The following is an email I just received, forwarded from the Lightsteam e-mail list, which includes a link to this webpage (http://www.flysteam.co.uk) about steam-powered, radio-controlled model airplanes, an intriguing and very unusual steam hobby which has attracted a handful of hobbyists. After this is my reply to this email. I thought some of the ideas in this email, and in my reply, would be of interest to visitors to my website, especially the inspirational apology at the end where I explain my strange personal preference for steam automobiles over the more popular, affordable, and easily-stored steam models. Both are lots of fun, and I do not fault model hobbyists in any way, shape, or form. I just personally prefer the bigger steam stuff. Read on, and learn why. :)

From: GB Gilbert

Yo Lurkers

check this out, info on model steam aircraft for the price of the postage!

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Subject: Re: project
Date: Mon, 26 Feb 2001 18:11:38 EST
From: Jim Reed ([email protected])
Reply-To: LIGHTSTEAM ([email protected])
To: [email protected]

Jim Reed wrote:

I have a project that is in it's preliminary stages. I am building a radio controlled aircraft powered by a piston steam engine. I am following the work done by Geoff Wolfe in England who has been successfully flying his craft for the last five years. I am proceeding in three stages as follows:

1) Currently I am converting a 1938 Brown Junior Co2 single acting "bash valve" model aircraft engine to steam operation. It has a bore & stroke of .178" for a displacement of .005 ci. It weighs .24 0z and runs at 4200 rpm. The "mule" will be a 1930's repro of a free flight aircraft with a wing span of 24", Initially the engine will use a simple drum type boiler. I also will develop a flash generator so that I may compare performance. The aircraft will be modified to a single channel r/c rudder only set-up. All up weight is expected to be under 15oz.

2) Reproduction of David Parker's Comet r/c steam plane using a 5/8" bore & stroke double acting verticle open colum slide valve engine. The Parker plane uses a 2" x 6" drum boiler with additional tubes fitted under the drum directly over the burner. The plane has a 6" wing span with a polyhedral wing. Ready to fly the plane weighs in at less than 40 oz!! David built his planes in the mid to late 60s. His work was the inspiration for Geoff Wolfe. Parker in turn was inspired by the work of the great model engineer H.H. Groves who produced steam model aircraft starting in 1912 and continued on until the outbreak of WWII.

3) Design and build my own powerplant and aircraft. I plan on using a twin cyl single acting rotary valve inverted rocking beam engine. Steam will be generated by a flash unit. The aircraft will be 4 channel- rudder, elevator, alerons and throttle control. The engine design is an adaptation of a compressed air engine created by the outstanding Bert Pond.

At age 52, I suspect this endeavor will keep me very busy until I take that last flight out. Lee Acree of Tacoma, Washington has also been infected by the virus of which Geoff is a carrier. As far as we know we are the only 3 so afflicted. Somehow David Parker found a cure and is involved in other pursuits. If this form of lunacy attracts you, mail me, or check out Geoff's site at www.flysteam.co.uk. I have a lot of info I will pass on just for the cost of postage as Geoff did with me.

Then there is the Stirling powered r/c aircraft built by a fellow out west. But that's another story altogether.

Jim Reed

My reply to this email and the link:

Wednesday, February 28th, 2001

Thanks for the forward and link, GB!

I remember seeing the Flysteam page some years ago while I was on the Lightsteam list. It is pretty amazing to see steam engines this small and light.

If I were going to build one of these planes, I would give it a valveless 1-cyl SA oscillating engine, similar to a Mamod engine, or a DA version, and a monotube boiler made from very small tubing, perhaps capillary tubing as used in ACR work. The "spirit burner", by which I think is meant a wick/Sterno type burner, would be fine for this. I'd feed the monotube from a water accumulator -- water kept under pressure and fed by compressed air. This could be made from one or more of those high-pressure CO2 cartriges used to operate Seltzer bottles and BB guns. This eliminates a feed pump.

This setup would be simpler and cheaper than the systems on the Flysteam page, though it would take lots of work to get it running well. I also think that the wick burners could be shielded to allow operation in stronger winds, with an externally-powered electric spark igniter and a tiny window to verify burner lighting.

��Because the powerplant would run at one load/speed, no burner/boiler/engine controls would be needed. Preflight procedure would include soaking the wick burner with fuel and filling the water feed accumulator with water and compressed air (co2?). Light the burner, wait a bit, then open the on/off water feed valve, and she's off into the wild blue yonder.

Run time/range increasing experiments could include an over-square cylinder with insulating disks on piston crown and steamed surface of cylinder head, to try cutting down on the ridiculously high surface/volume ratio of steam cylinders this small. Perhaps steam jacketing the cylinder (not sure how) would help. Constant boiler pressure could be maintained either with a diaphragm-type water throttle valve on the water inlet (opening up as accumulator pressure drops), or with a valve to meter compressed air into the water accumulator from a tiny air tank (another one of those Seltzer bottle cartriges), for constant accumulator pressure.

A deluxe version could have tiny plunger or diaphragm pumps for fuel and feedwater, Coleman-type vaporizing burner for white gasoline, condenser for water recovery, and feedwater heater for economy. A double-acting oscillating engine could be set for a high expansion ratio due to the constant load/speed. Synthetic detergent oil (allowing high superheat without carbonization) could be mixed into feedwater at a certain low concentration to avoid lube pump.

With everything properly designed and built, I bet a small steam engine like this could exceed the operating range/flight time of gas-engined model planes of identical fuel capacity and airframe. This isn't a tough goal, as those gas model engines aren't exactly "models" of thermodynamic efficiency. Or you could build it for more power than the comparable gas plane, with shorter operating time. Such steam planes would probably be more expensive than otherwise identical gas model planes, but we're talking models here. Some people actually prefer the more expensive toys, especially if they are exotic.

Unfortunately, my steam car project is absorbing almost all of my steam-related time and energy. I find it odd, but interesting, that good-running full-size steam cars can be built for about the same time and money that many people put into steam models. Peter Barrett once noted in an article that he put less time and money into building one of his road-capable steam cars than his live-steamer neighbor put into building a small model steam locomotive.

Many of the parts on a steam car are actually easier to design/build than those on steam models, because of larger sizes and wider tolerances. The only major downside is that the material costs are higher, but material costs are a relatively small part of the challenge in a properly-pursued project, even for folks on a budget.

Steam cars have one big advantage over steam models: you can drive and ride in steam cars, and give rides to others. Well, I guess that is 3 advantages. Plus, steam cars can take you and your passengers to an endless number of interesting people and places, often far from home. They are not just a shop hobby or outdoor sport, but also a prime source of travel adventure. Plus, the inventor in me likes the extreme challenge of designing a variable-load, variable-speed powerplant suitable for road use. These are the main reasons why I find steam cars much more interesting than steam models -- though I have (and have built) steam models myself, and enjoy them very much.

Steamcerely,

Peter