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Old Aug 01, 2006, 12:46 PM
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HELP Diagnose My Blade CP

Sadly, I've never gotten my BCP flying stably, struggled with sticky collective, then work got me busy so it sat on the shelf. Now its off the shelf & I'm determined to fly the thing as solid & stable as my modified Picolo FP dinosaur which I still love.

Okay, back in the day I moved the servo holes in to tone down cyclic, but had horrible sticky collective even after the fixes. BUT now when I disconnect motors & watch the inputs, I notice that cyclic input gets me changes in collective as well, is this normal? I tend to think not, & it explains why the Blade 'yo-yo's when I try to get into a stable hover.

Should I go back to the original servo holes & go from there?

I fear my machine is too far out of proper calibration to get back to stable performance, the urge to buy a new factory calibrated machine is tempting, but I'm determined to solve this.

HELP!

Lee
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Old Aug 01, 2006, 12:54 PM
Coaxially Fixated
copperclad's Avatar
Rochester N.Y.
Joined Oct 2005
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hi lee
i am betting you can get it to fly like new you just need to figure out what happened to it , i moved my "Z" bends in a hole also as it was too twichy for my liking , i did the bell hiller kit also and i really like it

when i move my right stick forward the front servo arm moves down and both rear servo arms move up , this is pretty standard with 120 degree mixing

when i move my right stick to the right , the right rear servo arm moves down and the left rear servo arm moves up
, but the front servo does not move at all

is this how yours works ? , dana
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Old Aug 01, 2006, 12:58 PM
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Portland, OR US
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With the blade, when you move the servo holes you alter the pitch range. Closer hole, more stable, less pitch, less lift, but way higher headspeed. And if you still have the collective sticky issue, this will get worse.
I suggest you leave things the way it is and add some weight to the flybar.
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Last edited by cat5; Aug 01, 2006 at 01:03 PM.
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Old Aug 01, 2006, 01:49 PM
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Thanks guys

Copper - Yup, mines the same

I just added an additional weight to the flybar, & moved the z-bends out 2 holes, 1 before the original placement, all collective twitching with cyclic input has stopped, seems having the pushrods on innermost servo-horn holes simply pulls too much on the blade holders

Gonna try a test flight tonight, maybe the sticky collective fixes worked after all *crosses fingers*
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Old Aug 01, 2006, 02:10 PM
Just call me crash.
Joined Jan 2006
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Quote:
Originally Posted by gargoyle7
... BUT now when I disconnect motors & watch the inputs, I notice that cyclic input gets me changes in collective as well, is this normal?
Generally, yes.

Quote:
... it explains why the Blade 'yo-yo's when I try to get into a stable hover.
The "sticky collective" should not be an issue with the three-BB heads, HOWEVER if you are getting a true yo-yo is could simply be something binding. Make sure the spindle is not bent, the O-rings are well lubed, bearings are smooth, and most importantly nothing is binding in the head anywhere, including the ability for the flybar to move up and down the shaft smoothly.

You can tell if there is a slight bend in the spindle (feathering shaft) by grabbing the grips and applying a little "bending" motion, if they squirt off in odd directions it's bent. If they hold perfectly opposite each other, it's good.

By "true yo-yo" I mean it will constantly yo-yo throughout the entire flight, irratically: up-down, down-down-up, up-up-down-up-down-up-up . . . like so. If it's intermittent, it could be a glitching servo or a servo with a broken tooth on the gear. Another completely different problem, but a glitch, if it is flying along just fine then out of nowhere it seems to lose all power for a split second then recovers quickly, that is something else altogether. Exactly what is up for debate.

Quote:
to buy a new factory calibrated machine is tempting
All BCP's will be out of trim, if that's what you mean by calibrating, a new one will be no better or worse. All helis will drift left on takeoff, don't assume it's out of trim for this reason, this is due to the increasing RPM of the rotor as it lifts and loses grip on the ground.

If you can get it into a hover for a few seconds, take note of where it drifts when you try to take your fingers off the left stick; adjust the swashplate pushrods accordingly for drifts to the left/right/front/rear, the proportional pot on the 4-in-1 for rudder drifts (you will have to disarm/rearm 4-in-1 for this to take effect.) Although it will never hover on it's own, the closer you get it to trimmed out at hover the easier it will be to learn to fly, I discovered this early on in my crash avoidance training.
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Old Aug 11, 2006, 01:40 PM
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A question guys

can anyone direct me to a good description/image of proper installation of 3 bearing blade holders for the Blade? I wanna make sure I get this right.

Many thanks

Lee
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Old Aug 11, 2006, 03:23 PM
Just call me crash.
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Try bladecprepair.com. It's pretty straightforward, put one bearing in from the side that faces the shaft, then the spacer followed by two bearings from the outside, between the grips. When you reinstall the step washers, just make sure the "step" faces the bearings.
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Old Aug 11, 2006, 03:34 PM
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Aurora, CO
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http://www.bladecprepair.com/manual_pop/expl_view.html
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Old Aug 11, 2006, 11:29 PM
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Thanks guys, been away from the scene, didnt know about that site, very nice

Another question on yo-yoing

A yo-yo effect in flight is what I'm trying to remedy, but thought I had narrowed it down to sticky collective, hence my installing the 3 bearing grips after not getting results with the regular sticky collective washer fix

Now, bladecprepair.com lists the fix for yo-yoing as either worn parts (not in my case), or faulty servo or motor

Now I've just tested my servos with motors disconnected & notice no stuttering or stripping, even with some manual resistance, so doesnt seem likely

My main motor doesnt chirp or anything

My fear is after this 3rd fix I still have yo-yoing, if I do, whats the most likely culprit? Motor?

Is the most common cause of yo-yoing sticky collective?

I wanna get this sucker flying, its impeding me improving my skills, stable hovers with my modified Piccolo FP just dont cut it anymore.

Lee
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Old Aug 12, 2006, 01:57 AM
Just call me crash.
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Even with 3BB grips and all new head parts - I would say something is binding somewhere if it still yo-yo's on you. Depends on "how" it yo yos, as I described earlier. Could still be glitching servos <shrug>.
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Old Aug 12, 2006, 10:11 AM
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Aurora, CO
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Quote:
Originally Posted by rocknbil
Even with 3BB grips and all new head parts - I would say something is binding somewhere if it still yo-yo's on you. Depends on "how" it yo yos, as I described earlier. Could still be glitching servos <shrug>.
I agree...servos can do funny things when the motor is spinning and they are under load. Slight problems can go undiagnosed without a load placed on them, and electrical noise can cause interference, though I doubt that's the case in this example. Make sure everything in the head is good and solid. If you're still having trouble, see about getting someone else to look at it...
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Old Aug 12, 2006, 10:45 AM
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Michael Paxton's Avatar
Nashville TN.
Joined Mar 2006
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If you can put downward pressure on the servos with little rubber bands, it will keep the servo from "jittering" from there own slop.
The S-75s have a lot of inherent slop. And when in use, they try to center themselves and go back and forth over this slop area which makes for a "jitter" with some very unpleasant other side effects...hope this helps.
ps. There are some posts about the rubber band fix....M
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Old Aug 12, 2006, 12:37 PM
Just call me crash.
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Wouldn't that cause them to burn out sooner and overheat the motors? These little micros aren't meant to take much torque . . .but that's an interesting idea . . .

I used to have severe up-down problems but it was obviously a glitch and not a yo-yo. I love my Futaba 3110's, but the wires are too short and you have to convert the plugs to JR and replace or extend the wires on the rear two servos to make them work. Otherwise they're a direct drop-in.
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Old Aug 12, 2006, 03:36 PM
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Very weak bands. Just enough to put pressure on them so they aren't "searching" for center..........M
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Old Aug 13, 2006, 12:59 PM
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Thanks guys, will try these - I have to say, this is a lot of work to get stable flight out of a supposedly RTF out of box heli

QUESTION - whats my best bet for lube? Especially the spindle shaft? Graphite based? WD-40? Grease?

Thanks again

Lee
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