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Super Light 3D Foam Board Profile Plane for indoor and outdoor Insanity!

#1
If you’ve never seen or heard of one of these lightweight 3D planes, look up a video of the Twisted Hobbies Crack Laser. These models pack a huge performance into a small plane! However, some of these airframes will run you over 80$... so to save some money, but still get insane performance, keep an eye on this thread. The goal here is to design a very lightweight airframe based on some of the designs from TwistedHobbies (check them out). Hopefully his will be running on the FliteTest Power Pack F due to its low weight and high power. I already drew the fuselage out in CAD, and am hoping to get a lot of work done throughout this week!!!

Here are some pictures of the Crack Laser from TwistedHobbies.
8AF9B4AC-9F0F-4ECC-8049-4431936F57C0.jpeg 14C86611-7070-4023-8523-3345E722E12D.jpeg
https://twistedhobbys.com/th-32-epp-crack-laser-lite-17-includes-lg/
 

Bricks

Well-known member
#3
Make the wings part of the horizontal part of the fuselage with a carbon rod in the wing. Then add 45 degree braces between the fuselage and wing on the bottom side.
 
#6
Thanks for the replies! I checked out that other thread, but I am interested in making my own. I have considered using a one piece fuselage and wing panel, however I’m not quite sure it will fit on a sheet of foam. Tomorrow I will take some measurements of the pieces to see what I’m working with. I have seen some carbon cross braces on some of these models, almost like struts for the wing. I am thinking that using fishing line under tension may be a strong and lightweight solution. I will have to do some testing.
 

Headbang

Well-known member
#7
My edge design will work indoor with a smaller motor. Even with a 2205 I have no issues keeping it in the space of a warehouse. If I were to do it indoor specific, I would design it around an A pack. It can go a lot lighter, indoor you do not have enough room to get up to speed to stress things much. 1 sheet wing with possibly a thin carbon fiber strip or even just a bbq skewer would be enough. Lots of options to lighten things up. My design is built to withstand the stress of high energy 3D.
My plans will be released in the next day or 2.
 

buzzbomb

I know nothing!
#8
fishing line under tension may be a strong and lightweight solution.
That would be a novel and unique approach! Just run down a wing, I can't see an added benefit, though. It seems like it would actually stress a wing in the wrong direction and contribute to it's folding, so that the tension can be released.

It'd be like gluing a rubber band at one end of the wing and stretching it tight to the other end. The only thing keeping the wing from folding is the strength of the wing. It's not adding to it, it's working against it.

It's just my mental visualization and my very poor 2c. I wish you luck! :)
 
#9
That would be a novel and unique approach! Just run down a wing, I can't see an added benefit, though. It seems like it would actually stress a wing in the wrong direction and contribute to it's folding, so that the tension can be released.

It'd be like gluing a rubber band at one end of the wing and stretching it tight to the other end. The only thing keeping the wing from folding is the strength of the wing. It's not adding to it, it's working against it.

It's just my mental visualization and my very poor 2c. I wish you luck! :)
Any string like braces have to be on both sides. Everything was done like this until about 1930.
 
#10
Headbang- I will definitely check out your plans.

By the string method, I meant that the string would come from the high point on the fuse as well as the low point on each side of the wing. Something like the picture below. I don’t think everyone just has some carbon fiber lying around, so I would prefer household materials, but if needed I will use carbon. If I have a spar that extends about halfway down the wing, that would provide a good hard point for mounting. I have also considered doing a fold over airfoil, as it gives it more strength with only a few more grams of weight if done properly. I will keep you updated

Also I will use a 2204 motor on the first version because it is rated for 2s batteries. If there is not enough power, I will move up to the 2205. I’m looking at using an 8 inch slow flyer prop- the motor will handle it just fine. Hopefully I can get the wings drawn out today!

Here is a design using carbon rods similar to the way I would use the string/line. FBED6441-6F8C-4B7C-998F-B5586B5D6877.jpeg
 
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buzzbomb

I know nothing!
#11
Headbang- I will definitely check out your plans.

By the string method, I meant that the string would come from the high point on the fuse as well as the low point on each side of the wing. Something like the picture below. I don’t think everyone just has some carbon fiber lying around, so I would prefer household materials, but if needed I will use carbon. If I have a spar that extends about halfway down the wing, that would provide a good hard point for mounting. I have also considered doing a fold over airfoil, as it gives it more strength with only a few more grams of weight if done properly. I will keep you updated

Also I will use a 2204 motor on the first version because it is rated for 2s batteries. If there is not enough power, I will move up to the 2205. I’m looking at using an 8 inch slow flyer prop- the motor will handle it just fine. Hopefully I can get the wings drawn out today!

Here is a design using carbon rods similar to the way I would use the string/line. View attachment 142990
I gotcha. My mental visualization was way off. I was seeing the string embedded in the wing like a rod. @sundown57 did a great tutorial on stringing a biplane that could save you some mental grease. You'll have to search his posts, though. I did a quick search and couldn't find it.

I like your ideas! Keep it up and I wish you luck! :)
 
#12
Sadly, I have decided that for now, the design of this plane is not reasonable. I will have to completely redesign this thing. I have another idea about scaling down an edge, peeling most of the paper, and removing as many parts as I can to make it lightweight. Honestly, I just want a cheap, good flying 3D plane to fly around in my front yard and get better at flying 3D. I have some other ideas regarding my previous design, but I would like to try the mini edge first
 
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SquirrelTail

Well-known member
#13
Sadly, I have decided that for now, the design of this plane is not reasonable. I will have to completely redesign this thing. I have another idea about scaling down an edge, peeling most of the paper, and removing as many parts as I can to make it lightweight. Honestly, I just want a cheap, good flying 3D plane to fly around in my front yard and get better at flying 3D. I have some other ideas regarding my previous design, but I would like to try the mini edge first
Planes 2-5 on this page all are $30 3D machines! http://www.valuehobby.com/airplanes/all-airplanes.html?p=2
 

L Edge

Well-known member
#14
Thanks for the replies! I checked out that other thread, but I am interested in making my own. I have considered using a one piece fuselage and wing panel, however I’m not quite sure it will fit on a sheet of foam. Tomorrow I will take some measurements of the pieces to see what I’m working with. I have seen some carbon cross braces on some of these models, almost like struts for the wing. I am thinking that using fishing line under tension may be a strong and lightweight solution. I will have to do some testing.
I tried string on a bipe wing with the net result being there is no way to adjust it once it loosens up. I have TH crack and the carbon struts is the only way to keep it's shape. I even tried kevalar thread. Model will not perform once it is out of shape.
 
#15
I decided to just go ahead and finish my design, and to my surprise it flew great! It was very floaty, however I need to make a battery slot so that the weight is centered. It was very nice at hovering and harriers, but was very out of trim due to the battery placement, so I did not try much more than that. I will continue to improve this design. I could tell the wing were flexing a little bit, so I may add add a spar. The plane has plenty of power, but sadly my 5 year old motor finally burnt out. I am going to switch over to a red bottom today- hopefully it’s not too much to handle. Also, the firewall mount needs to be redesigned as it came loose during landing.