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[Lifeboatman]

I think I'm starting to stumble.


This build is looking like its getting really hard to build. 


I really want to build this thing and use the IC engines. But the whole drive system is looking impossible. I can build one that just goes forward and no individual drives, but I'm really thinking I need the reverse even to just stop the boat.


To sum up today, 


Why is this getting hard on the brain... I'm not stupid, I've got a degree in agri engineering for crying out loud.


Looks like I may have to just buy some IC nitro engines and buy the gearboxes to go with them. Would make life easy I suppose. And mean making some stuff easier,

[Lifeboatman]

Ok. I've had a mini brain wave. Please bear with me.....


Ok. So I got electric motors for running. Easy, all the reverse problems sorted. Plus they can be independent..


But as I want the exhaust flaps to work I can use a small IC engine that will just run inside, that way if its effecting anyone I can shut it off and still use the model.


But next question. What motors? Water cooled brushless? What ones do I get and what ones to stay away from?


Looking at maybe going 3ft ish.


Plans are coming from RNLI soon. So how big does these plans make the boat?

[Neil]

you can easily achieve that effect by having cooling rings around the motors that take water in through a scoop under the boat like ICE lads do, and then eject it out of the exhaust flaps at the stern.
 
and then you don't need the ICE which is the big blocker to sailing on most waters, as even one for just producing noise and water effect will probably not be allowed most places.
 
neil

[Lifeboatman]

This is true Neil. 


But I do want some exhaust gas aswell. I know there are smoke generators but will one pump out enough to move the flaps.


I see the exhaust flaps all the time when I'm at the station, the water only just moves the flaps, the exhaust gas does most of the movement.


I have a load of electric stuff coming in soon from a crewmember from rc cars. So most of the servos and control boxes.


Going electric also means I can reduce the size of the model aswell.

[Neil]

have a look at this video at around 2.18 on the video you can see the exhaust flaps on the arun with the engine sound and exhaust smoke operating them.....if you look further on youtube you can find others with similar effects.
neil.
 
 
http://www.youtube.com/watch?v=-sAWSanEZak

[Big Ada]

If you are going to build a boat that is 7ft long it is going to be VERY heavy and you will need help to launch it.
All the answers can be found with the members of your local club at Dover and we will be pleased to help.
http://mba-dover.org.uk.freehostia.com/
Regards,
Len, Scale Secretary.

[Lifeboatman]

Can't wait now.


The plans have turned up today from the RNLI.


Just work that is going to get in the way next week. A busy week for me.


Going to start construction soon as I can. Havnt had a good look at the plans yet as I don't have a table big enough to spread them out on, so going to wait until I can get down the boathouse and lay them all out down there on the tables.

[Lifeboatman]

Ok so looked at the plans, still am looking.


One plan, and probably the most important one is in 1.25 scale, the other two plans are in 1.20 scale.


I've read about how to re scale the drawing, but couldn't make head or tails of it. Could anyone give me an idiots guide to doing this. Or should I just find my local printers and get them to re print it?

[vnkiwi]

your print shop should be able to scale them for you.
But, you need to know either of two things
a.  length you want the model, and the length of the original boat, then you have a scale to work with.
or
b.  the scale you want to build your model, then using the scales of the plans work out the %age to print the drawings
simple.
Without either of these its all pie-in-the-sky, as I couldn't find any of these in your thread.
cheers
vnkiwi 

[Lifeboatman]

Ok. I was going to follow the plans and go 1.20, but I guess I can't do that?


Was going to build the same size as the drawings.


I did say I was a novice. 

[vnkiwi]

yes you can.
you just need to enlarge the 1:25 plan to 1:20 scale.
That's a 1.25 times enlargement.
Any good print shop can do that for you.
Then everything should be the correct size on all sheets.
Go for it
cheers
vnkiwi 

[Lifeboatman]

yes you can.
you just need to enlarge the 1:25 plan to 1:20 scale.
That's a 1.25 times enlargement.
Any good print shop can do that for you.
Then everything should be the correct size on all sheets.
Go for it
cheers
vnkiwi 

Thanks, had a small panic then. Will see if I can find my locl printers, there was a few in my area but not even sure of they are still going.