Model Boat Mayhem

Technical, Techniques, Hints, and Tips => DC Motors (Brushed) and Speed Controllers => Topic started by: Koldness on January 08, 2007, 12:36:44 am

Title: running two motors
Post by: Koldness on January 08, 2007, 12:36:44 am

Hey guys,

Another question.  I have a kit that requires two motors, are there any plans or home remedies for making sure both motors run the same speed?  I dont have the cash flow for a motor mixer yet.

Thanks

Kris

Title: Re: running two motors
Post by: Doc on January 08, 2007, 04:45:35 am

Kris,
If you are going to use more than one motor then all of them should be the same motor (prop too).  If one ESC is used to control all motors there can be a very slight difference in motor speeds, which is fairly typical.  Rudder 'trim' should handle it.  For multiple ESC/motor combinations, if all the ESCs and all the motors are the same, rudder trim should be able to handle that too.  Some ESCs have adjustments to bring motor speeds at least 'ball park' close.  Then, (your right!) rudder trim.
Worried about one motor wearing out faster than the other one?  Don't waste a lot of good 'worry' on it, it'll probably live longer than you will, or at least your interest in that particular boat - lol.
 - 'Doc

Title: Re: running two motors
Post by: 2772e on January 08, 2007, 07:01:35 pm

Hi Kris,

I have run a couple of boats with twin motors and one esc. Works very well but make sure they are running counter directional. One of mine  runs a milisecond before the other one but when they get going they are as good as gold.

Just make sure your esc is capable of running both.

You can always add a mixer and another esc at a later date.

Regards

Simon

Title: Re: running two motors
Post by: glenpens on January 08, 2007, 07:39:17 pm

Has anyone got a diagram for wiring tow motors and what is required.
Glen

Title: Re: running two motors
Post by: 2772e on January 08, 2007, 07:45:19 pm

its fairly simple but i cant do diagrams.

One motor wire from esc to one motor and the other one to the other motor. then attach a wire from one to the other on the spare terminal.

Just check which way they are running before final fittment/soldering.

I think you can see on this picture.

Regards

Title: Re: running two motors
Post by: Martin (Admin) on January 08, 2007, 08:59:46 pm

How about this..... Twin Motors (http://www.modelboatmayhem.co.uk/Common/Electrics/Twin_motors.htm)

Title: Re: running two motors
Post by: Koldness on January 08, 2007, 09:18:06 pm

Thanks Guys!  You are are Helpful!!!

Title: Re: running two motors
Post by: Peterm on January 09, 2007, 02:37:58 pm

Martin, you beat me to it.   I have used Dave`s article for guidance on several boats, and its the best!

Title: Re: running two motors
Post by: glenpens on January 11, 2007, 09:55:02 am

Kris
Barrie has sent me a sketch of how to wire up what your asking for the only troubler for me is that the cost would be £68 when the  Ship only cost £20. ( I could try and send you this if you require it)
 I am thinking of buying another boat to use as a spare. Do you or anyone else know that ships/ boats sold as 27MHz  are all the same 27MHz ie last 3digits required. Retailers selling these boat don't know they just say 27MHz.
If any one has one of these boat if you take the TRANSMITTER rear cover off there is a good chance you can read the crystal.
I would be glad to hear what these crystals are to see if they are different ones or are they all the same.
Glenl

Title: Re: running two motors
Post by: barriew on January 11, 2007, 12:06:11 pm

Glen, Kris,

My sketch is effectively the same as Figure 5 in the link Martin gave. I just omitted the steering servo as I knew you didn't have the rudder.

Barrie