Dyson Digital Motor (Vacuum Cleaners)

[BillTodd]

I suspect that the main disadvantages of using this motor (i.e. bought as a spare part from Dyson) would be the difficulty of driving another spindle without buggering-up the dyson bearings and the very limited starting torque produced by this type of motor; It looks to me to be a single phase variable reluctance motor [edit - It's not it's just a brushless DC motor - I missed the bit about the neodyium magnet]. The start routine will be a hit & miss process i.e. apply a pulse, detect movement, test if it's spinning it the desired direction - correct if necessary with next pulse, then sync the pulses etc.

If you attach a spindle, the extra drag of AC bearing (for instance) might prevent the motor from starting at all.

From Dyson's POV the main advantage must be manufacturing cost (although their plant looks more like a small volume operation than a proper production line - I love the robot arm coil winder :))

I suspect you'd be better of sticking with a poly-phase permanent magnet motor as used in model aircraft (I've seen 1kW motors for ~£30, and 12v controllers for them aren't much more)

[bogflap]

I agree. That robot arm is something else.

I suspect that the main disadvantages of using this motor (i.e. bought as a spare part from Dyson) would be the difficulty of driving another spindle without buggering-up the dyson bearings and the very limited starting torque produced by this type of motor; It looks to me to be a single phase variable reluctance motor [edit - It's not it's just a brushless DC motor - I missed the bit about the neodyium magnet]. The start routine will be a hit & miss process i.e. apply a pulse, detect movement, test if it's spinning it the desired direction - correct if necessary with next pulse, then sync the pulses etc.

If you attach a spindle, the extra drag of AC bearing (for instance) might prevent the motor from starting at all.

From Dyson's POV the main advantage must be manufacturing cost (although their plant looks more like a small volume operation than a proper production line - I love the robot arm coil winder :))

I suspect you'd be better of sticking with a poly-phase permanent magnet motor as used in model aircraft (I've seen 1kW motors for ~£30, and 12v controllers for them aren't much more)