I bought a GEPRC Vapor-D O4 Pro Frame and here’s my experience with building a drone with it.
Requirements
First up, what are my requirements? Here are a few
- I want a FPV freestyle drone that is light enough to be taken for a hike in the mountains, yet powerful enough to handle windy weather and carry a GoPro or such. A 5″ deadcat frame generally meets the mark for that, as it’s not too heavy, yet can carry a camera and the props stay out of the video frame.
- The frame needs to fit a DJI O4 Pro VTX. The camera has larger dimensions that O3 or Walksnail cameras, is more susceptible to vibration, and thus my untried theory is that a frame designed for the O4 would be preferable.
- It should be able to carry at minimum a 6 cell 1550 mAh LIPO, or better, a 2400 mAh LIPO. This would give around 4-5 mins of flying in high altitude conditions (ascent + wind + GoPro).
- The frame should stand up to some abuse – such as landing on rocks, taking a tumble or so etc. Not bando-grade, but I don’t want to keep on replacing carbon fibre arms.
Components
With my requirements in mind, here are the components I decided to incorporate on the quad.
| Part | Manufacturer |
|---|---|
| Frame | GEPRC Vapor-D O4 Pro Frame (Deadcat DJI O4 Pro model) |
| Flight Controller | GEPRC TAKER GEP-F722-HD v2 |
| ESC | GEPRC TAKER GEP-BLS60A-4IN1 ESC |
| Motors | Axisflying-Blackbird 2307 1960kv Mind Reader motors |
| VTX | DJI O4 Pro |
| RX | TBS Crossfire Nano RX |
| GPS | Axisflying M10 GPS Module VIFLY GPS Mate (with buzzer) |
| Buzzer | Included in VIFLY GPS Mate |
Some comments on the parts:
- I chose the GEPRC FC + ESC over a different manufacturer as the Vapor frame comes with sidewalls that have gaps for the USB-C port, etc. If I elect to use the sidewalls, it would be a pain to have to cut parts out of it.
- I chose the Axisflying motors as I’d used their motors in the past and they were smooth, reliable and paired nicely with 5″ quads. The “Mind Reader” 1960KV motors are their most recent and look pretty stylish.
- The TBS Crossfire Nano RX – well, I’m in the TBS walled garden with a TBS Tango Pro 2, so it’s an easy choice.
- Finally, the GPS & VIFLY GPS Mate – my requirement was actually to have a battery-powered buzzer in case of battery ejection, so it’s a bit of an overkill given M10 GPS units have a fast lock, but I had kicking around.
Construction
Let’s get to it! The Vapor frame comes with a pretty clear instruction booklet and a multitude of different nuts and bolts in little plastic bags. Most are M2 or M3, which reduces the juggling of tools, yet many are of different heights. This will probably be a pain when it comes to taking it apart for services.
The first step of the assembly is constructing the base frame.
From there it’s a step-by-step set of instructions, fitting the 3D-printed parts as one needs. The capacitor mount is a nice touch. I dry-mounted the ESC, FC, RX, capacitor and GPS to see how they’d play.
As a side note, I started with the stock rear mounts, but switched to using these totally awesome rear VTX + tail sections and ditched the GEPRC rear 3D printed parts:
If one wants to have the side walls, one needs to trim the clips off the bottom-rear side walls. Time will tell if I keep the side walls – weight and ventilation may be a concern.
I prefer a socket-based XT60 power connector on the drone rather than a dangling cable. To that end, I created a 3D model that supports an XT60 connector at the front of the drone, allowing a battery to be plugged in on top of the drone in front of the battery strap.
Here’s the test print with the XT60 raised above the drone base, with enough space for the power cables to be routed into the ESC. It cuts down a bit of cable weight:
The effect from outside looks pretty nice, with the plate preventing the XT60 from moving:
It’s now time to solder everything together …
With the final result of :
And finally it’s ready for Betaflight configuration.
Post-build Thoughts
Each drone frame has pros and cons. After building a quad with the GEPRC Vapor drone frame, I’m generally pretty pleased with it, despite some minor complaints.
Pros:
- The final build looks solid, professional and the camera is reasonably well protected.
- All the carbon-fibre parts are well made, fit well together and should hopefully prevent any major vibration or resonance leading to jello footage.
- Instructions are clear for assembly, and all the nuts & bolts are in clearly-labelled bags.
- There is a fair amount of space in the frame for components, and one can choose to add/remove the sides of the drone. It remains to be seen if the sides cause overheating in flight!
- The default STL parts that come in the kit do an acceptable job, but there are community prints out there that make the rear cage for the DJI O4 VTX way better.
Cons:
- The side plates – if one wants to use them – assume that one is using a GEPRC ESC + FC, otherwise the holes in the frame will likely not line up with the FC. The FC USB-C hole is also very narrow – you’ll need a very thin USB cable for it to fit into the hole.
- The bumpers for the motors are welcome, but they prevent the default motor bolts from being used on two of the four motor mounts. It would be nice if the frame kit came with eight extra M3 bolts that take into account the extra 2mm on the bumpers.
- GEPRC don’t provide a download of their STLs – the community thus have to rebuild each of these. An example – if you damage a part, you either have to buy it from GEPRC or make/hunt down a community part. Just seems a waste of time and GEPRC are not orientated to a hobby where 3D printing is common.
- The GEP-Vapor-D5 O4 Pro Frame is not the lightest, at 221g without motors, etc. In comparison, the Axisflying Manta 5pro 5inch DC Frame is 217g, and has the excessive LED kit. Once the motors, VTX, GPS etc are added, one is looking at a drone of around 450g.