The Majik1's First Scratch Build

themajik1

Monkey/Bear Poker
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Not real flexible at all... When building the KF airfoil I noticed that it really stiffened the wing a ton. I really don't think I have to worry about the wing flexing much at all.

So I am thinking ailerons that are 12 inches by 1.5 inches and that should give me the throw I need.

Looking at the 2 PZ planes I have (T-28 and the P-51) it should be plenty.

After the completion of the wing and the rest of the sealing of the fuse, I will weigh and see what power system I need. My original Cessna 182 power plant I have I think is a little weak for it, so I am going to have to decide after the build is complete.

I will post all of the weights and dimensions once I am done.
 
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themajik1

Monkey/Bear Poker
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Hey again all, I have the ailerons cut, mounted, servos attached, and control rods attached.

Everything is going in the direction it's supposed to. I think I have enough throw, if not I will bring the control arms down on the horns and give me more travel.

Here is a short vid of the first test:


I am feeling good about this so far...
 

themajik1

Monkey/Bear Poker
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Looks good. Should be plenty of throw to control it.

I am thinking it will be good. I just watched the episode that FT did on airfoils again and this should fly well as long as I get the cg right and the right power plant.

Once I get the rest buttoned up and weight of the plane, I think I will check out Grayson Hobby and see which power combo I will buy. I have been looking at their brushless combo's and they have some really good prices.

I am really excited with this as it is my first scratch build and on top of that I didn't use any plans. Just started throwing it together.
 

themajik1

Monkey/Bear Poker
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What's the dimensions?

Wingspan is 36 inches, length is approx 30 give or take a little depending on how far the spinner will extend the nose.
The wing is approx 7 inches deep. Should have enough wing area for good lift, we shall see. Guess that will depend on weight.
 
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Ak Flyer

Fly the wings off
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It will definitely make it fly, just depends on how fast it has to go lol. A park 400 size would probably be more than enough power. More is better if you ask me. Are you going for a slow flyer, a scale type or a 3D type plane?
 

themajik1

Monkey/Bear Poker
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It will definitely make it fly, just depends on how fast it has to go lol. A park 400 size would probably be more than enough power. More is better if you ask me. Are you going for a slow flyer, a scale type or a 3D type plane?

I am thinking something along a 400 size would make this plane close to 3D, but really I am just wanting to make something that flies and is stable first.

I agree that more is better in the power department, and if there is enough to make it more of a 3D then I did more than I had hoped for. If there isn't enough for 3D, I will still be happy if it flies!
 

Ak Flyer

Fly the wings off
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I agree. A 400 approx. would be plenty and still give you decent flight times. A 1000mah battery, 20 amp esc and you're in business. I would recommend using a prop saver instead of a spinner, especially at first since you don't know what it's going to do. It will keep you from bending the motor shaft as easily.

I'm excited to see pictures of it completed. I love scratch built foamies.
 

themajik1

Monkey/Bear Poker
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I agree. A 400 approx. would be plenty and still give you decent flight times. A 1000mah battery, 20 amp esc and you're in business. I would recommend using a prop saver instead of a spinner, especially at first since you don't know what it's going to do. It will keep you from bending the motor shaft as easily.

I'm excited to see pictures of it completed. I love scratch built foamies.

I never even thought about prop savers, good idea! Thanks Ak Flier!!! I can't wait to get it finished either, I am thinking yellow and black for the paint scheme, not sure yet.

Once she is complete and everything I will have pics, and the maiden video as well. If I think she flies great I will draw out the plans and post here. If she doesn't fly well, we will have some exciting video for sure!
 

Ak Flyer

Fly the wings off
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I never even thought about prop savers, good idea! Thanks Ak Flier!!! I can't wait to get it finished either, I am thinking yellow and black for the paint scheme, not sure yet.

Once she is complete and everything I will have pics, and the maiden video as well. If I think she flies great I will draw out the plans and post here. If she doesn't fly well, we will have some exciting video for sure!

Anytime. :eek: Always happy to help. I know that when I by my motors from hobbyking, I get the turnigy easy match series and they come with both a collet adapter with a spinner and the prop saver. Comes in really handy having both, allows me to use a variety of props. They don't have a 400 size motor though and a 300 wouldn't pull it. I tried a 300 on my hawk and it was a dog. They have a 450 though. I'm still getting the hang of motor dimensions, but I would look up an eflite 400 and match the specs to another turnigy motor line, or like someone said, give Grayson Hobby a call and see whay they come up with. The guy seems pretty cool and super helpful plus he's a flitetester too.

Bumblebee colors....Awesome:D
 

Ak Flyer

Fly the wings off
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You know, this little HobbyKing Hawk in my avatar picture is a really powerful 3D plane, 32 inch wingspan.....might be able to get a motor like it has. It runs great for about 8 minutes on a 500mah 2S nanotech, but it's going to be lighter than what you're building......I'll do some looking and get back to you.
 

themajik1

Monkey/Bear Poker
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You know, this little HobbyKing Hawk in my avatar picture is a really powerful 3D plane, 32 inch wingspan.....might be able to get a motor like it has. It runs great for about 8 minutes on a 500mah 2S nanotech, but it's going to be lighter than what you're building......I'll do some looking and get back to you.

Oh yea, the Hawk is much lighter than what I have built for sure. I am still thinking about Grayson Hobby for my powerplant, they have some great prices for ESC and motor combo's.

I will be looking forward to see what you find, thanks!
 

Ak Flyer

Fly the wings off
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Oh yea, the Hawk is much lighter than what I have built for sure. I am still thinking about Grayson Hobby for my powerplant, they have some great prices for ESC and motor combo's.

I will be looking forward to see what you find, thanks!

Just found exactly what I was looking for on Grayson
http://www.graysonhobby.com/catalog/400480brushlessoutrunnermotorescgh2212series-p-427.html

The 1000 kv with a 10" prop sounds like what I was thinking of. Says it's approx. like a 400. Great price too. I think I may have to get one just to have for the next scratch build. For that price I might do a twin something or other.
 

themajik1

Monkey/Bear Poker
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Just found exactly what I was looking for on Grayson
http://www.graysonhobby.com/catalog/400480brushlessoutrunnermotorescgh2212series-p-427.html

The 1000 kv with a 10" prop sounds like what I was thinking of. Says it's approx. like a 400. Great price too. I think I may have to get one just to have for the next scratch build. For that price I might do a twin something or other.

I was thinking either the one you chose, or this one:
http://www.graysonhobby.com/catalog/480500brushlessoutrunnermotorescgh2217series-p-337.html

Let me know what you think of this one!
 

pgerts

Old age member
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Why the 1000 and not the 1400? The 8" prop is not as fragile when landing, does not give as much torque and is a little stronger if needed. A 10" looks really big on a plane with 36" span. The difference is that the 1400 uses less number of windings and perhaps a little thicker wire. A 1400 will give you a wider speed span and if you change the wing to something slimmer you will be able to get a 7*7 prop for high speed.
 

themajik1

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I would think the 1000 with a 10" prop would be better for a 3D type of plane to push more air of the control surfaces?

While yes the 1400 would give me more speed with a 8", or even a 7", and if I do go to a thinner wing, wouldn't the performance improve with the 10" as well?

I am new to tring to figure out the motor, prop, ESC combination and I am looking for help.

Once complete, I will post the weight of the plane and maybe you guys can help me in deciding what would be best!

Thanks!
 

pgerts

Old age member
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Some mathematics :
you will not get 1000 revs per volt with load - say 80% *12 volts give 9600 rpm.
times 5" -- 45 mph - am i right? That is going down without load and slip.
the other extreme 1400 give 13340 rpm.
times 7" -- 88 mph - if i am right.
Those speeds are not what you get unless you have no air resistance at all.
The plane you are building is not a 3D with the KF airfoil and high wing, but both motors will give you more than unlimited vertical performance unless you load the plane really heavy.
 

themajik1

Monkey/Bear Poker
Mentor
Some mathematics :
you will not get 1000 revs per volt with load - say 80% *12 volts give 9600 rpm.
times 5" -- 45 mph - am i right? That is going down without load and slip.
the other extreme 1400 give 13340 rpm.
times 7" -- 88 mph - if i am right.
Those speeds are not what you get unless you have no air resistance at all.
The plane you are building is not a 3D with the KF airfoil and high wing, but both motors will give you more than unlimited vertical performance unless you load the plane really heavy.

I am not sure at all. I really don't know enough about it, that's why I was asking. I don't think I need 88 mph, or even if I lose 20%, that is still 60+ mph which will be plenty fast. If I can get 35-40mph I think it would be quick, but not fast enough I couldn't call it a park flyer.

What about the question of a bigger prop, doesn't that give me more air over the control surfaces and make it more responsive in slower flight?

Thanks!
 

pgerts

Old age member
Mentor
I am sure that you will get plenty of response with both 8 and 10". In theory 10 will give you more air flow another one " out, but i have never seen any indoor plane with other than 8" props and they are the same size as yours but flat wings and only 3 mm (1/8") thick. On those 3D the motor, wing and stab are always in line (not true for 2-wing planes).
A better way to get more response is to build a mid wing with symmetrical profile. This plane is more "trainer type". With the KF airfoil you will get a lifting wing - the faster you fly the more lift and more down elevator you have to put in. A way to make it better is to put your motor with a few degrees down thrust.