title: RC Equipment description: My gear and the modifications I did to it parent: quadcopters position: 80 date: 2015-10-09 update: 2022-05-31 comments: true --- Over the years of flying quadcopters and other stuff I have grown quite the collection of self-made or customized gear. I transport it all in a [Quadguard BP X3 backpack](https://www.lowepro.com/global/quadguard-bp-x3-lp37090-pww/). ## Spectator Monitor When out flying alone or with a partner, often people walk their dogs nearby or families go on a walk together and see us. This often sparks a conversation. For these occasions, it turned out to be very useful to have some kind of second screen and receiver with me. A friend of mine even has a spare cheap set of FPV goggles with him most of the time. I decided to go a slightly different route. For my first experiments, I bought the [Quanum DIY FPV Goggle Set](https://hobbyking.com/de_de/quanum-diy-fpv-goggle-set-with-monitor-kit.html). I didn't really like the box-style of goggles, so I quickly took the monitor from the set and used it stand-alone. After I switched to proper FatShark goggles, I used the Quanum monitor again, this time for a spectator monitor. I built a simple wooden box out of left-over parts and hot-glue, with a large cut-out in the front for the monitor. Inside is not only a [FR632 Diversity Rx](https://hobbyking.com/en_us/fr632-diversity-5-8ghz-48ch-auto-scan-lcd-a-v-fpv-receiver.html) but also an [Eachine ProDVR](https://www.banggood.com/Eachine-ProDVR-Pro-DVR-Video-Audio-Mini-Recorder-for-FPV-Multicopters-for-RC-Drone-FPV-Racing-p-1061196.html?cur_warehouse=CN), 2x 18650 cells, voltage regulators, a fan and a voltmeter. The channel can be selected on the receiver, with cut-outs on the back. The DVR can be controlled using external push buttons. A power switch, as well as a switch to select either the Rx video feed or the DVR video feed, are on the top. The batteries hold up for maybe 3 sessions with spectators. I had to add the fan after the first tests because it simply got too hot inside the box and the first DVR died after a while. The quality of the Quanum monitor is great and it does not switch to a blue-screen when the signal is fading. The DVR does not work 100% reliable, but considering my FatShark Dominator v3 has a built-in DVR as well, I'm not really dependant on it. ## Customized Transmitter Many years ago, a long time before I even started getting into Quadcopters, my grandpa bought me a cheap 2.4GHz Transmitter from Conrad Elektronik. Because this was already available when I started building my own copters, I used it for that as well. Turns out, it is a Flysky-clone, with it's own shoddy PC software. So I wrote [my own Mac driver for it](2015_12_20_serialgamepad.html). After using it with its original receiver for a while, I decided to move into the FrSky ecosystem. So I swapped out the built-in transmitter for a [FrSky DHT](https://www.frsky-rc.com/product/dht-toggle-switch-2/) with the [TTL mod](http://majek.mamy.to/en/frsky-dht-ttl-mod/) to connect [my own telemetry display](2016_11_05_frsky_telemetry.html). Also see [the article about my Saitek X52 USB joystick experiments](2016_07_24_usb_host_cppm.html). ## Ammo Can Battery Charging Having so many high-capacity LiPo batteries around because of this hobby is kinda scary of course, after looking at a bunch of battery fires on YouTube. So I at least wanted to have some kind of fire-proof enclosure for charging my batteries in. I decided to go the common ammo-can route for this. When doing this, it is **very important** to modify the can so it no longer is pressure-tight. Otherwise you're building something more like a bomb. Many people remove the seal in the lid for this, but I decided to drill a couple of large holes into the can, as well as a rectangular cutout for the charging cables. The holes have a piece of mesh glued in front of them, to keep debris out. And the inner walls of the can have been padded with cardboard, to prevent any chance of short-circuiting on the metal sheet of the can. ## Ammo Can Battery Storage For far too long I stored all my LiPos in a cardboard box on a wooden shelf in my livingroom. After seeing one too many videos of LiPo fires, I decided to work on a solution for safe storage of the batteries outside, on my balcony. Like with the charger described right above this section, I decided to get some used ammo cans for this project. When you buy an ammo can like this used, I recommend giving it a thorough soap and sponge wash on both the inside and outside. Then you can pull out the gasket in the top with a large flathead screwdriver. Give it a good clean as well, and rub some oil on the gasket so it goes back in easier and lives longer. The most important part of a storage solution like this is the ability to vent gases that expand in case of a LiPo failure. So we absolutely need to add some holes to either the base can or the lid. This time I decided to put two 5mm holes in the lid of each one. Just to make sure no water gets in through the vents, I added rubber plugs, which can be pushed out easily by the expanding gas in an emergency. This way I feel relatively safe storing the cans on my balcony. Like with my charging can, I also added some cardboard on the inside for preventing any possibility of short circuits. ## Spectator Monitor 2 The files for the modified 3D printed case [can be found on my Thingiverse profile](https://www.thingiverse.com/thing:2003324).