Model Boat Mayhem

Technical, Techniques, Hints, and Tips => The "Black Arts!" ( Electrics & Electronics ) => Topic started by: Klunk on September 21, 2015, 05:42:27 pm

Title: Twin motor problem
Post by: Klunk on September 21, 2015, 05:42:27 pm

I have a Southampton tug which has twin motors. these run through the gearbox supplied.
The problem I'm having is that both motors start at different times.
 Also, there is a mixer in the boat.
 now forward and reverse the starboard motor switches in very fast but the port acts slower.
 both motors have their own esc (mtronics). When using the mixing function, port motor does not work at all unless at hi revs.
I cannot see any physical problem, but if I flick the port motor when in forward or reverse it bursts into life. Back to neutral it stops again.
 I have stripped the prop out and roller tested it on glass and its not bent, the gearbox seems to have all its teeth.
 Ive disconnected the mixer unit and the port prop is still the same with a y lead .
any ideas???

Title: Re: twin motor problem
Post by: Martin (Admin) on September 21, 2015, 06:04:12 pm

 
What happens when you disconnect the shafts?

Title: Re: twin motor problem
Post by: Netleyned on September 21, 2015, 06:06:41 pm

Sounds like brush gear/commutator problem on the port motor
Swop the motor leads and see if the same thing happens.
This should rule out the esc and point to the motor.

Ned

Title: Re: Twin motor problem
Post by: Capt Podge on September 22, 2015, 12:28:40 am

Hi Klunk, this is just a stab in the dark - are you using ESC's with BEC, if so, have you remembered to disable the red wires ?
 
Regards,
 
Ray.
 

Title: Re: Twin motor problem
Post by: Martin (Admin) on September 22, 2015, 01:24:34 am

 ..... (one of the red wires)

Title: Re: Twin motor problem
Post by: Klunk on September 22, 2015, 01:52:43 am

Yes done that already. So I'm looking at a change of motors which I have in stock.

0.....if this still happens is there a way to match the two motors to start at near the same time

Title: Re: Twin motor problem
Post by: Bob K on September 22, 2015, 08:09:08 am

Once you have ruled out a problem with one or other motors, and the shafts spin freely, it is probably the ESC set up 'neutral point'.  Not easy to match exactly on twin Mtroniks I have found.

For twin shaft boats I have moved to Action P94's, as an all-in-one twin ESC with mixer it eliminates all the port/starboard setup balance issues.  No set up required.  OK, not cheap, but well worth it.  I have 5 in various boats.