Yet another project.

[rcspaceflight]

I know I have a lot of projects started: The DC-3. I told someone I would design an A4 Skyhawk that I got really far on but still haven't finished. I still want to build another Swordfish and make it into an article. Same with the Basic Beaver. I want to buy a better motor (when I have money) and fix the design of the Skymaster.

However, my biggest priority is to get out there and fly. I love the One Sheet Trainer I made, but I keep breaking my cheap props when I land because I don't have landing gear on it. And I don't think it can handle the extra weight.

So... I decided to try an idea I've been thinking about trying for a while now. It's basically a Bixler clone, in a way. It's similar to CStence's Smash Drone, but without the wood boom and easier to build?

All I really want is to stop breaking props when I land. I'm perfectly happy with a RET 3 channel plane, but I can fly a 4 channel okay. I went with a 3 channel anyway.

My design uses the majority of two sheets of Dollar Tree Foam Board, so I'm calling it the Two Sheet Pusher.

Pretend that the piece on the bottom, the skid plate, is curved up along the bottom.






Build:

This is the only part of the plans that I actually printed off:


Everything else was measured out using a ruler.


Printed plans...


...cut out.


Fuselage all on one sheet, including skid plate.


I forgot to put a slot into the rudder in the plans, but this works too (see next pic also).




Gluing/laminating the three fuselage pieces together. The rudder gets sandwhiched in there too. (I just used hot glue to glue it together.)




Don't forget how useful packing tape can be. It helps to hold it all together.




Peel off the paper from one side of the skid plate.


Glue it as centered as possible and at a 90degree angle. Which I failed at, but not horribly.






Elevator glued on. With how I have the slots, it slide in there nice and tight and at the proper angle.


The FT Element Firewall is used.






Hot glue spar.


Hot glue the leading edge too. Makes it much stronger and prevents the paper from peeling off.


I cut 1/4" into the wing tips to create the angle. Which didn't turn out as well as I had hoped.


Wing tips glued on.




Finished plane. But I still have to add the electronics and I'm unsure of where to put the battery/how to mount it.


I went with a flat bottom airfoil on the wing tips to make it stronger, but it just made it awkward to mount the wing tips. Plus I may have them too small at 4.5" long on a 30" center wingspan. Making the total wingspan 39".

Plans will be coming if this plane works. The only thing I can foresee failing is the wing design. Otherwise the fuselage feels really solid and I love the skid plate. Should make for some nice landings. I'll still have to hand launch, but I'm used to that. ... I've never taken a plane off of the ground.

 

[Corbarrad]

Interesting concept, but why not build a pod for the simple soarer that lifts the wing above the fuselahe and offers a way to moundt the motor above and back?

Don't beat yourself up about not finishing projects one at a time. It's a hobby after all and sometimes more fun to come up with an awesome solution that actually going through with it.

Guess how many unfinished plans I have lying around... and yes, you can count the "bixpod" for the simple soarer among those.

 

[JohnRambozo]

Cool idea with the skid plate. I like the 1-sheet challenge. Is there a thread to show off 1-sheet designs?

 

[Ron B]

rcsf
I would suggest adding braces from the outside of your skid plate to the fuselage forming a triangle.
put a strip of velcro from front towards the rear of the fuselage and poke holes through the fuselage to add velcro tie strips to help hold the battery in place and it will be moveable to help get the balance correct.
Tape up the plate with your reinforced packing tape for landings.
I fly the smash drone alot and have another design in mind for it so seeing yours is very interesting as a quick and easy build.
Your design should take off from the ground

 

[rcspaceflight]

This was definitely a quick build.

Servos:




The wings felt sloppy, and I didn't even fly it yet. Or even glide tests. So I braced them with bamboo skewers. I thought about adding some foam board to brace the wings, but this was easier and should be stronger in the long run.



It sounds a bit like a prop and slot, and this is probably why.


Okay, I need to finish it up and maiden it.

 

[rcspaceflight]

Uhhhhh

I just maidened it and I found a fatal flaw. You absolutely cannot take off from the ground. And it is extremely difficult to hand launch. The thrust angle seems to be fine when I finally got it in the air. The problem is that I was holding on to the plane so low and where I was grabbing became a pivot point so it just wants to nose dive.

The skid plate forced me to hold onto the plane behind the motor, which is probably the problem, or at least helped to make the problem worse. I just re-watched parts of the Bixler episodes and it looks like they are grabbing it in front of the motor, but the Bixler has a thrust angle and you grab a lot close to the motor than this plane.

I'm not sure if adding finger holes to the skid plate would help.

I think wing tip launching is a must with the plane, but I suck at wing tip launching.


The plane can take a beating... at least the fuselage can. The wings are still intact, but... uh... busted. Probably from the thin fuselage being forced into it. It kinda broke. In half. In a way. The foam is cracked but the paper is intact. I'm calling the wings a weak point, not a flaw. I did nose dive it really hard about 5 times. You can't expect any foam board plane to survive that. But the fuselage is fine, it just needs new wings.

 

[JohnRambozo]

Well, now you know what needs work. Time for revisions!

 

[rcspaceflight]

Sorry it's too far away to see when I finally got it in the air. It was windy out. It seemed like I needed the perfect amount of throttle. Just enough for it to fly and not so much that it nose dived.

I think I'm going to put new, bigger wings on it and try it again.

 

[rcspaceflight]

Actually, re-watching the video, I think I'm just way too used to hand launching at full throttle even though I know I shouldn't do that. I should have gently added throttle until it felt like it wanted to go. Then I could have found the perfect speed to launch it more easily. Instead of destroying the plane.

 

[JohnRambozo]

There's something other than full throttle? I'm half-joking, because it could be a good learning opportunity and I am actually interested to know why less throttle might be better at launch. I don't have any experience with the slower flying planes. Is there some downthrust to account for in the pusher? Is it an issue of prop stall? If its prop stall, would a different prop pitch perform better?

 

[RAM]

I built a Mikey FPV3 and I remember comments similar to yours. Hand launching was a problem for a lot of people who built the original. He ended up moving the motor mount further back and lower on the fuse and that change solved the problem. Good luck with ver.2

Skip to 2:30 for his mod discussion.

 

[rcspaceflight]

I've decided to go with a very different route. So I'm not sure I can actually call it "version 2". I don't know how well I can describe it, but I want to make a tracker plane with two skid plates that act like skis. I want to make it like a tail dragger so the nose stays up. It should allow the plane to be able to take off from really tall grass since the thrust will be trying to pull the plane into the sky instead of the plane catching on the grass and nose diving.

So imagine two of the original planes side by side and with the tails up high instead of down low. I just don't know if I want to make it a twin boom or a regular plane with two big skis. The motor is going to be in front, but the skis will extend out in front of the prop/motor to protect it in a nose dive.


Now my goal is to make a plane that can take off from tall grass. I'm not super concerned with protecting the prop during a crash, I just want to protect it when I land normally.

 

[rcspaceflight]

I built a Mikey FPV3 and I remember comments similar to yours. Hand launching was a problem for a lot of people who built the original. He ended up moving the motor mount further back and lower on the fuse and that change solved the problem. Good luck with ver.2

Sounds like the exact problem I was having.

 

[rcspaceflight]

Something like this: (still some details to work out)








Because the CG will be behind the flat part, it will lay nose up. Hopefully the thrust being angled up will help make the plane slide across grass instead of snagging.