kill a LiPo. When the battery is close to its death and should be disposed of, you can not just throw it away. It still has some electric charge inside and can catch fire when not handled properly. Discharge with a low current will drain the battery to 0 in a safe way
Discharge it to the desired level. For example for storage. You plug the balancing lead, select cutoff voltage with a button and leave it for a night. Built-in microcontroller (STM32F103, the same that is in Naze32 or CC3D) will measure voltages and stop the discharge when voltage will drop to the level you want
Think about an electric motor for your 5 (or maybe even 6) inch acro or FPV racing quadcopter. What do you see? Something in a 2205-2306 size range with a KV rating somewhere 2300KV and 2600KV. Sometimes even more. And it works great, as long as you wat 5-inch props and 4S batteries. You can choose and choose and choose between different models of different manufacturers. But what if you want to go 6S or 7 inches? You have a problem. Very limited choice of motors (and propellers as well).
Luckily, it starts to change and you can actually but lower KV 220x and 230x motors. I got my hands on EMAX RS2 2206 1600KV since I'm not very happy with TBS Endurance I'm using on my 7-inch endurance drone. They seem to be missing some torque and when I've found that new low-KV (1600KV is still a lot) EMAX motors, I did not waited long to order. I love RS2205S and RS2306 and hope RS2 will not disappoint me.
What can I say about EMAX RS2 2206 1600KV before installing them on anything? (so far I got only 2, the second pair is on a way)
They finally changed those plastic boxes to something smaller
RS2 2206 1600KV look good for sure. Black and Red!
No bottom cap since, well, you do not really need it after all
29g with wires
4mm shaft made from titanium (at least they say so)
Bearings are 8x4x3 if I can measure
They kept this nice screw in the bottom instead of a c-clip
Mounting holes spacing has changed! Instead of a standard 16x19mm it is 16x16mm now! Check your frame. The great majority should accept 16x16mm but there might be some rare ones that will not!
Single wire winding. Looks ok, TBS Endurance has a nicer winding tho!
I have something like a personal problem with "the best FPV transmitter manufacturer". It's about ideology. So, when a few weeks ago I had to order a few 5.8GHz transmitters, I had something like a problem. With TBS Unify Pro on my "not wanted" list, the "wanted" list got somehow short.
I do own a few Matek HV VTXes and I'm quite happy with them. But I can not always buy the same thing, so when I saw Eachine TX805 for slightly more than $15 I've decided to give it a try.
It appeared in the mail today and here are some first thoughts about it.
First of all, it's slightly bigger than I expected and in fact, it almost looks like a clone of Matek HV VTX. Not that it's bad or something, it's just not what I expected.
RF circuitry is shielded. And that is good. I only wonder if there is any kind of thermo-pad between shielding and RF components. I hope since at 800mW heat can kill electronics pretty easy. I like MMCX connector since u.fl sucks so much. I also like the fact that all the connectors are solderable. I prefer that over JSTish connectors. A pretty bulky choke allows me to suspect that built-in 5V voltage stabilizer of the camera is at least decent as well. On the other hand, soldering on MMCX does not look "high quality". But hey, I got it for $15.99, I can not expect too much, right?
What else in a box? RP-SMA pigtail, whip antenna, and a short manual. It's a nice touch about that manual. It's quite nice and written in understandable English language!
Let's take a look at the new flight controller from Matek designed for airplanes: Matek F411-Wing. Comparing to its older brother (or sister or just a sibling) Matek F405-Wing it is much smaller, lighter and lacks many of the features:
After flying chinesium (XMR250, Reptile X4R 220, Martian II) and frames from DemonRC I've decided to switch to completely different brand. My choice is Armattan Rooster, the newest freestyle frame from Armattan.
Rooster arrived few days ago, and this is what I can say about it before putting all the stuff into it:
sunken nuts you have to install by yourself are a very idea. It's hard to do without tools and skills. It would be much much better is they were preinstalled. Armattan, please, fix it!
additional pair of standoffs between plates would not hurt
it is tight inside and I will have to be creative to fit X4R and TBS Unify Pro in the back of the frame
frame itself looks good tho. I might even say it is pretty
My quest for ultimate (?) DIY telemetry system for UAVs continues. Last year I was playing with HC-12 433MHz wireless modules with pretty decent results. After all, more than 1km of range for a few bucks is more than acceptable. Still, HC-12 has at least few problems:
433MHz band is very often polluted and used by other Rc systems/subsystems (LRS)
433MHz requires pretty big antennas
No frequency hopping
No easy way to build network of more than two HC-12
What is the biggest advantage of cheap servos? They are cheap. What is the biggest disadvantage of cheap servos? Well… everything else. Do not get me wrong, for last 2 year all my airplanes and other contraptions have been running cheap analog servos. Some better, some worse, but all were cheap. And I always felt that one can expect more from a servo…
Thanks to CarbonBird.com I will have a chance to find out. They provided me with a pair of CB215MG fast coreless digital servos woot woot. I do not know much about servos, but they surely looks solid and reliable. Metal casing, metal bearings and 333Hz refresh rate. I'm just putting them on my latest flying wing and I will know if good servo is really worth it. I really hope so!
Before we proceed, short clarification. Legal background of AnyFC F7 flight controller from Banggood is iffy. It's not that BG ripped the design from Sami Korhonen (sambas). Sambas published design of his AnyFC under Creative Commons BY-SA. So, it's free to copy this design as long as Sambas is referenced as author, and license is not changed. The problem is that "by attribution" part is not met. Sambas is not referenced as author on BG. Still, Sami wrote that he is fine with it, as long as boards quality is good enough.
Today I have something brand new to write about. Probably the first commercially available flight controller based on STM32F7 CPU: AnyFC F7 from Banggood.
I like to travel light. Also when going flying. This is why I’m not the biggest fan of all those metal or plastic suitcases. Not my style. I prefer a backpack, mini quadcopter attached on the outside of it, flying wing in one hand, travel chair in the second. Done.
Sometimes suitcases becomes handy (after all they provide some privacy and protection), so when I saw this little Eachine DIY Suitcase I’ve decided to give it a try. Description says that it can hold ZMR250, so also should not have any problems with 220 mini quad. It does have a problem after all…
Yesterday I've received new flight controller for my Reptile X4R 220 quadcopter: Flip32 F4 from ReadyToFlyQuads. This is my first contact with STM32F4 based flight controller and I'm really looking forward to see if it really puts a difference comparing to F3 boards like SPRacingF3 I've been using last few months.
STM32F405 CPU running at 168MHz
MPU6000 gyro connected via SPI interface
Integrated 1.5A voltage regulator
Flip32 F4 (and Airbot F4 which is exactly the same board) is supported by Betaflight, RaceFlight (that due to some GPL violations I'm boycotting) and INAV (at the moment of writing this post INAV support is not complete) and REVO target. Well, basically, this board was designed based on OpenPilot Revolution stripped from radio modem, barometer and those JST connectors (pin headers rules!). There are some differences between Revolution and Flip32 F4 in terms of hardware (voltage regulator for example) or separate LED header (which does not work).
There are two "problems" I've discovered so far:
Whole board is getting very hot. Looks like it's because voltage regulator and battery monitoring are connected. You can not have one without the other even when you have BEC somewhere else
STM32F4 does not have built in inverters. That means, S.Bus has to be connected to UART1, since this is the only UART with external inverter
Although I've been able to install it on Reptile X4R 220 already, I have no idea how it flies yet. Weather outside is very rainy…
Hey, don't leave yet, there is more!
Do you know that there is a YouTube channel with awesome, drone and FPV related video? Why don't you give it a try?