WeedWhacker ~ a Bushwacker fuselage mod for LEDs

by ToddMerrill | November 13, 2016 | (5 Ratings) Posted in Projects

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Hello FliteTest friends!

I’d like to share my story of how I created a wing and fuselage mod for my FT Bushwacker. Peter’s original design is awesome and has a broad flight envelope. But if you’re like me and are thinking about outfitting it for night flying with LEDs… perhaps my tamed-down WeedWhacker design is for you.

Let's rewind and start with my original Bushwacker. Fun Cub wheels, white and yellow packing tape and clear mailing label stickers that I printed at home make it look great. But how awesome would it be to fly it at night? 

I thought about just taping the LEDs facing out on the surface of the Bushwacker, but my long-time flying buddy, Brian, gave me some good pointers. He said, “These LEDs are so bright, that if they’re facing out, they can be hard to look at in the night sky. And you might consider choosing red LEDs for the left side of the wing (while you're standing at the tail). Then while flying at night you can remember the phrase "Red Right Returning" for orientation.”

I decided to build a new wing and try to incorporate new ideas. After all, the FiteTest team is always encouraging us to experiment right? So here are my wing ideas:

  1. a foam board spar “channel” that runs the entire length of the wing
  2. the bottom wing “sheeting” to extend the entire length of the wing
  3. winglets or wing caps - why not?
  4. a spruce stick in the center for added strength and
  5. the LEDs for night flying

So I downloaded the free Bushwacker wing plans and did my best to incorporate my ideas. I was most thrilled with how the LEDs could be glued facing out along the side of the spar "channel" to light up the inside areas of the wing. I’m hoping to draw up detailed full sized wing plans of my changes soon... but I hope you get the main idea from this picture.

Once the wing was finished, I needed to put a strip of white LEDs in the fuselage section towards the tail – again to help with orientation at night. The way these strings of LEDs are wired together I’ll describe later… but here's what they looked like in the Bushwacker. Sweet!

As eager as I was to try night flying, I remembered another pointer Brian shared with me, “Test fly your plane at least once during the day BEFORE trying it at night!”  So here’s my test flight of the FT Bushwacker with its new wing and LEDs. Notice the bounce the plane does on take-off!

It might not have looked like it from the video… but that was a knee-knocking flight! I could barely land this plane in the day let alone at night! As has happened to me before in this hobby, my excitement can get the best of me. WHY didn’t I do a proper CG (center of gravity) test after having put more weight towards the tail? Even Josh Bixler calls the FT Bushwacker a “strong intermediate” plane. It can do awesome, crazy maneuvers because it’s a little unstable… but add more weight to the tail and you’ve really got your hands full.

So rather than adding nose weight or getting a bigger battery pack (which would be the simple solution) I started to imagine another way to improve the balance of this plane. If I could extend the nose in front of the wing, my same battery could create more leverage to get the CG correct while carrying the LEDs in the tail section.

So my new fuselage considerations were:

  1. keep the aesthetics of Peter’s design
  2. extend the nose in front of the wing
  3. make the width a little narrower
  4. create a power pod that’s permanent (I don’t find myself swapping them out)
  5. only use 1 sheet of foam board

Here's some build pics as I went along. I have included the PDF plans for this fuselage mod at the end of my article.

After printing out the plans, I was a little worried I couldn’t cut the fuse out of 1 sheet of foam. But taking some engineering cues from the FT Simple Storch design... I created a seam to fit it all on 1 sheet. Here’s how I cut up the plans and arranged them to fit.

Here is another picture of the seam in the fuselage, once the parts are cut out.

Rather than follow Peter's construction exactly as on the Bushwacker, I created some simple formers at the front and rear of the wing saddle area. And in this same pic, you can see my idea for the permanent power pod taking shape. I’m just getting the length worked out. 

I have found that covering the sections (on the outsides) with packing tape while flat makes the finishing process go smoother for me. This works great on wings too!

Okay... here's the power pod being mounted on pop-sicle sticks. For the thrust angle of the motor mount, I’m a believer in 3 degrees right and 6 degrees down thrust. This thrust angle worked beautifully on my FT Tiny Trainer fuse mod. The same plywood firewall from the Bushwacker fits on the front of this power pod.

Here’s a pic to compare the Bushwacker fuse width to the new fuselage. I'm also eye-balling the landing gear placement.

And here's the new, longer nose section coming together. You can just see the LED "table" I built for the white LEDs that extends towards the tail. I explain the construction of this feature further below in the article.

And here's what the bottom looks like. Nice hook and loop strap to keep the battery pack in place.

Now let's jump ahead a bit in the build... motor and servos mounted along with the tail feathers. I liked the “counter balances” of Peter’s rudder, and elevator design… but I opted to simplify the hinge lines for ease of sanding their 45 degree bevel. With the fuselage now narrower, I bent a new, narrower landing gear wire but kept the same Fun Cub wheels.

IMPORTANT STEP. With everything installed (including my 1800 mah battery pack) I made sure to check the CG. Looks good!

Now to the very last steps, adding cosmetic details. Everyone has different tastes when it comes to how their plane looks. I always have to have windows on my planes (that’s where I’m vicariously flying them from!). I used the poster board and 3M77 spray technique that I learned from a past FliteTest video tutorial. It worked great. Tip: if you get a little overspray on the packing tape, you can carefully erase it using a cotton swab and a little nail polish remover.

So after all this re-designing, patient building and pre-flight testing… how does this plane perform? 

Here's a video to check it out for yourself.

If you’re a fan of the FT Bushwacker but would like to:

  1. “mellow out” the flight characteristics a bit

  2. have a plane that you can comfortably fly at night

then you might consider the WeedWhacker as your next project!

I really appreciate our FliteTest community and the joy our hobby can bring to young and old alike!


******* BUILDING INFORMATON ******

FULL SIZE FUSE PLANS: WeedWhacker Scale Plans PDF

Please bear in mind you'll need the wing plans and the tail outlines from the original FT Bushwacker to complete your WeedWhacker. I think I used no more than 3-4 sheets to complete the entire plane.

LED SET-UP: LED set-up PDF
 

CAMERA CRADLE: Camera cradle PDF
 




Comments

charleyza on November 22, 2016
Thank you for sharing! Very cool mods!

Would you mind posting some snaps of how you mounted your camera for your youtube videos? I got a little gopro type camera that I want to use and need some inspiration / tips :D
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ToddMerrill on November 28, 2016
Thanks! Let me see if I can find and post some pics of my camera mount this week.
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ToddMerrill on December 3, 2016
Hey charleyza! I added a new link (per your request) at the bottom of my article. Hope it gives you some ideas for mounting your camera!
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matjey on November 27, 2016
The fat and big tires look heavy to me, was it? Anyway, it is a nice mod on the Bushwaker. I'm not a fan of night flyer but your mod on the model might become handy for a tamer Bushwaker.
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ToddMerrill on November 28, 2016
The tires are actually made of foam and are very, very lightweight. My WeedWhacker ready to fly weighs 1 lb 14 oz ~ that'swith the LEDs and 1800 lipo pack on board.
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collins0627 on December 5, 2016
re the top and bottom of the nose area. is there a hatch? if yes, how is it attached when flying? What do you mean about the wing bottom? Is the wing bottom extended to the wing tips. What is the length of the nose extension? I read your article, ordered the plane kit and want to incorporate your ideas. Thank you very much....

thank you very much
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ToddMerrill on December 10, 2016
Hey colins0627, there isn't a hatch on the nose area. The bottom is open revealing the bottom of the power pod. I use the bottom of the power pod like a shelf for the battery to velcro to. I think you can see me flip the Weedwhacker over in one of my YouTube videos. Then for added insurance, I use a velcro strap to secure the battery in place. As for the wing bottom, you've got the right idea. It's a true cambered airfoil (similar to the Armin wing). Here's a video that might make it clearer: https://www.youtube.com/watch?v=karr67ZYho4 . If you are thinking of kit bashing your new Bushwacker yourself... I've got my nose sticking out 8.5 inches in from of the leading edge of the wing. Good luck with you new plane!
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