Teksumo center-pod mod

Every five years or so a new generation of RC plane emerges.   The current "it" plane for this generation is the Sonicmodell AR Wing  If you fly FPV you'll love this plane. If you don't fly FPV, it may not be a plane you need. The last great "It" plane from the line-of-sight era when it came to cheap and readily available delta wings was the Popwing 900mm or Teksumo sold by Hobby King.   For some reason, the orange Teksumo was owned by everybody in that era.  It's a great plane, and loved by many.  And, unfortunately, most are locked away in dark garages.




After years of trying to modify this plane Hobbyking updated it with a better motor mount and a small spot for an FPV camera.   It didn't transition well.  The beautiful fish graphics were replaced with graphics that looked to be designed by a high school student.   The Teksumo's familiar orange color was replaced with red, blue, yellow and green.    Now it looks as though yellow has survived as the other colors are now discontinued.  Thus, I'm uncertain what the future holds for the Teksumo.  (Update, Hobbyking discontinued the Teksumo)



New design of the Teksumo in blue, now marked as "Discontinued."

The issue is that time have changed, and people are into FPV.   Even  if they can't get INAV going they can still figure out how to hook up a video transmitter and FPV camera.  The Teksumo went along for the ride for a while.  There were a number of attempts to drag the Teksumo into the next generation.   Today we'll look at one, the V4 Blunt section sold by Hanger Cats.  RCGroups still has the inception, life and eventual fizzle out of  the center section project.  One engineering-oriented hobbyist came up with it, and for a while, people were very into it.  Today, it's resurrected and given another go with INAV.  This means that it has flight stabilization and other interesting modes.

Omnibus F4 V3 Clone Flight Controller

I just so happened to have an older orange Teksumo that I got on sale a few years back sitting in my garage.  I ordered the pod, painted it orange and covered it with wood glue.  I ran two spars that glued into the cutouts on the bottom of the plane.  The spars cut into the very cramped pod making it even less usable, so this was a mixed blessing. The spars didn't run far enough into the plane to be of much use.  At best it helps hold the foam onto the pod a bit more.  The plane needs to be hung up when not flying because it will warp.   I put on what I believe to be a DYS 2822 1400KV motor.  It's okay for this application. It provides for a tame flying experience. The pod holds the 4S 1300mAh battery which is perfect for the CG.  I fitted a VTX and FPV camera onto it, and it seems to work well.  The camera and VTX were Eachine and the flight controller is a clone Omnibus F4 V3.    This is a low budget build.  The elevons were replaced with  1/4 inch (6mm) balsa wood.


The first build was with a BR2212 1400 KV motor.  I used a battery that was too heavy and this plane barely flew.  It needed a lot of speed and I did not enjoy it. I was debating removing the pod and calling the project a failure.  I decided to drop the motor weight  and try to keep the plane light and nimble.  This proved to work well.  Getting it to the point that it could take a flight controller led me to hand trim this plane.   There was enough space for a flight controller.

How it flies

The All Up Weight of this plane with the 1300mAh 4S battery is 19 ounces (538g) which is insane for a plane of this size.  The center pod is 76mm and takes the wingspan up to around 1 meter (approx 40 inches).   The center section adds to the wingspan without adding very much weight.  Thus, the plane is inclined to glide quite a bit.

This formula of weight and power worked.  The takeoffs are fine but there isn't a lot of excess power.   Climbs are a bit slower than what I am used to, but it's not that bad.   I put the plane into a stabilized mode.  Keep in mind, the Teksumo has the tendency to float if you build it light.  What I did was turned it into a plane that floats a bit better than before.   It is surprisingly stable in the air.  It would be a nice plane to shoot video with because it doesn't move around all that much.  When you cut the power it doesn't want to fall back to earth.   It's a nice slow glide.

If you're into relaxed FPV, this is the plane.  It's only downside is that it may be a bit too relaxing.  Large and stable,  simple to fly, maybe a good platform for beginners.  INAV has a few stabilized modes and  3D Cruise.    You can put this plane into a 3D cruise, walk back to your car, get something, perhaps use the restroom on the way back.  Don't worry, it's not going to fall out of the sky on windless mornings.  It will just float.  It's nice  if you're into large and  simple flying.

Thoughts

It's a nice plane, I do enjoy flying it.  I think I am a bit stuck with a motor that works but doesn't scream.  I am not exactly motivated to change things around for the time being because I am overall liking how this flies.

I just don't think this is the plane where you can throw in fat spars and huge motors without the center pod breaking apart with less than stellar landings. For me, this is as good as it gets.  I am a bit skeptical that 3D printed pods would hold up much better.

My thinking now is to wait around a few more months and see if the Teksumo comes back into regular stock at Hobby King.  I still believe it's a popular plane that will stick around for five to 10 more years.

The fun next step for this plane wouldn't be a 3D printed pod,  but one made of foam. Perhaps a bit thicker foam than the wings, so  that that you could bury a battery.   It would be better able to take thick spars and place them where you like.   Just know that you'll be chewing into spars that are already in the wings. You need something that could take a beating  and still hold together.  I do have contacts in the foam industry.

Let's see what happens with Hobby King and the Teksumo.