Troubleshooting a Quadcopter

I decided to cut ties with my Mudskipper frame, and move back to my zmr250 frame. I liked the way it flew better, and it was much lighter. I had purchased nicer components for the mudskipper build, so I wanted to migrate some of them back to the zmr. This is where my troubles begin.

I started by tearing down both of my quads. I purchased a new FPV camera, because my old Sony 1117 is definitely showing signs of wear. I went with the RunCam Owl Plus due its wide FOV and low light sensing. Plus it was orange!

I also wanted a new FPV transmitter, since I was thinking I might maintain 2 quads at some point, and wanted 2 full sets of FPV components. For this I went with the Foxeer FPV TM25 Transmitter, because it was completely adjustable in output power.

And last, but not least, I ordered a new receiver – since I had destroyed my 2nd FrSky X4R-SB during a crash. I decided to try the new FrSky XSB, because it was smaller, and only had one connector on it. The only downside I see to this receiver is the inability to *easily* replace antennas. With the X4R, I could snap on a new one, but these are soldered on.

So here is my latest instantiation of my ZMR 250. So far I’m digging flying 4S batteries. Much more power!

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List of purchases for this project:

Amazon

Qty Product Price Notes
1 RunCam Mini FPV Camera OWLPLUS 700TVL 5-22V $50.94
1 FrSky XSR 2.4GHz 16CH ACCST Receiver S-Bus $30.64
1 Crazepony Foxeer FPV TM25 Transmitter 5.8G 40CH $34.99
1 RJX RROSD Distribution Board with BEC $23.98
1 Crazepony 4pcs EMAX RS2205 2300KV Brushless Motor $72.99

Heli Nation

Qty Product Price Notes
1 REDROTOR RROSD PRO V2 PDB $30.00

Building a Better Quadcopter

After flying my ZMR 250 around for a while, I felt like I was progressing in skill flying FPV. The more risks I took with flying, the more components started to break. I don’t know if it was because I didn’t really know what I was doing when I was building my first quad or what, but I was constantly having to come home to fix some broken soldering joint, torn wire, or order a new part.

I decided to look for a new frame, that would let me keep most of the components concealed inside for (what I would hope would be) better durability. I was browsing rcgroups and came across a new frame being released by RMRC. The Mudskipper 250. The kits are no longer available because I believe the ready to fly versions have been discontinued. I ordered just the frame kit, with a basic PDB.

Since I wanted to keep my ZMR 250 still flyable, I ordered some new components. I cannibalized the FPV camera and video transmitter from the ZMR, but ordered some new DYS XM20A ESCs, the new Emax RS2205 2300kv motors, another RMRC Dodo Flight Controller, and a new GoPro Hero 4 Session to be able to mount on the thinner HD camera mount on the mudskipper. The video and sound quality of the gopro blows away the xiaomi yi’s.

Once the kit arrived I started laying everything out trying to figure out how I was going to fit everything inside.

I soldered the ESCs to the motors, leaving all the slack in the leads so I could place the ESCs inside the body of the frame. I got the PDB installed and then soldered the ESCs to the PDB and started working on the flight controller connections.

This frame is different in that there are no standoffs holding the flight controller in place. Instead it gets stuck to the frame using double sided foam tape. I was skeptical, but it held up pretty good.

Some of my flush cut through hole soldering. There was no room for pins on this flight controller, so everything had to be direct soldered. Not too bad I’d say.

One I got the flight controller mounted to the frame, I had to tuck and route all the wires into frame cavity. It was a tight fit, but everything managed to fit.

And with the bottom plate attached

There; now all my components were safely inside the frame, protected from damage – or so I thought. One thing I noticed this far into the build is that this frame is heavy. It seemed much heavier than the ZMR, and I still don’t have everything installed. Pigtails seen here sticking out for the receiver, buzzer and FPV transmitter.

I ordered a receiver mounting plate off of great 3d, and stuck it to the back of the frame. I mounted all the FPV gear in the front of the frame. There is a FPV antenna holder on the HD camera mount, so it seemed logical for everything to sit up front.

I thought the frame was looking pretty good right now.

Ready for first flight. Damn this thing is really heavy now. I’m still flying 3S batteries. I could have probably been better off with 4S for this frame.

And a few minutes later…. Boom.

Nothing in this hobby ever seems to be easy. I fell out of the sky directly on to the Gopro, which pretty much destroyed the HD and FPV camera mount. This frame seems to just fall at little to no throttle – which was quite different from the ZMR I had. I had to order new parts to even be able to get back in the air here. That is one of the downsides of this frame – all the parts are unique.

Once I got the spares I needed I was back in the air flying. Again I fell out of the sky on to a parking lot and completely destroyed the receiver and the back of the frame.

Time to use some ingenuity and figure out how to salvage the frame now.

After some toying around, I decided to move the receiver up front and completely chop off the tail of the frame. This made things pretty tight up front, but overall I think I’m pleased with how it turned out…

Cut and sanded the carbon fiber tail.

Ready for the skies again!

At home in the wild.

Building a FPV Quadcopter

Like probably half of the guys in the world, once the Drone Racing League videos started coming out, I became fascinated with quadcopters. I started reading up on the carbon fiber racing quads, and watching all kinds of videos on how to build and fly them. My wife saw me watching build videos and asked me when the parts for mine would show up… I decided to order everything that afternoon.

I had always wanted to fly an RC airplane, but never got the opportunity. Now was my chance to build and fly something cool. I dove in head first, ordering most of the best gear I could find. On a recommendation from an online forum, I ordered a ZMR 250 clone kit, which included the frame, ESCs, motors and most everything to put it together. I ordered the 1st version of this kit from Multi Rotor Mania.

To get a flyable quad, I would at least need a flight controller, receiver and transmitter. Again on some recommendations, I went with the RMRC Seriously Dodo Rev 3 FC, the FrSky X4R-SB receiver and the Taranis X9D Plus Transmitter.

I had never soldered something this complicated before so I needed to order some tools. I headed to Amazon and ordered what I thought I might need. I got a new chinesium soldering iron, a soldering iron holder, some miscellaneous size heat shrink, M3 standoff spacers, a cutting mat that everyone online seemed to be using, and a heat gun for the heat shrink.

I also needed some batteries and a charger, so for those I took some more advice and procured a turnigy charger and 10 3s 1500mah 35-70C batteries from HobbyKing. These are really starter batteries, so they should do well for a first timer

Some of the tools arriving!

I ordered some fancy looking LEDs from RMRC, and decided to give soldering electronics a go. I didn’t blow anything up and they worked!

A few days later my quad kit and transmitter arrived, so it was time to get jamming…

I started assembling the frame. The instructions were pretty clear, plus it was kind of obvious where parts needed to go. I installed the standoffs to mount the PDB and flight controller. I also connected the receiver to the flight controller using this wiring diagram from rcgroups.com

I then bound the receiver to the taranis transmitter successfully, and verified the configuration in cleanflight with the flight controller hooked to my computer via USB. This was a pretty big accomplishment for someone who had never soldered anything resembling circuits before.

Now on to soldering the motors to the ESCs. For this I had to remove the heat shrink from the ESC and desolder the existing motor leads. I was nervous, because I didn’t know how hot I could get the existing solder to remove the leads before I would toast the ESC. After removing the leads, and then soldering the motors directly to them, I had to test them out. I used this handy servo testing unit. The motors all worked. I didn’t fry anything yet!

Now on to the FPV equipment. I wasn’t going to be able to fly this thing without seeing where I’m going. For these I went with a Sony Super HAD CCD mini camera and Hawkeye 200mW video transmitter. Connecting these was pretty straight forward. Power into video transmitter via 12 volt regulator and filter, and power from the video transmitter to the camera. Signal from camera to transmitter via a homemade cable. Viola.

Now that I’ve verified all the individual components, it’s time to button this thing up and assemble everything. I mounted the flight controller and PDB on the standoffs. Soldered power from the PDB to the LEDs and Flight controller. Connected up the ESC signal wires to the flight controller, and we are ready to put the top plate on and Fly!

And we are ready to crash! After my first crash, I realized I didn’t have the prop nuts on tight enough and lost one. I got a whole 30 seconds of flying…

A quick run to Home Depot for some M5 locknuts and I was at least ready to fly again. This time I tried FPV with my fatshark goggles. This was a little disorienting at first, and I wasn’t really ready for it. I crashed 10s of times and decided line of sight flying was good for getting the hang of the controls for now.

I attached my Xiaomi Yi HD cam to the quad and just started flying around.

I really sucked at flying. This is hard! Time to download FPV freerider, and connect my Taranis to the computer and fly the sim for a few hours.

After a few hours I felt comfortable enough to get out and fly some FPV. I took the quad to a field nearby and success! I crashed a few times, but was able to fly pretty damn good for a first timer.

Warning! The Yi’s sound sucks so this is abnormally loud.

After a few more sessions I felt pretty confident about flying…

I even got a fancy pelican 1500 case to carry all my gear around in. Now I’m cool.

Keep on practicing…

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List of purchases for this project:

Amazon

Qty Product Price Notes
1 Vastar 60W 110V Adjustable Temperature Black Welding Soldering Iron $16.99
1 Trakpower Deluxe Iron Holder with Sponge $8.54
1 Anytime Tools AT201262 Heat Shrink $6.70
1 Rosiness 180Pcs M3 Nylon Hex Spacers $8.99
1 Revell Modelers Cut Mat $11.71
1 TruePower 01-0712 Mini Heat Gun $18.74
1 GoolRC HJ Digital Servo Tester $10.99
1 YI 88001 16MP Action Camera $99.99
1 Pelican 1500 Case with Foam $109.95