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Scratchbuilt Wing-

JimCR120

Got Lobstah?
Site Moderator
#1
Ok, after crashing the Funbat enough times that required more props than I now care to count (though the last crash was a selfless act of mercy to spare the untimely demise of a spankin' new P-40) and also having seen the Joshes flying the Swifts, the Sumo, and the Bonzai I have come to determine that a flying wing looks much too easy to build and fly to not give it a go.

So, now I am going to build one of these and my goals are as follows:
1) I plan to use one sheet of FFF.
2) I want to maximize wingspan and wing area.
3) I want a bit of a dihedral for trainee friendly flying.
4) I want the first flight done by this weekend.
5) I want to paint it in a way that will allow my aging eyes to see if it's coming or going and upright or inverted.


I have no written plans but I do have some images forming in my noggin. I could say I'm going to play it by ear but perhaps saying, "I'm winging it" would be more appropriate. Pardon the shameless pun.

—Jim
 

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bmsweb

Site Moderator
#7
4) I want the first flight done by this weekend.
Can't wait to see how you go with this Jim! Yes please post progress pics! This weekend . . hmm we will see hey :)
 

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JimCR120

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#9
Ok, first a little confession...That pic I sent wasn't the foam I was going to use but actually two sheets I promised a friend. I was just too lazy to go downstairs and take a pic of the real material for this build. This first new pic is the real McCoy. Samson here is my witness.

1) First thing I did was mind the midline of the 2'x4' FFF.
2) Then I drew a diagonal line from one end of the midline to each of the opposite corners.
3) On these diagonals, I scored (did not cut all the way through) the foam.
4) Then I flipped the scored side down and used my straight edge to hold down the foam along the backside of the diagonals while I folded them back carefully so as to only leave the plastic side intact. This plastic will serve as my outer skin of the aircraft before I paint it.

My next step will be to cut away a little bit of foam from the sides of the scoring so that when I fold it over on itself it won't bind up too much.

Picture 3.jpg Picture 5.jpg
 

JimCR120

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#10
Since I was falling asleep on the job I called it a night. Today after some fellowship I got back to work on the wing. Here are the details of what I did last night since the last post and today so far.

5) I cut thin angled strips of foam away from the scored edges. (4 cuts)
6) I put the l wing belly down and folded each wing over as it will be when done just to assist the foam into assuming the position.
7) I marked of the area for the prop/motor area and cut it out.
8) I started gluing down the internal supports which will serve to hold the dihedral angle, firm up the area of the control surfaces and the motor mount, and give the wing a bit of a airfoil shape. I have a few more strips to glue in yet. I am using scrap balsa and Gorilla glue to laminate the foam. I usually glue in a few very thin layers for added strength.

Picture 3.jpg Picture 5.jpg Picture 6.jpg Picture 7.jpg

Friends are over so I need to go watch them fly too. I'll try to work in the glue time with the flights and keep this going so I can stick to my goals.

—Jim
 

JimCR120

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#12
Nice! What electronics do you plan to put in?
I have my standard electronics package that I intend to use:
Motor - Grayson Micro Jet V3
ESC - Grayson Programmable Brushless 20A ESC
Servos - (2) Corona 9g (CS-928BB)
Batteries - (2) Rhino 30C 3S 1050mAh, (1) Turnigy 30-40C 3S 1800 mAh, and (1) Turnigy nano-tech 25-50C 3S 1000 mAh (if I can get it working. It's brand spanking new and seems to not have all its cells rogering up.)
Transmitter - Hobby King HK-7X
Receiver - Hobby King HK-8X

I did get some work done on it today but not as far as I had hoped, certainly no maiden flight. I apologize for that. Soon though. The airframe is about complete. Then I will install the motor mount, motor, and then start looking to figure the desired CG with what's left.

Good night all.

—Jim
 
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#14
I have my standard electronics package that I intend to use:
Motor - Grayson Micro Jet V3
ESC - Grayson Programmable Brushless 20A ESC
Servos - (2) Corona 9g (CS-928BB)
Batteries - (2) Rhino 30C 3S 1050mAh, (1) Turnigy 30-40C 3S 1800 mAh, and (1) Turnigy nano-tech 25-50C 3S 1000 mAh (if I can get it working. It's brand spanking new and seems to not have all its cells rogering up.)

I did get some work done on it today but not as far as I had hoped, certainly no maiden flight. I apologize for that. Soon though. The airframe is about complete. Then I will install the motor mount, motor, and then start looking to figure the desired CG with what's left.

Good night all.

—Jim
Nice choice using the grayson esc and micro jet v3, I have used their micro jet v2 and their supermega jet motors they are some good quality products
 

JimCR120

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#15
@Colorex, hollow yes but not really ribbed. I'll post pix tomorrow. It's getting late.

@Pat, thanks. This set up has always worked for me and I have yet to use anything else aside from the stock electronics that came in my WildHawk. The only reason I'm on my second Grayson motor and esc was because of one unfortunate day when I flew in wind much too strong for my experience level. Soon, my whole plane was a small speck that I couldn't tell if it was coming or going. I lost the whole thing. It could have gone to Vermont for all I know.

Which reminds me, I didn't put down the rcvr in the list. I'll do that now.
 

JimCR120

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#16
As I was saying in #8 above I was gluing in internal supports. Across the bottom you can see a few layers of balsa I put in as a laminate with Gorilla glue. I also put some scrap foam along the leading edges and down the centerline for shape and support.

9) I folded the top part of the wing over and glued it in place, one side at a time so that I could use my sophisticated clamping system without pressing out my dihedral flat.

Another work week is coming to an end and I am hoping to get this in the air for flight testing and adjustment.

Oh by the way, since I mentioned a faulty battery in my last post I thought what was found was significant enough to mention it in the forum. The Turnigy nano-tech that wasn't working appears to have two problems, both have to do with a bad connection. One, it seems that by gently squeezing the battery sides that I am affecting a solder joint which sometimes conducts and sometimes doesn't. Two, this little doozie was noticed by Morgan, the red and black leads are soldered in backwards (the red lead is going to the negative socket in the XT60 connector). This is how is came in the mail. I think I should write HK about this one. I bet if this happened to me, it has happened before. I'm curious how they are going to deal with me on this.

Picture 8.jpg Picture 9.jpg
 

jetpackninja

More combat please...
Mentor
#17
Typically DOA items sometimes they will offer a new one- after you ship it back to them.
Most items it is not worth the shipping for a replacement. Not sure what their policy is on batteries, they may not even offer to accept a return for replacement. These are some of the realities of dealing with HobbyKing. For the most part, their stuff is cheap enough that an occasional write off is acceptable. The whole USA warehouse was supposed to address some of these customer service issues. I would definitely contact them and see what they are willing to do.

If HobbyKing wants to be a world class company, they need to offer world class customer support!

On the brighter side even if HK is unable or unwilling to fix it the battery is probably repairable. How are your soldering skills?
 

JimCR120

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#18
They said it's been too long. I'm out of the window. I still like the size/weight so I'll order another and hopefully I can work a way to fix this one. I was an avionics tech in the Navy so I've done some soldering.