do you need 2 speed controllers if you have a twin, or can you parallel 
the motors up????

Kevin wrote:
> do you need 2 speed controllers if you have a twin, or can you parallel 
> the motors up????

Sometimes it works, sometimes it works unreliably, but mostly it doesn't 
work a all.

A lot depends on the controllers start up algorithm. If it whacks a big 
pulse on one pole to synch the motors, then does a complex startup 
algorithm, it can work. Kontronik used to sell twin sets on one controller.

If it does work, you get absolute synch, which sounds great.

Some people have foud that spinning the props by hand before opening the 
throttle gets the motors in synch on other controllers, then open the 
throttle. But beware restarting non windmilling props±!

Instant smoke.

The Natural Philosopher wrote:
> Kevin wrote:
>> do you need 2 speed controllers if you have a twin, or can you 
>> parallel the motors up????
> 
> Sometimes it works, sometimes it works unreliably, but mostly it doesn't 
> work a all.
> 
> A lot depends on the controllers start up algorithm. If it whacks a big 
> pulse on one pole to synch the motors, then does a complex startup 
> algorithm, it can work. Kontronik used to sell twin sets on one controller.
> 
> If it does work, you get absolute synch, which sounds great.
> 
> Some people have foud that spinning the props by hand before opening the 
> throttle gets the motors in synch on other controllers, then open the 
> throttle. But beware restarting non windmilling props±!
> 
> Instant smoke.
> 
I might rethink the idea then and put two ESC in, mind you I could mix 
the throttle with the rudder as its a twin with no ailerons that way

Goedendag ;-)

And be careful with gearboxes, you might strip a gear or two in the process.

Vriendelijke groeten ;-) Ron van Sommeren
near Nijmegen, Netherlands
int. E-fly-in: http://home.hetnet.nl/~ronvans/

  ----- Original Message ----- 
  From: The Natural Philosopher
  Newsgroups: uk.rec.models.radio-control.air
  Sent: Saturday, October 06, 2007 2:00 PM
  Subject: Re: Dual brushless


  Kevin wrote:
  > do you need 2 speed controllers if you have a twin, or can you parallel
  > the motors up????

  Sometimes it works, sometimes it works unreliably, but mostly it doesn't
  work a all.

  A lot depends on the controllers start up algorithm. If it whacks a big
  pulse on one pole to synch the motors, then does a complex startup
  algorithm, it can work. Kontronik used to sell twin sets on one 
controller.

  If it does work, you get absolute synch, which sounds great.

  Some people have foud that spinning the props by hand before opening the
  throttle gets the motors in synch on other controllers, then open the
  throttle. But beware restarting non windmilling props±!

  Instant smoke.

Kevin wrote:
> do you need 2 speed controllers if you have a twin, or can you parallel 
> the motors up????


   yes you do need to have 2 controllers for this to work reliably. 
Please note that when joining up the 'servo' lead coming from each to 
the Rx, that you will need to sever the +ve lead from one of them or you 
will have both controllers trying to provide power to the rx.  A better 
alternative is to wire the +ve leads together but insert a diode 
(preferably Schottky type) into each wire before the join - this gets 
you the power from each of the controllers going to the Rx - a bonus, 
considering the poor power supply capability of most BEC's on these 
things.  I'm just completing a GWS Me262 using this arrangement.

hth,


  Dave