Model Boat Mayhem

The Shipyard ( Dry Dock ): Builds & Questions => Working Vessels => Topic started by: tjones27 on November 12, 2010, 03:12:11 pm

Title: Robbe Pala III
Post by: tjones27 on November 12, 2010, 03:12:11 pm
Hi, does anybody know the size of the motor in the Paula III, and could anybody suggest a suitable upgrade for faster performance/ has anybody done this??
Title: Re: Robbe Pala III
Post by: Martin (Admin) on November 12, 2010, 07:14:15 pm
I think the motor is a standard 540 550 type motor.
 The Paula III is a work boat, are you converting her to speed boat for some sort?
Title: Re: Robbe Pala III
Post by: essex2visuvesi on November 13, 2010, 09:43:08 am
If its 540 size then maybe some kind of hot RC car motor would work
Title: Re: Robbe Pala III
Post by: fatcat123 on November 13, 2010, 06:05:50 pm
I bought this boat for my mate, i'm 90% sure its a 550 motor. It goes well using a 7.2 volt pack.

Dan
Title: Re: Robbe Pala III
Post by: tjones27 on November 14, 2010, 12:09:16 pm
im not converting her to a speed boat, but i want to give her a little bit more umph! the the rudder is practically useless in reverse so im planning on fitting a steerable kort nozzle, but by doing this some of the power is lost, so to compensate for this i want to pack in a bit more of a beefier motor. im looking at maybe a 600BB or 700. but i think tht the 700m may be a bit of overkill, although i wouldn't have to run her at full steam! im also thinking of going completely overkill and fitting a small bow thruster just for fun.
Title: Re: Robbe Pala III
Post by: Martin (Admin) on November 14, 2010, 05:36:52 pm
Many single prop / rubber boats are rubbish going astern, a kort nozzle with ruder will help but it won't make it perfect.
A 600BB or speed700 will turn it into a guided missile so a hottish 540 will make it faster without too many alterations.

Be aware that the 600BB comes in different flavours....

http://www.graupner.de/en/products/80f55fc6-048f-41c2-b5fb-9180aec45a34/productcategory.aspx (http://www.graupner.de/en/products/80f55fc6-048f-41c2-b5fb-9180aec45a34/productcategory.aspx)
Title: Re: Robbe Pala III
Post by: tjones27 on November 16, 2010, 12:56:51 pm
thanks for the heads up. im in  hamburg at the moment, and they have all of the graupner motors on offer so providing i have enough spare pocket money i might grab a hot 540 and a 600bb for a couple of tests to find out which suits best. but yes it woul dbe a missile. i shall have to see. ive been looking for some bow thrusters too, any idea which size might be best as this will be the first time ive ever bought/experimented with bow thrusters.

also does anybody know how to work out what speed controller to use. i.e. with the voltage/ amperes of the power pack and the size of the motor??

I will post some images of the build if nayone wants to see how to make first class errors!!

Cheers  :}
Title: Re: Robbe Pala III
Post by: BigA on November 17, 2010, 01:44:07 pm
The Robbe EF76 II motor is an RS550-type. I run my Paula III with the standard motor but using an 8-cell 9.6V pack - it is, of course, way over-powered, but it's quite fun - especially unexpected by onlookers. Only problem is the original (kit) coupling - a rubber tube - is not up to a 9.6V pack - a proper UJ coupling would be better.

A Kort nozzle will lower the speed, though - see here: http://www.ef-uk.net/models/watercraft/paula3.htm.

There's a video on Youtube with a Paula III running on 8 cells, somewhere.

A.
Title: Re: Robbe Pala III
Post by: BigA on November 17, 2010, 01:59:18 pm
Oh, and my Mtroniks 25A ESC is fine with this set-up - I measured the motor draw as 15A at 8.4volts and 20A at 9.6volts (on the water). I attach the spreadsheet of the current draw vs voltage for my set-up (standard prop).
Title: Re: Robbe Pala III
Post by: BigA on November 17, 2010, 02:08:08 pm
Thats a Word document showing the graph - I couldn't download the xls sheet....