Model Boat Mayhem

The Shipyard ( Dry Dock ): Builds & Questions => Steam => Topic started by: mogogear on August 15, 2008, 05:36:27 pm

Title: Servo steam valve control
Post by: mogogear on August 15, 2008, 05:36:27 pm

When the engine you have has no speed control built into the reversing mechanism... and you need to employ a servo working on a steam valve to regulate speed...


Is there some pictures that can be posted for me to visualize a couple of different approaches ? I have vaguely seen a gear replacing a globe valve knob and a gear on the servo- meshed up to produce the desired effect. Is that the best; only ; preferred method?

But having very limited "mental pictures" I need some pro and con discussion on differing methods..

Thanks folks!!

Title: Re: Servo steam valve control
Post by: Bunkerbarge on August 15, 2008, 10:03:16 pm

The easiest method is a valve that is designed for control which fits into the main steam inlet line and it is operated by a lever as opposed to a wheel and instead of screwing the valve plug in and out it opens a port.  Just imagine a valve plug with a hole drilled through it, when the hole is in line with the pipe you are fully open and when you rotate it through 90 degrees the hole is fully closed.

Have a look through all the normal steam fittings suppliers to see if any of them do such a valve, I have one fitted to a Hemmens boiler so I know that John Hemmens used to supply them.

Title: Re: Servo steam valve control
Post by: Bernhard on August 16, 2008, 07:49:01 am

hi......here you can get it,,,.........  http://www.kramer-steam.ch/joomla/index.php?option=com_wrapper&Itemid=26

v31 

regards Bernhard

Title: Re: Servo steam valve control
Post by: kno3 on August 16, 2008, 11:03:01 am

Hi!

Many sellers offer special r/c steam valves, which are what you need to control the speed of your engine via a servo. They are easily operated with a servo because their arm moves less than half a circle from the "closed" to the"open" position.
It looks like this:

(http://www.dampfmodellbau-keifler.de/pic/14-30122.jpg)
Source: http://www.dampfmodellbau-keifler.de/w09.html

Title: Re: Servo steam valve control
Post by: Proteus on August 16, 2008, 11:14:05 am

mogogear 
                       is your engine a single cylinder by Graham ind if so I don't think they self start so you will not be able to stop or reverse and you will have to make shore you do not drop your speed on the engine as it could stop if your pressure is low, can you come back with your engine type

thanks   , Proteus

Title: Re: Servo steam valve control
Post by: Bernhard on August 16, 2008, 01:16:48 pm

     

                              http://www.dampfmodellbau-keifler.de/

Title: Re: Servo steam valve control
Post by: mogogear on August 16, 2008, 05:09:43 pm

Thanks all- Wow- after about 30 Google searches for R/C steam valve - you all delivered!! I can't believe there seem to be none in the US... As for the application- I was intending it if I bought the Graham twin engine..... I have a old Krick / wilesco twin that might need speed control also..I will find out more when it arrives in a launch I just purchased

(http://i39.photobucket.com/albums/e199/mogogear/LaunchENGINE.jpg)

I most likely will swap out the engine for this one I have which has speed and reverse combined..It is a oscillator from a now defunct little English company called Modeen..from about mid 1980's. I have been bedding it in on the airline as it was never used till now.

(http://i39.photobucket.com/albums/e199/mogogear/Modeentwinengine.jpg)

This is what is coming in a few days... a Fall project

(http://i39.photobucket.com/albums/e199/mogogear/Launch1.jpg)

Title: Re: Servo steam valve control
Post by: kno3 on August 16, 2008, 09:02:56 pm

The Wilesco twin in that picture already has speed control built into the reversing valve. You don't need an extra steam valve for that engine.

Title: Re: Servo steam valve control
Post by: mogogear on August 16, 2008, 11:57:05 pm

Thanks Kno3- I never could get a confirmation on that...It has had some dubious reviews ( the little I can find..) so I may opt for my Modeen...just because it is a solid runner..although not quite as "classic" looking. I do like the "octopus" appearance of this Not really a Wilesco and not really a Krick engine though... we will see- maybe I will be surpised ;)

Title: Re: Servo steam valve control
Post by: mogogear on September 10, 2008, 12:32:46 am

A plea once more for steamers in the US or Canada... Is there a source for R/C steam valves on this side of the Atlantic? The ones graciously provided once shipped and taxed and packaged from Germany would cost about $40+ , they were the perfect answer but were also in metric, which would incur yet another adaptation.

Sorry to be begging for a closer less expensive answer.. there may just be no other way..  Any more Help???

Thanks

Title: Re: Servo steam valve control
Post by: oiler on September 14, 2008, 08:57:49 pm

Give Ken at coles a try

http://www.colespowermodels.com/index.html

Ken's shop and home has just been through hurricane Ike that hit texas so I'm not sure his phone is up and working. But give him a try if you can get through.

Title: Re: Servo steam valve control
Post by: mogogear on September 14, 2008, 11:17:36 pm

I have spoken with Ken and just received their catalog #26- nothing there-I found him to be very nice. I hope they far well through the storm..I have a sister in Houston myself.

 I found the steam valves in stock at Polly Engineering in The UK for $16 pounds...I took it...