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No subforum for "steam powered"?

Old 06-13-2023, 03:52 AM
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1967brutus
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Default No subforum for "steam powered"?

Just a short question, since I do not yet really know my way around the boating section of this forum: Is there a general "steam powered" subforum?

Is it an idea to ask the mods to open one? I recently picked up an interest in steam powered RC boating, and I cannot find any subforum specializing in that..
Old 06-22-2023, 07:08 AM
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Well... given that there has not been a single post in this entire subforum for about 20 days except for the above, I guess there is no interest for "steam powered", and little interest for scale boating whatsoever... Too bad, oh well...
Old 07-06-2023, 03:23 PM
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Apologies for the foreign language audio... Just turn the volume down if it is annoying, the engine is virtually without sound anyway.
Old 07-07-2023, 06:32 AM
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Originally Posted by 1967brutus
Well... given that there has not been a single post in this entire subforum for about 20 days except for the above, I guess there is no interest for "steam powered", and little interest for scale boating whatsoever... Too bad, oh well...
You have to remember, boating is a very small part of the R/C hobby. For every boater, there are at least a couple dozen or so aircraft fliers, probably 40+ drone fliers and a couple hundred car/buggy drivers. Personally, I build and race scale hydroplanes. You would think that in the Pacific Northwest, home to most of the teams over the last several decades, it would be a thriving community. Truth be told, it isn't. Last race I went to had around 40 boats and 20-25 drivers.
Old 07-07-2023, 11:34 AM
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Originally Posted by Hydro Junkie
You have to remember, boating is a very small part of the R/C hobby. For every boater, there are at least a couple dozen or so aircraft fliers, probably 40+ drone fliers and a couple hundred car/buggy drivers. Personally, I build and race scale hydroplanes. You would think that in the Pacific Northwest, home to most of the teams over the last several decades, it would be a thriving community. Truth be told, it isn't. Last race I went to had around 40 boats and 20-25 drivers.
I don't think the boating community is that small, I just think they are not that vocal.
Competitive speedboating, I can see that going down a bit since it is a fairly expensive sport and especially IC boats, well, the public does not take too kind to the noise I guess.

But it is more that I was surprised to not see ANY steam related topic here. I'd expect a few seasoned metalworkers and lovers of classic technology here as well.

It is an interesting branch, and the whole experience of operating a steampowered model is quite different from running electric powered boats, scale or otherwise. A bit like the difference between powered flight and soaring, the operator has to pay attention to a whole different set of parameters.

But, fair is fair, if there is no interest, then there is no interest, it is what it is, and so be it. At least there was a reply, and that's something
Old 07-07-2023, 12:26 PM
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There would have to be sufficient traffic to warrant a new sub forum, discuss it all you like under general boating, I think its kind of neat but I don't see the traffic justifying a sub-forum.
Old 07-07-2023, 01:48 PM
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Cannot argue the lack of traffic... That by now is clear as day...
Old 07-11-2023, 03:03 PM
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Lack of traffic or not, here goes nothing.

4 minutes out of a 90 minutes session only interrupted for refuelling and slops disposal (about 2 minutes out of the water each pittstop).

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Old 07-12-2023, 03:19 PM
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That thing gets up and "hauls the mail". Very impressive for a small boiler and simple steam engine. I would love to see a video of the boat running that is from the operator's viewpoint
Old 07-13-2023, 01:20 AM
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Thou asketh, thou shallst receive

What it looks like from the waterside:

The "operator experience":

Preparations, including firing up and raising steam, warming through the engine and removing excess condensate from the oil collector, takes about 10 minutes.
Max burner time on one gas filling is about 50 minutes (60 grammes of LPG), but it works slightly better with a 30~35 minute fill (around 40 grammes).
The boat needs a water supply every 20 or so minutes otherwise the feedpump runs dry and you will need to cool down the boiler to prime it if that happens.
But with roughly every half hour a 2 minute "out of the water" pittstop for fuel, condensate removal and water refill the boat can be kept in operation until the receiver battery is depleted OR the cylinder lubricator is empty, which I estimate to be about 2 hours..
In between pittstops it is advisable to every now and then check waterlevel in the feedwater tank, but with a bit sensible powermanagement, 30 minutes is possible.

Such a pittstop consistst of raising steam pressure, (normally automatically controlled at 1,2~1,5 bar or 10~15psi) manually up to about 2 bar (30 psi) before landing, at landing closing off the main steam valve, kill the burner and stop the feedpump.
Blow off gastank and refill, empty the oil separator, fill up the feed tank, relight the burner, open steam valve, and on low steam run the engine until the condensate in the engine is out. empty the separator once more, and the boat is ready to go again. If you have your equipment ready and your sequence of actions laid out, it can be done in about 2 minutes if nobody of the onlookers cause distraction (which they invariably will do ).

It's not for everybody, but for me, the rather hands on intensity of operating such a steamplant is the appeal of it all... Because running the boat up and down the pond in itself is not all that exciting. The more traffic on the pond, the more fun it becomes, as manouvering the engine is less straightforward than an electric drive.

Originally Posted by Hydro Junkie
That thing gets up and "hauls the mail".
By the way, funny you say that... This type of boat originally was used in the German Bight area as an "Inselversorger" or island supplier, and as such did indeed "haul the mail", quite literally...

Last edited by 1967brutus; 07-13-2023 at 04:35 AM.
Old 07-16-2023, 02:14 AM
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So, traffic indeed is low.

In that case, I won't bore or bother too many people by giving a bit more background info.

The boat is a more or less entry-level kit into steaming, the "Borkum" from Krick of Germany. Pretty good kit, not flawless, it has a few minor screw-ups in the lasercut parts (a few tabs and slots not aligning by abt 2~3 mm (appr 1/8") but nothing really serious), but the supplied stern tube is downright unacceptable in quality and the coupler between shaft and engine simply is a joke. All minor issues, otherwise the kit really is fairly complete and of pretty good material quality. Very sturdy ABS hull, pretty accurately cut out of the mould with very little trimming left to do. A 55 mm (~2-3/16") brass propeller is included, that is a pretty good match to the boat. IMHO the kit is absolutely worth its money, and although I am absolutely not an RC boater at heart, I absolutely had fun building it. Took me some 75~100 hrs at a leisurely pace. Learned a few new techniques as well.
I deliberately kept the boat sober and left out a lot of the rather "blingy" accesories, I thought it more realistic to leave off the brass andrails, flagpoles and bells and lights. Just wood, no bling. Like utilitarian boats used to be in the very early 1900's in Europe.

The Engine is a Microcosm M29, a two cylinder double acting, slidevalve controlled, non-expansion steam engine, reversible via a Stephenson dual eccentric, and fitted with an automatic cylinder lubricator. Total displacement about 6 cc or .35 cu.in.
https://nl.aliexpress.com/item/10050...d=dPWRBsR6r2tP
It comes mounted on a bed, complete with boiler (I opted for the horizontal boiler, which for boats is less favourable compared to a vertical, but hey, what did I know, huh? I bought the engine first and then found out you need a boat or it won't be near as much fun, so...). Next to the boiler, also an oil collector, a burner, a gastank plus fuel line are supplied, the burner and collector are installed, the gas tank is "loose" and can be placed anywhere convenient. Two spare level glass tubes plus O-rings are also included. The horizontal boiler is fitted with a superheater made out of stainless steel, the vertical boiler is not.
Most likely, the horizontal boiler therefore is a bit more fuel efficient (even without superheaters, usually horizontal boilers are a bit better in that respect, the superheater improves that, but do not expect very shocking differences.
The machine is not really perfect "as is", but in my case, it started up at first try and ran as smooth as butter. It did however show a very high steamconsumption.
After reading up on it (user experiences from others) it took me only about 2 hours total to fix the main issues (poorly sealing slide valves and excessive clearance in the reversing mechanism) with nothing more than a small key file used very sparingly, a piece of 600 grid waterproof sanding paper and a few drops of white scouring household cleaner (don't know what it is called in other parts of the world, over here it is called "Cif", what the missus uses to clean stainless steel kitchen work surfaces).
And half that time was "spannering" and figuring out "how to", only maybe a 30 minutes were spent working the parts.
The steam consumption now is within acceptable limits at roughly 500 grammes (slightly over 1 lbs) per hour.

To make a true "installation" out of separate components, I hooked up a servo controlled gasvalve (Regner, from Germany: Gashahn RC- Regelbar | REGNER (regner-dampftechnik.com ) to control the burner, and an automotive pressure sensor 0-30 psi to read out the boiler pressure over telemetry, and since my TX is a Taranis with OpenTX, this pressure also directly controls the burner, keeping the boiler between 1,3 and 1,6 bar (appr 19~24 psi).

The boiler content is about 350 ml (just under 12 oz), of which about 180 ml, or 6 oz is "steamable", which gives an operating time of max 20 minutes if you take it easy, but the gas tank can safely contain 60 grammes of gas at 75% filling, which is sufficient for well over 40 minutes "balls out" steaming.
I did not like that. Lose track of time and the boiler runs dry, and the observation of the levelglass is less than convenient when the boat is in the water. So I also fitted a controllable feedpump (Servo-Pumpe inkl. Servoelektronik | REGNER (regner-dampftechnik.com) and installed a 350 ml (12 oz) feedtank. Since I could not buy a suitable tank (especially the shape was a problem), I made one myself out of plywood, aliphatic glue and coated with PU lacuer as used for wooden floors.
In the TX, the speed of the feedpump is matched with the steam valve, so the boiler by and large keeps level.
In itself, this tank only gives an operating time of about 30 minutes, but where a manual boiler refill requires taking the boat out of the water, depressurizing the boiler, filling it, then about 5 minutes to raise steam again, the feedtank allows to bring the boat alongside, pour some water in and be on your way again in 15 seconds all in all.
That brings endurance to close to one hour on a single gas filling with a bit of conservative steaming and one or maybe two very short pittstops.
Longer is possible but then you will need to take the boat out of the water for a refuelling (cannot be done safely with the boat afloat).

Normally, steam engines of this type are fitted with oiler cups on the bearing that hold maybe 2 drops of oil each, and need frequent manual refilling (every 10~15 minutes) and this requires taking the boat out of the water, and with a syringe or similar very accurately aim to get the oil where it needs to be or the entire "engineroom" will become a total mess.
I did not like that AT ALL... Not when the technology to remedy that exists basically as long as the steam engine itself. So I decided to use that technology, and made a small tank fitted with 7 wicks and as many oil lines to the lubricating points of the engine. Those are the 3 main bearings, the 2 excenter-pairs and the two crosshead guides. From the crosshead guides oil trickles down to the smallends and bigends.
This gives a continuous but VERY slow oil feed (think in the order of magnitude of about 1 drop every 30 minutes) to these lubricating points. Now the nice thing is: if you lubricate manually, most of the oil is flung off in the first few minutes without having done ANY useful lubrication, and the remainder of the time those points are running basically without oil. With the continuous feed, they remain perfectly lubricated 100% of the time with barely any fling-off. It pays off: This engine is made of brass, which is not known for its superduper wear properties, but the engine as it is now, has allready collected 25 runhours (22 of them in the boat) and so far, I cannt yet even see any running marks in the crosshead guides, or any play or clearance increasing. 5 ml (1/6th of an oz) will literally keep the engine lubricated for the entire day. I use regular full synth engine oil here, because that is what I have on hand, but basically any decent machine oil (sewing machine oil or other) will perform equally well.

Fuel consumption is about 60 grammes per hour, water consumption between 550 and 650 ml (18~22 oz) per hour, cylinder oil consumption about 1,5 ml (1/20th oz) per hour, machine oil, to be honest, very hard to tell exactly, but if I had to guess, "14 drops per hour".
For now, the project will be dormant for about 2 months due to me needing to go back to work (the hobby needs to be paid, after all) but next project, in 2 months time, will be the installation of a feedwater pre-heater annex condenser. This could potentially increase fuel efficiency by 5~7% while reclaiming about half or better of the currently exhausted steam, which with a little bit of luck will allow for running through a full tank of gas without needing to refill the feedwatertank. In order to achieve that, an additional oil separator needs to be incorporated in the feedtank.
The reduction in fuel consumption is rather irrelevant (it's only 5 minutes to the hour, after all) but being able to run the entire time without "pittstops" for water, will be a welcome improvement.

All in all it is a VERY fun way of operating a boat, real hands-on.

Last edited by 1967brutus; 07-16-2023 at 12:35 PM.
Old 09-24-2023, 11:10 PM
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No idea if anyone is interested, but...

Just for the heck of it, trying to "improve" the steam installation. More for technical entertainment and educational purposes than anything else, not expecting miracles, and it is not going to make the boat any prettier.

The boat, as is right now, has a boiler with a "steamable content" of about 6,5 oz, and a feedwater tank of around 12 oz. Water consumption is about 22~24 oz per hour, so with a safety margin of 2~3 oz there is about 20~25 minutes of operating time, because it is imperative that the feedwater pump does not run dry: When that happens, the boiler needs to be depressurized in order to prime the pump again.

The plan is to pre-heat the feedwater using the spent steam from the engine. This should improve fuel consumption by about 10%, give or take. This saving is relatively unimportant, because the fuel tank is not the limiting factor (suffices for cold start-up plus 50 minutes of operating time), and you have to blow off the unused fuel anyway, so any savings here are moot. It's just a (useless) bonus, but it DOES increase the boilers capacity to maintain pressure under load a bit.

The main reason for this mod is that doing so results in the used steam condensing into reusable water to feed the boiler, which extends operating time.
The pre-heating of the feedwater only results in a condensate flow of about 1/6th of the feedwater consumption, but any heat loss in the condenser (heat dissipation to ambient air) of course increases the return, and I expect to be able to reach about 40% return, extending operating time by the same. Theoretically that would mean 40 minutes of operating time instead of 25.

However, there is a problem with condensate return, and that is in that it can contain traces of engine oil (the engine is lubricated internally by injecting oil into the steam supply. Most of that oil is collected in an oil collector but traces can pass).

So step one is ot build an oil separator in the feed water tank. This has to work first, otherwise the entire project is useless. Oil in the feedwater can cause problems with the boiler fouling internally.

So first step was to build a tiny oil separator in the feedtank, in order to receive and pass the condensate.

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it basically consists (just like the real thing on real steamers) of a compartment divided by a bulkhead that forces the water to pass under that bulkhead in order to reach the spillway. Only difference is that in real life installations, these separators usually are a cascade of 3 to 5 bulkheads and overflows.
The idea is that oil, floating on water, will remain in the first compartment, only clean water will pass under the bulkhead and spills over into the feedwater tank.

The oil separation in the first compartment is assisted by (not pictured) a coalescent filter, a fibrous cloth material that has zero affinity with water, but good affinity with oil.
I have tested with a flow of about twice what is expected (appr 0,5 oz/min) and it appears to work well, except for the V-shaped overflow, which seems to be not the best choice WRT shape.

Next week the condenser.

Last edited by 1967brutus; 09-24-2023 at 11:13 PM.
Old 09-29-2023, 12:49 PM
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It still is a crude set-up, but I have the first prototype of a working feedwater preheater/condenser.


The feedwater, instead of at ambient temperature, now enters the boiler pretty hot (how hot I can't tell on account of the calibration certificate of my fingertips having expired, but I can't touch the feedline, near instant retraction reflex, meaning probably around 80 deg C (176F) or better, and it seems I am getting a fair bit of condensate in return.

I still have to do something about the steam outlet, because as it is right now, al that vapour in the boat sooner or later will cause problems with the wooden parts getting wet and distorting.
I also hope to be able to improve on the amount of condensate return.


EDIT: first (fairly crude) measurements appear to confirm a reduction in fuel consumption of about 10% (which has zero economical purpose, but the extension of operating time is always welcome) and the feedwater supply tank now suffices for 35+ minutes, while it used to be 25 tops.

But every upside has a downside, and I need to revise the piping a bit, because now there also is a lot of unwanted condensation in the boat. Mainly because where previously all steam was vented off at fairly high velocity, blowing all droplets present in the exhaust steam well clear of the boat, but now less steam is vented at a lower velocity, causing large droplets to fall back into the boat.

Last edited by 1967brutus; 09-29-2023 at 04:34 PM.
Old 09-30-2023, 03:21 AM
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Fuel savings and condensate reclamation have proven themselves to be consistent over three timed runs of 30 minutes each at the same power setting (3/4 throttle):
Fuel consumption has dropped by 10%, and condensate reclamation is about 35% of boiler water consumption, extending operating time significantly from 25 to 35 minutes.

Still a few minor issues to solve like optimizing condensate filtration and such. No biggie.
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Old 10-01-2023, 05:07 PM
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How does that saying go, Any improvement that can be measured is a good one
Old 10-08-2023, 03:14 AM
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Yup... I started out with a machine that allowed about 10~15 minutes of operation IF taking it really easy, with a rather hands-on firing up and shutting down procedure, and turned it into a 50 minute boat (under practical conditions, with a lot of manouvering... At constant higher speeds it still is only 35 minutes, but nobody does that...) with a starting up and shutting down procedure that takes very little attention.

50 minute non-stop runs without any manual interference, removal of slops or refills of water are routine now

Took a lot of R&D to get there though. But THAT is the fun in it...

The engine now has about 38 runhours on it (which, if I check around with fellow model steam operators, is an awful lot in a very short time) and runs incredibly smooth now, I guess it has gotten broken in properly in the meantime.
And the good thing is: I see zero signs of wear, slop, play or deterioration of performance. Especially that, was something nobody including me expected, given its Chinese origins.

I also learned a good bit about the effects of water quality on the behaviour of the system. The investment in a water destiller and a decent conductivity meter, and doing regular checks is really worth it, the system will perform significantly better.

Last edited by 1967brutus; 10-08-2023 at 03:36 AM.
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Old 10-09-2023, 01:16 PM
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Aww heck, why not?


11 minutes out of a 60 min non-stop and largely hands-off engine run (only added the 5 oz remains of my feedwater bottle during a 5 sec "pit-stop", that's all).

The whole set-up functions brilliant and absolutely hassle free.
Old 10-11-2023, 05:34 AM
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And apparently, the engine is STILL getting smoother and smoother.


New low speed record, 150 RPM, with prop in water.


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