Paddleducks
Paddler Modelling => Construction => Topic started by: Hankwilliams on January 19, 2020, 11:05:22 PM
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Hi friends and neighbors,
one part of my book about steamboat models will be a step by step instruction with text and pictures of building up a steamdriven model. The boat shouldn`t be too difficult, even for not experienced modellers. Now I think, this open Yarrow paddle launch may be the right object.
Scale will be 1 : 12 with a lenght of 113 cm and a breadth of 20 cm. Propulsion will be the Graham TV1A with a homemade boiler. Beginning was yesterday. At end of april I have to finish the manuscript - hope, that the little paddler will be finished with this time...
Thomas
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hello hank this is a fun project to follow this
this is not my language but try to do it as well as possible
greeting worrior
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This is a nice boat and project. But the Graham tvr1a doesn't seem very suitable, unless you radically modify it to drive the paddlewheels.
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Really? I use the Graham TV1A in 3 boats, two paddlers and one screw driven steamer. From my sight of view this engine is worth the money and with the hackworth gear rather close to an original steam engine. The only problem for the continental model craftsmen comes, if one screw or nut got lose - this kind of threat is not common here.
Thomas
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I'm not saying it'not reliable, it works very well. Just saying it does not look like a paddlewheeler engine and it would require modification if you wanted it to directly drive the paddle wheels, as done in full size practice.
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The Graham TV1A can be slighly altered to a diagonal paddle engine like in my Irrawaddy paddler "Mindon". My new little paddler - still without name - saw some progress, next and last work will be the paddles and paddleboxes. Boiler and engine will be installed in the middle of the boat. I hope, this boat will be not too difficult for an unexperienced craftsman. All steps of built will be documented with pictures and description.
Thomas
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Looking good Thomas. :clap :clap :clap :clap :clap :clap
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Again some advance with my boat. I named her "Presto", hope that the name will come true. Now the open hull with rigid paddlewheels (made of plywood) and - boxes is nearly finished. Material for the boiler is at hand and the kit of the Graham Engine also has arrived. I expect, that the boat will be finished in March. For the book I need good pictures of "Presto", probably next month the lakes are free from ice.
Best regards
Thomas
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I am always surprised by your speed of building Thomas. Only six weeks into the project and almost done.
Will you post pictures of the boiler making?
I have been looking at the Graham engines - very nice!!
Jurgen
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Hi Jurgen,
of course I will make pictures of boiler making and the building up of the engine. One bad surprise: The Graham engine kit former was not liable to duty, but now it is - more than 50 - Euro I had to pay. But the price of the slide geared TV1A with ca. 250 $ in proportion is rather low even in comparison with oscillating Regner engines. The lowest price of engines of this size I found in the Chinese Microcosm oscillating engine in V - shape, only 140.- $.
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I completed the TVRIA engine yesterday. The test run this time was very sufficient - it`s my forth TVRIA, with the first 3 engines in the beginning there was some adjustment necessery - but the present engine was running well from first rotation. Next job will be the altering to an diagonal engine like in the paddlers "MOL" and "Mindon". The "Presto" paddler`s casco is as good as finished.
Thomas
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Engine is converted to a diagonal one in a simple, but solid way. I am now considerìng, how the connection from engine reverse to the servo can be reached in a reliable manner. The 100 x 100 mm boiler will be installed directly in front of the engine.
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:clap :clap :clap :clap :clap :clap :clap
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Looks very good.
Actually you didn't have to alter the engine at all. You just made a support for the inclined installation. Or am I missing something?
Is that a 1:1.5 reduction at the gears?
Jurgen
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Yes, Jurgen. The engine itself isn`t altered. The gear reduction is 1 : 1,5 - we will see, whether this is favorable or not. The servo for the engine reverse will be installed in a crate behind it.
Thomas
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Some progress was made - RC with servos for rudder and engine reverse is installed. I think, this way with the servo in the crate is a quite good solution. The servo for the rudder is directly in the stern side by side to the rudder shaft. The servo for steam regulation will be in the starbord box vis-a- vis the receiver.
Thomas
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There is again some progress and I hope, next week the boat will be finished. Boiler, gas tank and hotwell are now finished and will be installed the next days. The deplacement isn`t very much, with only 3800 gramms the "Presto" will be one of my lightest models.
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:clap :clap :clap :clap :clap :clap
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Nice work Thomas. I follow your instruction pictures closely to be able to copy it somehow.
I would like to know how you make the boiler end caps. Do you hammerform these over dies you make yourself or are they available somewhere? To get the diameter of the straight flange right seems to be quite a challenge.
Jurgen
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Hi Jurgen,
it seems, also this project will be finished soon.
The boiler tube and its end caps were ordered by Regner in Aurach.
It`s also not too difficult to make this parts by oneselve. You need a form of hardwood in the diameter of the boiler tube. In the center of the form should be a screw. The soft red glowing brass or copper piece must cool down, then you fix it with the screw on themiddle of the form and with a wooden hammer you begin hammering from the center to more outer regions. The sheet must be glowed several times again, because it will be hard again with the hammering. At the end you must hammer the material angular araund the vertical parts of the form and cut it down to a lenght of 8 - 19 mm. Probablly the cap will still show some splits between the boiler tube and itself, but with precise strokes of the hammer they will vanish. When there is no more split larger than 0,4 mm you can solder with silver soldering.
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Hullo Thomas.......another beautiful set of tanks ...[as usual] :clap
......we have previously discussed such manufacture with the amazing U shaped Gas Tank from a previous build :hehe
......however I do not understand this tank manufactured in a T format with a singular port tapping at the top?
Derek
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Thanks for the explanation Thomas.
That is what I had seen in books and videos. It seems to be very hard to get this 0.4mm tolerance at the flange area.
So I am looking for ready made ones. I have been at the Regner website (veeeery slow!) quite often, but I don't seem to find any end caps there.
I found some on the Keifler website, but then again there is a message they are out of business.
Jurgen
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First steam up!
Good morning, dear friends and neighbors,
yesterday after some problems with a failing burner, the present Rothenberger was installed. After 5 minutes, first steam pressure came up. The presentation of boiler and engine was good. Minimum pressure for running engine was 0,4 bar, the engine was very fast with 2 bar, of course without any load.
Today I will connect the servo with the steam regulator beside the boiler dom.
Burner: I made one ceramic burner by myself, function was ok, but the sound - a loud howling - wasn`t acceptable. May be, I will order a Regner ceramic burner, but it seems, that Regnes is not working at time.
Jürgen: Boiler caps. The Regner boiler tubes and caps are not in the catalogue, but deliverable. Another firm, Hartmann Modellbau - with many different boiler tubes and caps, but not very trustworthy - obviously has closed.
Derek: For the gas tank I used again copper tubes and caps from plumber trade. After the gas cock there is the fast coupling, which one can loosen in a moment to fill the tank.
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OK.....thanks Thomas......each of your detailed photographs confirms a thousand words :kewlpics
In each of your boiler burners appear to burn with a very bright [light blue - high temperature] flame, have you ever experimented with a slip fit bush over the burner to alter [increase] the air draw?.....lower the temperature and also change or lower the boiler howl?
Looking forward to seeing Presto on the water...[is this your 12th or 13th Paddler?] :whistle
Derek :beer
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Hi Derek,
she is my 17th paddler with steam propulsion. Yesterday I finished the RC, the connection between servo and steam regulator is well functionating.
Today I will do a steam test in the test tank.
The original boat has had a very light roof of fabric nearly over the whole hull. I think, I will make this with very thin plywood (0,5 mm) and brass stanchions.
Thomas
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Wow.......17 steam paddlers.... :a102 ....I am sure this will be a PD Members world record.......
[my favourite :no1b is the Irrawaddi....with the two single Regner 12x36 engines close coupled to be a twin]
You may well be the best person to answer a question... :whistle
1. Models with a ships wheel if required to steer to Port, the ship's wheel turns to Port......OK so with the Radio Control arm, we send this over to Port to achieve the mirror of the ships wheel and the direction of turn
2. Now model ships with a hand or rope Tiller arm, to steer to Port we move the tiller arm to Stdb......so here is the question....do you send the direction of the Radio Control arm over to the Stdb to achieve this
Te action at 2. is a mirror of the full size steering motion, but is opposite to the visual image of the Radio Control arm
Naturally any other members with tiller arm steerage are welcome to comment
Derek
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When the model should go to port, I lead the RC arm to port, whether it is wheel geared or a with a tiller - to make a difference would be too much difficult to survey.
Yesterday I made the first steam test in water basin. There are some minor problems, like most steam tests with models on water: The gear reduction engine to paddleshaft must be altered to 2 : 1. With present 1,4 : 1 the engine is too much loaded, steam consumption is too hight. The hotwell wasn`t tight and also the connection oiler to engine. For the different gear reduction I`ve ordered two new cogwheels, the other points are already repaired.
At the "Mindon" model with it`s small 85 mm diameter paddlewheels there is a 1 : 1 transmission engine to paddleshaft. Obviously also in models the rate between engine stroke (15,7 mm) and paddle diameter should be no fare more than 1 : 5 like in the original paddlers.
The draught of the boat is 30 mm, a little more than expected - model weight with water in boiler and gas is about 4,5 kg.
For aestetical reasons I have add a bowsprit and shorten the funnel for 20 mm.
Thomas
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:clap :clap :clap :clap :clap :clap :clap :clap :clap :clap :clap :clap
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Yesterday one more test run with unchanged gear reduction 1,4 : 1. This time the presentation was better, minimum pressure for running engine was 0,6 bar in water with the fixed boat. Minimum number of revolutions to keep the engine running are between 50 - 60 Upm - independent of pressure. Of course it wasn`t possible to move the boat worth mentioning forward in the short test tank, but even throught the 1 m space the engine was running faster and more round, compared with the fixed model. The water swirl is very strong with 3 bar, but the pressure goes down fast to 1,2 bar. So I observet, that the steam consumption with this rate of gear reduction is rather strong.
Thomas
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Hello Thomas,
That's an interesting observation. I always thought that a steam engine was kind of "self" regulating regarding steam consumption.
I thought that if you overload the engine it would just run slower using less steam. Less rpm => use less steam.
If, on the contrary, you would let it run without load, it would rev-up happily consuming more steam.
Seems like I have to look into the books again.
Jurgen
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Hi Jurgen,
in opposit to combustion engines, steamengines can be overloaded, the steam in the cylinders gets more and more compressed. The result will be a very high steam consumption. Sometimes a steamloco with a heavy train got overloaded at a long ascent.
Today I got the new cogwheels. What a difference! It`s no problem, to hold 2 bar with paddleshaft revolutions of 80 - 100. The water swirl with 3 bar pressure is yet more than before. With gas and water one can drive the boat more than half an hour.
Last job will be the roof. In original it was made of fabric, I will make it of very thin (0,5 mm) plywood. Of course the roof must be fast removible.
Thomas
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Today I altered my home made ceramic burner. The sound, a very strong howling, was not acceptable. Now I drilled some holes for the air and the sound is completely vanished. The power of the burner is strong, more than the soldering burner.
Also both roofs are finished - next week will be the maiden voyage at the lake!
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:terrific :clap :terrific :clap :terrific :clap
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Maiden Voyage today afternoon on a sunny warm springday. All was ok, presentation of the boat was very good. I think, the model is well suitable for building also through a not very experienced model craftsman. running time was more than half an hour. Only it seems, that the swans don`t like the model very much - the came rather close, but furtunately don`t attak the boat.
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Congratulations Thomas.
She looks great on the water.
This is what I call a speed build.
Jurgen
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Ditto Well-done Thomas. :clap :clap :clap :clap :clap :clap :clap :clap :clap :clap
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Hi Jurgen.
Looks great on the water, Just right. Lovely build.
Very graceful.
Mike.
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Hi Mike,
I`m not Jurgen, I`m Thomas.
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Is your name not Bruce?
(Monty Python joke)!
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oopp's Sorry Thomas,
I got lost.
Mike
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Yes Thomas, Presto appears to be well powered with the revised drive ratio..... :kewlpics .....
.......and as we have discussed, 30 minutes is an adequate running time before the Skipper needs :coffee
What is the combined rudder throw? [total angle between port to stdb of the rudder which = the tiller angle sweep]
Derek
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Hi Derek,
the angle of the rudder from neutral to starbord or port is 35°, this is sufficient. The turns of the boat are rather narrow for a paddler. Today I will visit my old mother in Rhineland, more than 400 km away. Perhaps I can post some pictures of the boat on a volcanic lake in the nearby Eifel montains next time!
A glad Eastern to all - in spite of the restictions!
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Thanks Thomas......I remember the photographs you have of a few of your earlier model paddlers stored at your Mums home.......
So best regards to your Mum during this festive weekend.......a little surprising :police: you are allowed to travel that far
Derek
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Very nice. I like the boiler you made!
A video would be nice too.
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I will try to make some further pictures, perhaps a video. But in the meantime the plans of "Presto".
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Thanks for sharing the plans Thomas - I just wish I'd kept the Marten Howes & Baylis steamplant I once owned, it would have been almost ideal for this!
For those that don't remember my posts on the steamplant (It was about 15 years ago now!) you can see the complete thing at http://www.paddleducks.co.uk/smf/index.php?topic=1445.15 About the 5th post on the page...
Regards
Eddy
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Yes, Eddy, this Marten & Hoves and Baylis steamplant was a first class one. I remember when it was offered in the end of 1990tis. The little slide crank engine I own in my "Seekadett", made in 1993 - still functionable and in good condition.
Thomas
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Today we made some further pictures of "Presto". A few photos I modified with filters to an antique impression.
Thomas
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Very good Thomas.....from IMG_2420, Presto appears to have a good radius of steerage :bravo
Glad that pair of Wellington boots we bought you fitted correctly :hehe
Derek
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Oh yes Derek - this time I didn`t forgot the boots - there was a 4 meter distance throught water to the little dry isle!
Thomas
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A lovely model Thomas well done. :clap :clap :clap :clap :clap :clap :clap :clap :clap
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Nice pictures Thomas.
She looks nice on the water and seems to move really well.
Is it the picture or is Presto missing an E on starboard?
Jurgen
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Yes Jurgen, the boats name lost an "E", I watched at home - fortunately I had another one - the name could be completet again.
In the next days I will take some pictures of the Irrawaddy steamer "Mindon". The text of the book about steamboat models is finished since weeks, in the moment there is some work to coordinate the numerous pictures with the text. I hope, also this will be finished next week.
Thomas
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Please tell me what gear ratio did you use in in the beginning and how did you change it?
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As I wrote in the "Mindon" topic the load of the engine was the problem - high steam consumption with restricted range of sensitive regulation. I think, the present gearing ratio with 2 : 1 ist ideal for the dimensions of paddlewheels (120 mm diameter) and piston stroke (15,2 mm).
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Thanks but that doesn't answer my question.
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Perhaps we should have a look to the stroke of the engine in relation to diameter of the wheels. At original direct driven paddlers the engine stroke is between 20 to 35% of wheel diameter. This rate can be rendered to the model. With the 15,2 mm stroke of the Graham the wheels diameter should be between 50 to 75 mm direct driving. From my experience: When the wheels diameter is essential bigger, the torque of the engine will not be sufficient and the engine will be overloaded - steam consumption will be high. In this case a gear reduction is the better way, what was made with "Presto" and "Mindon".
Thomas
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Thanks for the answer but I think you misunderstood me :-)
I was simply asking what ratio you started with and how you modified it. NOT why you didn't use direct drive (which is an entirely different question).
Besides, stroke alone doesn't tell much about engine power and load. You also need to know the bore of the piston and then to calculate the volume of the cylinders, working pressure, all in relation to the paddlewheel diameter and to the surface area of the paddles being submerged at one time. Quite a complex calculation, if you think of it.