What is it

At US$39 these are possibly not worth repairing, but it’s always interesting to see what’s inside, how it works and there’s the challenge of making it work again.

Available from Hobbyking. Most parts are available as spares.

The problem – The repair

One motor then two wouldn’t go.

The motor pods push onto the square CF arms and the arms push into the central hub. The motor wires pass through the arms. There are small channels that guide the fine wires and just enough length. It’s tricky to get the arm in place and the correct wire length at each end.

There’s a plastic cover at the motor end of each arm that slides and clips into place. This was difficult to move so I cut it and reattached later.

The repair involved replacing the two wires in one arm and re-using the plug end. The hole throughthe arm is very small and cannot contain a wire joint. The connectors are very small so I joined the wires to the original plug/lead at the controller end. There is a socket at the motor end which is easy enough to solder new wires onto.

One motor is slow to start and appears faulty, but once under way is fine.

Battery charging

First a little Maxpro charger rant. The Maxpro Intelligent X6 was a bit expensive, and IMO really no better than a cheap Hobbyking LiPo charger. It supposedly handles most battery types but has a few firmware bugs, which means that other than for basic Lipo charging, I don’t trust it on its own. eg. The lead-acid (pb) cut-off settings don’t take effect and it over charges. The ability to hook it up to a PC would be good if it didn’t rely on a crappy piece of Windows software. Note to all companies making this type of product with a “also supplied” support software: make it multi-platform and open source. You are selling hardware, and you are crap at software; this applies equally to both Western and Asian companies.

My charger wouldn’t handle a single cell LiPo. The Q-Bot had 4 nano-tech 600mAh batteries so I made up a simple adaptor to charge them all as one 600mAh 4-cell. This worked well but took a little longer as the charger had to balance during the charge.

Don’t try this at home: Being simple, it’s essential to plug the cells and the adaptor in correctly. Get it wrong and you could damage a cell, the charger or burn your house down.

I charged the 4 cells at 0.5C to be on the safe side; that’s 300mA for a 600mAh cell.

How it flies

It flies quite well. Not very powerful but climbs reasonably quickly. Yaw is very stable, pitch and roll drift but can be rimmed at the transmitter during flight; but you have to be quick in a small space. Froward flight begins quickly but it soon levels out again, as if the flight controller re-zeros itself every few seconds. This may be a feature as without adding power it stops it picking up speed and running away.

This makes it quite flyable inside.