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        Fixed Pitch Blade Fix.....

#1 Geoffrey109 May 25, 2004 07:50 PM

Fixed Pitch Blade Fix.....
 
2 Attachment(s)
I came up with the idea today. I know about rotor dynamics, I was thinking the micro helicopters sometimes just don't have what it takes to keep the blades in line, and like a lot of other mods posted here to do so. I invented the spring mod for the Aerohawk and the like90's blades. I wanted them to be loose and still get a good tracking, I believe the blades are so light that the centrificial force will not realign them in flight they simply need help. Most everyone in the fixed pitch blade world knows that you have to start your heli with the blades slightly forward, the springs automatically do this, and talk about cheap: 1.69! In flight the dreaded wobble, I still get it in a hover until now, the springs keep the blades in perfect alignment.......Initial hover checks were very nice......better control......no vibrations......and I feel this is it.....the mod of all mods.......

Spring wire: .039, wrapped it around a .250 rod......to make it.....

Bought it for the adjustable swashplate mod. Two in one......for the money.


Maybe this is the fix for forward flight wobble and crash......I will attempt to fly it forward flight soon and post the results.....this is the smoothest and easiest hover I've ever had with the Hawk......I am now confident this bird will fly and fly with confidence....

I bet you didn't even notice my landing gear o-ring mod either......this really plants the bird on landing......no crashes yet....

#2 debogus May 25, 2004 08:37 PM

Cool
 
cool ,simple and cheap idea.
Did it work?
Probably going to need a stop to arrest foward movement .

IMO the blades dont have the mass required to recenter from lead/lag.
Weighting them increases the inertia not a good thing on FP.

Dave

#3 Geoffrey109 May 26, 2004 11:59 AM

BOO YA!!!! This is the best I've seen the Aerohawk fly to date. The springs kept the blades in perfect alignment and elimanated the hover wobble and vibrations. The blades are loose and didn't have to make any adjustments at all, sit it down and get to hovering everytime perfect! Aerohawk owner's This is a must mod, for the like90 blade setup........

#4 EddieNewYork May 26, 2004 12:24 PM

That's interesting, what kind of wire is "spring wire" and where can I buy some?

#5 Geoffrey109 May 26, 2004 01:08 PM

I purchased mine at the local Big Boys Toys hobby shop, for $1.69, I'm sure you can get it a Towerhobbies as well or any other on line hobby shop, it was for the new adjustable links, the thought of using it for springs was secondary, but they give you like 5 pieces in a tube so there was plenty to experiment with. I believe is is just regular music wire. I also added some 1/16 shrink tubing for blade protection. I cannot tell you how nice it is, control is awesome, and that sweet sound of perfect blade tracking and absolutly no vibrations at all.....

#6 Jarg May 26, 2004 01:52 PM

going to get a aerohawk in 1 month or so, after lerning to fly i will have to mod this on (won't do it streight away as i want to see the difference)

Jarg

#7 EddieNewYork May 26, 2004 02:04 PM

Thanx, is there anyway you can take some clearer pics? Kinda hard to see some of the detail. Also, the diameter of the loop seems larger than the screw hole, is there a reason behind this? And just to make sure I understand what is actually happening. Tell me if this is right... those pieces you made are on the left side of the blade, so when the rotor starts to spin clockwise, the blades will want to then go left, and that's what these pieces will catch on. Is that correct?

#8 Geoffrey109 May 26, 2004 02:23 PM

I have found this to be the problem, that the springs corrected for: On spin-up the blades want to fall into a retreating blade stall condition. Some power inputs also cause the blades to fall behind as well, causing a wobble/vibration. The spring tension holds the blades about an inch forward of the cord, and keep the blades from going into retreating blade stall with power changes. I believe the blades are so light that centrifical force cannot make up for. The blades fly now with a slight spring tension that keeps them in perfect cord alignment. It has elimanated all vibrations and hover wobble. The blades are loose so the springs can act upon them.

I made the hole in the spring to fit inside the blade grip around the spacer that came with the Like90 blades. I wish I had a better camera too, but tonight I will try to capture some better pics. The first picture has the springs I made that fit into the blade grips.....

You most likely will not learn how to fly this helicopter without the springs, I know I've put the helicopter into the ground a couple dozen times prior to this mod, and now it will hover without hardly a stick input.

#9 debogus May 26, 2004 10:18 PM

Good Job
 
I'll have to try it .All of my blades mount under the grip on my hummingbird.Should be easy enough to figure out.Thanks for the idea.

Dave

#10 Geoffrey109 May 26, 2004 10:42 PM

1 Attachment(s)
I hope this picture tells the story....see how the springs help keep the blades just forward of the cord, and in flight, see how they help with retreating blade stall, by not letting it happen........? the Springs keep the blades centered and balanced.....I did it, I found it, and It's perfect......

#11 Yukonho May 26, 2004 11:07 PM

This is a great execution of the spring idea. Way better than the elastic bands I have seen before. I still cant quite figure out how the other end of the spring is anchored though, cant wait for more pics.
If you could do a little how to, I bet a bunch of people would benefit from it.
I have long said that it is not the manufacturers that come up with the best ideas, it is the guys, like you, who use the products every day. Great work!
co

#12 humveeflyer May 27, 2004 12:56 PM

hey Geoffrey109, any up-dates on the "how-to-do" on these springs?

#13 Geoffrey109 May 27, 2004 08:43 PM

Really there is not an anchor for it......it just fits into the blade grip and does it's thing, the tension is just right, if you really look at the first pic, you can see the details of the design.......simple. The experiment worked the first time out.....and it' flies great......contol, vibration.....all are eliminated with it. A how to....is just a matter of looking at the photos......and reading the post.......you can wrap a .o39 wire around a .250 1 and 1/2 times? that's it.......problem solved.....

#14 debogus May 27, 2004 10:42 PM

Oh well
 
Looks like I'll try it later.What luck my latest blades dont wobble.
Hey if they pass the training gear test I'm happy.
Dave

#15 OzzieFlyer May 27, 2004 11:12 PM

Geoff the King
 
all resolved now..geoff and I are now good mates ! :D


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