Model Boat Mayhem
The Shipyard ( Dry Dock ): Builds & Questions => Steam => Topic started by: tonyH on September 05, 2012, 01:10:10 pm
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Hello All,
Next project will be a sternwheeler gunboat approx 1m long and about 10lb weight. Should, of course, be steam driven BUT I'd like to use some sort of longer stroke, possibly slide valve, engines, rather than a twin oscillator geared down.
It seems that some of the Wilesco engines, NOT the boilers, could fit the bill.
So, has anyone any experience of this option or can anyone suggest an alterative, economically viable, one?
Thanks
Tony
(http://s14.postimage.org/3ts64bbgd/moulun.jpg) (http://postimage.org/image/3ts64bbgd/)
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Since you mentioned Wilesco, you could purchase a pair of their cylinders, including cranks and eccentrics, and build longer con rods and valve rods to reach the paddlewheel. They make at least two sizes of piston valve cylinders which look similar. Depends on your project which are more suitable.
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Hi KNO3, Precisely what I was thinking :-))
They seem to be about £50 per side so they could be an interesting option IF they'd be happy running at under 200 rpm.
Have you (or anyone else) had experience of them?
Tony
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I think Wilesco did a paddle engine for the Graupner Glasgow...
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I have used the Wilesco D48 engines in my screw driven steam launch. Other than adding a separate displacement lubricator I found the engine works well, It was the boiler I had problems with.
Regards,
Gerald.
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Thanks Nick, I'll check that out.
Thanks Gerald. Was it a particular problem with the boiler or just a general lack of steam? I'm thinking of using a couple of smallish decent boilers, possibly with a balancing link of some sort, on gas rather than meths. Any ideas?
Tony :-)
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Hi TonyH
Looking for a power unit like this : -
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Aye Timo,
That's the sort of thing except I'd have to re-jig it for a sternwheeler :-)) That looks as if it's been geared down 2:1 or so?
I'd use a heavier boiler with gas and plumb it in fully with a lubricator etc. Probably still low pressure but more consistent.
Tony
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Thanks Nick, I'll check that out.
Thanks Gerald. Was it a particular problem with the boiler or just a general lack of steam? I'm thinking of using a couple of smallish decent boilers, possibly with a balancing link of some sort, on gas rather than meths. Any ideas?
Tony :-)
Hi Tony,
It was a problem with the original gas supply, I could not get longer than five minutes run out of it I switched to a homemade burner converted from a camping lantern, which solved the length of burn time. I then decided that I needed more steam (shades of Tim Allen), so I have been making modifications to the original boiler and making other boilers. My original unit looked like the one Timo showed.
Regards,
Gerald.
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Thanks for that Gerald.
Any idea what sort of running pressure they are generally rated to? I like the idea of using the 'spare-part' cylinder/valve rods direct to the paddles but I noticed that Timo's was geared down which suggests not enough torque. The hull form on the project is not exactly elegant, being rather like a dumb barge, so I'm not expecting miracles! I reckon it'll be rather like driving a Springer :embarrassed:
Tony
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You could also look at this, or maybe even two, with cranks set at 90 degrees
http://www.tonygreensteammodels.co.uk/index.php?main_page=product_info&cPath=110&products_id=446&zenid=191nn83bua5l2uo9pj0k2ahp43
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In a paddle steamer I'd go with direct drive, just like in the full size ones, albeit with larger/longer stroke cylinders than for a propeller engine for the same boat. It should keep engine revs low and save steam.
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Thanks for that Gerald.
Any idea what sort of running pressure they are generally rated to? I like the idea of using the 'spare-part' cylinder/valve rods direct to the paddles but I noticed that Time was geared down which suggests not enough torque. The hull form on the project is not exactly elegant, being rather like a dumb barge, so I'm not expecting miracles! I reckon it'll be rather like driving a Springer :embarrassed:
Tony
I measured the safety valve lifting off at 22psI have had the model running at as low as 7psi. I have a lengthened and broadened version of Mabel running direct drive with a 70mm 3 blade prop.
Regards,
Gerald.
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Hi all,
Thanks Nick, I've sent an e-mail off to TGSM to see what the stroke is - the longer the better. I'll let you know when I get an answer.
Thanks KNO3, thats what I'd like to do if atall possible. Looking at the photos, it would seem that I'd need a stroke in the 40mm range which may not be feasible in terms of available engines.
Thanks Gerald. It looks as if the D20/D24 engines might suit with that pressure and could be ideal IF I can engineer a way of increasing the stroke.
:-))Tony
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I wouldn't recommend just scaling down the cylinder stroke from the original. Better choose a bore and stroke suitable for your boiler and paddlewheel and according to availability.
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Hi KNO3, No I was just thinking in terms of direct drive and the approximate size of the crank in the photo.
Tony
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Won't meet your stroke desires and may not meet your check book either but PM Research has several horizontal engines that might work. Some are castings and some are machined. Bore/stroke combo looks big enough for a 1 meter
http://www.pmresearchinc.com/store/home.php?cat=4
I've been looking at kit bashing this one for a future sidewheeler project. Looks like the pitman arms would be fairly easy to extend.
http://www.pmresearchinc.com/store/product.php?productid=3092&cat=4&page=2
Ken
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Thanks Ken,
Looking at the pics, they still seem a bit too 'square'. I.e. not long enough in the stroke to give a slow enough rev rate.
It look as if I'm going to have to gear down to the target revs of 120rpm.
:-)) Tony
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Since most of these are not "marine" engines, I haven't seen any chatter on the forums as to how well they run slow. The 1BI model certainly has enough size to run with relatively low steam pressures.
I've seen some model thresher engines running slow enough at farm shows but I suspect the load is very low.
"Smoke Ash and Steam" has lots of various combinations on gearing (to include wooden gears) but they're mostly on gearing up, not down, i.e., for speeding up slow engines to drive screws.
[size=78%]Good luck,[/size]
[size=78%]Ken[/size]
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Hi Tony,
It was a problem with the original gas supply, I could not get longer than five minutes run out of it I switched to a homemade burner converted from a camping lantern, which solved the length of burn time. I then decided that I needed more steam (shades of Tim Allen), so I have been making modifications to the original boiler and making other boilers. My original unit looked like the one Timo showed.
Regards,
Gerald.
The D48 would be ideal for a boat up to 1m, I have had great success with this engine. The problem experienced by Gerald is a common one for this engine. The gas tank gets quite warm after the initial pre heat and will not take gas on board. I put the tank in cold water, the lake is fine, for about 30 seconds. This cools the tank enough to get a full charge in. You can easily get 20 minutes out of it then.
My model is a modified Helen with a 4 blade 65 mm prop, so lots of torque. I guess You woul need a gear reduction for paddle wheels
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A video of the D48 in my boat.
<iframe width="560" height="315" src="http://www.youtube.com/embed/wfZ4ME-5icw?list=UU3JEIAwzSpCMfyNlxSYmYJA (http://www.youtube.com/embed/wfZ4ME-5icw?list=UU3JEIAwzSpCMfyNlxSYmYJA)" frameborder="0" allowfullscreen></iframe>
And another with the engine out.
<iframe width="560" height="315" src="http://www.youtube.com/embed/xEFoLbo84jw?list=UU3JEIAwzSpCMfyNlxSYmYJA (http://www.youtube.com/embed/xEFoLbo84jw?list=UU3JEIAwzSpCMfyNlxSYmYJA)" frameborder="0" allowfullscreen></iframe>
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Thanks Max, but I get the rescue boat on those links. It's probably me :embarrassed:
Tony
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I to get the rescue boat on these links.
Just thought it was me and the Christmas Spirit combining. :o
cheers
vnkiwi
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O0 Yo, but with me it's age as well!!!
Happy New Year
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You tube is the pain.
try this
http://www.youtube.com/watch?v=wfZ4ME-5icw
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Cheers Max, It certainly runs well but probably needs to be too fast for a paddler unless geared right down. I think I'm going to have to think bigger and slower for this.
Tony :-))
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Check out this current thread on the Mamod forum. Its a build for a purpose made paddle wheel engine.
http://modelsteam.myfreeforum.org/about57389.html
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That's exactly the sort of thing I was thinking about!
All I need to do now is find one off the shelf!!!! :-))
Tony
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Tony Green Steam Models sell Mamod cylinder assemblies, you may be able to extend the connecting rods to make up your own paddle engine....http://www.tonygreensteammodels.co.uk/index.php?main_page=index&cPath=101&sort=20a&page=4
Regards,
Nick
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Thanks Nick, but it's the length of the cylinders that's the one thing that tells the full story. Long stroke, lots of torque and low revs are the targets.
Tony :-))