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Author Topic: Few Pre-brushless related questions  (Read 1838 times)

lee

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Few Pre-brushless related questions
« on: October 27, 2008, 04:27:08 PM »

Hi all, i have a Capricorn 54 RTR boat at the mo that i put my Sanwa Gemini 2 radio gear into and am now thinking of going brushless. Is this a problem with a plastic hull? I'm only going to go for 7.5t spec, not mental 4t. Do i need a metal prop? metal rudder? or any other parts? I noticed on the prop shaft it only sits on brass metal bushes, would ballraced bearings be better?

thanks
Lee
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Martin [Admin]

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Re: Few Pre-brushless related questions
« Reply #1 on: October 27, 2008, 05:18:09 PM »


A 7/5 t (turn, windings) motor is still quite hot, which one are you going to get?

 Still not knowing much about this but the little I have learned it you have to have the right size motor
and one that will give you the revs you require.

I'm guessing, you're going for a Speed 700 'size' motor which I think relates to the motor wattage,
(this is the same as saying a Speed500 is bigger and more powerfull than a Speed 400 motor), but I
haven't got the hang of how wattage relates to motor size ie. what's the Wattage of Speed 700BB
on 12volts?  (Eg. Speed700BB motors range from 200-1Kw!)

The PRM of brushless motors is stated in Revs. / Volt ie. a 1000 r/v motor will in theory do 10,000 on 10volts.

Winding are also important.
Lower Turn = Higher Top End/Less Torque
Higher Turn = Lower Top End/More Torque

There are also two basic types of Brushless motor designs,
Inrunner ( conventional spinning armature )
Outrunner (case and shaft spin around a fixed bearing end plate.)

Good luck with selecting the right motor, there only about 10,000 so far to chose from!

TIP of the WEEK! Go to Youtube, do a search for brushless, find a boat similar to yours with a performance
you like, leave a comment asking what setup they are using (if it isn't already there), look up the spec of that motor!
I've learnt a lot of useful stuff this way!

RUNNING GEAR.
You might get away with using the supplied running gear in the boat and using a higher powered motor, it's worth a try!
If it fails, fit all metal running gear. (Make sure you have fixed flotation in the boat and canopy!)

Don't work about the shaft bearings at the moment, you're probably going to have to replace the solid shaft with a
flexy setup anyway.

Let know how it runs out of the box and keep us informed with progress Lee.


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Martin [Admin]

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Re: Few Pre-brushless related questions
« Reply #2 on: October 27, 2008, 06:37:28 PM »

This is one of my favourite brushless video / setups.
http://uk.youtube.com/watch?v=bfVQFpUiMSg

On the up wind leg (left to right), the boat actually achives take-off speed!
That's enough speed around a Deep Vee hull to produce enough areo dynamic lift to produce flight!!?!?!?

Hull is a Toysport Triton Hull with a LMT 2240 /8 -

http://www.offshoreelectrics.com/proddetail.php?prod=TP-Triton -  Cheap!  :o
http://www.marinerc.net/fastelectrics/triton/triton.htm
http://www.lehner-motoren.com/ms22.php

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lee

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Re: Few Pre-brushless related questions
« Reply #3 on: October 27, 2008, 07:17:23 PM »

Dont want to sound thick but what it a fixed flotation for the boat and canopy?

also where would i get a flexi shaft? and metal running gear from if i were to need them?

thanks for all the advice much appreciated

Lee
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lee

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Re: Few Pre-brushless related questions
« Reply #4 on: October 27, 2008, 07:21:23 PM »


A 7/5 t (turn, windings) motor is still quite hot, which one are you going to get?


sorry forgot to reply to that, probably go for the nosram storm 7.5t
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Re: Few Pre-brushless related questions
« Reply #5 on: October 27, 2008, 09:35:41 PM »

Don't want to sound thick but what it a fixed flotation for the boat and canopy?

also where would i get a flexi shaft? and metal running gear from if i were to need them?


High powered boat take a hell of a beating, boats flip, canopies fly off but at the end of the day you still want to
go home with a whole boat .... even if it's more pieces than it arrived in!

For bits and pices see:

http://www.modelboatmayhem.co.uk/forum/index.php?topic=13504.0

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