The Holy Stone X400C is a WiFi FPV quadcopter from Hol yStone, the larger brother of the X300C. As most Holy Stone products it’s a rebrand: the original is the MJXX400C. While the manufacturer is Chinese, the X400C is high quality and well put together, overall a great product.
The X400C has all the electronics you can expect from such a small package:it has a 6 axis stabilization system, flip on button press, headless mode with a simple return home function, throttle limit and beginner and advanced modes and a WiFi camera for FPV.
The X400C is fairly fast and it’s flight is super stable. It has a 100 to 200meters range depending on the conditions, and can fly just as high too. The WiFi range for the video is about 30 meters.
The X400C is robust, it has landing skids and prop guards out of the box.
Still would anything happen to your X400C, compatible parts are available, for example Amazon has a set of props, guards and legs and replacement batteries too. The propellers are held in place by tiny screws, you will have to screw them out for the change.
The X400C weighs around 112 grams so it is not able to lift large weights.Still, tiny objects are no problem for it, for example a key chain camera is a payload it could lift. Due to the low weight FAA registration is not necessary.
The quadrotor can fly both indoors and outdoors, with it’s huge range it really shines when it can fly outside. The X400C can fly in winds up to 10mph, still, for best results fly only on calm days.
The expected range for the X400C is above 100 meters – just as other quadcopters using the 2.4Ghz transmitter technology the X400C too will simply shut down once it’s out of range.
The X400C has bright blue LEDs in the front, and red LEDs in the back,which help with the orientation and night flying.
The X400C has 3 sensitivity modes for beginner, intermediate and expert pilots, and has a throttle limit too, which makes this quadcopter very versatile. The expert mode can be a bit too much for this quad, however the two other modes are great for flying.
Due to the high performance motors, a 10 minute cool down period is advised between the flights.
As for convenience features, the Holy Stone X400C supports headless mode(when the front-back-left-right sticks direct the drone with respect to it’s takeoff direction, not the actual direction).
One key fly-back is available in headless mode too.
The motor-to-motor size is around 20 centimeters, shipping size is 40.6 x 20.3 x 8.1centimeters, shipping weight is around 900 grams.
The motors of the X400C are the fast-acting coreless type, and they drive the propellers via a geared setup. Still the X400C is a fairly quiet quadcopter.
The package includes everything you need for flying (even safety goggles), except the 3xAA batteries for the transmitter, and the smart phone for receiving the video. Warranty is three months.
The X400C’s camera
is a 2 megapixel unit, it transmits the live feed directly to an Android or iPhone smartphone. As such it does not have an SD Card slot, and the videos and photos are stored on the smartphone.
The video is sent to the smartphone via WiFi, so the phone has to be on WiFi for the video to work. The X400C has a WiFi hot spot inside. The camera functionality is controlled via the smartphone app, so you can take photos remotely, and start/stop the video recording remotely too. The WiFi range is around 30 meters.
The camera is removable, and can be tilted, so you will be able to adjust it according to your needs. It does not have a servo however.
Setting up the the video is simple, it comes in two flavors, the C4005 and the C4006. For Android smartphones, you can find the C4005 and theC4006 in the Google Play Store.
For iPhones iTunes has the C4005 and C4006 too.
After installing the apps, power on the X400C and bind it to the transmitter. Next turn on the WiFi on your smartphone, and connect to the WiFi network starting with “MJX C400”. Finally start the appropriate smartphone app and click on “Monitor”.
You can view the previously recorded photos and videos using the smart phoneapp. They can be loaded onto your computer too from your smartphone.
Despite the low resolution, the photo quality is good, the video quality depends on your distance from the quadcopter. Using the video for FPV is hard as it has a distinct lag, inherent to all WiFi based solutions.
However the live feed makes the X400C perfect for aerial photography,because you can actually see what you take photo of.
The X400C’s battery
is a single cell, 3.7 Volt, 750 mAhL iPo battery, which gives the X400C an 8 to 9 minute flight time, after a 70minute charge time. The battery is the same as the X300C‘s battery.
The X400C has a USB based charger, which works with most USB sockets. For best results use a 0.5 Amp socket, this way the charger will not overheat.
To charge the battery, first plug the battery into the charger, next the charger into an USB socket. The charging is finished then the red LED on the charger turns on.
As usual with quadcopters in this category, the battery uses a JST plug, so it’s compatible with other 3.7 volt LiPo batteries which fit the battery compartment and have a JST plug. You can use other charger with the battery too.
Amazon has upgraded batteries with charger.
When the battery is getting low, the X400C’s LEDs will start flashing. Once you see this land as soon as possible to prevent damage to your quadcopter.
The X400C’s transmitter
uses the interference-free 2.4 Ghz technology, you you will be able to fly together with other quadcopters.
The transmitter is required to control the quadcopter, only the quad’s video camera is controlled from the smartphone app.
The range is huge, 100 to 200 meters, which is very rare for quadcopters in this category.
The X400C’s transmitter uses a proprietary protocol, so it can not bind to other kind of transmitters.
The transmitter has a smartphone clip for the FPV flights, which can hold a wide range of smartphones.
The transmitter and the quadcopter bind automatically, all you have to do is charge the batteries fully, place the quadcopter on an even surface, and turn it on.
Next turn on the transmitter with the throttle pulled to the minimum, then push the throttle up to the maximum and down to the minimum again. This little dance binds the quadcopter and the transmitter.
The X400C’s transmitter supports modes 1 to 4 so you have a really wide choice.
To select the throttle stick, you need to use the buttons on the left of the left stick and on the right of the right stick. Switch both up to select the right stick as throttle,or switch both down to select the left stick as throttle. Never switch them to the opposite directions.
To select rudder and aileron stick, use the lower button on the left of the LCD.
the X400C is a great quadcopter, flies well,however the camera is a low quality unit, and the FPV lags. The FPV bumps upthe price too.