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How would you design a cyclocopter?

#22
Looks great! Just one comment: I recommend putting the pitching axis of the blades at the quarter-chord to reduce the required force to pitch the blades. The center of pressure is loosely located there (despite some weird cyclo aerodynamics at play) meaning the net moment about it when pitching is very low--making it easier to actuate
 

2jujube7

Well-known member
#24
Looks great! Just one comment: I recommend putting the pitching axis of the blades at the quarter-chord to reduce the required force to pitch the blades. The center of pressure is loosely located there (despite some weird cyclo aerodynamics at play) meaning the net moment about it when pitching is very low--making it easier to actuate
I agree that moving the pitching axis of the blades back a little would be beneficial. The trouble is that it still needs to be forewords of the CG because the airfoils use centrifugal force to push against the outside ring and vector themselves. I can still move it back a good amount though, and I think I'll do that. :)
 

2jujube7

Well-known member
#25
Adjusted it a little, here's a screenshot with a CG mark. It has an extremely aerodynamically optimized free-handed spline airfoil. :D

Screenshot 2021-03-15 at 20.48.58.png
 

Scotto

Active member
#26
Hey I was thinking about this again and I wanted to try to visualize it. I love this little program. I've spent way too much time on little virtual mechanisms but its a lot of fun.:geek:
Linkage App

cyclo1.png

@2jujube7 it looks like your creation would have full proportional control up, down, forward, back with neutral being actually neutral. That would be awesome for a lighter than air vehicle picking up payloads.
 

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2jujube7

Well-known member
#27
@2jujube7 it looks like your creation would have full proportional control up, down, forward, back with neutral being actually neutral. That would be awesome for a lighter than air vehicle picking up payloads.
Haha, not sure it's my creation at this point, I've been borrowing heavily from other's attempts. Let's call it reverse engineering. ;)

I put it on a scale yesterday to measure the thrust and I got none. I think it might be time for a complete redesign... :unsure:
 

2jujube7

Well-known member
#28
I recently started over and took inspiration from @Rcjetflyer2 's cyclocopter article. I CADed it out this week and started 3D printing it. This design is SO much less complex than the previous design I was trying to make, so it is printing very quickly.
Screenshot 2021-03-26 at 11.45.38.png Screenshot 2021-03-26 at 11.45.55.png
Above is the new design, below is the old one for comparison:
Screenshot 2021-03-15 at 08.39.26.png

I did have a thought though: Voith-Schneider propeller. I did some research, and it seems like it's been pretty developed (well enough for commercial use in boats). I can't see any reason why it's not being used in aviation as a cyclorotor, except that it's patented. Is that just it?
 

Scotto

Active member
#29
Im guessing this isnt used in manned flight because each rotor blade is being loaded, unloaded, loaded the other direction, and unloaded again each rotation. That would put a lot of stress on something big and aluminum, flexing back and forth. And to fight that it gets heavy. But small stuff like this I could see it having advantages over a normal quadcopter. But its that "fast, cheap, or quality. Pick two" thing however that goes.
Good luck on version 2! Hey just turn version 1 90 degrees and build a tug boat around it;):cool: