Model Boat Mayhem
The Shipyard ( Dry Dock ): Builds & Questions => Steam => Topic started by: Bernhard on February 24, 2019, 11:17:57 am
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Hi,, Any have one of this steam engine made in China by Jin...and if,,,are the nice good runner
https://www.ebay.co.uk/itm/New-Vertical-cylinder-steam-engine-Live-Steam-Q3B/151929825195?hash=item235fb927ab:g:paUAAOSwUdlWgAyA
Regards Bernhard
Admin: New Vertical cylinder steam engine Live Steam Q3B - £348.00
(https://i.ibb.co/d7fzFRh/s-l1600c.jpg)
(https://i.ibb.co/qCZR3Mz/s-l1600b.jpg)
(https://i.ibb.co/HzN98kR/s-l1600a.jpg)
(https://i.ibb.co/0QLzw5S/s-l1600.jpg)
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Looks like a copy of a Hemmens engine. But can't say how it runs.
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:-)) Yes .. Max2 red one,, ,, i have ordre 1 from china,,,but i cant find eny on running on youtube,,
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Well I just joined the forum so I can post almost the same question. I am taking a little gamble that Jin at Microcosm is making a good product and I just ordered this steam plant shown in the photos below. It seems like a very good value. The 2 cyl slide valve is spec'd at 12mm bore and 13mm stroke. I spoke to a man in Florida who has the engine (he called the M29, but I don't know how) and says it runs very smoothly. But I think Ed is using just air, so no word about the steam plant as an entity. The boiler is 80mm dia x 120mm L. Jin says it operates at 2.76 bar. It holds 420 ml water, and I don't intend to add a feed pump so it's just a guess right now as to whether I will get a decent run time (10 minutes I hope) from it on my new boat. This will be a 50" strip-planked shallow draft hull, originally designed for RC sailboat (Google Tippecanoe T50) but I will add full length keel/skeg and a barndoor rudder.
I don't know how long this engine has been in production and it differs from the others in this post, but if anybody has opinions or experience with it I would love to hear it. I have not much steam experience (I'll tell about my Mildura in a separate post) so I am taking a guess that this engine will be suitable for the launch I am making. Cecilia will be light weight and easily driven, and I bought 60mm 3-blade prop for her....so ....I better get busy and build it.
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Nice looking plant. I haven't tested any of Jin's engines, so can't comment on the quality. The boiler capacity of 420 ml doesn't seem to great for such a big engine.
Raphael from France has some of Jin's engines, including one like yours, and has put up a few videos on Youtube. You could ask him if he's pleased with it.
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Bonjour,
I have the first version of this steam plant in a tug : https://www.youtube.com/watch?v=TO16806-3pM (https://www.youtube.com/watch?v=TO16806-3pM) I just changed the oil lubricator because I did not like its initial position out of the steam flow : https://www.youtube.com/watch?v=AOgJV8Xc7qU (https://www.youtube.com/watch?v=AOgJV8Xc7qU), I siad that to Jin and I see he has taken my remark in account. Running at 1,5/2 bars (20/30 PSI) https://www.youtube.com/watch?v=WbSYRWHUCds (https://www.youtube.com/watch?v=WbSYRWHUCds) I have an autonomy of about 20 minutes and I like using the whistle O0
I also have an oscillating machine in another tug : https://www.youtube.com/watch?v=vutlswFW4X4 (https://www.youtube.com/watch?v=vutlswFW4X4) and it has a little problem with a piston axle which generates a steam leak.
The difficulty with China, not only with Jin, is after sales. if you have to return a product, it costs a lot...
Oh, I also have this funny accessory :-)) https://www.youtube.com/watch?v=as0Ct_MQ9_8
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hi Got the q3b from China,,looks and feel ok a heavy small engine,,so try it on air first,,no revers works,,and i try to find the timing,,have to email Jin,,and a few days got the timing,,so ,,works with very slow revers,,so try on steam ,,30 psi,,no revers,,and after a few minuts it stop,,have to open it ,,one piston vas lose,,
I had to separate it to correct the error..and on steam again,,run a few minuts,,now the other piston get loose,,I had to separate it, to correct the error again,
but no revers only very littel,,and the engine eat the steam fast,,i email Jin,, he sai that the engine have that construction there so it have not the same,,speed on revers,,i have get enof and spend times on this ,,so i didnt wont it,,Jin said i can send it to Rafhael in France,,he did a test,,and sai the same,no revers work,,
so i got a full refund from Jin,,only it have cost me 22 us to send it to france,,i have ask him to send that 22 back,,let se if he do that,
Regards Bernhard
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Bernhard's story of his bad time with the Q3B engine must have a been a disappointment for Bernhard a well as Jin. Good to hear at least there was an honest refund. But it is worth a little follow-up to see what went wrong? Sounds like Bernhard knew what he was doing to fix things but it just got out of hand so maybe Rafael can tell us what really was the problem and could it/did it get get fixed?
I am interested because I have one of Jin's 2 cyl engines coming in the mail to Hawaii, and I do hope it will work, because I have no help here, and very little steam engine experience. This thread started out talking about Bernhard's engine called Q3B (10 x 12) and I changed the subject a little by asking about Jin's 2-cyl steam plant which I believe has the M29C (12 x13) or later. Sent photos. These are different engines. So I hope mine will not experience the same troubles.
Rafael posted a video of what looks like M29 going very nicely and although I don't have translation for any of the audio except Bonjour, I think he is happy with what it does. Any other info about this engine and steam plant is appreciated.
Carl
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THANKS Carl..all the videos i have se om youtupe show that the engine you have ordre run strong and Nice.. it was the design on this engine..like Jin sai..
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Bonjour,
Sorry Carl, my Englsh is too poor to make good videos in this langage and there are already good English videos but none in French ok2
I have not the M29C but this steam plant http://www.microcosm-engine.com/new-twocylinder-steam-engine-live-steam-with-steam-boiler-with-p-214.html#.XJ1IlZhKjIU (http://www.microcosm-engine.com/new-twocylinder-steam-engine-live-steam-with-steam-boiler-with-p-214.html#.XJ1IlZhKjIU) and I confirm I have no problem with it, as shown in my videos. Jin sent me the broken parts (water level foot).
I have checked the mechine sent by Bernhard and confirm what he says, there is no reverse. The problem with this machine is that, in its conception, you can not open the reverse box to see if the axle, very accurately machined besides this,correctly or not aligned in both directions face to admission holes in the cylinders. This axle is cylindric and it has a small flat (1 mm depth) which is supposed to make the steam transfer from the pipe to the cylinders on one side or another.
The displacement between forward and reverse is 4-5 mm, the maximum speed id found on less than 1 mm so if there is as I guess it any mistake of 1 mm, the admission does not correspond and the result is teh one we note.
I am not a specialist but I have a significant collection which let me say that the conception of this machine is very original and does not allow any tolerance. As it can't be dismounted, if it is not tested before packaging, the result is a lottery and Bernhard lost.
Jin pays back when he knows that the buyer is honest, this is why he asked Bernhard to send me the machine, and unfortunately for him, some buyers are not like Bernhard and ask their money back for false reasons and keep the products.
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Raphael General Question.
Does Jin test his engines before sending to buyer.
George.
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Hi All I dont know about the engines but find crucial info on the boilers sadly lacking with no mention of tests performed eg hydraulic ,steam also is there a boiler certificate ,I am not suggesting poor quality however it is a substancial investment and I would expect more detailed information.
Steam Boiler Models For Marine Steam Engine
[/size] [/size]
[/size]The machine is Boiler exhaust pipe containing boiler full height 200mm diameter 80mm length 120mm, weight 2.6KG, valve pressure 0.5MPA, boiler capacity 420ML.Boiler surfaces using high-temperature paint, wood inner use insulation materials. Insulation can play a very good role. Steam output pipe modification of the heat recovery unit. Increase thermal insulation.
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Bonjour George,
All the products I have bought to Jin were brand new, so I think they are not tested. If they were, the brass would be tarnishedan customers would say they are used...
About boilers, I have not received any hydrolic test certificat with them, but they are not mandatory in France if the boiler contents less than 25 liters, this is perhaps why (I doubt).
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Simple approach here, we have eBay comms to Jin and will ask him the test questions: (I better do it any case before I run the engine!!)
1) Is the boiler pressure-tested to at least 10bar? (That's 2x the advertised valve pressure, standard safety factor). 2) Has the engine been seen to run for at least several minutes, in both Fwd and Reverse? (Specify by compressed air or live steam) 3) Is the safety valve set to a known psi/bar value; if not what is recommended? 4) Is the P5 gas flow adjuster (attenuator) been set to a recommended value? Of not, what is recommended? Finally, does your factory apply a "QC" label to the product that tells the consumer that the item is inspected and conforms to specifications? If not, why not?. These aspects of manufacturing the Microcosm products will save cost, not add cost, because scrap and returns will be eliminated.
Just a reminder to see the truth of this-- 20 years ago the USA automobile business took a huge nosedive when it started making junky cars which weren't tested and didn't work. Japanese manufacturers were quick to hit the "Total Quality" button and their cars sales were killers because people like cars that work. I'd think same true in China, and Jin seems enterprising and smart and if he is sending untested, nonworking junk that comes back not working, we won't be hearing about his company for long. Note I say IF: I expect my Microcosm M29 to be stellar!! Off the soapbox, sorry.
Carl
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I own the QB3 engine.
If I well rememver, I was the first buyer of this engine as soon as it appeared on Ebay with an "auction" listing.
It was probably well timed and well tested, at least on compressed air, before putting it on sale. My engine runs as it should and reverses as it should.
I am sorry to read some rightful complaints.
A timing instrution leaflet included with the engine could avoid the Calvary of sending the engine back to the factory thousands miles away with all related problems.
Jin has occupied a void place left with the gradual disappearance of many steam engines firms, mostly from the UK, flooding the market with his engines and accessories, some of them, at a ridiculous high price.
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Made my day today-- I received (with Free Shipping if you can believe it) my M29 complete steam plant from Microcosm today. :-)) It was well protected and made the transport OK and wow it is nicely made! It is exactly as shown in the photos I posted previously. No detectable flaws or sloppy stuff. Excellent machining all around. I need to study and set up a little, and clarify some of Jin's instructions but when I fire it will post the results. I hope to be as successful as what Rafael showed us on You Tube.
I did ask Jin about the pressure testing of the boiler, and whether the engine has been seen to run in the factory before being shipped. It sure feels good to my fingers. Will post answers if received. One quirk; the little 2" dia, refillable butane tank has no "feet" or cradle. No problem to make something, but what a strange thing to leave off... oh well, keep that price down!
It does seem as if Microcosm has made a bid to be a premier supplier of steam engines 'round the world.
Carl
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Hi All as I belong to one of the largest model boat clubs in Aus The St George Model boat club Sydney ,we have had a few members in early days of Chinese imports engines particularly the cheaper oscillating type suffering sealing problems and excessive steam usage ,fortunately the quality has improved greatly over last few years and have personally purchased from Jin and been very happy with the quality,however there are new kids on the block in China so proceed with caution.Cheers
John
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Bonjour Carl,
I wish you will be as happy with your steam plant that I have been with mine. As you will measure it, the autonomy "for me" is low (<= 20 minutes) but this plant operates very well at about 1,5 bars (22 PSI). Powerful, it allows easily a large 4 blades 2,5" (68 mm) steam pitch propeller as shown in one of my videos (sorry again, in French)..
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There were a few questions to pose to Jin at Microcosm concerning the testing and verification of the boiler and engines there. I asked these questions:
[/size]- Is the boiler pressure-tested to at least 10bar? (That's 2x the advertised valve pressure, a standard safety factor). I really am afraid to pressurize the boiler if it has not been pressure tested. (I do not want to be the tester!)
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[/size]- [/size]Is the safety valve set to a known psi/bar value; if not what is recommended?
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[/size]Jin's answer:
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[/size]"[/size]The boiler we have tested can reach 10BAI pressure, the working pressure of the safety valve is 5 kg."
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[/size]This sounds to me like a design verification test not a quality test on each unit. But there is no clarification. Note: The boiler is normally operated at .25- 3 mPa so IMO the tested safety margin is pretty high.(Not sure why he calls this kg. The pressure gage reads 0-.5mPa. I assume 10BAI means 10kg)
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[/size]I also asked several other questions, including whether the engine had been operated in a bench test, with no response.
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[/size]- Carl
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I am happy to report total success with the steam plant I received this week from Microcosm. :-)) I already mentioned how nicely it is machined, now I can say how nicely it operates! Hooray for Jin!
To start the operation, I tightened all the fittings, added oil, lube, water, and butane mix to the new Microcosm M29 steam plant, and lit it on the chimney, first try. Five short minutes later a beautiful little steam engine was humming along like a sewing machine! Oh my, what joy,
When I first opened the steam valve just a bit, there was no water head from condensate at the start; the engine started turning over immediately. After the initial few slow rpms, I opened the steam stopcock full and did all speed control with the RC steam valve you see in the photo. This is basically “out of the box” or “plug and play” and it was a wonderful experience. I will make a video. Most impressive is the wide speed range and control with the RC valve. Perfect Stevenson reversing even at very slow speed. Goes like mad at full steam, or barely clicks over at low steam...unbelievable. The P5 gas regulator is a gem—very sensitive and responsive; gas flow changes instantly when the rpms increase or decrease. (How do it know???). At the start before steam was up, the flame was howling; when being regulated at slow rpm, the flame goes down to a whisper. It really works, and was adjusted perfectly, so I am not messing with it!
The boil came up to 40psi in 5 minutes, and the WP stayed exactly at 30+psi the entire run, no matter the speed. I ran it for 25 minutes non-stop or until I thought the water was going off the sightglass. When I shut off the gas, the engine ran for a full 5 more minutes on the existing head of steam. The butane tank used only an 1.2oz of fuel, (about 1/2 its capacity), and although the tank did chill to 50F the flame never complained, so heating the fuel tank seems not required. Needless to say I am way impressed and happy as I can be. Better quick build that boat for it!!
The only issue is that the pressure gage on the unit vibrates very badly on its springy siphon tube. (Just like Rafael’s YouTube video, no surprise there). I intend to replace it with a ¾” gage on a short U of a siphon and it won’t shake.
These photos show the gas regulator in its original configuration. I needed to reduce the footprint of the steam plant so it will fit in my planned boat, so the other photo shows the regulator tucked in close by positioning it above the burner. This way the fuel tank can nestle in close and everything will fit my layout. Adjusting the shape of the copper tubing was very easy.
I will have to say that Jin's english translation of the instructions is pretty hard to understand. I have limited experience with live steam, but without the little I have, this would have been impossible. I am lucky to have a coupe of capable mentors on the forums. And thanks for Rafael's good wishes which came true.
This little engine is a beauty and I’d recommend it to anyone.
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[/size]I will post a video when it is available.
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[/size]-Carl
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Well that’s really good to hear I’m glad your happy with the plant. I’m looking forward to seeing your video :-)) Just out of interest what are the dimensions of the motor?
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Looks to be a very neat setup ,my only query is the gas regulator which I can only assume it works on hydraulic pressure as there would be very little steam at the bottom of the sight glass , also you may have to modify the gas feed from the tank so that it can be refilled out of the model.Cheers
John
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I wondered about the pressure side of the regulator, I agree no steam there but since there is no way to bleed the air out of the pipe going to to the regulator, there must be air in there? I guess the air could be bled by loosening the nut at the entry, but I didn't do that and the thing works fine. I will ask Jin if there is a procedure here. He did send spare diaphragms for the regulator, but no explanation of when they should be used, or for which side of the regulator
You can see the wood platform which is epoxied to the bottom of the fuel tank. The tank platform will sit in the boat on studs or with a clamping screw, and be easily removed from the boat for gas refill, once the pipe nut is loosened and the tank can be lifted out.
Mark T, the dimensions of the engine are 4 3/4" L from steam entry to shaft end; 3 1/2" W not counting the exhaust pipe, and 4"H. The overall length of the steam plant w/o the gas tank is 12 1/2". Tnere re some good photos pf the engine on Jin's eBay page at
https://www.ebay.com/itm/New-Two-cylinder-steam-engine-Live-Steam-with-Steam-Boiler-With-P5/152507501223?hash=item238227caa7:g:O34AAOSw~CFY7Zsw&frcectupt=true (https://www.ebay.com/itm/New-Two-cylinder-steam-engine-Live-Steam-with-Steam-Boiler-With-P5/152507501223?hash=item238227caa7:g:O34AAOSw~CFY7Zsw&frcectupt=true)
I just found (I wish I had seen it earlier!) Keith Appleton's informative and objective video on this engine, He shows it running smoothly on air, and has quite a few comments --mostly very favorable. I don't know the date, but he shows the M29 engine in detail. Since then, the oiler body is now made from glass, and all the slop in the revering lever is gone. The video can be seen at --check it out!
https://www.youtube.com/watch?v=lgg7YEf_X5g (https://www.youtube.com/watch?v=lgg7YEf_X5g)
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Thanks for the dimensions much appreciated :-)) As for the air in the tube - you need that. Its a buffer between the very hot steam and the diaphragm. Just set the pressure as you need it and don't worry about the air compressing as this would be accounted for when you set the pressure.
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https://youtu.be/mlnAdeo1dYw (https://youtu.be/mlnAdeo1dYw)
RUNNING ON STEAM,,,
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The principle is to mount a siphon to make an air cushion in order to protect the membrane from excessive heat. That said, I often install gas regulators against my boilers without any problem as you will hear it, for examples: https://www.youtube.com/watch?v=JdRwDXVLJIA (https://www.youtube.com/watch?v=JdRwDXVLJIA) or https://www.youtube.com/watch?v=utYZJDJPBVg (https://www.youtube.com/watch?v=utYZJDJPBVg)
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hi Got this Steam engine in trade with a friend yeasterday ,never be under steam so brand new, m29 with feed pump m5,,
so did try it under steam,have to solder one corner on the exhaust,,ajust the feed pump gear wheel and bigger o ring in the pump.tighten a few screws,,
it look to be a very well made engine,,nice size,run fin,,on 20-30 psi,,so a short video of it running,,
https://www.youtube.com/watch?v=vQkWtm01iiw&feature=youtu.be (https://www.youtube.com/watch?v=vQkWtm01iiw&feature=youtu.be)
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Runs nice but seems to have too much end play in the crankshaft 2.22 in the clip.Cheers
John
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ok.Thanks. i will look in to it later.
Did 2 small handle,,and som cooper pipe
ready https://www.youtube.com/watch?v=W9asddYBMr8&feature=youtu.be (https://www.youtube.com/watch?v=W9asddYBMr8&feature=youtu.be)
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What’s the build quality and usability of this motor compared to a TVR1A now you’ve had a chance to play with it?
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Im a big fan of tvr1a...have be used them for years,,look so good,,and a nice size to,and eny problems,or parts Robert from Graham have be so help full,,,but this engine run and look just great..made of brass and stainless steel,,look to be real well made,,much better than i think it was,,hex bolt to,,all in all to now, im very happy for this,,so lets see in time to come..and the price is not easy to beat,,
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The Microcosm-Engine M29 Steam Plant I received last month started right up out of the box, and as I reported, it is nicely made, and runs like a top. Now I have posted 3 YouTube videos and you can watch it in action.
https://www.youtube.com/watch?v=JEA3t3CWsVA (https://www.youtube.com/watch?v=JEA3t3CWsVA)
https://www.youtube.com/watch?v=FwkxCU-JyTI (https://www.youtube.com/watch?v=FwkxCU-JyTI)
https://www.youtube.com/watch?v=vdB1VIzt-Sk (https://www.youtube.com/watch?v=vdB1VIzt-Sk)
I noticed some improvements to the M29 steam Plant since Roy Burton posted his M29 video in Sept 2017 (Posted in this thread by Bernhard). Mainly, there was no need to rebuild the engine! For instance The cylinder cap has 5 bolts now, not 4; the oiler has a see thru glass body; and importantly Jin has added the "P5" gas regulator which you can see working in these videos.
Later this week I start building the boat-- the planks are in the mail!! I will start a build log of the launch Cecilia.
Carl
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Seems to run very well.
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Well 2 1/2 months since I got started on the steam launch Cecilia. The M29 steam plant works great on the bench; the only thing I did with help from George in Scotland, was switch out the pressure gage for a miniature gage sold by Clevedon, and now it has a much shorter and non-shaky syphon tube. (photo) Now she is just about finished ready for the final RC hook-up and the first launch under power. Maybe in the next couple of days there will be a video to show!
For now, have a look at a few pictures of the boat's creation, starting with the hull planking over a "strongback" that was previously used to make a Tippecanoe T50 sailboat. Western red cedar planks (although very blond) laid up then costed inside and out with epoxy. The transom construction was modified to adapt a "draketail" transom which I think makes this launch unique. Deck ply was epoxied over carlins, then the cockpit cutout was made and the laminated coaming inserted. The 1/16" okoume plywood deck was over-planked with pine and mahogany. Final touches outside are the coaming caprail and the toerails at the gunwale. Looks pretty realistic!
The keel is 1/4" ply and has the stuffing tube embedded. The prop is 60mm and the rudder should have good command. Making a powerboat out of a sailboat hull is not an everyday thing, bit I think it will work. My one photo at this time of the side view is not a very good shot, sorry.
Inside. the M29 plant sits midships on two pine stringers. The removable butane tank is at the forward end. Floorboards are mahogany and satinwood veneer laid on balsawood. The seats are leather upholstered and will be completed with upholstery "tufting" next week. A little steering station aft adds detail; it will have wheel, compass and barometer. The RC servos for the steam control and the Rx are mounted to the underside of the rear seat (nearly invisible) and the battery pack in under the foredeck.
The hull is unpainted now (it is epoxy coated at present) until I see how she looks underway. The bootstripe is temporary white tape, but it is where the waterline lies at 1lb displacement-- a float test confirms this.
One day I'll make a build log with details. Meantime have a look at Cecilia (named for my Granddaughter in Maryland; the inspiration for the draketail)
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Having a little trouble exporting these photos. These relate to my previous post
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Here are the remainder photos (whew!)
-Carl
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I couldn't resist.
BTW, this guy sets the scale of the model 1:8. He is 9" tall. This would make the LOA of a fullscale Cecilia at about 35'.
-Carl
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Bonjour Carl,
Beautiful launch indeed, and I am jaleous of your crew :} With such a thin hull, you won't need more than 20-30 PSI to navigate gently and save autonomy. Which propeller did you choose ? For my one, a 2,75" 4 blades Propshop, operated very easily at the pressure mentioned :-))
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:-)) top..
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Thanks for compliment Raphael. The prop for this boat is 3-blade 60mm made by MSM for Caldercraft. I may one day upgrade to 4-blade from Propshop; I have a 70mm from them for my larger launch (has Mildura twin cylinder steam plant) but I have not installed it yet. Certainly is thing of beauty,
I was just in Paris, cruised Seine to Normandy- what a lovely time. I should have thought to give you a call! Sure had great food! I loved Giverny! Took one thot that does a little justice to Monet
Best,
Carl
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Here's a teaser clip of Cecilia scooting on her maiden water trial steamed at 25psi on Microcosm M29. A few scale details to add, and bottom to be painted, but here is the proof that the LWL is Ok and the boat moves out! Fwd/reverse/speed control all perfect. Ran 15 minutes and stopped, still had fuel and water.Thank you Jin for the steam plant! And Tippecanoe Boats for help on the boat.
All up wet weight is about 11 lbs.
https://youtu.be/BsD9RT427rA
Carl
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The hull looks beautiful! How does the steam plant perform? Is it capable of more speed? Are you happy with the quality?
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Bonjour Carl,
Which propeller have you installed on your launch ? With which pressure do you operate ?
My tug "Vient de loin", more big-bellied, seems more efficient with the same plant at 2 bar with a 2.5" four blades Protean Design propeller.
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Cecilia's Microcosm steam plant which has a steam attenuator installed (which works beautifully) operates at 25psi in this video. It is turning a 60mm cast 3-blade bronze prop made by MSM (sold by Caldercraft) There doesn't seem to be much point in making the boat go faster. But I am changing the prop out to a 4 blade PropShop scale steam prop.
Since I posted the "teaser" clip, I made a 4 min movie of the boat on her trial launch and here you can see her performance and maneuverability. Not sure how she would go in a stiff crosswind. But it sure looks like a boat needing passengers.
https://www.youtube.com/watch?v=uUr8T3N7SWE&feature=youtu.be (https://www.youtube.com/watch?v=uUr8T3N7SWE&feature=youtu.be)
I think of this as a success for both the boat design and the steam plant. I did have a lot of help.
In line with the original subject of this thread, yes I am very happy with the quality and performance of the Microcosm steam plant. It worked "out of the box". Just don't be expecting detailed operating instructions. I think you can trust whatever you buy from them.
Carl
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Bonjour Carl,
25 PSI :-)) :-)) :-)) I like using the largest possibe propellers not for speed but for a gain of autonomy, I experienced it, this is why i mention it : https://www.youtube.com/watch?v=TVl2NCWmyXA (https://www.youtube.com/watch?v=TVl2NCWmyXA)
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Time for a Cecilia Update and a plea for a little help. I did indeed change out the prop to the PropShop 4-blade and yes it made a huge difference: the boat is now a rocket. Remember this engine is the stock M29 plant from Microcosm. I have completed the boat with her name graphics and canvas canopy, and got a few minutes of video and it's fun to see her go at:
https://www.youtube.com/watch?v=p6Ycsc_CzSY (https://www.youtube.com/watch?v=p6Ycsc_CzSY)
The rudder is twitchy you can see, and the operator needs a little practice on using less tiller, and maybe not so fast all the time. I am enjoying this model even in the confines of this little pond. Te zig zag you see was a rool test and the boat handles ok.
Of course I could not see the steam gage while the boat is going, but my guess is the WP is about 30-40psi. I do not think the 5 gas attenuator was working correctly to throttle the flame down. Leads to me next question--
But now about a little help, please. I think in the down time of the engine, something got sticky in the P5 attenuator valve. When new, it shut on and off with the smallest change in boiler pressure. Now it doesn't seem to turn off at all. I changed the adj screw both ways and the pressure simply kept climbing. Seemed like the valve is stuck wide open. (Need to adjust the safety valve too!)
So I have two questions-- Jin cannot answer because China is all "on vacation" during the virus epidemic and I think maybe his shop is closed. This seems like a basic Q, but which way do I turn the adjustment thumb wheel to make the valve operate at a different
pressure?) You can see the thumb screw in the photo below--red arrow pointer. 2nd Question-- I can take it apart OK, but if it ain't broke don't fix it. So does anyone else have experience. or suggestions about the P5 valve? Any tricks to be learned?
Appreciate any help
-Carl
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Bonjour Carl,
I have several Microcosm attenuators (I call them gas regulators) and I have had litlle problems with them. At first, their membranes :
https://www.youtube.com/watch?v=aU37YAuOkKM (https://www.youtube.com/watch?v=aU37YAuOkKM)
I also changed them with 0,5 mm nitrile ones : https://www.youtube.com/watch?v=5JUTaTuS-N0 (https://www.youtube.com/watch?v=5JUTaTuS-N0)
My procedure to adjust it :
- I close the little the idle adjustment screw ==> warning, it is VERY sensitive and a few degrees open change everything
- I unscrew the large spring which controls the pressure until it becomes almost loose, but not loose, the more it is unscrewed, the less pressure is needed to regulate
- I start the heat ==> in this configuration, I noticed that generally the gas stops at about 30 PSI ==> that shows the regulation operates (or not)
- I loose pressure with the whistle ;) and fire again to adjust the idle adjustment screw ==> VERY sensitive !
- I screw or not the large spring if I wish more pressure before regulation, but personnally, I like 30 PSI.
Example on a single membrane one : https://www.youtube.com/watch?v=7iE1wBIhKUc (https://www.youtube.com/watch?v=7iE1wBIhKUc)
The result : https://www.youtube.com/watch?v=Gc8bITIar2U (https://www.youtube.com/watch?v=Gc8bITIar2U)
I hope this will help you and do not let me know if it does not work for you.
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Raphael this is most helpful. Merci Bien! I'll try once more with steam up and see if I get some regulation of the gas flow. I see your video with one of the P5s taken apart and replacing the membrane; I just wish there were an English translation. But it is OK to watch and I think if I have to take it apart I know what to do. Adjusting the idle flow screw is the only question: I have made small adjustment there once, but are you saying as part of the P5 pressure adjustment that the idle screw should be fully closed? Then after the pressure is regulated (30psi is perfect), I open the idle screw to the low-flame position.
Maybe the idle screw is open too far already and that's why it seems like the gas adjustment is not occurring. I did not think about that.
In any case the several steps you describe in your post are very helpful and I really appreciate your writing all down. Knowing which way to turn the thumb screw is the most important! Jin's instructions are not very descriptive.
Thanks again
-Carl
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Bonjour Carl,
Thank you ! About the idle screw adjustment, as it is very sensitive on a few degrees, it is very easy to let it too open as you mention it.
This is why I start by closing it to be sure the regulator operates on this point because there are two parameters to manage, the idle and the pressure with the large spring and it is very difficult to manage these two parameters at the same time.
Sorry about the French langage in my videos ok2 , but I confirm it is very easy to open and close the regulator to check the membranes, you jut have to be careful when you screw it because the screws are very thin, I hold my screwdriver with two fingers :-))
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To be fair on Raphel, if you click "subtitles" on his "youtube" videos and then change convert to UK in settings -it's not perfect but most of the meaning is translated into English!
Se bon Missueur? in my worst french!
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Bonjour,
C'est bon monsieur RST ok2
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Reading back over the early days of this thread, which started out as discussion of the Q3B engine from Jin, I see not only did we discuss the Q3B, but the TVR1A gets a mention as well as our experiences with the M29. I'd like to back up a little and ask about experiences with the TVR1A and the smaller Microcosm engines Jin calls the M2B and the M36. My real question is whether anyone has run either these and what working pressure they might require to power a 1m, 14.5lb boat. Or perhaps I should say, would they work for such an application using a 2" dia. boiler??
I assembled a TVR1A and thought it would be OK to run such a boat using a Miniature Steam Models (MSM) 2" vertical boiler. I had very modest expectation for the runtime (autonomy) of the steam plant at 10 minutes. But the boiler was able to keep a sustained WP of only 8 or 9 psi, and while the boat moves along ok as you see in the video, the performance in my opinion is very marginal and I intend to switch out the 2" boiler for a 3" boiler and be able to have a wide speed range and possibly a steam whistle. The boat has a 2.4" 4-blade prop, and looks like this in her partially completed form
Here is my launch RIVAL on her maiden run in a small pond. Run time about 8 minutes. I had only RC rudder control, so speed and reverse are not included yet. I will say this certainly appears to be a scale-like speed.
https://www.youtube.com/watch?v=SxfB2gCK8ng (https://www.youtube.com/watch?v=SxfB2gCK8ng)
So this leads me to wondering the best thing and boat to utilize the 2" boiler? It looks like a smaller oscillating engine is the best candidate. I find 6 possibilities, as you can see on the attached comparison table. I like the MSM Clyde but MSM won't commit to saying it will run adequately on the 2" boiler. If I have to use oe of the smallest 8 x 11 engines, I'll have to build a much smaller boat!
I'm interested in experiences with any of these small engines knowing they are to be steamed from a 2" boiler.
I hope the photos are in the right order...if they appear at all (they are not appearing in Preview)
Thanks for any comments
-Carl
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Nice boat..I never go faster with mine boats . Why not just get a small waterpump in..elpume from regner from De they make great working , very small One..
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Bonjour Carl,
Based on my experience, your launch could operate with a 2 cm3. And for comparison, here are the French manufacturers sites for products ans prices :
- Anton : http://www.anton-vapeur.fr/ (http://www.anton-vapeur.fr/)
- JMC : https://www.jmc-vapeur.fr/ (https://www.jmc-vapeur.fr/)
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aaa
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Rafael thanks for the comment--
I am not familiar with the exact science of the engine displacement; I've been comparing engine size by looking only at bore and stroke, but the volume in cm3 makes terrific sense. I found this little tool on the internet that shows me when you say 2cm3 what size engine that might be.
https://spicerparts.com/calculators/engine-displacement-calculator (https://spicerparts.com/calculators/engine-displacement-calculator)
Thanks for the leads to Anton and JVC, I haven't looked there for these engines-- for one reason they are pretty expensive.
Can you comment on the general differences in comparing a slide valve engine to an oscillating engine, assuming they are about the same displacement?
When I substitute the 3" boiler here, I'll have the 2" boiler as an "extra" and it will need not only a new small engine, but a new small boat!
-Carl
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Well this confuses me now. I used that displacement calculator, it says 10 x 10 x 2 cyl is 1.57 cm3. The JMC literature says the JMC-3V which has 10 x 10 bore and stroke is 3cm3. For the JMC-2, the literature says 8 x 10 and 2cm3, but the calculator says this is 1.01 cm3 This is pretty big difference. Can you help me by explaining why these would be different?
for a 10mm x 10mm Displacement is this not: pi x 5r x 5r x 10 stroke x 2cyl= 1570 mm3= 1.57 cm3??? Why does JMC change these numbers? Maybe there is something I do not understand?
Silly to ask, but is there a difference between CC and cm3? (I don't think so)
-Carl
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If the engine is double acting you have to take into consideration below the piston too. It’s capacity is a little smaller due to the piston rod. So your capacity calculated x <2.
Jerry.
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Carl.....just a word of caution with that calculator .app below..........
.....it appears to only consider single acting volumes .......being the bore x the stroke x the number of cylinders in either Metric or Imperial end result
One of the difficulties with double acting engines ....it is not simply multing such initial results x 2 >>:-( ....as the actual effective bore diameter or volume of the return motion is reduced annulus area of the piston rod
To further complicate this is to need to understand that the thickness of the actual pistons plates themselves reduces the swept volume on the return motion even though the stroke remains unaltered :-X
Derek
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Ok subtract a tiny bit for the dia. and length of the piston rod lower section, but my question is why does JMC make these claims about the displacement of their Monobloc engines? Is this a marketing license, like poetic license?
-cm
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Here's what I refer to:
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Carl......lets let Raphael [a Froggrie] answer this with the aid of his mate Jean Michael [JMC]....
If you look at the engine you have copied from their WEB site describes it as a Monoblock....and other references indicate that Monoblock can be single cylinder and some as double acting, but no reference to single acting
They do use the term..... "double effect plan drawers".......which I believe may be translated as double acting
I suspect some form of dialect corruption here when the WEB pages were translated as the image you show appears as a twin cylinder engine with eccentric driven plate valving which suggests as double acting and with Stephensons reversing gear
This then rounds out an engine volumetric displacement in this format
Derek
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Yes I hope Raphael will explain. But read on, maybe he doesn't need to: This certainly looks like 2 cylinder double acting slide valve engine. I would assume bore is piston dia. and stroke is the max throw of the piston from top to bottom. I do the math, and yes make slight correction for the piston rod and piston thickness. This reduces the available volume, or displacement, on the down stroke only. Are you saying that my error is that the total displacement is the upstroke volume PLUS the downstroke volume? This totally explains why the JMC displacement number is much larger then just the calculated upstroke volume. This would be the total volume of steam displaced in one 360 turn of the crank, I get it! I think this is what Jerry was telling me.
This is probably so obvious to you steamer guys that nobody believed I had not thought of that. Hah
Ok, now I see further that this does NOT apply to the oscillator engines, since they are not double-acting.
When can I turn in my newbie badge?
carl
PS- I took Monobloc to mean it's all one piece. It seems like a descriptor more than a product name.
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Hi Carl, oscillating engines can be double acting too.
There are loads available.
Jerry.
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I have a couple of steam powered models (Canopus 1899 at 53" Victorian Battleship) which uses a Cheddar Models Puffin with MK1 boiler. The model weights about 35 pounds and sails at a good speed and I get exactly 30 mins sailing before the water runs out.
the other is Velox 1908 destroyer at 65" long - I don't know the weight but this uses a Cheddar Puffin Boiler Mk2 so has about 40% more volume and uses my own designed in line double actin twin oscillator. Maximum speed is a good walking pace and I get 30 mins sailing before the water runs out despite 40% more water and I put this down to the fact the engine is a little bigger than a Puffin and is turning over faster to get me the speed I need.
In general terms I have always understood oscillating engines to use more steam than either slide valve or piston valve. However oscillating engines are much easier to make whereas slide valve/piston valve uses less steam for the same power output. Is this really true or is it that they tend to run on slightly higher pressures and there is less steam leakage? (I read Oscillators are really limited to about 45 psi (3-bar) as beyond this the cylinders just move away from the faces causing leakage. Greater pressure springs could be used but this significantly increases friction so is a law of diminishing returns.
Has anyone actually done a controlled test between the two types?
Cheers
Geoff
Cheers
Geoff
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Historically some full sized oscillators used steam pressure to hold the cylinder to the port face.This allows for higher pressures.The only model one Iv seen is Malcolm Beaks 3 cylinder Paddle engine.
Generally oscillators dont have cut off lap/leed unless they are using the EVT concept or Harry Wedges ideas on porting as found in KN Harris book not the boiler one the other the title escapes me at the moment
From my experience the oscillators are more reliable when on the water although I have a couple of D/A slide valve engines waiting for a hull one designed by Malcolm Beak the MB22 that punches above its weight the other my own design.
Iv never tried to do a comparison but realistically would not think there would be much difference .
An often missed design point for oscillators is to reduce the mass of the cylinder especially around the pivot as the forces cause premature were and tears
From experience piston valves are difficult to get a proper fit and generally become worn quickly the old adage Slide valves wear in whilst Piston valves wear out comes to mind
Just my two bobs worth
cheers
Notes on the EVT concept for oscillating steam engines - By Michael Martin (http://www.panyo.com/oscillators/)
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Bonjour,
a week in the Alpes for skiying is perfect to wash my head :-))
As the langage bareer is always a pain fot me and because I have read lot f right things in the messages, Carl, could you please remind me your question if you have one?
To summarize :
At first CC, cc and cm3 are the same meanings for "centimètres cubes".
JMC and Anton do not build any single acting machine, only double and they can be with slide valves (Stephenson), cylindrical valves (vertical or in Vé) and sometimes oscillating (also vertical or in Vé) .
When I (and lot of people, manufacturers includes) calculate cylinders volume for any machine, we do not take in account the volume of the piston rod we calculate a theorical perfect volume of a double effect machine.
This is why a 8 bore (alésage) x 12 stroke (course) is noted as a 2,01 ==> 2 cm3 machine.
After, the choice of an oscillating or drumstick machine depends on building capacities, money, envy,opportunity... Based on my experience, for a same cylinders volume, an oscilating machine is cheaper but does not appreciate more than 2-3 bar (30-45 PSI) and seems less powerful.
And the most important thing to my opinion is to find the appropriate propeller to have all the benefit of the torque.
I always use 4 (or 5) blades propellers,
examplex: 1,5 - 2 cm3 = 50 mm max; 3 cm3 = 68 mm max; 5 cm3 = 78 mm max; 7 - 8 cm3 = 90 mm max; 20 cm3 = 120 mm :-))
For fun, my smallest baby, a 2 x 0,5 cm3 single acting bi oscillating runabout : https://www.youtube.com/watch?v=B5R6fVEhZko (https://www.youtube.com/watch?v=B5R6fVEhZko)
And I repeat that our boats are overpowerd.
My 16 kilos Fulgerul has 2 x Anton Quartz : https://www.youtube.com/watch?v=3jombigGCM8&t=541s (https://www.youtube.com/watch?v=3jombigGCM8&t=541s)
And my 20 kilos dreadnought Liberté will have these 3 x 1,4 cm3 : https://www.youtube.com/watch?v=So3cXcHA-VI (https://www.youtube.com/watch?v=So3cXcHA-VI)
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Thanks Rafael, I understand all that, translation is excellent.
Did you laugh when I asked about cm3 vs. CC?? I was mostly kidding....
Now I know that to find displacement in a double-acting engine, the volume of the cylinder is almost doubled, once above the piston, once below. So obvious nobody ever said it.
Yes I am installing 3" (85mm) boiler for my TVR1A. I might get a little oscillator to power with the 2" boiler-- but no boat for it, what shall I do???
Á bientôt,
Carl
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Bonjour Carl,
I have to confess that I did not really laugh, you, English people, drive on on the wrong side of the roads and use incomprehensible measures instead of universal ones ok2
And as usual unfortunately, obvious information is often omitted {:-{
let us know your experience with the TVR1A, as a 8 cm3 it is steam consuming and for several of my friends it is fragile. Mine is a BB with bearings ut still it its box ;
With your small boiler, I would kindly suggest you a 2 cm3 machine and a little boat like my launch Antje: https://www.youtube.com/watch?v=xG_hJ9nj5x4 (https://www.youtube.com/watch?v=xG_hJ9nj5x4)
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Bonjour, Rafael, The UK has been metric for many years we just stick to the proper measurement system out of cussedness and even the metric system has its problems
A little light reading perhaps.
http://www.vapeur45.fr/normes-et-regles/113-dimensionnement-du-moteur-oscillant (http://www.vapeur45.fr/normes-et-regles/113-dimensionnement-du-moteur-oscillant)
http://www.vapeur45.fr/normes-et-regles/5-reglementation-sur-les-chaudieres (http://www.vapeur45.fr/normes-et-regles/5-reglementation-sur-les-chaudieres)
cheers
frazer
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Bonjour Frazer,
I was joking ! I'm sure I'm as comfortable with metric measures as you are with imperial ones.
Thanks for the links, but I acquired my knowledge through practice for 12 years and the chance to have a large collection of various boats and machines. I always have a hard time with book theory, especially since I practice with tiny machines at a pressure of about 2 bar / 30 PSI.
In France, officially, only boilers of more than 25 liters have to be certified every year by an independant organism as APAVE, this is why the few scale 1 launches or locomotives or trucks built there have 24,99 liters boilers max ok2 which may be auto certified in their clubs.
Vapeur 45 is a club who has edicted his own rules, more restictive than the previous I wrote because they evoke 2 liters but I make perhaps a mistake, especially bacause I have no boiler of 2 liters, I prefer smaller ones with feed pumps ok2
[/size]And I also guess that this is why our manufacturers as JMC or Anton may deliver a certificat for 10 bar and they may do it by themselves, they would not take the risk to be outlaw, and I wonder if they build boilers of more than 2 liters...
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Just a note that even though I joked about cm3 vs. CC, in Hawaii we do drive on the "correct" side of the road. And, in USA we have failed at use of metric units-- I have to confess, I am guilty. But now in this steam engine business I am being forced to mix metric and SAE units all the time. Gets confusing at times. But so far I am lucky to not have encountered any BE threads (I think). But I am really happy that 1/4-40 seems to be almost everyone's favorite pipe thread.
Thanks for the comments and knowledge you all share! :-))
Carl
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So Carl says....." lucky to not have encountered any BE threads" ......not sure Carl......but you may mean BA which is a complicated Metric thread form.......
"The angle of the thread is 47.5° and the depth of thread is 0.6 times the pitch with rounded tops and bottoms. Thus the shortening at the crest and root is given by 0.26817p with a radius of 0.18083p at both crest and root {-) "
But there is also Model Engineer thread form
"The British Model Engineer Thread is based on the Whitworth thread with a pitch of 32 and 40 TPI. A commercial use of this standard does not exist. The flank angle is 55°"
Then there is the famous 26tpi constant ''Brass" thread O0
You Folks in the US of A decided to complicate the available nuts never to screw onto anyone elses bolt >>:-( with all of that UN series milackary
At least the Froggies and the Germans had the educated sense to stick with metric thread forms, then just to complicate added Metric Fine
So not to be outdone, the Japanese decided to used JIS Metric whos' nuts also didn't screw onto a French or German bolt
Jin from Microcosm's Chinese machine shops standard 15 mm diameter 4 bolt flange set for 1/8" & 5/32" tube has M2 diameter bolts with 3.5mm AF head to a Chinese Metric Standard whilst the same 15 mm diameter a standard 4 bolt flange set 1/8" & 5/32" tube as supplied by Winfried Niggle from Germany had M2 bolts with 3.0mm AF heads to ISO Metric Fine Head
In reality, I suggest if starting from scratch.....we would ISO Metric and ISO Metric Fine :-)) ......at least we wouldn't get our nuts in a tangle %)
Derek
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Derek
I am in awe, all the more so as I realize just how lucky I am to not have experienced any of these. (I thought BE = British Engineering--I twisted BME, made up a whole new thread!) Another joke gone awry.
Career Manufacturing Engineer, 40 years USA aerospace industry; never had to worry once about all these funny threads. Safe was I in my ignorance!
-cm
(as in centimeter)
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Bonjour,
This discussion, even if a little bit far from the title of this topic is very instructive and thanks to Derek, I realize that "I" (my manufacturers) effectively use sometilmes two metric thread measures : 5 x 0.50, 6 x 0,75 - 7 x 0,75 - 8 x 0,75 or 8 x 1.0, 10 x 0,75 or 10 x 1.0 and curiously no 9 x nn.
But I do not know the different thread angles.
Hopefully, for all 3 mm pipes, all accessories or connectivity is based on 6 x 0,75 links, but sometimes nuts are 7 mm and sometimes 8 mm... Am I true... ? In our passion too it could be done with optimizations :}
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Yes...... :o ...each Japanese SAITO steam engine has inlet and exhaust outlet tube retaining nuts are M7.0 mm x 1.0 P......... O0
As Carl says .........it is good that many manufacturers have adopted the 1/4" x 40 TPI as their standard tube/nut connection......
[but any member with a beautifully/functional Niggle Glass Quatrz tubed lubricator will find the tube connections are M6 x 0.75P threaded connections]
Derek
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Come on Derek not much Brasso here ,have you launched Decoy yet ?
CheersJohn
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Need a little help, I want to start a new thread on how to make the leather upholstery on a model boat, I have it written but needs to have in-line (embedded) photos and I cannot tell how to do that in this forum. Can somebody remind me how this is done?
Here's a view of what I want to describe, but no longer relevant to this thread
And why cannot I not see the photo attachments in the preview?
Grrr
Carl
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If you upload the pictures he'd top the forum, I don't think there's a way to display them as you'd like in a single posting.
But there is a work around: make a new post for each picture (or group that fits together with the same description), that way the text stays together with the corresponding picture.
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If you use a picture host rather than the attachment facility, you can insert the photo link in your text where you want. I assume the Mayhem picture host works this way but haven't used it.
Hope this helps,
Barrie
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Raphael I need a memory jog. In some forum you had some sage words abut how to adjust the Microcosm P5 gas attenuator. I need to try doing it, never got to it and now I forget where you told me that good stuff. Do you rememner? or if not can you tell me again the sequence for adjusting the P5 after the diaphragm is replaced? My unit is totaloy ut of adjustment since I messed with it.
The M29 with P5 is in my launch Cecilia which is a separate thread but I don't find the subject there.
And BTW I see in this thread I made some references to the build I was doing of the cllnker style launch with TVR1A and 3" boiler. I finally go it to the water and it is a big success and a lot of fun to see go.
https://www.youtube.com/watch?v=EglzcUZKxzU (https://www.youtube.com/watch?v=EglzcUZKxzU)
Carl
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Bonjour Carl,
I would be very happy if my videos (In French, sorry) would help you. Here are the ones I talk about adjustents.
My process is simple, I adjust my attenuators step by step :
1 - I close the little idle screw to hear if the pressure acts when the steam part is dismantled and wheb I press on the piston with my finger. The fire might almost die., not obvious on this example : [/size]https://www.youtube.com/watch?v=qE5naje6s7g (https://www.youtube.com/watch?v=qE5naje6s7g)
2 - If Ok, I keep the screw closed and install the attenuator to see at which pressure it operates. Adjust it by unscrewig the spring to low or scewring it to raise the target pressure (personally, I like 30 PSI)
3 - When this is OK, adjust the idle screw which is VERY sensitive ! A few degrees ans it is full open, as if you had no attenuator, main issue for lot of us : https://www.youtube.com/watch?v=pvwAnXhN4WE (https://www.youtube.com/watch?v=pvwAnXhN4WE)
I hope this will help you.
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Jin now sells a pack of the diaphragms for the P5.
https://www.ebay.co.uk/itm/153869304544 (https://www.ebay.co.uk/itm/153869304544)
The implication of having so many is that the diaphragm needs frequent replacement. Is this really the case? My usage is very low so I don't see why the diaphragm should fail unless it gets rotten.
Thanks for the instruction above, just one question-- in step two, is the flow screw closed completely? If it is closed completely, how is there any flow during the adjustment?
Carl
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Bonjour Carl,
To my opinion, Jin's diaphragms are made of rubber, hence their quick deformation and the need to change them often,
https://www.youtube.com/watch?v=aU37YAuOkKM (https://www.youtube.com/watch?v=aU37YAuOkKM) Furthermore, rubber becomes hard as wood aftera while: https://www.youtube.com/watch?v=a56Y87gb-NU (https://www.youtube.com/watch?v=a56Y87gb-NU)
that's why I use 0,5 mm nitrile : https://www.youtube.com/watch?v=5JUTaTuS-N0 (https://www.youtube.com/watch?v=5JUTaTuS-N0)
My step 2 is to be sure that the idle screw is closed enough to hear when the pressure operates the shutdown. As I say, I wish to adjust one parameter after another.
It does not matter if the gas is closed or not, I make several trials by making the pressure drop. Hopefully, on most of the attenuators I have, even full screwed, there is some gas passing through, enough to be heard but not enough to have a reliable idle level in the wind of the pond, otherwise I have to light again the torch when the gas comes back with the dropped pressure.
When I have adjusted the spring on step 2, The pressure parameter is set, I drop one more time the pressure, the gas comes back full speed and I go to step 3 which is, as say, very accurate because a few little degrees on the neddle screw change everything as you can hear it on my videos.
I am sorry if I am not accurate enough, do not hesitate to ask further information if needed.
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It's almost a year later. I took my P5 apart and replaced the diaphragms (what a funny word) and in being forced to rebuild it, I learned how it operates and which way to turn the thumb screw. (clockwise on the thread increases the cut-off pressure--again, so "obvious" nobody said it) I have it set again at 30psi, and Cecilia with her Microcosm M29 is ready for another splash. I followed Rafael's steps, easy.
I didn't see a pack of spare diaframs (there, much better spelling) offered from Jim, so I wrote and asked and he is supposedly sending me 6 pairs for $25US. I didn't attempt to obtain nitrile and make my own-- who could make replacements at $2 a pop?
And now Jin has the P5B-- does anybody have that and does it work? Looks smaller/simpler. I wonder, probably has the same life limitation as the P5? But maybe it has only a single diafram. Experience, anyone?
BTW back to the thread start-- I see Q3B and its reverser valve looks sweet. I looked at the Q2 but it is sold out, and was pretty expensive anyway. Nice on-line video of it. Q3B seems a little expensive as well, in my opinion.
But who knows what Jin's M36 engine does? It sure looks like the MSM Avon but bigger. B x S is 10 x 12mm; He says displacement is 7.6cc but I calculate r2 x pi x L x 2 x 2= 25 x 3.14 x 12 x 4= 3.76cc , or what did I do wrong? Seems like a deal for only $210 and free shipping to US. I cannot find a video of it, or anyone's experience with it. The reverser valve looks like a nice tight fit, no leaks up there. And the outrider bearing looks very substantial. This ought to be a winner, why not?
http://www.microcosm-engine.com/m36-new-twin-cylinder-oscillating-engine-p-166.html#.YItwFi9h1QM
-Carl
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Bonjour Cartl
Your calculations are correct, I find 3,78 cm3 ok2
I have not this machine but several oscillating ones and 60PSI (+/-4 bar) seems too much as operating pressure to my opinion.
And about prices, the demand makes the offer in our case as there are less and less manufacturers, especially in France :((
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I am curious about the Microcosm M36, so I ordered one. Jin sent me a cryptic note that it might leak-- which of course an oscillator will do, so no way 60psi, more like 25psi, and let's see what it can do. I also ordered another M29 with a 85mm vertical boiler to see what sort of boat that will go in. Hmmmm-- I might have more engines than boats-- any suggestions? %)