We've been following the development of the PowerUp FPV ever since the project was launched on Kickstarter in late 2015. The primary goal of the PowerUp FPV package ($200) is to provide an FPV flying experience using a paper airplane as the vehicle and your phone as the controller. This concept builds on the success of the PowerUp 3.0, a product that enables line-of-sight remote control of paper airplanes. I was recently given an opportunity to try out a pre-production version of the PowerUp FPV. Actual production units should start shipping sometime in mid-November.
An Inside Look
The soul of the PowerUp FPV is its FPV module. This plastic and carbon fiber unit clips on to a folded paper model to provide power and control. The only moving surfaces are the propellers attached its twin motors. Differential thrust is used to turn the model in flight, while the overall throttle setting determines whether the airplane climbs or descends.
The FPV module is completely assembled at the factory. Fit and finish of the plastic parts is quite good. I appreciate that the nose of the module has a soft rubber bumper to help minimize damage in a crash. A camera is perched on top of the front end of the module. The view from this camera is downlinked to your phone for FPV flying. Video can also be recorded at 320x240-resolution to an onboard micro-SD card.
A 1S-550mAh LiPo battery is used to energize the PowerUp FPV. This battery is removable, so you can keep a few batteries on hand for more flight time. The battery is charged via a micro-USB connection through the FPV module.
My kit included 8 paper templates to fold as many examples of a paper airplane design called the Invader. I don't know much about paper, but these 16.5" x 11.75" templates have a weight and texture somewhere between typing paper and construction paper. Fold lines are printed on the templates, which is very helpful. Folding instructions can be found on the PowerUp website.
While it is marketed as an FPV device, the PowerUp FPV can also be flown via line-of-sight. The obligatory phone app includes on-screen throttle and rudder controls for this type of flying. Alternately, you can insert your phone into the included Google Cardboard headset for FPV flying. In this mode, you tilt your head up or down to control throttle and tilt (not twist) left and right for turning…all while watching from the airplane's perspective.
Flying the PowerUp FPV
Since I was testing a beta version of the app, not all of the features were functional. I really only had access to the basic flight controls, but that's all I needed. Test glides of the Invader without the FPV module attached went well. The next step was to clip the module onto the paper and try line-of-sight flying.
The module has a unique feature where the motors will not start spinning until it senses that it has been thrown for launch. The same system shuts down the motors after a landing (or crash). I soon figured out that if my windup for launch was too quick, it would sense that movement as the actual launch and start the motors. Then my forward throw was subsequently sensed as the landing, making the motors stop. I experienced several very short, unpowered launches until I figured out what was going on. With a gentle windup, it all works just fine.
The first thing I noticed once I had the PowerUp FPV flying is that it is rather fast. It responds well to control inputs, but I think its speed would make it challenging for beginners to fly. Due to the limited range of the Wi-Fi based control link, frequent turns are necessary to maintain control.
One of the primary shortfalls of using paper for the airframe was apparent after the first (minor) crash: it isn't very durable. Every contact with the ground, whether an unplanned crash or a well-executed landing in the tall cushy weeds, would tweak the shape of the model to some degree. It was easy enough to straighten things back out, but it was always a little different than before. The end result was that the airplane never flew the same way twice. My first two battery packs netted a few dozen flights…only a handful of them lasting more than 10 seconds. That first Invader quickly became war-weary and unflyable, so I folded a replacement for subsequent flights.
This particular paper is quite absorbent. Looking for calm winds, one of my outings with the PowerUp FPV found me in a dew-soaked field just after sunrise. The airplane sopped up water with every landing, causing the paper to distort and the folds to relax…not to mention the extra weight. It didn't take long for the model to become unairworthy. Even after careful drying, this airframe could not be salvaged. I am told that production units will utilize better quality paper, but I do not have any specifics.
I think that my initial disappointment with the PowerUp FPV boils down to the fact that consistent flight performance demands a consistent airframe. Using paper introduces a lot of uncontrollable variables and removes any plausible hope of consistency.
Most of the marketing for the PowerUp FPV focuses on the nostalgia of it being based on a paper airplane…something we can all relate to. I think that specific novelty would wear thin very quickly for users who have the same initial flight experience that I did. But I wasn't ready to give up on the PowerUp FPV. I saw potential for it to be a more fun, consistent, and practical model.
Rather than its paper-based foundation, I think the true selling point for the PowerUp FPV is the FPV module. It contains a control system, power system, and FPV system all in one small, lightweight, clip-on package. I don't know of any other product like it. All that it's missing is a rigid, durable, and water-resistant airframe to carry it.
I created a new airframe using 2mm thick sheet foam. The particular foam I used is called Depron. Its properties are close to that of the foam used for meat packaging. The 2mm thick sheets of Depron can be tough to find in the US. I'm sure that the more popular 3mm thickness could be used as a substitute…or other types of sheet foam such as CellFoam88 (or maybe even balsa). See what your hobby shop or art supply store has available.
In addition to a more rigid airframe, I also wanted the model to fly slower. This meant that I would need a larger wing. I retained the basic delta wing shape of the Invader, but I increased the footprint a little in each dimension. I ended up with a wing that has more than twice the area of the Invader. Since the foam wing somewhat emulates the shape of the Invader, I figured the name should be similar as well: Infoamer. OK, maybe I'm not so good with names.
The Infoamer is made of a single piece of Depron. No glue is required. For the upswept wingtips, I scored lightly along the fold line with the edge of a credit card and then carefully folded the seam. I held the tip panel at a 45-degree angle using a drafting triangle and then applied a short piece of Scotch tape to the inside surface of the fold line to lock it in place. The upturned elevators on the trailing edge did not require tape to hold position. Coincidentally, the completed foam airframe weighs exactly the same as the 13.1 gram Invader. With a little trial and error regarding positioning of the FPV module, I was able to attain the proper center of gravity without having to add any ballast (I would have used modeling clay if necessary).
Since the Infoamer lacks the lower center keel that most paper airplanes have, I had to find a different way to grasp it for launching. I found that holding it by the forward part of the FPV module and using an underhand launch with full throttle works well. With most launches, the model will wallow for a few feet and then stabilize into a gentle climb.
The Infoamer allows much slower flight speeds than the paper airframe. With a gentle breeze, you can almost walk beside the model as it flies into the wind. It also responds well to control inputs. Really sharp turns are possible. I think it would even be conceivable to fly comfortably within an indoor basketball court.
With the foam wing, I am able to pull the throttle back and cruise around for several minutes at a time. Now when I crash, it's usually because I've drifted outside of Wi-Fi range. When that happens, the FPV module starts beeping, the motors stop, and the Infoamer makes a sufficiently gentle glide to the ground. Unlike the paper airframes, no post-landing tweaks are necessary before the foam wing is ready to fly again.
Once I got line-of-sight flying nailed down with the new wing, I stepped into FPV flying. The Google Cardboard isn't exactly comfortable to wear. I think the elastic strap is just a bit too tight for my huge noggin! I'll have to make an extension for it.
While FPV flying is not a new experience for me, tilting my head to control the model is. I'm still getting my neck calibrated for those motions…especially the up/down throttle control. When turning, I tend to overcorrect and fly a weaving flight path. I'm slowly getting the hang of it.
It's always a good idea to have a spotter when you're flying FPV. I think that's especially true here. Since the Wi-Fi range is limited and your situational awareness is impaired by the goggles, it's easy to drift out of range without an extra set of eyes. I've had a few instances where the video feed froze in flight, so I had to pull off the goggles and quickly switch to line-of-site flying. The model flies so slowly that it hasn't yet caused a crash. There is a small bit of latency in the video signal. But again, the Infoamer flies slowly and gently enough that the delay is not critical…or even noticeable in flight.
Keep in mind that I used pre-production hardware and beta software for my testing. Some of the problems that I experienced with the PowerUp FPV may be corrected in the released versions. Different airframe designs and/or alternate types of paper could potentially mitigate the frustrations that I had with the folded paper wing.
Personally, I'm excited to continue experimenting with the FPV module and foam airframes. I've always enjoyed coming up with unique aircraft designs. The all-in-one nature of the FPV module means I can sketch out a design, cut it out of foam, clip it to the module and be testing in less than an hour. Modifications are easy as well.
If a design flies well, it may end up being something I want to continue developing on a larger or more complex platform. If a new design is a flop, it's no big deal since I have so little time and material invested in it. I'm interested to see the innovative airframe designs that emerge from users around the world once the finalized PowerUp FPV hits the market.
Terry is a freelance writer living in Lubbock, Texas. Visit his website at TerryDunn.org and follow him on Twitter and Facebook. You can also hear Terry talk about RC hobbies as one of the hosts of the RC Roundtable podcast.