklin trains, modify the bodies, for use as narrow gauge trains. Yes I know using Marklin to model narrow gauge trains is not very normal, other then using the Minex Marklin produced in the early 1970's. I prefer to use Marklin because of the extra reliability of the 3 rail system, easier layout wiring, and the very durable Marklin locomotives produced in the 1950s to 1980s. I like that vintage Marklin locomotives have metal gears.

And to prevent anyone having a potential heart attack, I would be using the inexpensive small steam and diesel locomotives, such as the Marklin 3000, 3029, 3087, 3090, 3078 and 3080. Nothing valuable or rare. And using small inexpensive freight cars, such as the 4503 low sided gondola car. And other inexpensive small freight cars, which can be modified for narrow gauge railroads. And I will be using the stud rail Marklin M track, from the middle 1950s to the end of production in 2000.


My questions are these. Do you think it would be better to use them as AC powered locomotives, with my 30 VA 6153 blue plastic Marklin transformer for the American market? I have two Marklin blue plastic transformers produced from 1973 to 1991. The bigger transformer Marklin 6153 is 30 VA, while the smaller one is 10 VA, which was from a set.

Or convert it to DC control, with a permanent magnet and 3 or 5 pole rotor? And use my MRC (Model Rectifier Corporation) Tech 2 DC power packs?

Personally I don't think I need digital, because I will only be operating one or two locomotives at a time. On a small layout.

My other question is should I keep the normal Marklin Relex couplers or convert to body mounted Kadee couplers? I want to do switching shunting maneuvers.
Anyway I already own a few Marklin locomotives, about 11 of the 4503 low sided gondola, some other Marklin freight cars wagons. Overall I currently have about 20 Marklin freight car wagons. Over half of them have the metal Relex couplers, and the rest have the common plastic couplers Marklin produced in the 1980's and 1990's.

I don't mind body mounting Kadee couplers on the bottom of the chassis, especially the older freight car wagons with the metal chassis and Relex couplers. Or the newer wagons with the plastic chassis and plastic couplers. The buffers and Relex (metal or plastic) couplers can be removed, and Kadee couplers body mounted to the chassis floor with screws. The problem would be those old vintage locomotives, with those metal hooks. I would need to remove the metal hooks (like for example on a vintage Marklin 3000) with a Dremel type rotary tool.

I own enough Marklin M track to build a simple layout, with four manual switches (turnouts, points), and a couple crossings, and three uncouplers. I will be purchasing some more Marklin M track in the near future, including some more switches.

And I have two of the Marklin blue plastic transformers produced from 1973 to 1991. The bigger transformer Marklin 6153 is 30 VA, while the smaller one is 10 VA, which was from a set.

I also have a couple MRC Tech 2 power packs, because I also run regular 2 rail American DC powered HO and N scale trains.

Personally I don't like the typical small (2 rail) 0-4-0 and 0-6-0 type (or 2-6-0, etc) On30 locomotives, because they sometimes stall on switches (turnouts, points). And I'm not a fan of the plastic gears in Bachmann On30 locomotives, they have a tendency to get cracks and cause problems.

Instead I would rather use the small 6 wheel Marklin locomotives, or the small 4 and 6 wheel locomotives Marklin made in their Primex lineup. Marklin locomotives such as the 3000, 3029, 3087, 3090, 3078 and 3080, and similar. They far more rugged and reliable, compared to any small 2 rail DC locomotives. And it's a lot easier to wire a Marklin 3 rail layout, compared to any 2 rail layout. Especially when using reversing loops , wyes, or a turntable is used, to reverse the direction.

I would prefer to run my vintage Marklin locomotives with my MRC Tech 2 power packs, because they have better slow speed control, and a bigger range of control (270 degrees) on the speed dial, compared to my Marklin transformers, which have a much smaller range of control of the speed dial, and not the greatest slow speed control. I'm considering removing the reversing unit, and running them strictly on DC power. I could keep the field coil and 3 pole rotor, and wire in a couple of diodes, as I have found a diagram online. It would allow to converting the Marklin locomotives to be converted and run on 3 rail, DC power. Keeping the field winding and coil, and the original 3 pole rotor. And adding in a couple dollars worth of diodes, to reverse direction on DC power. It's basically the same method, how the original Marklin electronic reversing computer chip operated, when it was introduced in the early 1980's. Instead of an electro-mechanical reverse unit like before, it was replaced by a simple electronic circuit.

I believe some of the early Marklin locomotives (1950's and older) can be manually reversed with the lever sticking out of the body shell. How would those work on plain DC power? Could I reverse the direction (with the lever sticking out), without making any changes to the motor, reversing unit, or field coil?

Additionally I have the option to completely remove the reversing unit and field coil, and just install a Hamo type permanent magnet and keep the original 3 pole rotor, for control on DC power. It would be a little more expensive using a permanent magnet compared to wiring a couple of diodes in, but not a huge amount of money. I only plan on converting a handful (perhaps around 5) inexpensive locomotives to On30 anyway. Obviously if I decide to continue using the regular Marklin AC transformers, and I keep the field coil and reversing unit, then the only changes would be to the body shell.

Either way, I would be giving it a bigger cab for the O scale engineer and fireman, and a taller smoke stack, bigger headlight in the front, and a few other detail parts. And making freight car wagons a little wider (and taller as needed), and passenger cars taller and wider, for O scale passengers. Unless I find enough of the Minex Marklin sold between 1970 and 1972.

Currently all of my Marklin locomotives have the traditional reversing unit, common from the late 1950s to the 1980s. All of my Marklin locomotives will reverse from the 24 volt pulse from the Marklin transformer. With all of my bigger and nicer locomotives, I will be keeping them intact, as regular HO scale models. I'm only talking about using the small and inexpensive 6 wheel steam and diesel locomotives, such as the 3000, 3029, 3087, 3090, 3078 and 3080, for my On30 conversions.

Like I have said, I would be using Marklin M track, with the studs in the middle, produced from the middle 1950's to the end of production around the year 2000. I'm on a tight budget, I want to keep my expenses low. I already have enough M track to make a small layout, but I will be purchasing a few more switches (turnouts). And purchasing a few more inexpensive freight cars, and a few inexpensive Marklin locomotives produced in the 1950's to 1980's. Thankfully used Marklin from the 1950's to 1980s are very reasonable in price on the used market. I'm talking about M track and small locomotives such as the 3000, 3029, 3078, etc.

Does this sound feasible? What would you recommend? I would really like to build a small On30 layout, but using Marklin components. I would like to do some switching (shunting), not just run trains continuously around an oval of track. I want to operate the model railroad, like it's a real railroad with a purpose. To move around and deliver cargo, and passengers. I might even build a point to point switching layout, with no ability to run around an oval. On30 would give me something unique, something a little different, compared to the typical HO scale, 3 rail Marklin layout.

I will be using a 30 inch by 72 inch table in my apartment. I don't really have the space to put an oval on it, unless I use the very sharp 5120 industrial curves. I currently own four of the manual switches (turnouts), and will be purchasing a few more of the manual switches. I don't really need electric powered switches with the solenoid switch machines.

I can still run my larger Marklin trains on the floor (on the carpet), using the larger 5200 radius curves I own.

My preference for a Marklin type On30 switching layout, would be running the small inexpensive Marklin trains with my DC power packs, remove the Relex couplers and buffers, and add body mounted Kadee couplers (such as the Kadee #5 couplers). For slower speed and smoother speed control. Reversing direction by changing polarity on the DC power pack. Instead of using the traditional Marklin reversing mechanism, and without the added expense of Marklin Digital or DCC command control systems.

By the way, just in case someone reads my earlier messages at this Marklin forum, I no longer own any Marklin digital or Delta locomotives, they have been sold years ago. I'm only interested in going analog and using vintage 1950's to 1980's locomotives with metal gearing, the classic Marklin reliability. I'm completely analog control with locomotives made mostly from the 1950's - 1980's, without any of the DCC, MM, Delta, MFX, mLD, ESU, or Uhlenbrock decoders, etc. I just want simple and reliable trains, I can cheaply and easily repair and do routine maintenance on myself, as needed. I don't want to damage or destroy an expensive and delicate digital decoder, or weld the wheels to the track, because of an overload or short circuit. I also prefer M track to C track, because it's rugged and made from metal. And a lot cheaper compared to the C track.

Perhaps if I had lot's of space for a permanent and large layout, I would be using Marklin K track, and it's flextrack. Along with good condition M track in certain areas, like inside tunnels, and staging tracks, in a helix, etc to save money. But I'm on a tight budget, and I live in an apartment.