Model Boat Mayhem - Forum

Technical, Techniques, Hints, and Tips => BRUSHLESS Motors and Speed Controllers => Topic started by: Swefred on May 04, 2011, 08:20:14 PM

Title: Choice of motor, controller and battery pack, help appreciated!!
Post by: Swefred on May 04, 2011, 08:20:14 PM
Having been out of the model boating for a number of year I have no knowledge on the subject of brushless motors etc.

I do, however have a 1:6 scale model of the Fletcher Arrowbolt 21 and a rare Hirobo Volvo Penta 280 Outdrive (1:6) that I intend to install on the Fletcher.

(http://s2.postimage.org/yfgma6uc/P1010008.jpg) (http://postimage.org/image/yfgma6uc/)

I have freed the boat from the ugly red paint. It is now back to it's original 70's cream gelcoat.

(http://s1.postimage.org/ops243k4/B_wb_P9_B2k_KGr_Hq_N_j_MEz_Kg5pjb7_BN_q_Wjo_Tvg_12.jpg) (http://postimage.org/image/ops243k4/)

The boat is slightly over one meter in length and should be powered by a glow plug engine from .60 and up. The outdrive is said to be able to handle up to 26cc gas engines.

Could anynone please help me in recommending a suitable power combination. I'm not looking for warp speed, more like the scale equivalent of the 50 knots a full scale version would do.

BTW, does anyone know which company manufactured the Fletcher model.

Thanks in advance,
Fred


Title: Re: Choice of motor, controller and battery pack, help appreciated!!
Post by: nick_75au on May 05, 2011, 01:31:13 PM
Thats a wicked looking outdrive you have there, wow :-))
Hi Fred,
What size of propeller is on it, but as a rough starting guide, if you peruse the Hobbyking website they have brushless motors they say are equivalent to various size glow engines, though you will need around 8-000-10,000 RPM, so if you pick a motor of a certain Kv then divide 10,000 by that number this will give you the battery voltage you need. you will find that as motor size equivalent goes up Kv will go down, requiring a higher pack voltage, In general fast boat motors run at a higher RPM than Air motors of which the hobbyking are basing as their equivalent so voltage or Kv may need to be upped somewhat from that reccomended by the site. 

0.60ci glow equivalent
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=14405
1.6ci
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=14408

Biggest capacity lipo in the voltage required, they can be series-ed or parallelled to make up the required volts and capacity

Nick
Title: Re: Choice of motor, controller and battery pack, help appreciated!!
Post by: terryn on May 09, 2012, 09:34:49 PM
Hi Fred I bet you didn't think there was another person in the same position as you. I too have the same boat and drive system and also have issues with power. Did you ever sort it out and how does the boat look now? I will post some photos when I have time.
regards Terry
Title: Re: Choice of motor, controller and battery pack, help appreciated!!
Post by: nick_75au on May 10, 2012, 10:05:08 AM
Yes I would like a bit of feed back as well,  :D

Nick
Title: Re: Choice of motor, controller and battery pack, help appreciated!!
Post by: dave67 on May 12, 2012, 11:10:58 PM
Hi if i was to go brushless i  would probably go for a 36kv with a 70amp esc all water cooled running on 3 cell but thats  what i would try ( personal choice)
hope this helps regards dave
Title: Re: Choice of motor, controller and battery pack, help appreciated!!
Post by: phillnjack2 on August 28, 2012, 03:31:03 PM
the fletcher arrowbolt was a Cambria model  (dont think they exist now)
they also done the fletcher arrowshaft at the same time.

i had one of these many years ago and wish i still had it.
they came with what was called a zip strut, looked a bit like and outdrive with a rudder on it.
like todays surface struts.

mine was cream, they made them in every colour you could think of as long as it was cream ha ha
they also had a interior with the seats all one piece and a back bathing pad.

i wish i still had mine or could find one out there to do up.

I got mine secondhand and it came with a measly little OS 35 and could not get on the plane.
you do need the power of a 60 to make the boat go as it should.
when i put an enya 60 in the boat it was a real quick boat that handled well.
the original engine mount also came with these and was made by weston.





phill