With the Bonsai FPV wing going so well it was time to step things up a notch. Enter the “SupaBonsai” and Tek-Sumo FPV flying wings…

Going ballistic with the SupaBonsai

10986108_1429868877307890_1742652089_nIn my previous post I had upgraded a Turnigy Bonsai EPP wing with a CNC cut “blunt nose” section cut from 1.5mm aviation ply. This little pod allowed a larger motor and LiPo to be used and provided safe mounting points for a small FPV camera and Mobius action cam.

Even with a flying weight nearly double that of the original Bonsai the performance was outstanding. Worry free proximity wing flying was achievable in a package that could be thrown on the passenger seat of the car.

The plan with the SupaBonsai was to see how far I could push the design by switching to a similar pod cut from 1.5mm G10 fiberglass.

Obviously this was going to offer even more protection for the FPV gear but it was also going to be a lot heavier. The original size and shape was retained but the design was augmented with as many holes and slots as I could fit in to keep the weight to a minimum.

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The result was a pod that weighed around 45g and fitted into a slot cut in the nose of the wing in just the same way as before.

Of course, this extra weight needed extra performance so the 1806/2300kv motor from the ply version was upgraded to a 2206/2150kv “Baby Beast” motor. The LiPo was also increased to a 1300mah 3S pack.

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All up, this new version weighed in at 400g (compared to 300g for the ply version). As I intended to try to run a 6045 prop on this version I also cut the inboard elevons back a little to make way for the prop.

So does it fly?

The first time I took it out no! I discovered two things very quickly:

  1. You need a good handful of up elevator mixed in (fake reflex)
  2. Full throttle is actually too much at takeoff

I swapped to a 5040 prop to calm it down a little and tried again. This time with much more success. The following video was flown after upgrading once more to the 6045 prop.

So there you go! With the 6045 prop it is fast and furious fun. The 1300mah LiPo is giving me over ten minutes of flight time, which is just awesome for a wing this size. I actually find the lighter ply version better for proximity flying, but that is just because I’m getting old and it flies slower!

Going large with the Tek-Sumo

IMG_20150607_195804~2The Bonsai and Tek-Sumo go hand in hand. I had always intended to make a similar pod for the larger wing as some people just don’t like the twitchy nature of the Bonsai. The only difference I had in mind for the Tek-Sumo was that it needed to be able to carry a GoPro size camera.

The design of the pod follows exactly the same principle as the Bonsai pod only it is more rounded in the nose to accommodate the taller camera. The larger size also means I could swap to a heavier CCD camera. The material is once again 1.5mm G10 fiberglass.

The build follows the same method as the Bonsai – build the wing first, then convert it by cutting a slot in the nose and pushing in the pod. As with all wing builds I pushed the Rx and VTx out to the wingtips, keeping only the cameras, LiPo and ESC in the center of the wing. I did also upgrade the servos like before. The slots are for 5g servos but I fitted some nice 9g units instead.

The power system for this one was again an upgrade on the basic Tek-Sumo. I used a Turnigy Park 450/1200kv motor and 30A ESC. This pulls power from a 2200mah 3S LiPo to turn a 9×6 CRF prop. I had originally wanted to use an 8×6 folding prop but it just kept slipping on the motor shaft so I made the switch.

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With the 2200mah pack towards the rear of the tray the wing balances perfectly as per instructions. The all-up weight of 850g is heavier than a stock Tek-Sumo, but not beyond the realms of possibility for a wing of this size.

So with batteries charged it was off to the field for a test flight…

This video is NOT from that flight (it was too windy), this is from a couple of days later when the weather was calm…

Just awesome is how I would describe the Tek-Sumo with the pod attached. The extra weight makes it a fast and stable platform for medium range FPV. I’m pretty sure I’ll try flying some more proximity with it sooner or later but for now I’m just enjoying cruising around, exploring my surroundings.

The wing exhibits none of the yaw “waggle” seen in many videos of this type and in light winds there is absolutely no twitchy behavior. After the demise of my GoPro Hero 3 Black I bought a Xiaomi Yi as a cheap replacement and with a strip of MoonGel underneath it I am more than happy with the results.

The 2200mah pack is giving me well over 10 minutes of flight time – 20 minutes would be possible with careful throttle use. I even think the wing could handle a little more weight so may try a 3300mah pack soon.

Conclusion

The idea behind the Bonsai and Tek-Sumo pods was to give new FPV pilots a way to easily convert an existing wing without having to hack loads of holes into the nose, thereby weakening the structure and offering limited protection to those valuable cameras.

I haven’t gone into massive detail about the actual build for good reason – there are hundreds of reviews on both wings out there and all you need to do is follow the instructions! The recommended power setups are listed on the Red20RC store product pages but for the wing just use the supplied components, set the recommended throws and balance it where it says to (just measure from the point of the nose before you cut it off!).

The only thing I have noticed after a few flights with both of these wings is a slight tendency to raise the nose at high throttle. I’ve therefore added a couple of 1mm washers behind the top motor screws to add some downthrust and will test again soon.

Both the Bonsai and Tek-Sumo FPV pods are available now from the Red20RC store