The Majik1's First Scratch Build

[themajik1]

I agree guys, but I will say I was doing this to make it as simple of a build as possible. I just glued 3 sheets of the foamboard together and this is what I got. I know it is a little heavy for my taste, but I am going with it anyway. After the maiden (successful or not) I will see about building another wing for it by hollowing the other sections of the wing to reduce weight. I am not going up to the larger battery I spoke about earlier, but still going with a 1800 mAh 3S and see what happens.

You guys are great for getting me to think about how I am doing something and I really appreciate the helpful tips and thought provoking comments!

 

[Ak Flyer]

I think you will be happy with the 1800. Wish I could be there to watch the maiden.

 

[themajik1]

Well, everyone that has been part of this thread will get to see the maiden, although I wish everyone could be here for it as well!


As soon as I get the motor and battery, some good weather it is going to be maiden time!!!

 

[Ak Flyer]

Cool. Keep the mid build pics coming too.

I was thinking about leading edges again and what do you think about doing the three piece but letting the middle piece stick out ahead of the other two to give it some curve? Would that help or hinder the airfoil? I'm dying to see how it flies. I want to do a really big foam plane, like an 8 foot wing and I'm thinking of using this type of wing.

 

[themajik1]

AK, I am not sure, seems that the drag would be the same wouldn't it? Of course it could have the opposite effect on the KF airfoil itself. From the explanation the step down is what gives the plane lift. As the air builds turbulence at each step over the wing, it slows the air on top and causes lift. If the step was on the bottom, even one step, the turbulence would have the same effect right?

I think your thoughts of rounding the leading edge, making the inner steps of foam hollow is the way to go. I just don't want to build the other wing yet, as I need to go get more foam for it. LOL I am a little lazy and its been cold here anyway.

I will round out the leading edge this weekend and post more pics then. Going to order motor combo tomorrow, payday and all.

I will let everyone know what is happening!

 

[Ak Flyer]

I was just thinking that having the three stepped in a way that would give it sort of a rounded edge without having to shape anything might help it flow better. The lift is generated by a smooth separation of the oncoming air and the increase in speed over the step section causing a low pressure. I was just thinking there may be a simple solution without adding more weight. Who knows, the blunt edge may not be as detrimental as I'm thinking it is.

 

[jetpackninja]

AK, I am not sure, seems that the drag would be the same wouldn't it? Of course it could have the opposite effect on the KF airfoil itself. From the explanation the step down is what gives the plane lift. As the air builds turbulence at each step over the wing, it slows the air on top and causes lift. If the step was on the bottom, even one step, the turbulence would have the same effect right?

Google KF airfoils or come to think of it, I think there is a Flitetest episode. anyway there are several different types and some use a step on the bottom, some on top, some on both and some with more than one step. Different KF airfoils for different results. yesh, some of this stuff is counter-intuitive but works anyways

 

[jetpackninja]

linked from wikipedia

 

[Ak Flyer]

Hmmm. Interesting. I started looking for information and came across this.



Looks like there's a bunch of ways to make one all right. I have to try it now. lol

I think I'm going to add a step section to the flat wings on my Profile 3D plane and see if it starts producing lift without having such a high attack angle.

 

[themajik1]

JPN, thanks, I didn't even think to look there!

I am going to have to round out the leading edge with the foam. Mine looks like the KF #9.

AK, you were right all along. You both are right that the KF family some has steps on top and bottom.

Wow, learn so much from you guys asking questions and helping look around to find the answers!

At some point we need to have a FliteTest get together so we can all meet, at least the ones that may be able to make it!

What fun we would have!!!

 

[Ak Flyer]

Here's the rest of the article I got the chart from. It's a letter to rcfoamfighters.com from Dick Kline, the inventor of the KF airfoil. It's a pretty interesting read.

http://rcfoamfighters.com/blog/?p=249

I think a Flitetest fly in would be a blast. It would be great to meet everyone.

I'm having a great time learning about these as well. Like I said, I have a scratch build on the brain now.

 

[jetpackninja]

Agreed- a Flitetest flyin would be awesome. I grew up in Ohio and would love to make a trip in that direction someday...
Sadly, that would be a longgggg drive for me I live in Utah, if you guys ever make it out this way we could have a small Flitetest gathering here in the mountains.

 

[Ak Flyer]

I would have to fly there and hit the hobby shop and build a plane when I get there lol. Bring my own electronics in a carry on but there's no way I'd trust one of my planes to an airline. Is that ironic or what lol

 

[jetpackninja]

I'm with you there. One of the guys on the Assassin thread was a military guy on temporary duty in Japan. He ordered all the stuff and built it in a hotel room.
The same guy also purchased a case like you would use to carry a compound bow, he modded it so he could carry his combat plane on a plane, I think it worked out for him but with the extra charges the airlines charge for luggage now I'm not sure it would be worth it

 

[fwa2500]

At some point we need to have a FliteTest get together so we can all meet, at least the ones that may be able to make it!

What fun we would have!!!

Iwould definitely be in for that! It seems like there are a good number of us in the midwest so maybe somewhere central like indianapolis or something, though I don't see why it wouldn't be possible to have multiple regional events.

This build is making me want to try my own, keep it up

 

[themajik1]

I ordered the motor, ESC, props, connectors, and battery for my build today! It is supposed to be in my hands by Jan 25th. Everything ordered from Grayson Hobby. Man, they have some good prices on most of their stuff, check them out. I will let you all know how the order goes and take pics of the parts before mounting. Maiden getting close!!!

Oh, and I will get the weather stripping on the leading edge of the wing this weekend and will post pics of that and hopefully get some paint too.

 

[themajik1]

Well, no paint. Been too cold to paint outside, but maybe this week as it started warming up today.

Did get the weather strip on the leading edge and I think it is going to work out very well. Here are some pics for critique. (I am sure there will be, and I am hoping maybe some better ideas!):



I am thinking about adding a landing gear on it, A tail dragger, Yes or no???

 

[KKArioKA]

amazing work !!!

i saw the first few pages and forgot to subscribe .... now you have almost done !!! good job !!

the leading edge will work fine !!

 

[themajik1]

amazing work !!!

i saw the first few pages and forgot to subscribe .... now you have almost done !!! good job !!

the leading edge will work fine !!

Thanks KKArioKA! I am just playing around, but it has been a lot of fun putting this together. I cannot wait for the motor and other parts to get here so I can mount them and maiden. Going to film the maiden and everyone will be able to see what happens fly or crash!!! It really doesn't matter which, as it has been a learning experience, and if it doesn't I will investigate what went wrong and rebuild. The anticipation is killing me!!!

 

[Ak Flyer]

Looking good. I like the way the leading edge came out. I think it will perform much better now.

I prefer tail draggers, and they are the easiest to build. Trike's are easier to land but it's harder to make the nose steer than it is to put a wheel on the rudder.

Coming along well.