Model Boat Mayhem

The Shipyard ( Dry Dock ): Builds & Questions => Pleasure boats, Sports, Race, Power and Leisure Boats: => Topic started by: essex2visuvesi on March 19, 2012, 11:08:14 am

Title: Precedent Huntsman 36" powertrain questions
Post by: essex2visuvesi on March 19, 2012, 11:08:14 am
Well I stole a Fibreglass Huntsman kit on ebay last week, its only the baby one (36" hull) and I have a couple of questions regarding the powertrain and parts suitability

Will this rudder be OK? the instructions just say "Large"
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=190386430817

And this propshaft?
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=200638458535&var=500025050284
or should for a larger M5 propshaft?

Power will be a 6S lipo (Got several from my RC Helis) and brushless motor at about 800-1000Kv
Title: Re: Precedent Huntsman 36" powertrain questions
Post by: HS93 (RIP) on March 19, 2012, 11:25:08 am
the  instructions for this model was based on  Ic I think so think about shaft placment the ones I have seen that sail well have the prop further back have a look on REG181s build I know you know Paul so pm him he will help you.

Peter
Title: Re: Precedent Huntsman 36" powertrain questions
Post by: essex2visuvesi on March 19, 2012, 11:27:58 am
Yep I have been talking to him about the upcoming build but didn't want to keep pestering him with every little detail lol
Title: Re: Precedent Huntsman 36" powertrain questions
Post by: triumphjon on March 22, 2012, 08:08:14 am
morning essex ! , ive built two hulls up , one as a huntsman the other as the spear ( enclosed wheelhouse spearfish ) and moved the shafts back towards the stern , both having 8 " m4 stainless shafts from marks model bits in newport . having them on twins shafts reduces the amount of roll when cornering at speed . for motors ive got a pair of model motors direct 777 in the huntsman being driven by a single  electronize 15 amp esc , whereas the spear is running two eflight park 450 brushless motors , with fusion tornado escs ( one per motor ) each being fed with a 11.1 v lipo , its still very much in the testing stages but is already lifting the bow , and giving a reasonable 40 mins of running time ! jon
Title: Re: Precedent Huntsman 36" powertrain questions
Post by: essex2visuvesi on March 22, 2012, 08:58:41 am
thanks for the reply
is it difficult to convert to a 2 motor setup?
Any chance of a couple of pictures?

I've been busy collecting up bits and bobs ready for the arrival of the kit (last seen leaving Copenhagen according to the tracking number lol)

I have a 200A watercooled Brushless speed controller on the way.  Not expecting it to be 200 proper amps as its rated in the much smaller chinese amps :) and a 1020Kv 4240 660W brushless outrunner. This will fitted to a watercooled mount (After discussions with Red181 I decided to go with a slightly smaller motor than the one he suggested as His Huntsman is a 48")
This should give a no load shaft speed of around 18krpm allowing for about 20% loss
Batteries are 2800Mah 40C 6S lipos from my Trex-500
As outrunners are known for heat soak after running I may run a small auxillary water pump to keep water flowing through the cooling system

Props are yet to be purchased depending on my decidion of 4 or 5mm propshaft (leaning towards 4mm for better prop selection), but I will be buying a selection of plastics from 30mm upwards for testing purposes.  Once testing is complete a suitable brass prop will be found

There will be lots more questions over the coming weeks I think
Title: Re: Precedent Huntsman 36" powertrain questions
Post by: triumphjon on March 22, 2012, 06:44:02 pm
although both hulls were purchased as second hand models ive removed everything , glassed up the original holes from inside and started again , in order to gain a little freeboard my cabin sides are also permanently fixed into the hulls , both the cabin roof sections and cockpit floor are removable on the huntsman while the spear has the front cabin roof , rear floor and rear of wheelhouse / floor removable . the motors are below the cockpit floors on both models
(http://s16.postimage.org/la756s8qp/001.jpg) (http://postimage.org/image/la756s8qp/)

(http://s16.postimage.org/kjef106dd/003.jpg) (http://postimage.org/image/kjef106dd/)
Title: Re: Precedent Huntsman 36" powertrain questions
Post by: essex2visuvesi on March 27, 2012, 01:41:36 pm
Ive decided to go with a single prop setup for now, but I'll probably live to regret it lol

So next question should I go with a 4mm or 5mm propshaft? There seems to be more choice of props in 4mm, but I'm wondering if the extra thickness/rigidity of the 5mm shaft would be better
Title: Re: Precedent Huntsman 36" powertrain questions
Post by: triumphjon on March 28, 2012, 07:55:21 am
ive gone for the 4mm shafts on all of my models as there is a reasonable range of props available at my local model shop ! my brushless spear is currently running a pair of handed 30mm 2 bladed jobs from graupner , at least with the lipo packs ive managed to save a little weight .