Model Boat Mayhem
The Shipyard ( Dry Dock ): Builds & Questions => Steam => Topic started by: mikew on October 29, 2020, 04:42:23 pm
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Hi All
Does anyone know where I might get a mechanical boiler feed pump to run off the rear of the crankshaft of a Saito twin please, either made or drawings, to feed a 3-1/2" horizontal boiler.
Thank You
Mike
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Bonjour Mike,
I would suggest you a Microcosm pump :
http://www.microcosm-engine.com/microcosm-m5-live-steam-boiler-feed-pump-p-182.html#.X5r8PohKjIU
I have bought two of them, not yet mounted :
https://www.youtube.com/watch?v=s3RwwaC2Ztk
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Mike will watch with interest your progress with this, I agree the microcsm pump is a good option, it is one that I have considered using with my Saito T2DR engines, the crank is 4mm and the pumps eccentric is 4mm so should be an easy fit, have you photos of what you are making?
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Thank you for your replies, What I intent to build is the MBD Solent cutter, the decision is what engine to put in 2 or 3 cylinder Saito, I have a 3 1/2" boiler and I thought it would need onboard water tanks to give e a reasonable sailing time using the 2 cylinder instead of the 3, hence looking for information on a feed pump.
At present using the bare hull and just moving steam plant bits about.
The M5 pump looks nice and as stated the shaft size is compatible just looks abit pricy {:-{
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Mike one thing i have learned from the good folk on this forum is that the burner and boiler dictate the performance, so if your boiler makes x amount of steam then that steam is all you have got, then it s then used to turn the engine, so the choice of two or three cylinders is crucial - you will need 50% more steam to turn the 3 cylinder Saito compared to the two cylinder (dependent on which 2 cyl version of the Saito) check out the cc of each engine - the 2 cylinder is 5.4cc and the 3 cylinder 9cc, so if you have 100cc of steam it will turn the 3 cylinder engine 11 times however it will turn the 2 cylinder engine 16 times. this is important since that is how many times your prop will rotate and will affect your speed and duration. So the next thing to do is to fit the largest prop the engine will drive with the steepest pitch you can. This will make the boat go further, faster and use a lot less steam, therefore extending your run times. I am sure others will explain this better than I since I am still learning. I have looked into this and am learning about it for a build that I am collecting parts for, it will use two twin cylinder Saitos, so wish you well with your build.
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DBS88:- Thank you for that information, very interesting, the engine is the 2dr 5.4cc, I've yet to find out the best prop size.
What boat are you planning to build and what boiler will you need to 2 engines ??.
Mike
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Bonjour Mike,
I have 8 different 5 cm3 steam machines in my collection and based on my experience, I would kindly suggest you a 4 blades steam pitch propeller (dia 2,75" x pitch 4.1"):
As Propsho phas become protean design https://www.youtube.com/watch?v=nGRDus7uIJQ (https://www.youtube.com/watch?v=nGRDus7uIJQ)
I have even put two of them on my tug Aggrip and her 11,5 cm3 Regner Neptun machine : https://www.youtube.com/watch?v=CagA7tJTPrs (https://www.youtube.com/watch?v=CagA7tJTPrs)
DSBB88 : I also have twin machines boats, example : https://www.youtube.com/watch?v=3jombigGCM8 (https://www.youtube.com/watch?v=3jombigGCM8)
If you already have the steam machines, would not suggest you to think about the idea to chooze oscillating or cylindrical valves ones, they just need one servo each to go ahead and astern.
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Bonjour Raphael
Thank you for your advice on the prop I will be checking out their website soon.
Regards
Mike