Model Boat Mayhem

Technical, Techniques, Hints, and Tips => The "Black Arts!" ( Electrics & Electronics ) => Topic started by: Ted_H on July 19, 2013, 09:54:45 pm

Title: buggy pack in series
Post by: Ted_H on July 19, 2013, 09:54:45 pm
ive just test sailed my frigate powered by a 7.6v buggy pack through a elecrtronize 43x speed contrler with a BEC , however the speed seem somewhat slow.. would ther be any detrement to wiring in another buggy pack in series , efctively pringing the voltge up to 14+ volts ..
Unfortunately i cant give details of the motor nor remove it and im not in a position to change the prop either.
Thanks
Ted :police: 
 
 
 
Title: Re: buggy pack in series
Post by: Stavros on July 19, 2013, 10:21:28 pm
Cant see a problem as long as your speed controller can take the voltage ,let alone the motor


Dave
Title: Re: buggy pack in series
Post by: Shipmate60 on July 19, 2013, 10:30:09 pm
What size is she?
What size props?
And
What motors are you using.


Bob
Title: Re: buggy pack in series
Post by: Ted_H on July 19, 2013, 10:42:06 pm
shes around 4ft , a frigate so long and slender, prop is around 35mm. motor unknown but direct drive ( no gearbox)
Title: Re: buggy pack in series
Post by: Martin (Admin) on July 20, 2013, 01:40:11 am
 
 Does the motor sound like it's labouring or is it screaming?
Title: Re: buggy pack in series
Post by: Ted_H on July 20, 2013, 07:23:02 am
neither .. just running slow .. as if underpowered
 
Title: Re: buggy pack in series
Post by: john44 on July 20, 2013, 09:37:50 am
Cant see a problem as long as your speed controller can take the voltage ,let alone the motor


Dave
Electronise are usually o/k up to 24v, but check motor max voltage.

john
Title: Re: buggy pack in series
Post by: Martin (Admin) on July 20, 2013, 09:45:07 am
 
 no stiffness in the drive chain?
Title: Re: buggy pack in series
Post by: Ted_H on July 20, 2013, 09:50:31 am
no its all free turning .. I think ive fit the wrong motor all those years ago, I dont think is  a 6v one as its too slow on 7.2v
 
 
Title: Re: buggy pack in series
Post by: malcolmfrary on July 20, 2013, 09:52:44 am
What size is the motor can?  This gives a starting point for guesswork.  Can you measure what current is being taken?
If its a 12 volt motor, it will be a bit calm on 7.2 volts.  I say 12 volts because that is a very common value, what with almost every car in the world having 12 volt electrics and each being loaded with small electric motors.
Title: Re: buggy pack in series
Post by: Ted_H on July 20, 2013, 10:06:19 am
unfortunately i cant measure the current  i don't have the boat to hand as i type this.... but all i can say its a common sized can for a boat of its size ,certainly not a fan motor size... sorry i cant add any more info. :(( 
edit .... following a call home the motor is around a 40mm dia
Title: Re: buggy pack in series
Post by: malcolmfrary on July 20, 2013, 05:21:54 pm
A 540 is 54mm long, dia 36mm.  If running anemically on 7.2 volts (540s and 6 cells being sort of standard for buggys a while back) either its likely to be a 12 volt one, or it could be a dud.  One trick to help figure something about it is to rotate the prop by hand - you should be able to feel "compressions" as the armature poles pass the magnet poles.  Count them for a full rotation, divide by 2, you have the number of poles.