Model Boat Mayhem

Dry Dock / Shipyard: Builds & Questions => Steam R&D: => Topic started by: Kenhsilver on March 11, 2020, 06:33:57 PM

Title: Connecting a steam engine to side paddles
Post by: Kenhsilver on March 11, 2020, 06:33:57 PM
I am new to model boating but have completed an Aeronaut Queen which does not sink and goes quite well. As a garden rail enthusiast I am keen to get into steam. I want to build the side paddle steam boat PS Adelaide which still plys the Murray River in Australia.
My question is, what is the best way to connect a steam engine to a set of side paddles. The prototype appears to be fully integrated. Are these available or are there gear boxes (similar to driving train wheels). Could you use a chain drive? Any help would be appreciated.
Title: Re: Connecting a steam engine to side paddles
Post by: derekwarner on March 11, 2020, 09:34:55 PM
Welcome Ken......


Whilst you did not ask, the Australian Company....."Float a Boat" produces a 2 plan building set of plans in 1:24 scale of PS Adelaide.....


The plans were drawn [as measured on the original vessel - including every timber size & section] by the Principal and are in an excellent layout format suitable for the building of the model


https://www.floataboat.com.au/ (https://www.floataboat.com.au/)


As you note, Adelaide has a twin cylinder horizontal engine direct drive to the paddle shaft, so from this steam models could use gear or a chain reduction dependent on the model steam engine chosen


Derek
Title: Re: Connecting a steam engine to side paddles
Post by: derekwarner on March 12, 2020, 06:11:15 AM
SPD/SI in the US provide 3.75mm pitch chain & chain pinions [which can be modified]  O0


This is my 4.8:1 chain reduction from the 4.0 mm diameter engine shaft to the 6.35 mm diameter paddle shaft......[a little of trial & error  :-X ]


Derek
Title: Re: Connecting a steam engine to side paddles
Post by: Kenhsilver on March 12, 2020, 08:56:14 AM
Thank you Derek,
All my Christmases in one!
I am on my way for a holiday in Melbourne later this month and will seek out "Float a Boat". I have been looking at Miniature Steam Models as a possible source of an engine and boiler. Have you any views or experience of their products?
My plan was to build the Krick Alexander next and then the PS Adelaide. The latter will be a winter project so now is a good time to do all the reseach.
I do really appreciate your help and obvious deep expertise.


Ken   
Title: Re: Connecting a steam engine to side paddles
Post by: KNO3 on May 06, 2020, 12:59:36 PM
Hi Ken, the best way, imho, to connect a steam engine to the paddle wheels is also the simplest: direct drive. This also keep revolutions low and saves steam.

Steam engines, even in model size, have high torque at low rpm, basically from a standstill for any two cylinder double acting engine. To get a better idea of the torque available: there are countless live steam model locomotives that can pull long trains from a standstill, n a full grown person. They are direct drive, not geared.

Unless you plan to connect a small engine to huge paddle wheels, there is no need for gearing.
Title: Re: Connecting a steam engine to side paddles
Post by: rhavrane on May 06, 2020, 10:02:37 PM
Bonjour KNO3 ok2
I do not wish to contradict you, but qualify your words and provide additional information.
I fully agree with you if the engine has torque enough to run slowly directly.
Based on my different experience, this means large. My 35 cm3 Bernard Retif plans machines are able to operate at 20-PSI and aboyt 60-80 RPM: https://www.youtube.com/watch?v=OHD1gKkfRTA (https://www.youtube.com/watch?v=OHD1gKkfRTA)  or https://www.youtube.com/watch?v=133sYTE7i9U (https://www.youtube.com/watch?v=133sYTE7i9U)

But already with this 17 cm3, I needed a redution : https://www.youtube.com/watch?v=GhpJoPB0eAY (https://www.youtube.com/watch?v=GhpJoPB0eAY)

And it is obvious if the steam machine is a 2 cm3 : https://www.youtube.com/watch?v=U_ZwIiZKMGk (https://www.youtube.com/watch?v=U_ZwIiZKMGk)


Chains are easier to install than cogwheels
Title: Re: Connecting a steam engine to side paddles
Post by: KNO3 on May 06, 2020, 11:20:19 PM
Raphael, please explain why a reduction is necessary instead of direct drive. And allow me to disagree on the need for a reduction :-)
Title: Re: Connecting a steam engine to side paddles
Post by: rhavrane on May 07, 2020, 08:12:43 AM
Bonjour Calin,
Please note that I have made a nuanced reply to your affirmation.
Based on what I have noticed, the smaller the machine is, the less torque it has at low RPM, this is why we need to let them operate with small propellers.
If you watch accuratly the video of my Glasgow, you will see how fast the 2 cm3 Quartz is, far from the 80 RPM I wish for the wheels.
On the contrary, the 35 cm3 have a lot of torque, even at 14 PSI, run slowly  and do not ,eed any reduction.