buzzbomb
I know nothing!
Ironically, everything I'm learning on this forum I'm learning on the internet....
Boeing B52 Stratofortress build update
- Thread starter Clement
- Start date
As @Grifflyer said, somewhere around the 2cm mark should work for thickness at the root. In terms of examples of an FT style flat bottom wing, the closest pattern I can think of is the wing for the FT Racer which is swept back a little. You might also look at the plan that @Mid7night used for his large B-52 build. It might be possible to scale this down to meet your needs.
DamoRC
buzzbomb
I know nothing!
I can't let this go. I've said before in other posts that I'm a hard-headed son of a gun. My info came from Bix himself.
About the two minute mark. What he's saying, and I am seriously paraphrasing here, is that yes, we've got all the math, we can build and create and it works. BUT, and it's in caps because it's a big but: Even though we can make lift work, there are two conflicting theories about WHY it works.
The math works because if you build a wing a certain shape, it works in a certain way. WHY it works that way, according to the Bix, is still up in the air. (No pun intended)
That's where I got my interwebs info from. Ya'll take it from there.
About the two minute mark. What he's saying, and I am seriously paraphrasing here, is that yes, we've got all the math, we can build and create and it works. BUT, and it's in caps because it's a big but: Even though we can make lift work, there are two conflicting theories about WHY it works.
The math works because if you build a wing a certain shape, it works in a certain way. WHY it works that way, according to the Bix, is still up in the air. (No pun intended)
That's where I got my interwebs info from. Ya'll take it from there.
Thanks guys. I checked out the B52 built by @midnight7. I posted a picture of two options of airfoils 1st option and 2nd option. @midnight7 used the 2nd option. My questions are
1. Which of the options should I use.
2.If I use the 1st option, what should be the value of x in cm
3. If I use option 2, what should be the values of a, b and c in cm.
Please help out guys, I really appreciate you guys and I am learning so much from you. Feel like taking you all out for lunch or something. Just hola any time you are in Nigeria
1. Which of the options should I use.
2.If I use the 1st option, what should be the value of x in cm
3. If I use option 2, what should be the values of a, b and c in cm.
Please help out guys, I really appreciate you guys and I am learning so much from you. Feel like taking you all out for lunch or something. Just hola any time you are in Nigeria
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Generally, when there are two conflicting theories, one or both of them are wrong because something is missing from one or both of them. Not long ago, they applied aerodynamic theory to the bumble bee, and proved that it couldn't get enough lift to fly! Clearly, they missed something.
The way I look at it, there are much more important questions to answer. What is reality? Why are we here? Where did we come from? Are we actually here? Do gods exist? Are they Aliens? If so, where did they come from? How can a guy have a medical problem, but have no pain, when his twin brother has no medical problem but he has the pain that his brother should have? It's possible that the answers of these questions will reveal new fundamentals that explain everything.
Hello guys, please help with answers to my previous questions,
1. Which of the options should I use.
2.If I use the 1st option, what should be the value of x in cm
3. If I use option 2, what should be the values of a, b and c in cm.
Pleeeaaase.
Also I got a quadcopter, ( Airufo sky phantom 2.4G 4CH radio control quadcopter). Decided to use 3 of the motors, one behind each wing and the third at the tail of the B52. Since they will be pusher props I had to change the direction of the propellers and also had to rewire the motors to spin in the opposite direction. The 3 motors are working perfectly now like pusher props.
The issue I have now is with the gyroscope. It alters the speed of the 3 motors such that they spin at different speeds and this is not good. Please does anyone know how to disable the gyroscope? I have attached pictures of the circuit board. Thanks guys
1. Which of the options should I use.
2.If I use the 1st option, what should be the value of x in cm
3. If I use option 2, what should be the values of a, b and c in cm.
Pleeeaaase.
Also I got a quadcopter, ( Airufo sky phantom 2.4G 4CH radio control quadcopter). Decided to use 3 of the motors, one behind each wing and the third at the tail of the B52. Since they will be pusher props I had to change the direction of the propellers and also had to rewire the motors to spin in the opposite direction. The 3 motors are working perfectly now like pusher props.
The issue I have now is with the gyroscope. It alters the speed of the 3 motors such that they spin at different speeds and this is not good. Please does anyone know how to disable the gyroscope? I have attached pictures of the circuit board. Thanks guys
Attachments
I would go with option 2 mostly because Mid7Night has shown that this wing flies (albeit at a significantly larger scale) and the plans for that wing shape are available. I reversed engineered this wing in sketchup and captured the following (white panels are the upper surface, grey panels are the lower surface. Note that Mid7Night wing is thinner at the root than the tip (at the root his spar is 0.8cm tall, at the tip its just 0.1cm - ignoring the thickness of the upper and lower panel foam. The dimensions you requested are in the image.
On the gyro, unless there is a way to connect that board to a laptop or flight controller programmer, you are not going to be able to turn off the gyro. There may be an option to physically hack the board, but I wouldn't know where to start. I would caution that any attempt to interfere with the sensors on the board will just confuse the controller and you may brick it.
As we discussed earlier, the flight controller was going to complicate the control of the motor speeds. I think this is more complicated if you use three of the motors.
DamoRC
Not quite. His bottom plate is 9.6 cm. His top plate is longer because it will fold over the spars and the trailing edge will overhang the bottom plate by approx the width of his aileron. The .8 cm is the height of his spar when the wing is scaled to 60cm. However his original wing design probably also took the foamboard thicknesses into account. That being said, 0.8 to 1cm spar height should work okay. You should mock it up to check. On the root spar, I don't think you will need the spar to run all the way to the root to support this wing. Half spar height at half wing length should do it. Remember, I am just reverse engineering his original drawings and these numbers are just guidance and not necessarily 100% accurate.
DamoRC
GMalatrasi
Active member
I have all the respect for Josh and what he does, but as far as I know he's not an engineer.
As I mentioned before these two "theories" aren't mutually exclusive. So there is no conflict.
Both aspects contribute to lift.
If you have an airfoil shape with no angle of attack, you can get lift from the Bernoulli effect.
If you have an air foil with and angle of attack, you get more lift because you add in the deflection effect.
buzzbomb
I know nothing!
Thank you.
GMalatrasi
Active member
You bet!
Lol. Actually bought a whole bundle of the takeaway packs.
Thanks DamoRC. I wasn't able to defeat the quad's gyro. Would have to manage the motors with the gyro.
