Live "diesel". Would it work?

Garden Railroading
1

I have recently been on a “buying streak” for old engines (i.e. old lawnmower engines) and I have been able to get started on servicing them. However, I’d rather not restore them, and then have no use for them (other than a good way to make noise). So I have this sort of crazy idea: How about a Live “Diesel” locomotive?

I beleave that it would work (not only would it be a division of Live Steam, with modern locomotives, but I think the 2-stroke engines would look great in a scratchbuilt ALCO) but I’m not too sure.

What’s your input on this idea? Do you think it would work?

Also, has anyone done something simaler? If so, can you share any tips or secrets to getting a locomotive built?

2

What scale / gauge are you thinking about? If you are looking at making a G scale loco, lawnmower engines are a little oversized, although it may be possible to shoe-horn a smaller weed trimmer engine in one. Any live diesel I’ve seen in G scale used a model radio control car engine (take a look at http://www.youtube.com/watch?v=gSwha_Ug7sk&feature=related ). However, if you are thinking of going bigger, then it’s not only possible but relatively common. I’ve seen “diesels” built in 5" gauge on up, and I’m sure it’s been done for the smaller gauges, too. I am in 12" gauge and have built 3 different “diesels” with Briggs & Stratton engines, as well as a railtruck with a McCulloch Weed Trimmer engine (see http://nfrailroad.com/page10.html ). Drivetrains run from the simple to the exotic in this aspect of the hobby. Some simple, four wheel switchers just use a go-cart type clutch with appropriate speed reduction via roller chain and sprockets to drive the axles, no reverse. Two of the locomotives I built have a little more complicated mechanical drive to incorporate forward and reverse. One of the engines I built used a hydraulic drive. I’ve seen locos with hydrostatic and electrical drives, too. I know it’s prototypical, but an electrical drive is usually the most expensive and complex system to use. Most model locos use a hydrostatic or hydraulic drivetrain with a mechanical drive being probably the second most common.

Let us know what size you are thinking of, and welcome to Live Diesel!

  • James
3

I am in the process of designing two Gauge ‘3’ Diesel locomotives, one Diesel Mechanical (DM) and one Diesel Electric (DE). I have most of the DM parts worked out and the DE is for me the most easiest -which is why I am doing it last!!! I have based my designs on model marine engines with cooling systems and fluid torque convertors not unlike the Voith system. http://www.cabbagepatchrailway.co.uk/fell.html regards ralph

4

Ralph, I enjoyed the link! Keep us up to date on progress, I would love to see video when you get it running.

  • James
5

Well, I forgot about that. I plan on (hopefully) doing a 1/6 scale railway (1/6 scale is the same scale as the 12-inch tall G.I. Joe action figures, and I figured I could tie them into the railway as it being a military base’s railroad.)

I also purchaced a huge (about 50 LBs) 2-cylinder 16 HP Briggs&Stratton horizontal-shaft engine, and, if all goes well, I could conect a power-generator unit to it and build a very large (over 8-feet long) model of an EMD F-45 (like the prototype, this will be Diesel-electric) but I don’t think that will happen, and the engine will become the power unit for a “Rat-Rod” that I can drive around at the machinery shows.[#offtopic]

O.K., back to the trains: As stated before, I have 4 engines that could work:

2 Clinton 2-stroke engines ( No they have no tie to Bill Clinton)

1 Pennsylvania Electric 2-stroke engine (I think it use to be a generator)

1 Techumsheh 5HP 4-stroke engine ( Luckily, parts are still avalable; the timing gear needs to be replaced)

1 Briggs&Stratton 16HP 2-cylinder engine (this behemoth will throw your back out if you don’t use the team-lift system. Unfortunately, I doubt my F-45 fantacy will come true, so off to the junkyard to find a transmition and a rear axle to use)

I would definately like to try to build all Live diesel locomotives as Diesel-Electric, like their 1/1 scale cousins.

Unrelated Note: Do you think the exaust from a 2-stroke engine is convincing enough for an ALCO?[(-D] I know that ALCO locomotives were notorious for spewing oily smoke in their exaust, and I figured that it would work. (If all else fails, and I can’t build an ALCO, mabe I can build a GP 7 and claim turbocharger problems[swg])

6

Well, let’s do some math. 1/6 scale of standard gauge would be about 9" gauge - workable, but unusual. An F-45 would be a pretty hefty locomotive, but the 16 HP twin would be right at home. Not to be a discouragement, but I do want you to have a realistic expectation when it comes to building such an engine. Unless you are willing to build your own electric motors and generators, you will need to purchase these items. New, items in this horsepower range are very pricey. Surplus can be found a little less pricey, but still expensive. Finding usable stuff in a salvage yard for junk prices is all but impossible. Also, there is the matter of fabrication, ie wheels, trucks, frame, body, etc. A 40" wheel in 1/6 scale is 6.7" diameter - you will either need to buy it machined or buy the material and machine it yourself. Again, this isn’t meant to discourage you, just to give you a good idea of what you are in for. This would be quite a project!

Here is a suggestion: How about for a first project, building a railroad maintenance of way speeder out of one of the Clinton two-strokes? Only four wheels to contend with, a simple mechanical drive train and the engine will be appropriate for the application (older Fairmont speeders used a big two-stroke engine). You could oversize it a little so you could ride on it. If you build it in 7.5" gauge, there are tracks around the country you could run it at. I’ve seen a variety of these built.

You could certainly use the two-stroke for a somewhat smaller scale Alco, I think they would be underpowered for a 1/6 scale locomotive. I don’t know how convincing the exhaust would be, Alco’s tended to belch black smoke, whereas your Clintons will tend to put out a blue haze. But, beauty is in the eye of the beholder…[:D]

Just my two cents worth…

  • James
7

Well, I didn’t have high hopes for this project even getting off the ground, accually. I doubt my mother would give me the rights to lay track over the whole yard[:-^] So, that leaves me to build some sort of Rat-Rod for when we go to a machinery show. Don’t worry, James, it wasn’t discouragement you were giving me, that came about 5 secconds after I asked to expand to the whole yard (mom said “No” quite fast. In fact, alot faster than normal, almost as if she knew I was comming) so, I guess I’ll work on a design for the “Rat-Rod 2.03” Again, [#offtopic] on my part

I know, I went out of order, but I didn’t think about this sentance when I responded.

I know that it will be a very big area, but I always like to have a challenge. As you said for the F-45, I would need to machine a whole lot of parts (wheels, trucks, bearings, etc.) and that’s where a big miscalcul

8

I have an idea for getting these motors at cheep (yardsale) prices, if they would work:

How about used bench-grinders? They have fairly large electric motors, dual-ended ones can be used like traction motors on a locomoitve Replace the grinding and wire-brush heads with wheels, and it should work, right?

I thought about this today; as I was looking for something to retrieve our lawn-mower (it’s a big, heavy 0-turn model, and it hit a soft patch of Famous Florida’s Dry Soil, and it’s stuck in the most inacessable area of our yard) when I found my dad’s (somewhat used) benchgrinder on a shelf.

I figure that obtaining 6 or more will be fairly easy, as the county I live in has plenty of yardsales, and some of the easiest things to find are used bench-grinders.

While I think it would work out for a scale Diesel-electric, but I would like your imput on how you think it would work before I go and buy some.

Again, thank’s for the help you have offered for this (and other) projects (which, admittedly, have been vary few)[:)]

9

AC drives are tricky. There is a reason that prototype locomotives have only began to use AC drive systems recently. The problem is variable speed. On a rideable locomotive, it is nice to be able to vary the speed and start the train smoothly. You can vary the speed on a DC motor by simply varying the voltage. If you reduce the voltage on an AC synchronous motor, the amperage will begin to increase to the point of burning up the motor. Since bench grinders are meant to operate at just one speed under load, they use a type of synchronous motor. Speed might be controlled with a variable frequency controller, but finding one with enough capacity to run 4 or more bench grinder motors will not be easy, unless you buy new, then it won’t be cheap. Also, you can’t just vary the frequency of the AC by slowing down the gas engine driving the generator, because that will also cause the voltage to drop, which will eventually destroy the motors. There are also issues if you want to reverse the locomotive. A final consideration is HP, a bench grinder is about 1/3 hp, so 4 of them would only deliver 1.3 hp, not nearly enough for the size of loco you are thinking about.

One suggestion, if you really would like an electric drive, would be to find old treadmills. They typically use a permanent magnet 90v DC motor to run them, and the motor is usually fine, the electronics tend to smoke. The gas engine could drive a common 120/240 VAC “generator” (a misnomer, they are technically an alternator) which could run through a rectifier to drive the motors. The gas engine speed can be varied to vary the voltage, frequency won’t be an issue since AC will be rectified to DC for the motors. Also, permanent magnet DC motors are easily reversed just by switching polarity. However, HP will probably still be a problem.

Another option might be

10

What you also have to remember is TORQUE to WEIGHT ratio. I do a lot of calculations in my work and I have learned to “cheat” … This is Maxitrak. http://www.maxitrak.co.uk/ on their website you will find most of the information that you are looking for -STEAL IT!!! I would also recommend that you use DC traction as it is far easier to calculate the parameters for. As I have said elsewhere if you want the calculations doing then I will willingly do them for you. I am sat in front of an £8million computer design system… regards ralph

11

I’m back, and after a search on Bing for a 1/6 scale vehicle supplier (for my other hobby of collecting the 1/6 scale G.I. Joe action figures) I accually found a website for 1/6 scale electric locomotives. Here’s the link, feel free to take a look, although it seems like the company is only doing custom builds now (almost all of their product pages are “defunct”) http://www.carrslocomotives.com/ I did get an idea, though. How about a narrow-gague model of a G.E. 70-ton switcher? I think G.E. made a few of those. If anything else, I could use it as a learning experiance with serious metal-to-metal construction.

12

You may want to look at this: http://plumcovestudios.com/axles_01.html . They have a motor that might work for you and it says they will make wheels/axles to custom gauges.

13

If you’re really hung up on doing this electrically, you’ve already been given some very good advice. Personally, I’d do it with hydraulics. I’m not sure (maybe a little help from Ralph here) but I think hydraulic motors develop full torque at zero speed as DC motors do. Speed control is easy as is reversal, and, the prime mover can be run at constant speed at the full horsepower RPM.

14

Diesel Hydraulics do indeed develop maximum torque at zero speed. The pulling power of a “Western” is legendary for its smoothness as it throttles up. But I honestly doubt it could be built with the “delicacy” required of a scale model. The maths are fairly simple -but it is the pumping part of it that would be the problem -as would be all the hydraulic couplings. You would also need some form of air to fluid cooler to prevent the fluid expanding too much under the work load. regards ralph

15

When I built my 4 wheel switcher in 12" gauge, I used a hydraulic drive. This is just my own design and build, I used Parker Hydraulic components for the motor and pump. Here is a picture of locomotive #2001 without the body so you can see all the good stuff:

NFRR Loco 2001 Hydraulics

The ideal situation is to use a variable displacement pump, so you can get all the benefits that the guys mentioned. Eaton makes an all-in-one hydrostatic drive, the Model 7, that a lot of 1.5" scale guys use. However, the Model 7 is a little weak by the specs for a larger locomotive with reasonable horsepower, so the Model 11 would be a better pump. However, variable displacement is a relatively costly pump, so my little switcher made do with a fixed displacement pump, running through an open center valve to a motor that drives the axles through the roller chain. This was a very good locomotive, smooth running, with more than enough starting torque even without the variable displacement pump. It was built to 2.5" scale, so it is about 5 1/2 feet long and 2 feet wide. The cab was full width, with the engine in the cab, and a 12" wide hood over the pump, motor and oil tank. No oil cooler was needed if the tank capacity is at least equal to the pump capacity at full RPM, and I never had any heat related issues.

Just some info to give you guys some ideas for locomotive transmissions!

  • James
16

Dear JamesP,

I highly appreciate your invention. Thank you for giving us ideals about locomotive transmissions.