XK K110 - Mods to make it even better!

While in lockdown, micro helicopters have become the must have among rc helicopter pilots, and the general consensus is that the XK K110 is one of the best micros out there, hands down.

It is cheap, it flies incredibly well, it is powerful, and really allows pilots to test manoeuvres with the feeling of having a real helicopter. For more information and some beginner settings, read here.

All good things come to an end though, even the excitement of owning the best micro heli on the market: you will eventually get bored of it, and you will want more.
Luckily for us, many clever people on the web have experimented and tested lots of upgrades and mods for this little gem. I would like to mention Salrica, SHYguy, BirdBarber, Kiwi Craig and Flyngboats, among others, for their great contribution to this subject.

I divided this article in different chapters, to help you find what you might be looking for.
Take your time, there is a lot of information here, and it is susceptible of evolve with time, so come back and check it from time to time!




Affiliate disclaimer: some of the links are affiliate links. Should you purchase some items through these links, I would get a small commission from the vendor, as it was advertising. 
Nothing changes for you, the purchase price stays the same. Thank you!

General troubleshooting / upgrades

• If you experience erratic collective behaviour, check the main gear, 99% it has slipped down on the main shaft and needs to be pressed up again. You can use a dab of hot glue to fix it in place;
• Put o-rings on the swash balls and on the blade grips: this will reduce slop a lot
• The gyro is quite sensible to vibration, and usually translates them in tail wag, or tail problems in general. Some factors that can generally cause vibrations:
• Bent or broken parts (main shaft, spindle, ...);
• Slop in the blade grips (insert a bit of thread in the screw hole, through the blade, and put the screw back before trimming the thread. This will reduce the slop and make the blade tight again;
• The adhesive holding the FBL unit can unglue itself and let the unit move around. Change the adhesive foam with something stiffer;
• The tail blades can bend a little inwards or outwards after a crash. It is important to straighten them, because this can induce vibrations;
• To extend the life of your canopy you can use some transparent tape on the inside of it;
• If you crash hard enough, and break the pins on the frame, have a look here for how to repair them. It is an article about fixing the frame of a Blade Nano S2, but the same principle applies;
• If your K110 bogs a lot, try to lower your pitch end points, and to use a V throttle curve;
• Avoid the bling! There is absolutely no need for metal upgrades, the helicopter flies perfectly with its plastic bits, will absorb impacts much better and it will be cheaper to repair;
• Keep it light. No explanations needed;
• To program your ESC, have a look at this write up by BirdBarber on RCGroups, where he explains the procedure in detail;
• Instead of replacing the feathering shaft every time, you can bend it back :

Compatibility

• The XK K110 is practically the same helicopter as the V977. All the pieces are interchangeable, and usually V977 pieces are cheaper. The only differences are the flight controller, the ESC and the tail motor (1mm diameter shaft on the XK K110, 0,7mm on the v977);
• The XK K110 and the XK K120 share the same head, but use different blades;
• You can replace stock servos with Hobbyking's HK-5330. Servo arms are different, so it is better if you keep the stock arms and replace the servos. In same cases the connectors is different, so this is a thing to check!
• You can use K120 canopies, just drill new holes;
• The V977 canopy is the same as the K110 one, sometimes it is sold cheaper;

XK K110 and XK K120 side by side. Image courtesy VD2021@Helifreak.com

• The XK K110 tail will hold much better if you upgrade it with a SUT tail motor and XK K120 tail blades. I only changed the tail blades with the ones from the K120 and it flies very well.
• For more headspeed, get a 9T pinion, from Banggood;
• Another solution is to convert your K110 to 2S power. Birdbarber and other forum members have extensively tested many solutions, which are far too complex for this little compound, please find a link to his findings here;
• When you manage to snap the tailboom, get a solid one on ebay. Dimensions are 2,5mm x 2,5mm. You will have to run the motor wires on the outside: just wrap them around the boom;

The brains of the XK K110. Image courtesy SoloProFan. View original post