Hello all; I have seen some references to the use of coreless and or brushless motors in the use of model trains but the information seems to be sparse and incomplete. I wonder if some members of the forum can give me a somewhat more complete picture of these motors. Do they have advantages such as improved performance or torque? Disadvantages? Thanks
Old Fat Robert
Advantages of Coreless Dc Motors:
Disadvantages:
As Coreless Dc Motors usually can reach very high rpms and has a compact structure, these motors can heat quickly. Especially when running at full load for a short time. So it is usually advised to use a cooling system with these motors. Overheating can be an important problem specially for Coreless Micro Dc Motors. So a disadvantage of a coreless motor is, it cannot handle overloads when compared to a cored motor. The bonding adhesive that holds the windings can lose its bonding character and the motor will be broken
Happy times!
Ulrich (aka The Tin Man)
"You´re never too old for a happy childhood!"
Ulrich: First off thank you for your reply. Does the heat factor (in your opinion) make these motors a good fit for model trains, specifically HO scale. When you speak of a cooling system are you speaking of added ventilation or an actual on board system?
I have never seen any cooling device in a model loco using a coreless motor and I don´t think it is necessary. They do get a bit warmer, but, unless you stall the engine under full load, there is little danger of overheating.
Coreless motors work best with pure DC. The don't like pulse width modulation (PWM) with low frequency, which can lead to overheating.
That was the reason they were deemed unsuitable for DCC for some time. Faulhaber, one manufacturer, recommends a PWM frequenzy of more than 20 kHz. Most current decoders comply with this recommendation.
Brushless motors are not suitable for model locomotives for a number of reasons, I think.
They need a special controller that creates the rotating magnetic field that makes them turn. DC track power is obviously not suitable. A speed controller is needed in the locomotive that needs controlling, possibly radio control.
Todays DCC is not able to control brushless motors either. The speed control part of a decoder needs to be changed.
A brushless motor wouldn't be a drop-in fit for a locomotive. Those with fitting dimensions turn at about 25,000+ rpm at 12 V, too high for the current locomotive gear ratios.Regards, Volker