Model Boat Mayhem

Mess Deck: General Section => Model Boating => Topic started by: colin-stevens on September 10, 2014, 07:56:47 pm

Title: motors for a RAF crash tender boat
Post by: colin-stevens on September 10, 2014, 07:56:47 pm

Hi the collective,
Trying to get some info together on my next hopefull project. It is going to be a 46" Vosper RAF Crash Tender. It is at a scale of 1/12, huge. From the product info a Scorpion 4020-14
 Motor Specifications
 Io = 1.59A at 21V
 Kv = 484 rpm/volt
 R = 0.024 Ohms
 Length = 41.2mm
 Diameter = 48.7mm
 Weight = 297g
 Continuous current accepted = 80A
 Maximum continuous power = 1500W
 Shaft = 6mm carbonised steel (protrudes both ends)
 Collet-type prop adaptor and back-mount supplied
 Motor fixing = four 4mm bolts supplied
 Male 4mm bullet connectors fitted to motor
 

gives good results. However this is for a one shaft boat. I want to be a purist and fit 2 shafts. My plan is to fit a motor of just over half the previous mentioned spec. Got myself totally confused and need help. Any one got any ideas?

Title: Re: motors for a RAF crash tender boat
Post by: Subculture on September 10, 2014, 08:43:27 pm

I would look at something like this. Huge number of poles will give  you superb low speed throttle too.

http://hobbyking.com/hobbyking/store/__41619__4010_485KV_Turnigy_Multistar_22_Pole_Brushless_Multi_Rotor_Motor_With_Extra_Long_Leads.html (http://hobbyking.com/hobbyking/store/__41619__4010_485KV_Turnigy_Multistar_22_Pole_Brushless_Multi_Rotor_Motor_With_Extra_Long_Leads.html)

http://hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=41628 (http://hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=41628)

A pair of these controllers will run the boat all day long.

http://hobbyking.com/hobbyking/store/__28375__HobbyKing_X_Car_60A_Brushless_Car_ESC_sensored_sensorless_.html (http://hobbyking.com/hobbyking/store/__28375__HobbyKing_X_Car_60A_Brushless_Car_ESC_sensored_sensorless_.html)

I use these ESC's in cars and they're superb, however I can't think of any reason why they shouldn't work fine in a boat too. One thing I would warn you, they come with no instructions, but as they're basically a cloned Hobbywing controller you can use their instructions. I purchased a USB dongle with my ESC's which makes it easy to update the firmware and configure the controllers using a PC.

Make sure you use lipos for best performance.

Title: Re: motors for a RAF crash tender boat
Post by: red181 on September 10, 2014, 09:56:14 pm

have you read this Colin?

It might help :-))

http://www.modelboatmayhem.co.uk/forum/index.php/topic,39278.0.html

Title: Re: motors for a RAF crash tender boat
Post by: colin-stevens on September 11, 2014, 06:45:28 pm

Hi Red181, did a search and didn't get your thread, so thanks for replying, haven't had time to read all your thread as yet, but have asked for a summary.

thanks for taking the time.

Colin