CX2 Flybar Mod Gone very Wrong
09-08-2007, 03:09 AM
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CX2 Flybar Mod Gone very Wrong
I have read that a shorter and/or lighter flybar can help prevent blade strikes so I decided to try it. I cut my flybar even with the inner ends of the hooks and put 2 wheel collars on each end. There was very little wind outside so I decided to try it out in a nearby store parking lot under the lights. There was really no change from the original flybar so I moved the collars inward about 1/2 inch. That made it more responsive but it still hovered nicely. This was what I'd been looking for. Then I got brave and tried some high speed forward flight. I did a couple of passes with no problems. Then it happened. My CX2 was headed toward the light post and fast. I managed to slow down and turn the other way but then it just kept going. I tried to stop it but it just wouldn't. It just kept getting faster and heading toward the ground. When I saw it was going to hit the ground, I pulled the throttle all the way down. It hit the ground hard and fast and skidded about 10 ft. The tail is now toast, the upper head broke off and I broke all the blades. It was flying so well, too. I don't know what went wrong. The only thing I can think of is that the battery died. I used it to test the reassembled heli and it wouldn't even lift off.
So, as I'm walking around the parking lot looking for parts with heli in one hand and TX in the other, a cop pulled up. He observed me for a minute and then asked if I was out flying my helicopter. DUH! I thought of a few creative answers to his question and then just said yes.
Chris
So, as I'm walking around the parking lot looking for parts with heli in one hand and TX in the other, a cop pulled up. He observed me for a minute and then asked if I was out flying my helicopter. DUH! I thought of a few creative answers to his question and then just said yes.
Chris
09-08-2007, 07:52 AM
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RE: CX2 Flybar Mod Gone very Wrong
OUCH!! It hurts just to read about it. That's a bitter pill to swallow. You went from docile hover heli to a real flier - to junk in seconds. I did note a few things in your post that are interesting - and no, I'm not going to tell you that you didn't follow directions or something else as stupid.
You cut your flybar even with the ends of the hooks - That was my intent when I described it. Excellent. And the two weights on each end does give stock flight characteristics, except that the directional stability is a bit better and the heli weighs a few less grams.
Moving the collars in a half inch might be a bit aggressive for some. I recommend that the first time out, a flier leave the outer collars at the ends of the rods and move only the inner collars. It seems that you had no problem so obviously you are OK with moving both collars together. And it did work for you. Good hover and more performance.
You tried some high speed flight. That's something that most CX/2 pilots never see. Suddenly the heli is requiring a pilot who has never flown a heli moving quickly to learn 'on the fly'. Slowing down is a challenge. Simply releasing the right stick will allow the heli to slow gently and not flip over. Pulling back on the right stick will put it nose-up and that's a tough recovery. Mine usually goes nose into the asphalt if I get too aggressive. But pulling back GENTLY and lowering the power a bit will stop forward flight. Another way is to rotate the heli gently either right or left in an arc. Again, GENTLY or it will invert. Yes 3D guys - it will invert. It will do a full roll.
I flew mine at full assault speed across the back yard and slammed into the garden shed. It was a bug-on-the-windshield crash. Had the lipo gone to flame it would have been spectacular.
"It kept getting faster . . ." and I'll bet it seemed like an eternity, but in fact your fast forward /out of control lasted maybe 3 seconds? Given 3 seconds, if you have to think about what to do it's already too late. The guys who fly collective pitch helis have the "what do I do next" plan burned into their brains. I believe that those of us with coaxial helis are fully capable of learning, but we haven't had to learn this stuff yet. The closer we get the coaxial heli to the flight characteristics of a collective single rotor heli the more we need to learn to fly. Hover is used for take-off and and landing and that's really all that we have been required to learn to do. While hover is not insignificant, we finally need to learn to FLY. That's a good thing.
I know that the coaxial helis are pretty much at the bottom of the RC Helicopter food chain. They are an excellent place to start. I am still of the belief that these helis can be made to fly way outside of the design performance envelope. Many of us fly coaxial because we aren't ready for single rotor or we realize our limitations and we simply aren't going to fly a single rotor. But the mechanics / dynamics of a coaxial helicopter is most certainly not second rate. Look at the Sikorsky X2. http://aeronode.com/aero/18/sikorsky...run-in-october
That's some cool stuff. I honestly believe that there will come a time when those of us who appreciate a coaxial will have a performance heli to play with. We are seeing the possibilities as we mod the humble little CX/2. We have a lot of work to do and that will require learning to fly better as we boost the performance envelope.
I'm in the same situation as you. With every performance upgrade comes at least one new set of blades and more tape on the bodywork. I quit bandaging the tail and replacing skids by using the boomtown parts, the broken upper hub was resolved with the aluminum piece. I still use a plastic lower hub, but I drilled out the posts that drive the lower rotors and replaced them with a little aluminum wire nub, so those don't break any more. My limitation is my ability to fly, not my creativity. For me to go farther down this road I need to be able to fly better. And as a single rotor (fixed pitch) pilot, I really suck.
So where are you going next? You have rebuilt the heli? It will probably take a bit of work to get the solid flight you had, but you'll get there. Mine always comes back and I'm not magic or anything close. Good luck and keep me posted.
And push the envelope. That what it's there for.
You cut your flybar even with the ends of the hooks - That was my intent when I described it. Excellent. And the two weights on each end does give stock flight characteristics, except that the directional stability is a bit better and the heli weighs a few less grams.
Moving the collars in a half inch might be a bit aggressive for some. I recommend that the first time out, a flier leave the outer collars at the ends of the rods and move only the inner collars. It seems that you had no problem so obviously you are OK with moving both collars together. And it did work for you. Good hover and more performance.
You tried some high speed flight. That's something that most CX/2 pilots never see. Suddenly the heli is requiring a pilot who has never flown a heli moving quickly to learn 'on the fly'. Slowing down is a challenge. Simply releasing the right stick will allow the heli to slow gently and not flip over. Pulling back on the right stick will put it nose-up and that's a tough recovery. Mine usually goes nose into the asphalt if I get too aggressive. But pulling back GENTLY and lowering the power a bit will stop forward flight. Another way is to rotate the heli gently either right or left in an arc. Again, GENTLY or it will invert. Yes 3D guys - it will invert. It will do a full roll.
I flew mine at full assault speed across the back yard and slammed into the garden shed. It was a bug-on-the-windshield crash. Had the lipo gone to flame it would have been spectacular.
"It kept getting faster . . ." and I'll bet it seemed like an eternity, but in fact your fast forward /out of control lasted maybe 3 seconds? Given 3 seconds, if you have to think about what to do it's already too late. The guys who fly collective pitch helis have the "what do I do next" plan burned into their brains. I believe that those of us with coaxial helis are fully capable of learning, but we haven't had to learn this stuff yet. The closer we get the coaxial heli to the flight characteristics of a collective single rotor heli the more we need to learn to fly. Hover is used for take-off and and landing and that's really all that we have been required to learn to do. While hover is not insignificant, we finally need to learn to FLY. That's a good thing.
I know that the coaxial helis are pretty much at the bottom of the RC Helicopter food chain. They are an excellent place to start. I am still of the belief that these helis can be made to fly way outside of the design performance envelope. Many of us fly coaxial because we aren't ready for single rotor or we realize our limitations and we simply aren't going to fly a single rotor. But the mechanics / dynamics of a coaxial helicopter is most certainly not second rate. Look at the Sikorsky X2. http://aeronode.com/aero/18/sikorsky...run-in-october
That's some cool stuff. I honestly believe that there will come a time when those of us who appreciate a coaxial will have a performance heli to play with. We are seeing the possibilities as we mod the humble little CX/2. We have a lot of work to do and that will require learning to fly better as we boost the performance envelope.
I'm in the same situation as you. With every performance upgrade comes at least one new set of blades and more tape on the bodywork. I quit bandaging the tail and replacing skids by using the boomtown parts, the broken upper hub was resolved with the aluminum piece. I still use a plastic lower hub, but I drilled out the posts that drive the lower rotors and replaced them with a little aluminum wire nub, so those don't break any more. My limitation is my ability to fly, not my creativity. For me to go farther down this road I need to be able to fly better. And as a single rotor (fixed pitch) pilot, I really suck.
So where are you going next? You have rebuilt the heli? It will probably take a bit of work to get the solid flight you had, but you'll get there. Mine always comes back and I'm not magic or anything close. Good luck and keep me posted.
And push the envelope. That what it's there for.
09-08-2007, 09:02 AM
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RE: CX2 Flybar Mod Gone very Wrong
You did a normal beginner thing which is not really your fault, it's just a reflex called chopstick. Most new fliers tend to chop the stick when they get in trouble or panic causing the heli to crash down quickly. Experience will get you past this, be patient, rebuild and try again. Avoid flying near light poles
and I think you'll be fine. Learn through experience.
and I think you'll be fine. Learn through experience.
09-08-2007, 11:20 AM
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RE: CX2 Flybar Mod Gone very Wrong
Soloboss, you're right, I didn't know what to do. I knew from previous experience not to pull back hard on the cyclic. The CX2 can do a backflip. It looks like chopping the throttle at the last second saved my gears and 4-in-1. Surprisingly, the blades were broken about half way out but the lower shaft is perfectly straight and no broken hub. I honestly believe my weak battery was a contributing factor. Changing directions requires power. Also, the CX2 tends to go up when flying forward, not down. What's weird though is what happened at the light pole. It was flying too fast forward and it was going up but I didn't stop it before the pole. I turned almost 180 degrees in a very tight turn and kept going the opposite direction. It did slow down in the turn and probably didn't accelerate forward at that point. It just accelerated downward. I think? Maybe it was a semi stall turn? What I'm worried about is did I get the CX2 in a situation it could not possibly recover from? Could the flybar have been forced into an angle that pitched the upper blades forward?
Anyway, it flies again. I had an aluminum upper head in my parts stash just waiting to be used and plenty of extra blades. Now I just need to get that CF boom. I'll try to straighten the flybar but that's harder now since the wheel collar setscrews keep it from rolling on the table. I do have a question about the CF boom. I noticed that the plastic one acts like a vertical stabilizer when moving forward but the CF is full of holes. Is any directional stability lost with the CF boom? Also, could someone tell me or post a pic of what position the gain pot is set to. There are 2 dots on one side of the slot that rotate between the 4 o'clock and 2 o'clock position. Mine is set about 10 o'clock. The propo pot goes from 10 o'clock to 8 o'clock and is set about 3 o'clock (almost centered). I have one more thing to add that I haven't seen mentioned anywhere. My plastic upper bearing cup and a replacement one were both off center. That causes the upper blades to wobble when the lower blades turn. I replaced it with aluminum a while back. I think this is worth adding to an FAQ somewhere 'cause it was a bear to figure out.
Chris
Anyway, it flies again. I had an aluminum upper head in my parts stash just waiting to be used and plenty of extra blades. Now I just need to get that CF boom. I'll try to straighten the flybar but that's harder now since the wheel collar setscrews keep it from rolling on the table. I do have a question about the CF boom. I noticed that the plastic one acts like a vertical stabilizer when moving forward but the CF is full of holes. Is any directional stability lost with the CF boom? Also, could someone tell me or post a pic of what position the gain pot is set to. There are 2 dots on one side of the slot that rotate between the 4 o'clock and 2 o'clock position. Mine is set about 10 o'clock. The propo pot goes from 10 o'clock to 8 o'clock and is set about 3 o'clock (almost centered). I have one more thing to add that I haven't seen mentioned anywhere. My plastic upper bearing cup and a replacement one were both off center. That causes the upper blades to wobble when the lower blades turn. I replaced it with aluminum a while back. I think this is worth adding to an FAQ somewhere 'cause it was a bear to figure out.
Chris
09-08-2007, 12:27 PM
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RE: CX2 Flybar Mod Gone very Wrong
Auch, that's a pitty! All of your hard work tweaking, fidling, adjusting down the drains...
I also learned the hard way not to 'chopstick' when it's almost going wrong. It'll make things go even more wrong.
But better a steep learning curve than none at all.
Mine does the same thing, when i fly forward pretty fast and then rotate (with left stick) it still goes backwards (which was forward) for a bit.
Stall turning is a pretty hard thing to learn, i'm trying to, but constantly find i don't have enough space (in either the surroundings or my head
)...
Currently, my gain is set to almost 10 o'clock and my proportional is around 'half past 3'. So sounds similar. But this doesn't mean a thing i guess, especially the propo one.
That's really depening on your batt, weight distribution, engines, friction, and so on. On stock the gain was a bit beyond 11 and prop around 2.
The most annoying thing i find is that when it comes close to an object or wall, it is almost like it's sucking itself to it!
I don't know the aerodynamics which cause this (actually almost none at all
), but i guess there isn't anything to do about it? Or is it just me?
I also learned the hard way not to 'chopstick' when it's almost going wrong. It'll make things go even more wrong.
But better a steep learning curve than none at all.
Mine does the same thing, when i fly forward pretty fast and then rotate (with left stick) it still goes backwards (which was forward
) for a bit.Stall turning is a pretty hard thing to learn, i'm trying to, but constantly find i don't have enough space (in either the surroundings or my head
)...Currently, my gain is set to almost 10 o'clock and my proportional is around 'half past 3'. So sounds similar. But this doesn't mean a thing i guess, especially the propo one.
That's really depening on your batt, weight distribution, engines, friction, and so on. On stock the gain was a bit beyond 11 and prop around 2.
The most annoying thing i find is that when it comes close to an object or wall, it is almost like it's sucking itself to it!
I don't know the aerodynamics which cause this (actually almost none at all
), but i guess there isn't anything to do about it? Or is it just me?
09-09-2007, 12:37 PM
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RE: CX2 Flybar Mod Gone very Wrong
Well, my heli is reconstructed and flies again but still needs trimming. Ordered a CF boom from Boomtown. I found out small cracks in the plastic tail can be repaired with CA but not this. I'm currently enjoying the wonders of packing tape.
I have some tech info I'd like to share but I'm not sure where to post it. Can someone point me in the right direction?
Chris
I have some tech info I'd like to share but I'm not sure where to post it. Can someone point me in the right direction?
Chris
09-10-2007, 08:05 AM
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RE: CX2 Flybar Mod Gone very Wrong
Mine needs almost constant trimming, every flight area is different and i adjust accordingly.
What's CA? I'm no American, so dont know all the abreviations (like LHS; is that Local Hobby Shop or Local Hardware Store? Or both?).
Currently we're setting up a new website with a knowledgebase about the CX2 (and coaxial flying in general).
So if you can extend your patience a bit, we'll have a place for your tech info!
As soon as it's available well let you all know.
What's CA? I'm no American, so dont know all the abreviations (like LHS; is that Local Hobby Shop or Local Hardware Store? Or both?
).Currently we're setting up a new website with a knowledgebase about the CX2 (and coaxial flying in general).
So if you can extend your patience a bit, we'll have a place for your tech info!
As soon as it's available well let you all know.
09-10-2007, 09:24 AM
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RE: CX2 Flybar Mod Gone very Wrong
That's great news about your new site Sufflez!! I, for one, am anxious to see it and haunt it like I do this one
It's funny how a little $200.00 helicopter can get one so addicted to it. I know I am and it looks like we'll have even another place for even more knowledge!!
It's funny how a little $200.00 helicopter can get one so addicted to it. I know I am and it looks like we'll have even another place for even more knowledge!!
09-10-2007, 09:32 AM
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RE: CX2 Flybar Mod Gone very Wrong
Chris,
No, you are not alone in experiencing the seemingly magnetic attraction that my CX2 finds with walls and other obstructions in my flying space. I am no aerodynamics expert, but I believe that the rotor wash interacts with walls and such to create an area of low pressure between the Heli and the wall. The Heli is naturally then attracted to the wall. As long as you are aware of the effect, you can counter it with good flying, but that first time is always a "gotcha". Also note that you can experience ground effect when trying to spot-land the heli on platforms and such. I find that when I fly over and hover above a landing platform of any size, I have to carefully reduce the throttle to compensate. It also can make positioning the Heli above the pad somewhat challenging.
No, you are not alone in experiencing the seemingly magnetic attraction that my CX2 finds with walls and other obstructions in my flying space. I am no aerodynamics expert, but I believe that the rotor wash interacts with walls and such to create an area of low pressure between the Heli and the wall. The Heli is naturally then attracted to the wall. As long as you are aware of the effect, you can counter it with good flying, but that first time is always a "gotcha". Also note that you can experience ground effect when trying to spot-land the heli on platforms and such. I find that when I fly over and hover above a landing platform of any size, I have to carefully reduce the throttle to compensate. It also can make positioning the Heli above the pad somewhat challenging.
09-10-2007, 09:43 AM
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RE: CX2 Flybar Mod Gone very Wrong
BenMer,
Soloboss and i are currently working on it.
We're trying to gather as much info as possible, bring back mr. Soloboss' setupguide, tech-facts, FAQ, upgrades, statistics (weights, voltages, amps, etc).
We'll post it asap!
Soloboss and i are currently working on it.
We're trying to gather as much info as possible, bring back mr. Soloboss' setupguide, tech-facts, FAQ, upgrades, statistics (weights, voltages, amps, etc).
We'll post it asap!
09-10-2007, 10:14 AM
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RE: CX2 Flybar Mod Gone very Wrong
I know that Solo's setup guide has saved alot of people ALOT of misery and I have the feeling that between you and Solo, your info will help us newbies, and experts alike, keep our little birds where they belong....flying!! Unlike Chris, whose bird likes light poles, mine seems to favor Oak trees, so hopefully you'll have a section on how to avoid future disasters!! Actually, I could solve my problem by cutting down my Oak tree, but I'm afraid that Chris may just run into some opposition if he tries to 'cut down' a light pole in the middle of a mall parking lot!!!!!
Actually, I could solve my problem by cutting down my Oak tree, but I'm afraid that Chris may just run into some opposition if he tries to 'cut down' a light pole in the middle of a mall parking lot!!!!!
09-11-2007, 12:27 AM
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RE: CX2 Flybar Mod Gone very Wrong
Good one, BenMer. Shufflez, CA is cyanoacrylate or super glue. You know, that stuff that causes a true bonding between you and your balsa wood plane, lol.
OK, before I forget, here is one of the tips. In the center of each blade there is a number. I have only seen 2's and 3's. When you buy a pack of 4 blades, they are a close match in weight and all will have the same number. What I have found is that if the top blades are 2's and the bottom blades are 3's or vice versa, you will have trouble adjusting the proportional potentiometer. That was part of my problem. To prove it to myself, I added tape to the #3 blades to make them the same weight as the 2's and the pot was almost centered. When I removed the tape, the heli rotated counter clockwise. I adjusted the proportional pot CW and it was much better but still not stable. I then put 3's on the top and bottom and had to adjust it back near center. Look for these numbers when you buy blades. Keep them all the same and you will be happy. If someone els can prove this wrong, it won't hurt my feelings.
Chris
OK, before I forget, here is one of the tips. In the center of each blade there is a number. I have only seen 2's and 3's. When you buy a pack of 4 blades, they are a close match in weight and all will have the same number. What I have found is that if the top blades are 2's and the bottom blades are 3's or vice versa, you will have trouble adjusting the proportional potentiometer. That was part of my problem. To prove it to myself, I added tape to the #3 blades to make them the same weight as the 2's and the pot was almost centered. When I removed the tape, the heli rotated counter clockwise. I adjusted the proportional pot CW and it was much better but still not stable. I then put 3's on the top and bottom and had to adjust it back near center. Look for these numbers when you buy blades. Keep them all the same and you will be happy. If someone els can prove this wrong, it won't hurt my feelings.
Chris
09-11-2007, 03:53 AM
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RE: CX2 Flybar Mod Gone very Wrong
Thanks for that info Chris!
We'll incorporate it into the new and improved Soloboss' CX/CX2 setup guide at:
[link]http://cx2.r-2.nl[/link] if that's OK with you.
Here you'll currently only find Soloboss' guide, but in the near future an update version of the mod guide,
specs, weights and more tech. info.
We'll incorporate it into the new and improved Soloboss' CX/CX2 setup guide at:
[link]http://cx2.r-2.nl[/link] if that's OK with you.
Here you'll currently only find Soloboss' guide, but in the near future an update version of the mod guide,
specs, weights and more tech. info.
