Question for you advanced pilots:

How do I balance the blades and what is the difference between balancing the weight and balancing the center of gravity? I assume balancing the weight is as simple as placing the blades on a scale and making sure they are equal??? Or perhaps I can stick a long rod or screw thru the screw holes and find some way to make the blades stick out opposite each other and see if the whole assembly tilts to one side?? I'm kinda of getting anxious about this because I crashed into a tree and the heli vibrates a lot when I give it more speed. I know it isn't the main shaft because I replaced it after the crash.


Thanks!

I'm new to all this too, but I think the CG of each blade is what you're after. That is, if you stuck the two blades on a balancer, you'd be able to guarantee that both weigh the same and have roughly the same weight distribution from base to tip, but for the real stickler's out there who want to eliminate as much instability as possible, the CG of each blade has to be tuned and matched -- individually, and across both axices (base-to-tip and leading-to-trailing edge -- even top-to-bottom if you're crazy 'nuff).

It's one thing if the two blades weighed the same, but finding and tuning the CGs takes balancing the blades along each axis. I've used a taped-down round metal rod on a flat & level plastic surface to do some rough CG matching. I set the blade down on top of, and perpindicular to, the rod and nudged it back and forth with a pen until I found the center along that axis. Rotate 90° and repeat, and again repeat those two steps on the other blade... Then compare it to the first. That's when you get to do the real balancing of the blades.

You can see that if the blades need to weigh the same, and need similar CGs (if not idealized CG's for optimal performance), and you've used glue or tape to do repairs, that it'll be difficult to balance all these parameters out if one (but not the other) of those parameters (weight and CG) is askew... if that makes sense

Yep you're right flaxen. However, I think it's unnecessary to match the CG on anything except base to tip, so you wouldn't need to get the lateral CG. Also, remember that if you add any weight to even out the CG's, make sure you add it ON the CG, otherwise you'll get all screwed up. If you need to move the CG towards the base of the blade, add tape a bit closer to the base of the blade than the current CG is and that will move it, and then you'll need to compensate on the other blade by adding tape on its CG to make the weights the same. It takes time and patience. But in most cases, if you're using the same blade set and after a crash they're not balanced, I think you need to get new rotor blades because something has come of or been seriously displaced enough to not only make your heli vibrate like crazy but also since something is probably wrong with the blade shape now the airflow over it will be all screwed up.

Remember, rotor blades are a consumable. If you're beating up a pair, don't try to keep using them. Replacing them will solve a lot more problems (yes, it adds up, but welcome to helis!) and it will help avoid a serious possible safety hazard, say....a lead rod zooming out of the rotor blade and flying like a missile towards something...just hope it's not you.

I'm not trying to scare you, but if your blades are all screwed up you might as well replace them.

Helicopter=balance.. The deeper you learn the balance of the rotor head.. the more predictable you can make it.. period.. Balance is essential to anything that relies on centrifugal force. if its out of balance.. "reguardless of its axis" its not performing to its optimum..Balancing the center of gravity is an " optimum" option.. it allows you to loosen the grips on the blades. Which in turn makes the head more effecient.. for when ya need it.. BAD. ..

Actually, I'd agree the grip-to-tip direction is the most important, as this will be responsible for most of the wobble, however, if you don't center it along the lead-to-tail direction, there would probably be performance issues that only appear at certain higher RPMs, where the forces on the airfoil start to count more. Tho, the effects would probably be hard to notice if the grip-to-tip CG was out.

As for the consumability of blades goes... I do what I can to prolong their life. I've had great success with fiberglass/CA versus the plastic wrapper it comes in.. Also, since I'm adding so much weight, I've taken out the lead (I was disgusted to find it in there, really) and replaced it with a small carbon rod (on my flat blades) and balsa to fill the gap before glassing 'em. My glassy sym blades are only 1.5g over stock, but took me something like 6 hours to prepare..........

I've had several pretty gnarly crashes on my stock blades, and they still fly great. They've survived well with 2 or 3 layers of fiberglass in the leading edge/tip. The consequence of making the blades rigid is that the shear pin goes often, and maybe a higher risk of bending the shaft or spindle... and I've shattered my tail boom... but those are acceptable risks for me since all that's easier to fix than shattered wood that needs to be balanced.

For those having problems with the bushing pulling out of the tail rotor motor.....seems to be a common problem...

The only fix I've seen to work with that is to solder the bushing to the motor can. Several in our club have been doing that for a while now and it works just fine.

this tip came from a fellow club member who told me that's what he and others did in their slot car racing days. Many thanks to flying buddy Geoff!!!

Use a dremel cutoff wheel to clean a spot on the can and on the bushing. Make sure the bushing is fully seated before starting.

With a hot iron, quickly solder the bushing to the can. Loosly mounting the motor in a vice would probably help as a heat sink, alhtough I've never had to do this.

I solder both sides of the bushing at spots 90 degrees to the screw mounting holes.

after soldering there will be a little ridge of solder from the bushing to the can. I use the dremel wheel to carefully grind this away from the front face of the can to allow easy remounting of the motor....

nothing to it really.

works like a charm

cheers
Papa Sharptooth

Bouncing about the living room, my then three year old grandson declared himself "a kangaroo".
"If you're a Kangaroo, what is Grampie", I ask.
His reply: "you a dinosaur"

Whoa, shattered the tail boom? Ouch.

I managed to smack my finger into the CF blades today, I was holding the heli and checking its black tracking and holding it like I usually do, right when I shut off the throttle I tried wobbling the heli side to side which stops the blades faster, only to have my right pinky somehow raise up and get SMACKED by one of the rotor blades. It stopped the blades eventually, but a pinky doesn't stop rotor blades like the side of your arm does. IT HURT. Now it's all bruised and a little swollen on the side, aching right now so I'm not typing on it....but yea.

Oh, and about those glassy blades...sounds like you should just get the CF blades. They're quite durable (I was originally under the impression that they would shatter on impact with something) but they've already survived several crappy impacts, but they just keep pounding on through. And there's no visible damage either, still nice and sleek and no breaks. They weigh less and they look great too, and they're far more durable than the wooden blades. Really a sure winner I think.

That aside, my heli's doing great. I'm getting a lot better at controlling it, perfecting my throttle curves and such, and hopefully it'll be all nice and trimmed out to perfection soon. I still don't use Idle Up yet, but I think I should start using that mode for forward flight. I'll try it out tomorrow morning if I'm doing OK with the heli.

Oh, and when it comes to loops and rolls: Do you have to give negative collective pitch when the heli is in an upside-down orientation in these maneuvers, for example like the top of the loop and the 180° mark on the snap roll. Or do you just maintain neutral collective pitch? Something I hope to be doing soon =D

So, I should probably get a balancer tool to ensure accuracy in my blades? My boyfriend is starting to learn to fly my Blade and is doing quite well except for a few run-ins with stationary objects in my backyard. Have you guys ever noticed that the heli will seemingly gravitate towards the one lone obstacle that is not even in the way?? I think it's Murphy's Law in full effect. A new pilot won't even come close to hitting obstacles that are in his/her way, but will nail the smallest object that is at the far end of the field.

Have you any suggestions for more durable blades? I won't mind a decrease in performance so long as the blades are beginner-friendly and can survive a few hard hits. The wood ones have the tendency to crack and the plastic wrapping easily peels off even after a minor scrape.

Thanks!

i got a BLADE CP and lately ive been noticing that when i first lift off my heli does a spin and then maintains a hover. How do i stop this spin?its annoying. I have messed with the proportion with no luck, and my Gryo is set to 3/4. What do i do to fix this. Thanks

Sometimes you just have to steer it. ;-)

LOL, in fact.. not just sometimes.. All the time. '_;

there is no specific setting angle to the reciever pots for adjustment, Its something you have to tune with trial and error. I have found it best to first work with the gyro gain, Crank it up a little at a time until the tail wags, then back it off 1/8th of a turn at a time after powering down, until the wagging stops. if your heli is spinning try and compensate as best you can with left stick lower trim for now. After you feel confident all the sporadic left right movements from the gyro are in check, then you need to add throttle and notice which direction the heli favors, when ya give it throttle and the nose wants to favor right, that means the tail is blowing too hard and the proportional needs to be backed off.. and visa versa, remember.. small incriments, its sensitive, the better you fine tune the settings, the more predictable the helicopter will become..

Mina, the only obsticle that really gets on my nerves is the ground.. . There are a few tools that would come in handy for keeping your helicopter tuned to perfection. 1) a micro heli pitch guage so you can verify that you are maintaining the optimum pitch for the range of throw on the rotor head. 2)Dubro High Point Balancer to check blade balance and flybar balance with the head assembled out of the heli. 3)An accurate digital scale for weighing the blades individually, and there are specific blade balancing tools out there that can take the place of the scale. These things are not dire necessities mind you but take alot of the guesswork out of keeping it all in check.

oh yeah, about tougher blades.. they make carbon fiber they're 30-40 bucks a pop, they are a tad more resilient to very small incidence, but by no means are impervious to breakage.

The carbon blades do seem to be more durable in ground strikes. The downside is that they will crack the tail boom when they strike it.

Phillip

if you balance the CG on your rotor head properly.. it will never get even close to striking..

I don't see how balancing would effect the blades striking the tail boom in a crash.
Phillip

if the cg's are balanced they will flip back to a more desireable attitude much quicker than you could imagine.. balance..

I'll have to agree with Jimmy. I've cracked a tail boom with carbon blades on a hard landing.[]

if your blade wobbles between lead and lag to find true in several rotor revolutions.. its center of gravity is not balanced correctly.. though if the CG was balanced properly, it would assume its proper attitude instantly.. The Blade has to be in a lead or lag attitude to strike the tail..

I understand it's important to balance the blades, but when a heli hits the ground I don't see how balancing could help. A friend crashed his JR Voyager E (.30 size electric) straight down after hitting the battery cutoff yesterday. He suffered a dent in his tail boom from the blades even though he has a perfectly balanced setup and is using MS carbon blades. Maybe if the o-ring dampers were worn, that could increase the chance of a boom strike. I don't understand how balanced baldes would effect boom strikes in a crash. Please explain. Thanks.
Phillip

your right.. i cant hold the sticks for ya..

Yea, in a crash not much will keep those rotor blades from slapping your tail boom.

I've been using the CF blades for about a week now, I'll never go back to wooden blades. The CF blades have already taken plenty of abuse and they look good as new! They're polished with some nice sealant or clearcoat that adds an extra layer of protection, so it will take quite a lot it seems to start to shred the blades. They're also thinner it seems than the wooden symmetrical blades, so they fit in the blade grips without any trouble. Also, they're lighter I believe, because I've been getting much more consistent performance with the CF blades than with the wooden blades, but they also don't flex like wooden blades so that probably contributes a little. The head speeds of micro helis are around 2700-3500 rpm I believe, so that flexing makes a much bigger difference than it does on a larger heli where the head speed is around 1800-2200 rpm.

Seriously, you need to check these rotor blades out. They're just about twice the cost of wooden blades at $30 a pop, but they've already outlasted two sets of rotor blades for me, taking a few dings which would have ruined the tips of my wooden blades by now. Strong stuff, it is.

A side question: are there any heli sites that have basic tutorials on the basic maneuvers necessary to perform heli aerobatics, be it a loop or a snap roll? I want to get into this stuff soon....

Of course the best way to learn would still be a simulator

My blade suddenly dropped from the SKY
I found there was no power in the reciever and it had loose parts inside so i opened it and found a bunch of electronic parts that were supposed to be soldered to the board in the reciever came un-soldered from the board
the 4-1 must get hot after a while and so hot that the parts can fall off []
strange...

Balencing the blades on CG and such will help alot, but in a crash I dont think its going to make much difference.

1. In a crash, the blades hit the ground, which causes them to swivel in the blade grips. Normally by this time they are'nt spinning fast enough for a properly loaded blade to swing back out, and it strikes the tail.

2. The blades on the blade helicopter will hit the tail boom with no lead/lag. The rotor head has that much play in it in its stock configuration. Coming down the backside of a loop, if you have alot of rear cyclic, and you shove collective into it, you can have so much cyclic in that it will blade strike on the tail.

One of the local guys has stiffened up his head QUITE considerably by adding another o-ring in between the blade grips and the main head. I will probably be doing this to mine also, as it VASTLY improves the heli's responsiveness, and makes it move even quicker.