Model Boat Mayhem

The Shipyard ( Dry Dock ): Builds & Questions => Steam => Topic started by: CliveJ on February 22, 2021, 09:38:43 am

Title: Miranda/Choupette - Engine suitability ?
Post by: CliveJ on February 22, 2021, 09:38:43 am
Hi,


Advice & help please


I am looking to build a Choupette steam launch. I have plans for the Miranda steam engine (+ plans for the Miranda steam launch).


On reviewing all plans it appears the Miranda engine may be too powerful for the Coupette (The Miranda plans detail a 2 1/2" propeller, the Choupette 40mm)
The reason I am choosing to build the Choupette in this instance is that it is a far faster build time.


Can I simply reduce the bore size from 1/2" to 3/8" on the Miranda engine to reduce the power and thereby reduce the size of the boiler ? if so at 3/8" bore I am assuming it will be powerful enough ?


Or is there a better option in an alternative engine ? I'm interested in building the engine from bar stock & not purchasing a kit/castings


Thanks in advance  :-))


Clive



Title: Re: Miranda/Choupette - Engine suitability ?
Post by: SteamboatPhil on February 22, 2021, 11:07:20 am
You could reduce the bore, but the other option is to build as is and just reduce the steam pressure that you run the engine at, that way should you need more power at any time it will be there
Title: Re: Miranda/Choupette - Engine suitability ?
Post by: KBIO on February 22, 2021, 04:49:57 pm
Good evening.
I've been looking and asking around but no chance. {:-{
[/size]The only drawing that I found is below. Good enough to do the work when you have decided what length you want.
[/size]Also , is a chart of the propeller size according to the engine capacity. The left column shows the weight range in kg.
[/size]The Choupette should weight  a small 5 kg for a meter long.
[/size](Sorry, it's in French but the numbers are universal)Hope it helps !Regards.
Title: Re: Miranda/Choupette - Engine suitability ?
Post by: CliveJ on February 22, 2021, 05:30:08 pm
You could reduce the bore, but the other option is to build as is and just reduce the steam pressure that you run the engine at, that way should you need more power at any time it will be there


Thanks Steamboat Phil, I was looking to reduce (Miranda) boiler size - if I keep the standard engine will I need to keep the 'larger' boiler ?
I guess I was looking to reduce the size/weight of the whole steam plant but still retain sufficient power & a reasonable rum time


Thanks again Clive
Title: Re: Miranda/Choupette - Engine suitability ?
Post by: CliveJ on February 22, 2021, 05:31:53 pm
Good evening.
I've been looking and asking around but no chance. {:-{
The only drawing that I found is below. Good enough to do the work when you have decided what length you want.
Also , is a chart of the propeller size according to the engine capacity. The left column shows the weight range in kg.
The Choupette should weight  a small 5 kg for a meter long.
(Sorry, it's in French but the numbers are universal)Hope it helps !Regards.

Hi KBIO, apologies for the confusion - I have the Choupette plan - I was just seeking advice in respect of the power plant

Thanks Clive
Title: Re: Miranda/Choupette - Engine suitability ?
Post by: frazer heslop on February 22, 2021, 09:36:32 pm
The boiler for Miranda even when gas fired  to be kind is a bit lacking
cheers
Title: Re: Miranda/Choupette - Engine suitability ?
Post by: KBIO on February 24, 2021, 10:57:52 am
Hello Clive !
I thought  of you and I found out the answer to your question.
I have 2 files concerning teh Choupette and the steam set to go in.
Unfortunately, I cannot post pdf on the Forum , so if still interested, give your mail on MP and I shall send you the complete doc.
The engine (easy to machine down) is a 3cc.
If you have any question, do not hesitate to ask.
Have a good day! :-)
Title: Re: Miranda/Choupette - Engine suitability ?
Post by: CliveJ on February 24, 2021, 11:50:47 am
Hello Clive !
I thought  of you and I found out the answer to your question.
I have 2 files concerning teh Choupette and the steam set to go in.
Unfortunately, I cannot post pdf on the Forum , so if still interested, give your mail on MP and I shall send you the complete doc.
The engine (easy to machine down) is a 3cc.
If you have any question, do not hesitate to ask.
Have a good day! :-)


Great :)  thanks for the offer PM sent


Regards Clive
Title: Re: Miranda/Choupette - Engine suitability ?
Post by: KBIO on February 24, 2021, 12:41:22 pm
Hello !
Done !Sent by ail!
Sunny day here today and the grass is high enough ! Can't delay anymore ! O0
Best regards.