Walkera Dragonfly 4 motor upgrade
This page talks about upgrading the Walkera Dragonfly 4's original stock motor to a better performance brushed motor.
It is of course possible to upgrade to a brushless motor for even better performance, but this involves changing the ESC too, so we won't go there just yet. A good quality brushed motor, combined with a Li-Po (lithium polymer) battery pack gives perfectly adequate performance.
My personal choice was a Slo-Max 300 (part #61107 from Team Orion Avionics), purchased from good ol' eBay (find it on eBay). This motor is a trusted Park Flyer brushed motor that gives plenty of power for the Dragonfly 4 electric helicopter. Made by electric motor kings Mabuchi, it's a solid electric motor, and cheap to buy!
Above, the new Slo-Max 300 next to the original Walkera stock motor
Swapping the motors over is a fairly straightforward job. Something that you might want to do, but isn't necessary, is to change the connectors. As the photo above shows, the stock Walkera motor is fitted with the red JST connector, whereas the Slo-Max isn't.
This actually isn't such a big deal because the male JST connector from the rx/ESC does fit snuggly into the Slo-Max one. Not as snug as into a female JST obviously, but secure enough to stay connected, the lugs clearly interlock. But, if you want to be absolutely sure, fire up your soldering iron and swap the leads and connectors over from motor to motor.
Incidentally, if you do this note that Walkera's pink corresponds to the black negative lead of the Slo-Max, and Walkera's white to the red positive.
The other thing to do is put a pinion on the new motor; it probably didn't come with its own pinion so you'll either have to buy one separately, or take the one off the Walkera motor. This can be a bit tricky as it's such a tight fit on the shaft; take lots of care not to damage the teeth of the pinion, brass is soft and is easily damaged!
Putting the pinion onto the new motor can be equally as tricky so, again, take great care. There is no magic to this, it just slides onto the shaft. Obviously, this job is done with the motors removed from the helicopter.
To remove the original motor and fit the new one, turn the helicopter upside down. The two motor mounting screws are clearly visible at the front of the main gear (shown right).
Remove both screws and carefully lift out the motor, putting the new one in its place. Be careful to get it in exactly the right position, so that the motor pinion interlocks well with the main gear. The mounting screw slots do have some play in them, so it is possible to mount the motor slightly away from its optimum position.
Before you completely tighten the screws, turn the main gear and make sure that everything revolves freely, without much friction. Similarly, check that the pinion teeth and main gear teeth are actually interlocking, and not missing each other.
You'll be pleasantly surprised at how much extra power your motor upgrade will give your Dragonfly 4 helicopter! The stock Walkera motors do wear relatively quickly, and the symptoms of a tired motor match the symptoms of a dying battery; your helicopter will struggle to stay airborne even on a fully charged battery pack.
Your new motor will have you hovering on a power setting much much less than you were having to hold with the worn out motor, so flight times will be longer and performance much better!
Related pages
Battery upgrade - time to go Li-Po.
Landing gear & skids upgrade - add a touch of class to your helicopter.
The Dragonfly 4 - what you get and what to do with it all.
Spares & repairs - useful tips for the Dragonfly 4.
Rotor blade balancing - a crude but effective way if you don't have a balancing tool.
Rotor blade tracking - how to get the blades tracking correctly.
Flybar balance and paddle pitch - more ways to stop vibration.
Main frame replacement - guidelines for the worst job of them all!
Index - to all Walkera Dragonfly 4 related pages.
