Cant let webby have all the fun

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jharkin

Minister of Fire
Oct 21, 2009
3,890
Holliston, MA USA
Taking a break from airplane building to join the fun in rotary world. Maybe in a couple weeks when I get this air born I'll try and get a first flight video. If I don't crash ;)


This is no drone, so no onboard video...
 

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That frame is all carbon and aluminum with some plastic bits. Only took an hour to get this far.

Next step was building the rotor head. This took over 2 hours of fiddling with tiny screws, greasing bearings, loctiting everything, measuring and aligning. Once its all together there will be more hours of setup, alignment and balancing.
 

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Took a break to pop on the blades and tail boom to get a look. That's a 12in ruler.

This is a "medium size" electric, and flies on a 2200ma 3 cell lipo battery. These come in sizes small enough to fit in you palm all the way up to monsters with 6+ ft rotors running on gas.
 

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Awesome. That looks like some good fun right there. Mount a couple of bottle rockets to the skids with electric igniters....==c
 
JATO I dare ya. ::-)
 
Ha... Yea I can see myself getting a bigger one eventually. These things are HARD, much harder than learning to fly regular airplanes, as I am sure is true in full size also. The first thing you have to do is learn how to hold it stationary in a hover in all positions (facing away, facing toward you, sideways) and it has a feeling kind of like balancing an egg on the tip of your finger. (unlike the quad rotors this has no gyro stabilization other than the tail rotor/rudder control)


Just like the planes, these model helis are capable of stuff the full scale is not like inverted hovering. To give you an idea of what these are capable of in Pro hands, take a look below. I don't think Id ever even want to try those stunts!

 
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Yeah, it is nuts - that's freestyle competition where they are trying to demonstrate the limits of what the machine can do and what a human can keep up with. I wouldn't want to fly like that even if I could.

Here is a video of one of the expert heli pilots at my club flying at our field. This is slightly more sedate...

 
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Not RC but the real thing. But on the subject of flying the ass off of one...

 
Like with Golf, I give up before I start...and, yes, you will crash.......although I like your careful approach!

Same with guitar. You can play for years and then watch some a-hole pick the thing up and make it sing sweet......

I give up...on everything! Well, sorta......

I consider myself a test pilot. That is, I am destroying stuff so others don't have to. See what it can do. Yesterday, I took my v959 (toy quad with little camera) up to as high as it could go...but it kept going! I found it about 10 minutes later. Video was a bit corrupted, but you can get the idea....

Pic below shows me as a tiny dot with shadow at the bottom of the screen. Keep in mind that this is a 3 ounce quadcopter....
high.png

Here is the vid......

I'l also destroying and pasting together my new heavy iron (2 lb quad). Unfortunately, I am learning what Newton and Galileo opined on.....about falling bodies. In this case, I am learning a lot about triage. I have pasted stuff back together which should not be back together. Fun!
 
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..and, yes, you will crash.......although I like your careful approach!

Oh I know I will. Ive had some spectacular crashes over the years with the airplanes. I'm going slow with the heli because the kind of crash you just had on the quad could do well over $100 in damage to this thing, if not destroy it altogether.

Actually I have already had a minor crash. I landed too hard on flight #6 and the tail rotor hit the ground. The way this works is like a full scale helicopter, the tail rotor is driven off the main rotor by a belt that runs through the tail boom. You slide the boom in a clamp to set belt tension, and there is a servo motor that drives a rod down the tail to a bell-crank that controls the tail rotor pitch. The tail pitch servo is hooked up to a heading hold gyroscope and that in turn is hooked up to the rudder (yaw) output from the receiver. The way it works is that the gyroscope senses rotation of the heli and adjust the tail pitch to keep it pointed in the same direction unless it get a rudder/yaw signal from the controller (without it, the tail would bounce all over the place, since the main motor RPM goes up and down as the pitch of the main blades changes under load though maneuvers resulting in changes to the tail rpm).

Ok so why all that explanation?... my "crash" caused the tail belt to slip and the boom to move. I had to reset the boom and re tension the belt. It looks like the pitch control got wacket also because even tigthening everything there is now some play in the tail pitch bellcrank... Its TINY, i mean if you push on the tail blades they will twist about 1/64" or maybe less than a 10th of a degree - but that appears to be enough to cause that tail wagging you see in the video I posted. The gyro send a correction signal to the servo but the slop makes it overshoot and then it dances around.

Thats one of the things I like about these single rotor helis though. Its all very complex and you have to have everything mechanically perfect, we measure blade angles to a tenth of a degree or less. Heaven for a MechE geek ;)
 

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"I have not failed 700 times. I have not failed once. I have
succeeded in proving that those 700 ways will not work."

Ah. The scientific method. Proving the null hypothesis. >>
 
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Ah. The scientific method. Proving the null hypothesis. >>

I think my wife provides the ultimate test. If she cannot understand or use something, then 80% of the population cannot.....
;)

I'm pleased to report that the iphone and ipad actually pass that test.
Apple TV also. Same with most cars. Most kitchen appliances.
But nothing else....
 
Thats one of the things I like about these single rotor helis though. Its all very complex and you have to have everything mechanically perfect, we measure blade angles to a tenth of a degree or less. Heaven for a MechE geek ;)

So you are saying you can't take yours for a walk in the woods and leaves like this?

 
That's an expensive leaf blower there chief.
 
Well, it was bound to happen. First big crash on flight #34. Having graduated to forward flight circuits I was getting ambitious with hover practice and was doing slow pirouettes in the yard (spinning hover in place). Lost orientation when a big wind gust came through and flew it into a tree.

This thing doesnt bounce like a quad :(

2013-05-26 15.49.10.jpg
 
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