Hi Everyone + Blade tracking help  
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Hi Everyone + Blade tracking help - 3/30/2008 4:33:48 AM   
rcowboy


 

Posts: 19
Joined: 2/17/2008
From: , FL, USA
Status: offline 		I've had the axe for about 3 months now and I'm loving this thing. I still feel uncomfortable turning the tail away from me even though i've got quiet a bit of sim practice of nose in flight. Anyways, about a week ago I got brave and decided to do a few piroettes while at altitude and lost control. Banged her up pretty good. Blade grips, tail boom, tail mount, tail motor mount, and main blades were all replaced. Everything seems to be pretty good except I have a vibration in the head somewhere. When I got the heli, out of the box it had the same vib, but has seemed to be worse after my mishap. I've read here and there about blade tracking causing this problem, but haven't found anyone explaining this thoroughly enough for me to attempt to correct it. I don't have a pitch guage, nor a way to balance the blades, but i'm pretty crafty with making stuff. Can someone explain to me the proceedure for checking and correcting blade tracking from start to finish? Which blade should I make the adjustment to, and exactly how to make the adjustment.

rcowboy
       Post #: 1

RE: Hi Everyone + Blade tracking help - 3/30/2008 4:53:39 AM   
Flying Foot Doc


 

Posts: 334
Joined: 7/11/2002
From: Jupiter, FL, USA
Status: online 		Did you check to see if the feathering shaft and main shaft are both still completly straight? That is where I would look first...learned from experience... There are several links on blade balancing and on tracking as well on this & other sites. Good luck, let us know what you finally find out. Doc

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(in reply to rcowboy)
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RE: Hi Everyone + Blade tracking help - 3/30/2008 4:55:05 AM   
gboulton



Posts: 1862
Joined: 5/28/2005
From: La Vergne, TN, USA
Status: offline 		1) Check the main shaft and feathering shaft. if you dorked it, chances are pretty good one or both are bent. They're not terribly expensive, and easily replaced.

2) Buy a pitch gauge. Yes, you can track the blades without it...but not "right", so to speak.

3) Blade tracking is simple:

Mark the leading edge of one blade tip with an expo marker or something. Or use a small bit of tape...or whatever. Just mark it in some way to distinguish it from the other blade. Call this blade the "master" blade. Doesn't matter which one, if you don't have a pitch gauge. If you do, then you want this master blade to be at a known pitch at half stick (usually 0 degrees, flat)
Hold the heli with the blades at eye level, and bring the throttle up to half stick.
Watch the LEFT side of the blade disk (probably on your right, presuming you're holding the heli with the nose facing you). You'll see how the colored/marked "line" created by the master blade is higher or lower than the other blade's "line".
Raise or lower the "other" blade by lengthening or shortening the pitch arm on its side. Try first adjusting it by 1/2 turn.
Repeat the process. If the blades are closer, keep repeating the adjustment till they form a single line. If they're farther apart, adjust the arm in the other direction.

That's really all there is to it. Not sure about the Axe manual, as it's been a WHILE since I had mine, but I know the Blade 400 manual (http://www.e-fliterc.com/Products/Support.aspx?ProdID=EFLH1400#manuals) has a pretty good description of how to track blades. Obviously, the linkages won't be the same, but the process of identifying the low/high blade will be identical.

Good luck!

*EDIT : Sorry for the duplicate advice on the shafts. Was posting while that other post was going up. *

< Message edited by gboulton -- 3/30/2008 4:56:13 AM >

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RE: Hi Everyone + Blade tracking help - 3/30/2008 5:49:06 AM   
rcowboy


 

Posts: 19
Joined: 2/17/2008
From: , FL, USA
Status: offline 		Thanks guys, I really appericate your responses. I'm gonna take a closer look at it in the morning. You can see a whobble in the head button on top, but like I said it had some of that in there the day I recieved the helicopter. It flys pretty good just has a darn vibration that you can see in the tail rotor. I though there might be an adjustment I could make. I'm quiet the perfectionist I guess...

(in reply to gboulton)
       Post #: 4

RE: Hi Everyone + Blade tracking help - 3/30/2008 2:35:59 PM   
COPO



Posts: 112
Joined: 7/7/2004
From: Southwick, MA, USA
Status: offline 		I have the same problem with the head wobble and vibration. I just pulled off the whole rotor head assembly right down to the aluminum main shaft and put an indicator on it. The shaft is not bad. within .001. Then I looked at the cross piece that mounts to the main shaft and you can see that the hole is not centered in this piece. That would explain why it wobbles so much.

Wondering if the aluminum upgrades are a little more precise to help eliminate any vibs and run more true?

Also just tried the tracking method described here. Seems to work but what I really noticed is that if the flybar paddles are not perfectly flat with each other this also causes the blades to not track correctly. The blades don't track well at low speed now that i messed with them, but when I go half stick they track nice. I guess this is what I want.

< Message edited by COPO -- 3/30/2008 2:36:45 PM >

(in reply to rcowboy)
       Post #: 5

RE: Hi Everyone + Blade tracking help - 3/30/2008 5:04:35 PM   
gboulton



Posts: 1862
Joined: 5/28/2005
From: La Vergne, TN, USA
Status: offline
quote:

ORIGINAL: COPO
Wondering if the aluminum upgrades are a little more precise to help eliminate any vibs and run more true?


Yes.

Well..to a point. See below...

quote:


Also just tried the tracking method described here. Seems to work but what I really noticed is that if the flybar paddles are not perfectly flat with each other this also causes the blades to not track correctly. The blades don't track well at low speed now that i messed with them, but when I go half stick they track nice. I guess this is what I want.


It's not uncommon to find a heli that tracks differently at various throttle settings, but is "in track" in one range or another. In fact, it's possible for a perfectly set up heli to demonstrate this behaviour. Ideally, they'll track all the way through the range, but it's rare to find a heli that does that perfectly, particularly one with as much play in the top end as the stock Axe has.

Referencing your question above, ime, the metal blade grips will do more to remedy this problem than any other upgrade...and are also the best "bang for your buck" upgrade out there. You'll get a more noticable improvement to the heli for less money with that upgrade than any other, imo. Part of the very problem you're describing may well be attributable to nothing more than the play inherent in the Axe's stock plastic blade grips.

It's probably also worth balancing the blades, AND getting a pitch gauge and MECHANICALLY setting the blades to 0 pitch at half throttle. Both of those tasks are likely to remove a bit of vibration, and bring the blades closer to "true" throughout the range.

Finally, and this is STRICTLY my experience...the experience of others differ, I know, so take this for what it's worth:

I found the metal blade grips to be a GREAT investment, the CNC flybar cage and swashplates to be "it's better, but not a lot" purchases, and the CNC head actually DEGRADED the heli's performance.



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The free man will ask neither what his country can do for him nor what he can do for his country. - Milton Friedman

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RE: Hi Everyone + Blade tracking help - 3/30/2008 6:50:43 PM   
rcowboy


 

Posts: 19
Joined: 2/17/2008
From: , FL, USA
Status: offline 		Okay, I think I got some of this sorted out. Before I did anything to the heli this morning, I removed the new main blades and installed the old main blades back into the grips. There was no visable damage to the old blades, but I didn't want to take a chance of them seperating during flight, so I bought new ones. (The wood stock blades). I marked the leading edge of one blade just like gboulton said, and spun her up. The blade I had marked was definitely higher above the disk plane than the other. I took the spindle to that blade grip and closed it up a half a turn. This made it much better. I also noticed my old blades were better balanced then the new ones, so some of the problem is in the difference of the blades them selfs. Although it didn't eliminate it all togeather (the vibration) it has made it better and less noticable. I'm happy with it at this point. That is unless it gets worse, and besides I'm most likely going to end up crashing it again, so I pretty much just think i'm going to leave it as is.

Thanks to everyone for all your help,
rcowboy

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RE: Hi Everyone + Blade tracking help - 4/4/2008 5:46:56 PM   
BigTruckDriver


 

Posts: 197
Joined: 10/2/2004
From: , TX, USA
Status: offline 		Any one have a pic of the link that needs adjustment to correct tracking?

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If it isn't broken,adjust it till it is.

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RE: Hi Everyone + Blade tracking help - 4/4/2008 6:06:55 PM   
PilotLight



Posts: 817
Joined: 8/15/2003
From: Benton Harbor, MI, USA
Status: offline 		Here ya go. Make this link longer on the low blade to bring it up.

Attachments
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(in reply to BigTruckDriver)
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RE: Hi Everyone + Blade tracking help - 4/7/2008 10:18:43 PM   
BigTruckDriver


 

Posts: 197
Joined: 10/2/2004
From: , TX, USA
Status: offline 		Thanks Pilot Light for takin the time to pull that up. I just got my blade balancer and kind of figured it out. Boy, balanced blades sure do make a difference. By the way the blades are tracking at what I would call 100% correct but I am new to the heli thing. All ways have done on and off road cars/trucks.

Would a pitch gauge help?

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If it isn't broken,adjust it till it is.

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       Post #: 10

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