This post is written by Artur Banach, a member of our multirotor facebook group. He recently built his first mini quad and would like to share his experience.
First Quadcopter Build – Game Changer
Sometimes it only takes one moment, one spark to change something in our life. For me it was one YouTube video that changed the direction of my hobby. It was an interview with Charpu and Norman from tested.com. Charpu explained how to build an FPV mini quadcopter. 33 minutes of pure geeky fun. It was amazing and totally got me. As a result I wanted to build a quadcopter for the first time, a 250 class FPV racing quadcopter, and I managed to do it in less than few weeks!
What was my experience with RC flying? Just a little bit with a tiny 3D toy grade helicopters that I crashed and wrecked within days since purchase. My first quadcopter was Hubsan X4 and thanks to it I decided to stick to four spinning rotors instead of just one. Been flying it for good 10 months and gained a lot of experience on how to control a multirotor.
I am an engineer by profession, but only have basic knowledge in electrical stuff. I didn’t even know how to use soldering iron!
Selecting Parts for First Build
My first resource was that Charpu interview on YouTube. In the movie description there was a list of parts used in the video to create a mini quad.
Quick goggling revealed Oscar’s 250 parts list post that helped me a lot finding the right hardware for the project. Initially I thought it would take about 5-6 weeks to complete. Eventually I got it done in couple of days after all the parts been delivered. Research and shipping took the longest time. Bought all the parts in the UK. I am impatient when it comes to shopping and saving few £££ on a postage wasn’t a case for me.
My initial setup was:
- ZMR250 Carbon fibre frame (Blackout clone)
- DYS 1806 2300kv motors
- EMAX 12A SimonK ESC
- Naze32 Acro
- 36×36 PDB (power distribution board)
- Turnigy Nano-Tech 3S 1300mah 25C battery
- FatShark PredatorV2 Kit (package includes 600VTL Camera and 250mw Video Transmitter)
- Spironet antennas for FPV Transmitter and Goggle
- Mobius Action Camera
- Spektrum DX6i with AR6100 receiver.
The most expensive part of this setup was a radio and FPV gear. I didn’t have either, so I had to spend some money on it. Quad itself was around £150 on its own which was less than I expected. Here are the thinking behind the process of choosing the right gear for my build:
Mini Quad Frame
I have chosen ZMR250 frame as it was cheap and still looking good. Initially wanted the Lumenier QAV250 but for a total beginner it could have been simply an overkill.
Motors were chosen based on Charpu recommendation.He mentioned that for 3S setup the best motor speed is 2300kv. DYS seemed like a sensible option after reading some reviews. On the rotorgeek.com website, in their online shop DYS sits right next to Cobra brand motors and David expressed very positive opinion on them.
I have chosen them pretty much randomly. There’s tons on the marked. 12A were the most suitable for this setup based on motor power draw and rotation amount.
I picked the Naze32 as the flight controller based on many youtube reviews and online recommendations. At first thought about Open Pilot boards but after more research I gave up on. Here is a post about the difference between CC3D and Naze32.
Again, Charpu said it all in the video. FatShark kit is the easiest thing to buy and setup. It is being sold as Plug and Play solution. Video transmitter can take up to 4S lipo batteries which is great (used it with 3S and 4S without any voltage regulation required etc.). It was no brainer. I didn’t buy Teleporter kit because it has really poor video quality and the goggles itself are very limiting. Didn’t want to spend too much money on Dominators (yet:) ) so the choice was simple – Predators. Check out this post for a through out comparison of FPV goggles on the market.
At first I bought Spektrum DX6i with receiver. It was great radio for beginners but for additional £40 I could have bough FrSky Taranis which was Charpu recommendation as well. After few happy weeks with Spectrum I switched to Taranis and never looked back. With Taranis configuration possibilities are endless. It can even play mp3 songs by pressing the switch – simply amazing! If you’re a geek or only partial-geek, this is the radio for you!
After watching quite few build videos on Youtube, I decided to go with power distribution board as it is easier to solder than power harness (for me at least). It is also much easier with upgrades – just a matter of re-soldering to the corresponding spaces.
Talking Through Mini Quadcopter Building
Mounted motors on frame arms and prepared the workplace. Tried to keep the workplace tidy, to avoid loosing anything. Power cables between ESCs and PDB are organised by a zip ties. Motors are ready to be soldered to ESCs
PDB Installed and Naze32 FC sits on the top of it. Used plastic stand offs to maintain the gap between the two. For Pro and cons of using PDB and Power Harness. Despite what Charpu was saying in his video – vibration is not much of an issue here and we don’t need to use double sided tape to fix the flight controller.
Naze32 connected to a computer for checking motor spinning direction and for basic port configuration. This was my workspace as well. Indestructible IKEA computer desks. Courtesy to Swedish design!
Top plate fitted along with transmitter. Battery installed on the top. Quad is ready for an action. Spectrum receiver antenna was inserted in the straw to keep it as much vertical as possible. Here with Mobius and FPV gear installed.
Mini Quad building tips and notes
Building this little racer was pretty straight forward. To achieve that I used most of the things listed in Oscar’s article. However, I needed to learn how to use the soldering iron. This isn’t the easiest thing to do sometimes, believe me, I learned it the hard way with burned skin on my thumb and pain for a good few days.
During the build I came across few issues/accidents and came out with couple ideas/solutions:
1. Video antenna cable extension mod. This was the most important one. Had antenna mounted directly to VTX and crashed into a tree once. Quad fell on the ground and detached antenna along with SMA connector. By relocating antenna using the cable extension you can save your VTX in a bad crash. Radio antenna mod.
2. Changing propeller nut cap. During the maiden flight I lost original nut cap after 2 minutes. Replaced them with M5 nuts. They require pliers to undo them but are rock solid.
3. Landing gear. Although 250 quads do not need landing gear like bigger quads, a little protection to the underside of the frame is a great idea. I used little piece of flexi wiper and duct tape, works perfectly.
4. Radio antenna mod. After a crash one of the props started cutting my FrSky antenna. I used a fix described in Oscar’s ZMR250 build log to resolve that issue and to repair it. Took minutes and I didn’t have to worry about buying bag full of straws!
5. Tilting flight camera and FPV camera. When we want to speed up our quad during the flight it changes the angle itself for maximum thrust going forward. Having camera tilted up help to maintain good view angle during faster flights and is recommended unless you enjoy looking at the grass during the faster runs.
It is much better to use Mobius or RunCam HD instead of GoPro for beginners. You will crash a lot so it is better to crash a £50 camera instead of £300 one.
6. Labelling Lipos. Since I own labelling printer already I have printed labels for each lipo battery for easy identification. I use 1300mah and 1800mah 3S and 4S batteries. Every one has different number written on the label. If there is a problem with any of them, I can simply take a note which one was it.
Recent ZMR250 Upgrades and Improvements
I’ve been flying with above setup for nearly 2 months now. Quad took quite a bit of abuse but the only thing that was damaged and got broken was just one arm which had to replaced (around £4 on Banggood). Overall experience with ZMR250 was great but I wanted more power and efficiency. This was only possible with more voltage which meant going 4S setup. Oscar has already covered how to move from 3S to 4S for mini quad.
I have replaced Emax 12A ECSs with HK BlueSeries 12A flashed with BLHeli in order to use Oneshot125 for better responsiveness. Naze32 was flashed with Cleanflight as well.
DYS 1806 are rated for 4S as well and I had a great success flying them on 4S battery.
I must say that 4S is the way to go under one condition – enough experience with 3S is required. 4S comes with more power, more speed so we need to learn how to control the quad under various conditions and how to do it safely of course. Especially when flying anywhere close to other people wondering about. Those quads can go very fast.
At this moment I am awaiting my Cobra 2204 1960v I have ordered from rotorgeeks.com.
Here are few pictures of the quad in the current state, with upgraded ECS end 4S battery.
Here is one of the flight video with this mini quad.