Radio Control for 3/4 scale???

[sherwin]

It's the new guy here with yet another question. Can locos in this scale be run by radio control? What is involved in such an undertaking?

Thanks all!

[gordonfrench]

Most of the clever dicks that you will find here can do most anything. Rigging a live steam locomotive to run from radio control would not seem out of the question.

But... Why?

Being pulled by one that is running by virtue of control by your own hand directly on the cab controls is one of the thrills of a lifetime. Why miss it with unnecessary complication?

Gordon

[Harlock]

Well, I would say that if you want to watch a scale locomotive pull a scale rake of cars in a very authentic fashion without full scale riders, R/C would be the way to go. However, if that's your primary interest, I would highly reccomend going G-Scale and buying an engine from Roundhouse Engineering in the U.K. They make very fine radio controlled live steamers for garden railroads. www.roundhouse-eng.com/

For American locomotives, they have a Fowler and a 2-6-2 Baldwin, finely detailed for the price. The Darjeeling comes standard with R/C. Load it down with some cars to give it realistic motion.

Anyhow, if that's not your taste...here's some thoughts on R/C'ing the A3. (I've thought about it as a fun side project after completion)

You'll need to fire it on propane, with an R/C actuated propane regulator valve. Anything else will require too much interaction, although you could get away with oil.

The MAJOR safety issue will be water, as with normal firing. You'll need a reliable method of monitoring the boiler water level from the remote, as well as a remotely operated steam injector or pump.

Working for an aerospace company, I have seen every kind of little widget for remote sensing, control and data acquisition, so I know that the water monitoring issue can be solved, but the transducer could be an expensive item. A cheap way would be to attach a miniature wireless camera pointed at the sight glass, with a little LCD monitor and receiver on the remote control. In either case you have to PAY ATTENTION. With a level transducer, you could include an alarm that triggers at a specified level as a backup.

If you use a miniature camera, the same camera can be pointed at the boiler pressure gauge.

You need to reserve another channel for the drain c0cks, and another for the whistle. And then the throttle and reverser. The A3 has no brakes.

An R/C airplane controller is ideal for this, modern ones are highly configurable for such things as landing gear and flaps, so they have lots of auxiliary channels. And they don't cost much anymore compared to what they did in the 1980s.

Again, the biggest danger here in my opinion is accidental dry firing from not enough situational awareness. But that's something that can be overcome by operator attention and multiple redundant systems. If you want to 'automate' it even further, you can have the level transducer actuate the steam injector automatically through the use of a step-logic controller (conveniently hidden in the boxcar behind the engine along with all the other goop)

A lot of live steamers I talk to (especially the coal fans) love the hands on aspect of the operation, and wouldn't think about going R/C. But I think the ability to remotely control a 3.5" gauge loco would be a fine thing and would bring a much different kind of enjoyment - the same kind that comes with flying model airplanes.

A lot of this discussion revolves around locomotive automation, which if steam locomotives had survived into the computer / ladder logic age we would have seen a lot of. I believe at least one locomotive at the Disney Fort Wilderness Railroad was automated in such a fashion.

--Mike

[sherwin]

Good points I had not considered. Alot of the pleasure of building the A3 will come from being able to actually ride the thing.

As far as G goes, I have not seen much in the way of plans for building ones own locomotive, if there were more out there I may reconsider and go that route. Mike thanks for the info on RC control, sounds too far out of my league, besides would be more fun to ride and operate myself now that I've thought about it. Will keep the idea of RC control in the back of my head however.

[Harlock]

Yea I would say build the thing to spec from the book (as I am) and then think about modifications later.

Our own Ed Hume is building a Kozo Heisler for G gauge track...and by the most recent photos, it looks like it's done! He scaled down the plans from the 3/4" version. You could do this with any suitable set of plans including the A3 as long as you account for the physics of scale on the major operating parts (boiler) and make a few changes. Pictures of Ed's Heisler can be seen on the companion Yahoo group that some of us use to post pictures. ph.groups.yahoo.com/group/Builders_of_Kozos_Engines/photos/ You need to join the yahoo group to access the images.

The way that Roundhouse Engineering solves the dry firing problem is they design their boiler and firebox so it runs out of fuel before it runs out of water. Their locos were designed to run autonomously, before they started adding R/C.

you will definitely find riding on your engine a lot of fun. Yesterday I pulled a bunch of people around our club track on someone else's 7.5" gauge engine and had a blast. The most fun I've ever had was driving a 3 3/4" scale roll models engine. You sit in it instead of on it, and it's still small enough to see over the top. I think it's more fun than the few full sized engines I've driven. Unfortunately, I don't have $40k to plunk down for one myself.

[Harlock]

Today I received my latest Live Steam and Outdoor Railroading issue in the mail. There is a great article with plans for building a propane / LP gas regulator that regulates output based on steam pressure from the boiler. It regulates the gas burners on a propane fired loco so that as you let off the throttle and coast downhill, quickly building steam pressure does not cause a blow off and subsequent loss of water.

In essence, it's input is the same as a safety valve, but serves the purpose of catching the pressure before it trips the safety valve. The author designed this valve partially to allow new drivers to ease into the operation, so they could just pay attention to the water level at first.

Such an item could play a great role in R/Cing a loco, coupled with an in-line R/C manual burner control / shut-off.

[Harlock]

Another live steam article from the Nov / Dec 07 live steam takes another step towards steam automation or remote control.

A gentleman has devised an accurate water level transducer that will give an electrical signal if the water falls below where the sensor is located. This would be very useful in this application.

Just adding this post here for future reference.

--Mike

[Harlock]

Adding another goodie to the list'o'automation widgets...

Bill Shields came up with a blower control valve that's based on the pressure in the steam chest. A needle valve operation.

bbs.livesteam.net/showthread.php?t=969 (must login to see the thread)

[pkastagehand]

The smaller scales often use R/C for garden railways that are too small to ride on.

[Harlock]

All of Roundhouse Engineering's higher end models are R/C'd... www.roundhouse-eng.co.uk/

I'd really like the Darjeeling B-Class but with the exchange rate I could buy a mill with DRO for that price... (and I'm going to...)

[dennisintexas]

¾” scale seems to be perceived as only a ride behind scale. The problem with this is it becomes just the loco and the driver. Running it as an R/C engine allows the concept of a train with the locomotive and cars. If one looks at the Gauge 1 locomotives, many are in 1:20.32 scale which means that a D&RG K27 ends up being fairly large physically. These seem to be R/Ced very successfully. Another scale are those who model 2’ prototype on 45 mm track. These locomotives in the 7/8” scale or 1:13.7 are also large, but there is no interest in riding behind them. Instead, trains of freight and passenger cars are pulled in prototype fashion.
One of the problems of scratch building in gauge 1 sizes is the fiddly pieces. There is an old adage that the smaller the scale the tighter the tolerances. Drive mechanisms for gauge 1 are precise pieces of master machining. Masters of that art should be respected, but I tend to be a little looser in my shop.
The down side of ¾” scale is the need for having to make everything. In gauge 1, a person could pick up various pieces and even complete chassis to modify. In ¾” scale, at the present time, there is very little available off the shelf. In the future this may change, there are new vendors in this scale and those tired of balancing on a narrow track for the ride on experience and those who would like to build their own, but don’t want to build watches to run on Gauge 1 make migrate to ¾” scale/3 ½” gauge.
Give it a try, you might be a pioneer.

Dennis in Houston