The Bucket Foundry

[MikeT1]

Sorry for the off topic, the plane is a Pietenpol aircamper, 1929 design, 2 seat parasol, with a 40 hp model A Ford engine, considered to be relatively strong and vice free. I chose to build it because of the above and its vintage appearance. Whilst the steam plant is 100 pounds lighter than the model A engine, the water required is considerable hence the passenger seat will do duty as a tank support. 200 pounds of water should give me an endurance of between 20 and 40 minutes flight, it operates on the total loss principal. The boiler is a liquid fuel fired monotube along the lines of a Doble boiler, I have been playing around with Arduino microcontrollers for the boiler and combustion control. Initially I intend to use a mix of diesel and petrol for ease of ignition and fuel energy density. The monotube boiler design is considered relatively safe in the event of bursting as it contains only a small volume of water, albeit at up to 1000 psi. The boiler housing and cowlings are designed to direct any escaping steam away from the pilot. The main challenge is to keep the engine alive as steam at high pressure is at high temperature as well, in excess of 750 degrees, at these temperatures oil will carbonise and ally pistons will fail, the inlet valves are subject to erosion and the inlet manifolds glow. On top of that the torque produced by steam is higher than an internal combustion engine so the bearings / crankshaft etc have to be beefier yet still well balanced in order to handle the high rpm at which the high engine efficiency is produced. Steam whilst less dense than air at the same temp and pressure is far more viscous therefore needing larger passageways and well designed porting. For efficiency the inlet valve needs to be open for no more than 60 degrees, as opposed to the 270 degrees in a fourstroke internal combustion engine, so the loads on the valve gear are immense. There is very little usefull information available concerning steam engines operating at the ragged edge, an internal combustion engine is well documented and much simpler by comparison, perhaps this explains the scarcity of steam powered vehicles nowdays.

[WilDun]

Extremely interesting info!
If (I mean when) you do fly it, will you need special dispensation from EAA etc. to use the steam engine? Maybe an engine drivers certificate as well, the old regulations no doubt have not been upgraded since the 'days of steam'.

I mentioned earlier about Pietenpol confounding his scientific critics by flying with the Model A engine, guess you'll do the same by flying it with steam!
When you say 'high revs" do you mean similar revs as way up in the four stroke IC range, or will there still be the same stump pulling torque you would expect of an old time steam engine with no gearbox?
Guess Flettner could sort you out with a reduction box.

[Yow Ling]

Sorry for the off topic, the plane is a Pietenpol aircamper, 1929 design, 2 seat parasol, with a 40 hp model A Ford engine, considered to be relatively strong and vice free. I chose to build it because of the above and its vintage appearance. Whilst the steam plant is 100 pounds lighter than the model A engine, the water required is considerable hence the passenger seat will do duty as a tank support. 200 pounds of water should give me an endurance of between 20 and 40 minutes flight, it operates on the total loss principal. The boiler is a liquid fuel fired monotube along the lines of a Doble boiler, I have been playing around with Arduino microcontrollers for the boiler and combustion control. Initially I intend to use a mix of diesel and petrol for ease of ignition and fuel energy density. The monotube boiler design is considered relatively safe in the event of bursting as it contains only a small volume of water, albeit at up to 1000 psi. The boiler housing and cowlings are designed to direct any escaping steam away from the pilot. The main challenge is to keep the engine alive as steam at high pressure is at high temperature as well, in excess of 750 degrees, at these temperatures oil will carbonise and ally pistons will fail, the inlet valves are subject to erosion and the inlet manifolds glow. On top of that the torque produced by steam is higher than an internal combustion engine so the bearings / crankshaft etc have to be beefier yet still well balanced in order to handle the high rpm at which the high engine efficiency is produced. Steam whilst less dense than air at the same temp and pressure is far more viscous therefore needing larger passageways and well designed porting. For efficiency the inlet valve needs to be open for no more than 60 degrees, as opposed to the 270 degrees in a fourstroke internal combustion engine, so the loads on the valve gear are immense. There is very little usefull information available concerning steam engines operating at the ragged edge, an internal combustion engine is well documented and much simpler by comparison, perhaps this explains the scarcity of steam powered vehicles nowdays.

So a steam turbine is out of the question?
No complex valve gear,
Im sure there is a technical reason, I just not sure what it might be.

[MikeT1]

High rpm being 4,000 - 8,000. Yes a reduction drive is required. The boiler size should be covered by the model engineering regulations. Small steam turbines (below 500 hp) are very ineficient. The engine efficiency is the key as the engine that gets the most usefull work out of the steam will use a smaller boiler and less fuel and water for a given amount of power output. Small boiler + less fuel and water = much less weight = far better flight characteristics. Hence the dyno and experimental engine, which has taught me a lot, and confirmed a few suspicions as to what is the most effective way to utilise the energy in steam. Perhaps I should enter the bike in a bucket race and see how its 20 cc goes against the 50 cc ic bikes, provided I can get it to complete a race without something going wrong!

[F5 Dave]

Well starts should be absolutely awesome. But imagine a crash with scalding water adding to the threats

[WilDun]

One ton of sand turned up today, roll out the foundry, let the casting begin.

Are the castings going to be made in quantity this time? (a ton of sand is quite a lot).
What sort of sand do you use anyway?
I am using some ordinary silica such as you would buy at Placemakers. I do like to riddle out a few bits of foreign grit and stuff before I use it and last time I dried it before mixing.

[Flettner]

Are the castings going to be made in quantity this time? (a ton of sand is quite a lot).
What sort of sand do you use anyway?
I am using some ordinary silica such as you would buy at Placemakers. I do like to riddle out a few bits of foreign grit and stuff before I use it and last time I dried it before mixing.

I was only going to get 20 bags but for $35 extra I got 40 bags, so there you go. Yes I do have some casting to do, more 700 twins, seems there are other people out there wanting 700 twins for autogyro's. They understand these are only prototype units but want them anyway. Plus I'm sure I'm going to need some spares.
700 twin track bike engine is on the drawing board, patterns are being started soon via a second party.

MikeT , steam. Have we talked before? I'm sure I remember something about a steam powered aircraft. I'm affaid I would have probably thought it not possible but it seems you are in advanced stages of prototyping and have done some homework on the subject. Good on you, I for one would be real keen to see a steam powered aircraft fly, imagine that!
I might have a spare 700 twin if needed

[Flettner]

Will, the sand is fine silica sand, I mix (stuff? I forget what you call it) with it so it can be CO2 hardened.

[Frits Overmars]

Sorry Frits we are using the 'KISS' thing a bit out of context and turning the thread into chaos (Dave started it, all Dave's fault).

Unless you've been working in Italy, you have no idea what real chaos is, Will. And a thread going in all directions need not be a bad thing; fresh ideas may be born that way.
(Google Translator can do that too: feed it with some dull piece of text and brilliant suggestions that you'd never have thought of may come out at the other end).

[husaberg]

Will, the sand is fine silica sand, I mix (stuff? I forget what you call it) with it so it can be CO2 hardened.

Sodium Silicate or waterglass, supposedly if there was someone you didn't like if you were to put some in there oil magic would happen.

[MikeT1]

Yes we spoke when you gave an enlightening talk at the Auckland SAA meeting a year or so back, sodium silicate is the hardening agent, do you need to ensure the co2 permeates the sand well? I have recently purchased the ingredients but have not tried it yet. I am thinking to apply the low pressure co2 to one end of a core box and let it diffuse through the sand. Does it take long to cure? Hope to try some co2 cured sand very soon. Got some pure talc and tried it as a parting agent last weekend with no luck. Chalk dust was no better, looks like graphite is the best release agent, will have to find some more. The castings I did with patterns on a parting board worked very well after the ingates were increased in size. Have run out of gas for the furnace now and the bottle is out of its test date.

[WilDun]

Unless you've been working in Italy, you have no idea what real chaos is, Will. And a thread going in all directions need not be a bad thing; fresh ideas may be born that way.

Yes, Geoff Duke (who died about a month ago) spoke of the time when he rode for Gilera, so after having spent some time in Italy, he had a lot of good things to say about their passion for motorcycles etc. compared to the sour faced manufacturers in Britain (at that time of course, particularly Norton, who he had won so many races for).
He said that the directors and managers etc. were not even interested in racing at all, yet that's where their income came from.
Italy on the other hand was a chaotic place where everybody from the managing director to the floor sweeper loved bikes
and seeing the machinery they have produced in the past just goes to prove that there must be order in chaos!

[Flettner]

Unless you've been working in Italy, you have no idea what real chaos is, Will. And a thread going in all directions need not be a bad thing; fresh ideas may be born that way.
(Google Translator can do that too: feed it with some dull piece of text and brilliant suggestions that you'd never have thought of may come out at the other end).

Not a truer word spoken Frits.

[WilDun]

Was just mixing some sand yesterday (using a riddle of course) and thinking about the " riddle of the beam" we have created (or to be more precise Flettner has created).
If "HARRY" is the Harry I was thinking of, then I don't believe that he will be able to enlighten us much, so it's up to you Flettner to enlighten us, it does look like a "ROCKER" (of some sort) of course, but what did it come off or if you made it, what was it intended for?
If you can't enlighten us, then we can KISS goodbye to ever understanding this enigmatic piece of equipment!

Oh, and Dave, don't go complicating things any more!!

Sometimes I think I'm lagging behind a little these days in the intelligence stakes, or maybe I've just spent too much time outside the circle (ie for the last thirty years or so!)

[F5 Dave]

Was just mixing some sand yesterday (using a riddle of course) and thinking about the " riddle of the beam" we have created (or to be more precise Flettner has created).
If "HARRY" is the Harry I was thinking of, then I don't believe that he will be able to enlighten us much, so it's up to you Flettner to enlighten us, it does look like a "ROCKER" (of some sort) of course, but what did it come off or if you made it, what was it intended for?
If you can't enlighten us, then we can KISS goodbye to ever understanding this enigmatic piece of equipment!

Oh, and Dave, don't go complicating things any more!!

No, no, you seem to have that under control.