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Old Jan 30, 2010, 10:55 AM
Micro Flyer
United Kingdom, Marham Airfield
Joined Jun 2005
784 Posts
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Ripmax Magic Vee

Hi there. I was in the model shop today buying repair stuff for my bf109 that piled in today! I spotted high on the top shelf this little racing vee!

http://www.ripmax.com/item.asp?itemi...ry=050-010-010

when i got back i found the only video online of it and thought id like 1. turns out i had the wrong size prop for the plane so another trip later......... i brought 1


looks nippy on its 180 but was thinking lipo/brushless bullit!
any1 have any idea on ideal motor/esc and prop? im new to the boat thing!
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Old Jan 30, 2010, 11:40 AM
Boaters are nice people.
Sneek, Netherlands.
Joined May 2004
5,087 Posts
Hi Chris,

Be aware of the fact, that small hulls are easily overpowered; on the video the hull already starts to porpoise with the stock motor, with more power this will get worse up to undrivable, unless you alter the entire set-up to match the power installed.

Regards, Jan.
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Old Jan 30, 2010, 12:26 PM
Micro Flyer
United Kingdom, Marham Airfield
Joined Jun 2005
784 Posts
right ok, points noted. wont be going crazy with this then. maybe a a nice lipo setup to increase the speed a little and the run times. this thing comes with a cheapo plastic transmitter so thats def going!
the stock battery is 7.2v 260mah
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Old Jan 30, 2010, 03:23 PM
Micro Flyer
United Kingdom, Marham Airfield
Joined Jun 2005
784 Posts
are there any better 180 brushed motors out there?
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Old Jan 30, 2010, 03:32 PM
nick 30
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Joined May 2009
2,790 Posts
not really, although you could try graupner, its a german company, as your english, try cornwallmodelboats.co.uk they have some, how about trying the equivilent size lipo to the nimh batt you have now
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Old Jan 30, 2010, 03:38 PM
Micro Flyer
United Kingdom, Marham Airfield
Joined Jun 2005
784 Posts
surely something like this
http://www.fast-lad.co.uk/store/prod...oducts_id=2261
Can a 180 heli motor be much different?
and yeah i was going to look for a little lipo similar to this.

7.4V 500mah ? (.2v bigger cant hurt can it?) the stock esc is 5A
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Old Jan 30, 2010, 04:49 PM
Boaters are nice people.
Sneek, Netherlands.
Joined May 2004
5,087 Posts
Hi Chris,

The heli motor has replaceable brushes, that's a good thing as far as lifespan is concerned.
But, most likely it will rev way too high for a boat in direct drive, as most heli's work with gears on both the main and rear blades.

Sadly that info isn't available in the link.

If it has between 25.000 and 33.000 rpm under load, it would be an option, much more will just result in foam, not speed...

Regards, Jan.
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Old Jan 30, 2010, 06:41 PM
Micro Flyer
United Kingdom, Marham Airfield
Joined Jun 2005
784 Posts
iv looked all over the place for the rpm of this motor no luck.
any ideas where i can find props this small too? smallest iv seen are like 35mm
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Old Jan 30, 2010, 10:46 PM
I feel the need for speed!
scorpion1's Avatar
Southern U.S.
Joined Jun 2008
7,299 Posts
Small beryllium props:

27mm - http://www.offshoreelectrics.com/pro...?prod=oct-x427

27mm - http://www.funrcboats.com/ProductInf...oductid=OCX427

30mm - http://www.funrcboats.com/ProductInf...oductid=OCX430
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Old Jan 31, 2010, 04:39 AM
Boaters are nice people.
Sneek, Netherlands.
Joined May 2004
5,087 Posts
Hi Chris,

This is the smallest Graupner two blade:
http://shop.graupner.de/webuerp/servlet/AI?ARTN=2318.29

And this the smallest three blade from Graupner:
http://shop.graupner.de/webuerp/servlet/AI?ARTN=2299.30

But, you don't want to go the high revs, small/tiny prop way, the efficiency of the small props is on the edge, along with the (lack of) efficiency of those small motors.
As an example:
http://shop.graupner.de/webuerp/servlet/AI?ARTN=6394
This motor converts only 55% of the electric energy you put in, into motion, the rest is lost in heat and friction...

If it physically fits, one of the brushless motors, suggested by Scorpion would seem a better upgrade to me.
Keep in mind you'll need to watercool the motor 'properly', as the stock solution is rediculously inefficient for a brushless motor.

If the motor you select, doesn't come with a watercooling fitted, like this one (which, if it fits, will be major overkill):
http://www.hobbycity.com/hobbycity/s...WaterCooled%29
you'll need something like this:
http://www.swanghobby.com/hobbywing-...1-pr-1723.html

Regards, Jan.
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Old Jan 31, 2010, 08:37 AM
Micro Flyer
United Kingdom, Marham Airfield
Joined Jun 2005
784 Posts
i got hold of a cheap xtreme se 180 motor. going to see what that does first.
this little boat does have water cooling but it looks like a poor attempt.
after the motor upgrade il see how it does, then il get a 7.4v lipo
am i right in thinking mah will give me better run times? so say a 500mah pack will last longer than my 260mah pack. it wont add speed as thats only voltage.
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Old Jan 31, 2010, 08:56 AM
Boaters are nice people.
Sneek, Netherlands.
Joined May 2004
5,087 Posts
Hi Chris,

Yes, you are correct.

Keep us posted on your 'speeding up attempts'.

Regards, Jan.
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Old Jan 31, 2010, 11:00 AM
Micro Flyer
United Kingdom, Marham Airfield
Joined Jun 2005
784 Posts
Cheers. yeah i will do
I took it to a small bit of stream near me today.

Here is what i think:

1. Mine is not 20kph.
2. My motor shaft isnt the straightest thing around.
3. The layout with the Nicad makes the boat sit lopsided!
4. because of the above it turns sharper to the left.
5. After 2mins i had quite a bit of water onboard.
6. My servo rod has a bit of backlash in 1 direction.

What i hope will happen.

1. find a straight shaft.
2 the lipo will be lighter and thinner so i can balance the boat.
3. lay a thin layer of silicone at suspect leaks.
4. bend the control rod better to eliminate backlash.
5. find a better prop.
6. fit the xtreme se180 motor.

The stream was pretty tight and after 3 seconds i had to rescue the boat.

Is there any rules on balancing a boat? should i place more upfront it it porpoises?
would a long motor shaft out the back help in any way apart from larger prop diameter.

another thing. those little fins at the back.......
what are the for and why and when would you adjust them??

Think it would make a nice Monster Energy/DC boat!


Cheers Chris
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Old Jan 31, 2010, 12:45 PM
nick 30
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Joined May 2009
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for self righting you want the battery as close to the prop shaft as you can, keep the battery about in the middle of the boat, the fins are there to aid stability when turning, a long prop shaft will make the boat prop walk, i would try to make the shaft shorter at the motor to bring the prop closer to the transom or find a strut small enough for the shaft
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