Model Boat Mayhem
The Shipyard ( Dry Dock ): Builds & Questions => Steam => Topic started by: CliveJ on November 04, 2020, 04:37:56 pm
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Hi, I am looking to build Miranda - Has anyone copies of the build articles from Model Boats Magazine (July, Aug & Sept 1983) they would be happy to share with me ?
Thanks in anticipation Clive
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I will be able to get them you but will take a few days unless someone has them to hand. Sure I have them scanned in but can not find it just this second, think they are isolating somewhere !!!
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Is this the steam launch with the funny engine?
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Belli, Re the funny engine, I have just got one the same and have been reliably informed by a fellow mayhemmer that it is a Basil Hartley design. I have had it running under steam and it certainly looks and sounds impressive, it has a large bore and stroke, looks to be a double acting twin cylinder 5/8 bore and 1 inch stroke oscillating engine (have not taken it apart to verify the dimensions). Will have to wait a while now before I can get it out on the lake - its being used to drive a Thames Steam Launch. Will use the lock down to get it up and looking the best it can. In the mean time I wish you every success with your build.
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Yes that is Basil Harleys engine for Miranda. A nice runner although the boiler is a bit lacking
I think it was based on this one built around 1880/90 for a paddle steamer. The trunnion and porting is a lot more complicated
https://www.youtube.com/watch?v=ZbahxB87K5I
cheers
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Bonjour, [/size]Based on your information, this steam machine is a 20 cm3 ! To my opinion, I only hire me of course, i fear that the boiler we see will hardly provide steam enough for this beast and you won't have a significant autonomy.
I usually couple 4,5" 4 blades steam pitch propellers to my 20 cm3 thanks to their torque, which is the diameter of your propeller ? The smaller it is, the faster your machine will operate...
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Ok, maybe 'funny' wasn't the best choice of word, perhaps 'unusual' is better. It is certainly different to most little steam plants but still an attractive little engine.
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Bonjour,
My opinion seemed too serious, sorry also for the wording, I wouldn't have like to find you disappointed. As soon as you almost know what you do, without any idea of hyper optimization of your steam plant, it is actually funny to try some unusual things :-))
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Maybe of some interest to any builders of Miranda
https://youtu.be/Bzv8TfON8lk
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The plans list this engine as 1/2" bore and 3/4" stroke. That's 4.6cm^3 displacement (for both cylinders).
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Bonjour Belli,
If the engine is double acting machine, please note it is a 9,65 cm3, this means a huge and heavy boiler plus a large propeller to preserve some autonomy.
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Beli, I have been doing some further research and agree with your findings, the Basil Harley plan is for 1/2 inch dia and 3/4 inch stroke. I have not dismantled my particular engine to check, since it runs well, I chose to leave it alone.
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Indeed, 9.65 cm^3 for double acting... ok2
The boiler on the plans is listed at 2.75" dia. (O.D.) and 6.5" long but is drawn at 6" long. I haven't checked where the mistake is exactly. There are six cross tubes of 15mm dia. each.
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The boiler as drawn if gas fired rather than the mustard tin burner on the drawings will drive the model but you have to keep stopping to allow pressure to build up. The boiler simply does not generate enough steam .
The engine is a 1/2 bore 3/4 stoke DA twin and is a reliable little unit
From memory on the hull drawings one of the formers is wrong but it is a long time since I made her so could be wrong
The plant in the pic is not to Basils original design and has what looks like a commercial boiler
I plan on refitting my boat someday and the boiler will be getting a larger radiant burner and failing that will be filed under B1N
cheers
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A big thank you to TheLongBuild for helping me out with my request :-))
& now the project begins !