Model Boat Mayhem

The Shipyard ( Dry Dock ): Builds & Questions => Pleasure boats, Sports, Race, Power and Leisure Boats: => Topic started by: 3838Derrick on August 30, 2015, 03:59:38 pm

Title: Genesis cat
Post by: 3838Derrick on August 30, 2015, 03:59:38 pm
Hi all.  I'm pretty new to fast boats and this is my first catamaran. I have just the bare hull at the moment.  I am using a flex shaft and was wondering where to place the strut. ( i.e. on the centre line, level with the sponsons,),  Any tips before I let loose with the drill, would be a great help.
Thanks,  Derrick.
Title: Re: genesis cat
Post by: Danny on August 30, 2015, 09:43:45 pm
Hi Derrick
The strut is usually on the centreline and behind the transom, which then has an offset rudder level with the front of the prop.
So strut position depends on rudder position.
What cat are you setting up?
Title: Re: genesis cat
Post by: JimG on August 31, 2015, 10:15:38 am
From the name in the title perhaps one like this http://www.hobbyking.com/hobbyking/store/__29871__Genesis_Offshore_Brushless_RC_Twin_Hull_1045mm_UK_Warehouse_.html (http://www.hobbyking.com/hobbyking/store/__29871__Genesis_Offshore_Brushless_RC_Twin_Hull_1045mm_UK_Warehouse_.html)
There are some photos on this page showing the prop and rudder setup.

Jim
Title: Re: genesis cat
Post by: 3838Derrick on August 31, 2015, 11:04:30 am
It,s the Hobbyking 1045mm Genesis.  Thanks for your tips guys,
Title: Re: genesis cat
Post by: 3838Derrick on September 10, 2015, 05:28:33 pm
Well..........I put her in the water for the 1st time yesterday and to say I'm chuffed would be an understatement! She absolutely flies!!.
Title: Re: genesis cat
Post by: Jerry Hill on September 12, 2015, 09:31:13 am
Any pictures or video?
Title: Re: genesis cat
Post by: 3838Derrick on September 21, 2015, 05:00:38 pm
Hi all, Is there a formula for working out prop sizes.  My cat has a 3180KV motor 3/16 flex shaft and I'm running an Octura X442 prop.  (42mm Dia. X 58mm Pitch).  It's running well but I have no idea if I'm attaining the right rpm?????
Is there such a thing as Tachometer for rc boat use?
Title: Re: Genesis cat
Post by: derekwarner on September 22, 2015, 03:04:02 am
Yes.....digital laser hand held tachometers....about AUD$22.00 including air parcel post from Honk Kong

The specification says it all  :-)) ... Derek


http://www.google.com.au/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0CBwQFjAAahUKEwirt93qxonIAhVmHaYKHSkdAdE&url=http%3A%2F%2Fmakezine.com%2F2012%2F11%2F07%2Ftool-review-dt-2234c-digital-laser-tachometer%2F&usg=AFQjCNGJfaCst6tbHoWP6rgtd1wQHidiXA
Title: Re: Genesis cat
Post by: JimG on September 22, 2015, 09:54:59 am
You could use a data logger such as http://www.rc-log.co.uk/v4-micropower-e-logger-kit-100a-cable-type.html (http://www.rc-log.co.uk/v4-micropower-e-logger-kit-100a-cable-type.html) with a suitable rpm sensor http://www.rc-log.co.uk/brushless-motor-rpm-sensor-v2.html (http://www.rc-log.co.uk/brushless-motor-rpm-sensor-v2.html). This also allows you to check current and voltage during the run.
For extra detail http://www.rc-log.co.uk/boat-data-recorder.html (http://www.rc-log.co.uk/boat-data-recorder.html).
Alternatively some modern 2.4GHz radio sets have the option of adding telemetry including rpm and this will show on the Tx screen.

Jim