speed control for rc

[Big Jim]

Can anyone recommend a good and reasonably cheap speed control unit suitable for a 12v rc loco?

[steamie1]

http://www.ebay.co.uk/itm/Mtroniks-MICR ... 1e9061ac85

Try this sort of thing. Make sure you have the capability for what you want to do. And check for Brushed or brushless as well as Fwd and Reverse. If your pulling a lot 30amp if not 20amp. Nine times out of ten we use old style 540 or smaller brushed motors.Hope that helps

[philipy]

http://www.ebay.co.uk/itm/Mtroniks-MICR ... 1e9061ac85

Try this sort of thing. Make sure you have the capability for what you want to do. And check for Brushed or brushless as well as Fwd and Reverse. If your pulling a lot 30amp if not 20amp. Nine times out of ten we use old style 540 or smaller brushed motors.Hope that helps

I've got two of these and very happy with them.

Make sure you do get the 'loco' version though, not just the plain Micro Viper. The difference is that the loco version keeps going if it loses the signal ( in a tunnel for instance) whereas the plain version just stops ( to prevent a car/boat/plane from keeping on going and getting lost!).

[Big Jim]

Ahh, does this mean I can switch off the handset and just let the loco run then?

[Peter Butler]

Yes Jim, it does.... I have one fitted to my diseasel! You can pre set any speed then switch off the controller. It will just keep on going until you switch on again.

[philipy]

You beat me to it, Peter!
I'll just add that if the transmitter stick is self centring to zero, then simply switching it back on, will stop the loco dead in the event of an emergency.

[TonyW]

... check for Brushed or brushless ...

Can I ask, please, what is the difference?

[GTB]

... check for Brushed or brushless ...

Can I ask, please, what is the difference?

Brushed is for conventional DC motors.

Brushless, as the name suggests is for brushless DC motors. Unlike conventional motors, they don't have a commutator and brush gear. Basically they are inside out, the magnet is the rotor and the coils are the stator. Being stationary, the coils are switched electronically and don't need brushgear or slip rings.

http://en.wikipedia.org/wiki/Brushless_ ... tric_motor

Electric model aircraft use them and so I think do high performance model racing cars.

Not all r/c ESCs are created equal. Aircraft don't usually need reverse and if you connect a conventional DC motor to a brushless ESC it will just quiver and then let the magic smoke out.

Hence the advice to check the ESC to make sure it is suitable for model loco. use.

Regards,
Graeme

[TonyW]

Thanks Graeme!

[Big Jim]

They seem to do a standard 10amp one, that is quite a current for a small motor, what sort of draw would a six coupled Essel Engineering chassis have?

[GTB]

They seem to do a standard 10amp one, that is quite a current for a small motor, what sort of draw would a six coupled Essel Engineering chassis have?

My old Merlin Motor Mule is more or less the ancestor of Essel locos and has the same arrangement of a Como geared-head motor and bevel final drive.

It draws about 1A when slipping with a heavy train. I fitted a 2A PTC resistor between the battery and it has never tripped out in service. The PTC resistor is there to protect the motor and speed control if something gets into the final drive and locks the gears up, as the stall current for the motor is something north of 4A and I don't want the magic smoke to escape.

The max motor current in service will depend on the weight of the loco., as that sets the load at which the loco will slip. The Como 950D is the larger motor used by Essel and is about the same performance as quoted above. He also uses the smaller 918D motor.

Regards,
Graeme