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[1967Brutus]

In a dutch forum, when I reached 40 runhours, someone commented that the quality of this engine was apparently, based on my reporting, much better than expected. The subject of that thread is the question whether the "cheap chinese machines" are worth considering or not.
Suffice to say, any prejudice I had, is gone and they absolutely ARE worth considering.

Today, I have landed at 70 runhours, and re-reading that forum I stumbled upon that old post from back then.

This is the comment I posted today in that thread (ran it through Google Translate of course, duh...), because I simply wanted to share my thoughts here as well for those that have the same question I had (whether these engines are any good):

    In the meantime I can report that I have almost 70 operating hours, and the machine is still running without any visible deterioration, no mechanical rattles, no obvious play or clearances, the Stephenson arches do not rattle (although I am quite precise with lubricating them),    the performance does not deteriorate, the steam consumption is quite constant, the behavior of the machine, for example when reversing under load or running extremely slowly, does not change.   The crossheads are still tight, both in the guideways and in the crosshead pins, and the piston rod seals have not yet shown any visible deterioration.     The seals of the control valve rods show some steam oil leakage, but that is actually a good thing, because that oil helps to lubricate the Stephenson arches.     Ditto for the piston rod seals: No steam leakage, and the oil that escapes helps keep the crossheads in condition. 
     
    BUT ALSO: The gas tap on the gas tank, main steam valve, feed water valve, steam control valve, etc., not only still function flawlessly after all this time, they are also all still 100% tight on both the valve itself and at the spindle gland.   The functioning of these items is what keeps an installation safe to operate IMHO...
      The steam regulator does not close 100%, but it never did and cannot be expected from a stopcock of this construction.   It also does not have to: a minor leakage her assists in keeping the engine warm when stopped.
     
    The parts in the installation that appeared to work less smoothly were the RC controlled burner regulating valve and the feed pump, and both were from Regner, not Microcosm... 
     They are also working well now, by the way. 
     
    I am absolutely aware of the fact that the machine as delivered out of the box and used without further consideration with regard to lubrication and water quality will probably show significant deterioration within a few dozen of runhours. But I think that goes for most engines. 
    Virtually all engines come with simple oil cups on the bearings etc etc, which is nice for bench runs, but not for "active duty". IMHO, wickfeed oiling is the only way to go.
      The fact that this brass engine lasted 70 hours with all signs suggesting that it will last many hundreds of hours to come, that speaks volumes.
       
     In short, the basis of the machine is 100% good, it is a "machine with potential", so to speak.   Install proper   lubrication (wick feed), and polish the running surfaces of the steam slides (the only thing I can really fault my engine for), keep an eye on your water quality, and the thing will work as well as any other machine.

[Martin (Admin)]

 Post below fixed, Admin   

[1967Brutus]

 Post below fixed, Admin   

Thanks Martin! I seem to very much NOT get along with the "editing programming" of this site. Happens quite often that I quote a post or try to edit a message and suddenly the entire format (sizes, fonts etc) have changed completely...

[Martin (Admin)]

 
Computers ..... Just keep posting, I'll fix anything the Matrix breaks!   

[1967Brutus]

You da man!

[1967Brutus]

https://www.youtube.com/watch?v=WJJe1eHWLmw


Select subtitles and set to auto translate to your language of choice to know what the hell I am babbling on about.

[1967Brutus]

While I'm at it, Borkum loses a lot of speed with the rudder hard-over, and does not turn very tight at rudder angles that do NOT rob speed. So I thought I would like to experiment with a Fishtail rudder while I'm at it. No particular reason, just to see what it does...

On this part (post from end of Februari) I can now finally, after about 90 minutes or so on open water, report that indeed a fishtail DOES make a difference.
I have the vague impression that the boat turns about the same with a reduced rudder angle, losing less speed, but those differences are small.

What is not small, is the differnce in "feel" of the boat. Steering is more defined and sensitive, while straight-run stability seems to have improved. Also at lower speeds. I have to say, I like that. For example, control during short kicks ahead seems to be a lot better.

Steering when backing up however has noticably deteriorated. That is a bit of a shame.

Bottom line is: a fishtail rudder DOES make a difference (bad or good is anyone's own to determine) which in all fairness, was not something I really expected.

[1967Brutus]

Yesterday (Sunday) a demo-day at a townsfair...
Unfortunately pretty big winds and some rain. but the boat not only handled the weather well for 2 hours in runs of 30 minutes, the organizer had 5 of those "Dicky tugs" availlable for the kids to have a go... Now these kids, well, bumpercars come to mind describing their boat handling skills...

Ravika Putri did not back away from the brawl, and stood her ground...

[1967Brutus]

The intended coolingwaterpump has arrived (about a week early, but I'm not complaining )


This pic for size (housing diameter vs thumb)





The brass tube is not part of the pump, just to be clear.

It is about 1/4th~1/3rd the size of the Volvo windshieldwiper pump I was using in the experiments.

As for performance: The Windshieldwiper pump would not run a lower voltage than 2S NiMH (under load maybe 2,3V), draw 900 mA when actually pumping (which is 2,1W of power absorption) and would deliver about 300 ml/min against the backpressure of the condenser coil.

The condenser NEEDS only 100 ml/min, but is not critical for a bit excess water.

This tiny thing runs well on 5V, and then draws 180 ml at open delivery, pumping about 1L/min, but against the backpressure of the condenser drops to about 200 ml/min and a currnt draw of about 170 mA. That's only 0,85W, and low enough for to allow direct power from the receiver busbar.

Now relocating the overboard discharge to above the waterline for visual confirmation of function (centrifugal pumps do not always self-prime), and installing the pump under the floorplate, and Ravika Putri will look again as if nothing happened...

[1967Brutus]

Pump glued in on a wooden spacer. Spacer holds 8 magnets 3 x 6 mm in a circular pattern.




Suction opening needs to be made flush with the hull.


The magnets in the pump base serve to hold a strainer over the suction opening in place. Strainer to be made of tin sheet and steel wire.

[1967Brutus]

Meanwhile....

Things slowed down a bit due to an episode with BPPD knocking me out for a while, and the gradual return to work.

Meanwhile, I finished the condenser cooling set-up. In the last post, the pump was installed and it stopped there.
Thinks left to do were hooking up the pump directly to the stabilized 5V servo busbar by means of a JR servo connector.
That makes the pump run continuously, but it only draws about 110 mA dry and about 175 mA submerged.
Submerged, the pump is inaudible and delivers about 250 ml/minute,  which results in a delta-T over the condenser of about 35 deg C at full steam, and an absolute full condensing of any and all exhaust steam.

Because the boat is going to be used in open water, an intake strainer is advisable. I made that one out of an M12 steel washer, 8 short pieces of 1 mm round wire and a bit of Epoxy.



The 8 magnets I incorporated in the pump base hold the strainer in place, and make removal for cleaning easy



The original optics of the boat have been fully restored with the exception of the visible water supply and discharge tubing



Water discharge is overboard above the waterline, for visual confirmation of full flow/detection of clogged strainer




I think I have mentioned it before somewhere, but this basically means that the installation is complete. Maybe some cosmetic work in the future, but technically, I can't think of anything else to add. Maybe one day I will rearrange the slop-discharge such that the oily water and feedwater tanks will be relocated to the doule bottom. That would unclutter the engine space a bit. But to be honest, that would be a lot of work for things I do not really care about.
As it is, the system now consumes less than 100 ml of water per hour of running, and it can stay out on the water for that hour, WRT fuel, water and slop capacity.

It has been good fun!

[rhavrane]

Bonjour Brutus,Great job indeed but I have a question, where is the whistle  ?

[1967Brutus]

Bonjour Brutus,Great job indeed but I have a question, where is the whistle  ?

I think I posted my opinion on whistles... waste of precious steam

Just kidding a bit... But no... for one reason or another, whistles do not appeal to me.

[rhavrane]

Bonjour,
https://youtu.be/k9cC0AUeuxM 

[1967Brutus]

I like to silently sneak up from behind the horizon...

[1967Brutus]

In general a word of warning about the Microcosm:

The safety valve has a steel ball as the sealing element.
This ball is NOT made of Stainless Steel in mine, with as result that it rotted stuck and did not open even at over 6 bar... (setpoint when I commissioned the boiler was 3,5 bar, never touched the setting afterwards).

Be aware!

[1967Brutus]

Meanwhile I found this: https://www.bengs-modellbau.de/en/Grafi-sil-valve-balls/12799 and that should solve the issue permanently.

[1967Brutus]

Meanwhile I found this: https://www.bengs-modellbau.de/en/Grafi-sil-valve-balls/12799 and that should solve the issue permanently.

Balls have arrived, first try is promising: Safety valve seals properly at working pressuree, and unmistakibly "pops" at set pressure.
There is a slight hiss from about 0,5 bar below set pressure, but I can live with that, since my operating pressure is set at 1,5 bar and the set value of the safety is 4 bar.

All I need to know is that the valve seals properly at working pressure and opens reliably when needed. And since this material cannot corrode, it can't get stuck so that should be OK.

EDIT: took out the ball after the first test, where I let the safety blow continuous for about a minute, and I saw zero deformation or damage to the ball-valve.

Steamed for 1 hour, which passed with zero leakage from the valve, and took the ball out again. Still zero deformation.

I am currently using the 5 mm ball, which is same size as the original steel ball.
I ordered additionally a 6 mm ball, which should result in a bit more of a "high lift" characteristics. Will test that too, to see if there is a difference in opening and closing behaviour.

But so far, I am absolutely convinced that Grafi-Sil balls are a safe option for use as safety valve in low pressure boilers (opening pressure 4 bar).

[rhavrane]

Bonjour,

Just for information, most of my safety valves are like these ones : https://youtu.be/if7rpSANj7g

However, I have also successfully tested a more than 100 years old one :  https://youtu.be/W7pxeN_leUk

[1967Brutus]

Good info! One of these days I will make a vid detailing the Microcosm valve.

[1967Brutus]

Meanwhile, I noticed something I did not really like...

The pond that my boating club uses, has pretty dirty water. Normally after an evening of boating, there is a pretty dark brown smudge on the hull around the waterline.

Ravika Putri now has about 6 or 7 hours of steaming with the functioning cooling water pump, and it has been working pretty much flawless, but non of that runtime was done on the club pond, until this evening.

I launched the boat, and after about 10~15 minutes I saw a whiff of steam from the condenser at full speed. Brining the boat in, the cooling water flow had reduced to a trickle. I checked the intake strainer and it was clean. So it has all appearance the condenser coil clogs up.

I could blow it through, restoring the flow again, and the remainder of the fuel the waterflow remained acceptable but reduced visibly.

So... water quality apparently also has an effect if heat load is significant... It fouls the cooling surfaces. I really did not expect it to be that noticable...


EDIT: Apparently, the particular dirt in that pondwater is pretty water soluable... I put the boat in the Lab test basin (AKA my bathtub ) and to my surprise the restricted flow restored itself in about 2 or 3 minutes of flushing. The pump slowly dropped in RPM, while the flow simultaneously slowly increased. I did not see any visible dirt come out.

[1967Brutus]

I launched the boat, and after about 10~15 minutes I saw a whiff of steam from the condenser at full speed. Brining the boat in, the cooling water flow had reduced to a trickle. I checked the intake strainer and it was clean. So it has all appearance the condenser coil clogs up.

I could blow it through, restoring the flow again, and the remainder of the fuel the waterflow remained acceptable but reduced visibly.

So... water quality apparently also has an effect if heat load is significant... It fouls the cooling surfaces. I really did not expect it to be that noticable...


EDIT: Apparently, the particular dirt in that pondwater is pretty water soluable... I put the boat in the Lab test basin (AKA my bathtub ) and to my surprise the restricted flow restored itself in about 2 or 3 minutes of flushing. The pump slowly dropped in RPM, while the flow simultaneously slowly increased. I did not see any visible dirt come out.

1,5 month later, I can report that this phenomenon ("clogging" of the condenser) has not returned, in several hours of steaming, both on the club pond or other places.
Water consumption has DRASTICALLY reduced from 3/4 of a litre to about 100 ml tops per outing. I haven't had to use the distiller plant for ages now.

So far, I do not see any signs of the boiler fouling, or other malfunctions due to the re-use of condenser effluent for feedwater.
Although I try to maintain the habit of bringing in the boat every 15 minutes or so for a quick check of boiler and feedwater level, but basically the installation has become quite literally a matter of "fire up and forget".
The very simple variable timer linked to the steam valve has proven rather accurate and reliable: the other day I sent the boat out with the usual 60 grammes of fuel, and went about fairly conservative with the steam valve, and the result was about 2,5 grammes remaining when the counter hit zero, after a 1 hr 10 minute run.

The Grafi-Sil valve does an excellent job as a safety valve, entirely leak-free.

EDIT: Engine and boiler runtime is now nearing 77 hrs. Which roughly means that 4,6 kilograms of fuel have passed the burner, roughly 77 kilogrammes of steam have been generated, and the current feedpump with its modified Futaba S9254 servo has now about 27 operating hours (the original Regner servo only lasted about 5 hrs). About 120 ml of cylinder oil, and maybe 60~70 ml of engine oil have been consumed...

[DBS88]

Well done on a great piece of steam engineering and for the detailed updates, from which I have learned a lot, so thank you

[1967Brutus]

Well done on a great piece of steam engineering and for the detailed updates, from which I have learned a lot, so thank you

You are very welcome!

Hope to see your results one day.

[1967Brutus]

Meanwhile, the boat gradually started to produce more and moref noise when running ahead, which I expected to come from either the crossheads or the Stephenson arcs: crossheads are asymetrically loaded, the arcs are most of the time in one position, so those were my first suspects.
It did not surprise me (it's a "cheap chinese" engine after all) but it worried me a bit, because my possibilities for overhaul/repair of the engine are limited

Today I took a soundrod went over the entire installation, listening to tocs, rattles and other noises.

Great relief to find that the noise is somewhere in the universal couplings or the propshaft, the engine is running as smooth as silk WRT mechanical noises. No measurable wear on the arcs, no detectable lateral clearance in the crossheads or guides, no sloppy conrods, no audible difference between fwd and aft cylinder. Not bad for close to 80 runhours in less than 14 months. Wick-feed lubrication, I can recommend it!

But jeez... Now the task of figuring out where that noise comes from...