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CX2 servo linkage - 7/6/2008 11:31:39 PM   
snobelt


 

Posts: 39
Joined: 6/23/2008
From: Richfield, WI, USA
Status: offline 		About a week ago JPEE, Helistyle, Blue cnc, Soloboss and I had a thread going about moving the servo linkage of the CX2 to the second hole instead of the default first hole. Soloboss suggested going to the HOWTO WIKI web page for info on exactly that topic. The info was authored by "friends of RC Universe". If you go there you will see, under para #12, an article called "Clack is Wack". Read it. I did move my servo to the second hole and the CX2 flew great, with plenty of power. I ran a couple of batteries through it in a mild breeze and it handled great - - - until - - I needed to stop forward flight as I was approaching a tree too fast. I pulled full back on the stick and then heard the dreaded Clack. All four blades shattered. No, I did not hit the tree. The upper blades made contact with the lowers. Fortunately the heli was only a foot off the ground so no other damage besides the blades. I just wanted those of you who are interested to know that the WIKI author knew what he/she was talking about. Today I replaced the blades (and servo arm positions) and also took the advice in WIKI about balancing the CX2 blades before installing them..I was surprised at how much difference there was in out-of-the-package blades - and how easy it is to correct that. It does make a difference. My CX2 is quieter and flies smoother than it ever has.
       Post #: 1

RE: CX2 servo linkage - 7/7/2008 12:57:29 AM   
rchotrodz


 

Posts: 276
Joined: 2/26/2006
From: Y-Town, OH, USA
Status: offline 		I have mine out to the second hole with a short fly bar and I have had no problems it is very responsive

(in reply to snobelt)
       Post #: 2

RE: CX2 servo linkage - 7/7/2008 2:31:31 AM   
soloboss


 

Posts: 1650
Joined: 9/17/2006
From: Fort Wayne, IN, USA
Status: offline 		The secret is to get the flybar lighter / shorter so it is more responsive. That flybar is intended to resist any movement that you command via the lower blades (the blades that you control). The stock flybar is very good at its job. Moving the linkage to the second hole does work in conjunction with the flybar mod so it has less mass.

A good sequence for new fliers is outlined in the Wiki article. I know it works.
From stock, when you in control and want a little more, remove the brass weights from the rubber flybar boots.
Fly that way until you are always in control, then try the flybar mod that I outlined. Actually, you can remove the rubber boot from the stock flybar without damaging anything. With the boot removed, add two wheel collars to the 'hook' at the end of the flybar. Get collars with 1/16" hole in the center and a locking set screw.
Remove the upper blades and spin the flybar to be sure it is in balance.
If all is well, go fly.
For more performance, remove one of the weights, leaving one weight on each end. YOu should be getting pretty good performance now.

At this point, move the linkage out one hole.
I never moved my linkage at all, I just adjusted the flybar weight via the flybar mod that I outlined in the Wiki. I could get the performance so radical that I couldn't fly it. It was just too crazy.

Following the publication of the Wiki How-To, Wolfpackin put together a really nice flybar using Xtreme flybar hubs, CF rod and end weights. The finished flybar is sold on US Hobby Supply web site (ushobbysupply.com). If wolfpackin says it works, it works.

Good luck and welcome to the wonderful world of helicopters. One day in the not too distant future we'll look for you guys on the "Struggling with Single Rotor Basics" thread within the Eflight forum. Most everyone on that thread came from the wonderful world of CX2's and the modifications we all used.

At the beginning of the Wiki aritcle is a note; "A compilation of compelling comments from the incompetent flier known as, Soloboss"
That's me.
The actual publishing to the Wiki was done by a friend who I haven't talked to in a very long time. If you find the paper worthwhile, PM DrunkYoda and tell him thank you.

It's good to hear that someone is still using the guide.

Blue Skies,
Soloboss

_____________________________

Soloboss
If everyone''s thinking alike, then somebody isn''t thinking. George Patton

(in reply to rchotrodz)
       Post #: 3

RE: CX2 servo linkage - 7/7/2008 3:06:15 AM   
JPEE



Posts: 214
Joined: 3/14/2008
From: Porter Ranch in Southern Calif, CA, USA
Status: offline 		Snowbelt and Solo,

Sorry if I/we did not warn you about the DEATH blade clack. When you take an inside Heli and start making mods things can happen. I too have exploded blades in the air outside but not in a long long time, because I knew to watch out for it. Again sorry it wasn't mentioned, we all try our best to help those pilots that are where we have just come. Then we rely the senior class ahead of us.

Solo, heak yes I use that site too. It had been so long since I used the CX2. I took her out and she had toilet bowl syndrom, but I forgotton what to do. It is in my Favorites.

_____________________________

CX 2, Hirobo SRB Quark
Blade 400s, #401, #402, Trojan T-28

(in reply to soloboss)
       Post #: 4

RE: CX2 servo linkage - 7/7/2008 3:48:12 AM   
snobelt


 

Posts: 39
Joined: 6/23/2008
From: Richfield, WI, USA
Status: offline
quote:

ORIGINAL: soloboss

The secret is to get the flybar lighter / shorter so it is more responsive. That flybar is intended to resist any movement that you command via the lower blades (the blades that you control). The stock flybar is very good at its job. Moving the linkage to the second hole does work in conjunction with the flybar mod so it has less mass.

A good sequence for new fliers is outlined in the Wiki article. I know it works.
From stock, when you in control and want a little more, remove the brass weights from the rubber flybar boots.
Fly that way until you are always in control, then try the flybar mod that I outlined. Actually, you can remove the rubber boot from the stock flybar without damaging anything. With the boot removed, add two wheel collars to the 'hook' at the end of the flybar. Get collars with 1/16" hole in the center and a locking set screw.
Remove the upper blades and spin the flybar to be sure it is in balance.
If all is well, go fly.
For more performance, remove one of the weights, leaving one weight on each end. YOu should be getting pretty good performance now.

At this point, move the linkage out one hole.
I never moved my linkage at all, I just adjusted the flybar weight via the flybar mod that I outlined in the Wiki. I could get the performance so radical that I couldn't fly it. It was just too crazy.

Following the publication of the Wiki How-To, Wolfpackin put together a really nice flybar using Xtreme flybar hubs, CF rod and end weights. The finished flybar is sold on US Hobby Supply web site (ushobbysupply.com). If wolfpackin says it works, it works.

Good luck and welcome to the wonderful world of helicopters. One day in the not too distant future we'll look for you guys on the "Struggling with Single Rotor Basics" thread within the Eflight forum. Most everyone on that thread came from the wonderful world of CX2's and the modifications we all used.

At the beginning of the Wiki aritcle is a note; "A compilation of compelling comments from the incompetent flier known as, Soloboss"
That's me.
The actual publishing to the Wiki was done by a friend who I haven't talked to in a very long time. If you find the paper worthwhile, PM DrunkYoda and tell him thank you.

It's good to hear that someone is still using the guide.

Blue Skies,
Soloboss


Soloboss - Okay, I have read and re-read all the good info you and Drunk Yoda provided on the CX WIKI. One thing I'm not clear on - - the flybars were cut down to 3 3/8" of exposed metal. Is that 3 3/8" of each flybar rod half or of the combined halfs? In other words, would that dimension be from locking collar to locking collar - that seems pretty small but your photos almost look like it could be. In any case I have an extra flybar and I'm ready to mod it per the CX article. Side note - where did you get the boom and any advice on that mod?
You know, I've been driving this thing around the house and garage since last fall and was kind of losing interest until I discovered there are guys outside with some minor mods made.
So I'm ready to try some new stuff. If I break a few blades, what the hell - it's better than watching the heli sit on a shelf. Thanks much.

(in reply to soloboss)
       Post #: 5

RE: CX2 servo linkage - 7/7/2008 4:08:20 PM   
UTM


 

Posts: 529
Joined: 3/11/2008
From: Indianapolis, IN, USA
Status: offline 		A shorter flybar is a must if you are planning on increasing the preformance of a CX2 by moving the servo horn positions. I was also on the receiving end of clack a time or two as I progressed through my CX2 comfort zone. I ended up modding my flybar to a shorter length and adding bullet weights on the end. I now have my servo horns on the very outside hole on the elevator and the 4th hole on aler. With the shortened flybar I can almost not get my blades to clack. I have not spaced my blades apart with a lengthened shaft as is said to be a requirment. It's not. A shorter flybar is. You can order a shorter bar from www.boomtownhobbies.com that approximates what I did to mine.

Good luck.

Uri

_____________________________

Rules are made for people who aren''''t willing to make up their own....Chuck Yeager

(in reply to snobelt)
       Post #: 6

RE: CX2 servo linkage - 7/7/2008 5:07:16 PM   
soloboss


 

Posts: 1650
Joined: 9/17/2006
From: Fort Wayne, IN, USA
Status: offline 		Sorry the information was ambiguous ( i love that word).
You want 3 3/8" of exposed metal ON EACH SIDE of the plastic part of the flybar. You are absolutely correct that a total length of 3 3/8" is too short for a flybar. You could go that short if it weighed enough, I suppose, but it would be as heavy as the battery pack!!

Remember that the control from the flybar is a result of the spinning mass. You have a choice of using a long flybar with light weight or a short flybar with heavier weight.

I had a brainstorm once and used a flybar with NO weight. I cut the hook off the end of the metal and put a long piece of CF tube over the metal. The CF tube we . . . wow, I don't recall exactly, but I'm thinking it was 8" long measured from the plastic hub to the end - oneach side. That flybar was a bit longer than the blades. I think it would have worked, but the wind resistance from a long flybar like that was too much. It slowed the upper rotor response.

That brings out another issue. If you get the flybar to spin more easily (some combination of shorter / lighter) the upper rotor assembly (blades and flybar) will accelerate faster. Ideally the upper rotor assembly and the lower rotor assembly will accelerate at the same rate so the tail stays in alignment when you hit the power.

Keep playing with the flybar and we'll see if you come up with something we missed.

EDIT: I forgot to answer our questions about the boom. That's a BoomTownHobbies boom and skids. They are about as close to unbreakable as it gets.
Soloboss


_____________________________

Soloboss
If everyone''s thinking alike, then somebody isn''t thinking. George Patton

(in reply to snobelt)
       Post #: 7

RE: CX2 servo linkage - 7/8/2008 2:01:03 AM   
snobelt


 

Posts: 39
Joined: 6/23/2008
From: Richfield, WI, USA
Status: offline 		Soloboss - you are brilliant! I closely followed your plans to build a lighter flybar. (see photos)
I very carefully balanced the new flybar and it makes a world of difference. Smoother and more responsive. I have not yet moved the servo linkage back to the second hole and I'm not sure I need to. The response is quite impressive and it handles easily - I can finally lock in a dead steady hover. I am still getting a little drift as the airborne stuff heats up but I will mod the case with vent holes as soon as I get the chance. I do already have the motor heat-sinks on and the motors seem to tolorate successive flights quite well. BTW - do I see heat shrink on your flybar? Were you worried about the collars coming loose? Thanks for all your input.

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(in reply to soloboss)
       Post #: 8

RE: CX2 servo linkage - 7/8/2008 2:31:49 AM   
soloboss


 

Posts: 1650
Joined: 9/17/2006
From: Fort Wayne, IN, USA
Status: offline 		Snobelt,
Thanks for the good words. I do what I can. As I said in the article, just between you and me and 20000 others listening, I'd go with the flybar mod first. Many find that they don't need to move the linkage. I never did. Most others do. Get happy. It's your helicopter. And you can keep moving that weight inboard as you get better. Expect that you will find a place where the weights are so far inboard that you can't control the helicopter, but just before that point the little bugger will be quite athletic. When you get to that point, spin it up quick and go fly 'cause it won't hover.

Yep, you do see heat shrink. Good catch. I wanted just a little more weight for the way my CX was set up - and I wanted the black-out look to include the weights. So I figured heat shrink is the way to go. Works fine, by the way.

A word of caution is also in order. When you decide where you want the weight collars, it's a good idea to use a Dremel and put a little divot in the flybar rod so the set screw of the collar has something to lock into. You DO NOT want the collar flying off at speed.

Something you might try. CF tube is really tough but the fibers that make up the tube run lengthwise - like bamboo. You will eventually whack something that will split the CF tube. And usually it splits at the inboard end next to the plastic center thing. You might want to shrink a quarter in long piece of sleeve at the inboard end of each CF tube, just to make it really tough.

And that's one pretty CX2 you have. Very neat and tidy with the nearly invisible flybar. Of course you can paint the flybar and CF tube if you like. If you clearcoat it, it goes invisible! LOL
And I like the full body. I always thought that the CX handled better with the full body on it, but I went with the boom because I kept breaking the tail section doing . . . experiments, as I recall. And of course the majority changed to the boom because - you guessed it. The heli handles better with the boom. The boom is less susceptible to side winds. Whatever. Be happy.

Have a ball with the CX and don't worry about the folks moving to the single rotor helicopters. Most guys do move to the single rotor helicopters eventually. And most of us still have our CX / CX2 sitting, ready for duty. Glad I could help!

Big Happy!
Soloboss

_____________________________

Soloboss
If everyone''s thinking alike, then somebody isn''t thinking. George Patton

(in reply to snobelt)
       Post #: 9

RE: CX2 servo linkage - 7/8/2008 11:56:46 AM   
bluecnc


 

Posts: 30
Joined: 6/3/2008
From: Castle Hayne, NC, USA
Status: offline 		FYI Some where I read that someone had removed the weights from their stock flybar and it flew great. I tried it. I do not recommend it. Talk about loss of control. I like the clean looks of what you have done with the flybar snobelt.

Rob

(in reply to soloboss)
       Post #: 10

RE: CX2 servo linkage - 7/9/2008 12:15:02 AM   
snobelt


 

Posts: 39
Joined: 6/23/2008
From: Richfield, WI, USA
Status: offline 		Well, that isn't mine design - credit to soloboss for that, but thanks anyway. This is kind of nuts though. I was getting a bit bored with the CX2 until I realized I was only half way up the curve with it. It has become a far more interesting little machine since that change. The other part is that I also discovered how very important balance is, even in a counter-rotator. Now that I am flying it outside in mild breezes, it has become a lot more fun and challanging. Of course we all aspire to a 450 (or bigger) collective and I'm sure I'll get there but for now this'll do.
I've been busy flying planks this year too and can only do so much, but ain't it great to have such a dilema?

(in reply to bluecnc)
       Post #: 11

RE: CX2 servo linkage - 7/9/2008 4:52:59 AM   
stariondriver


 

Posts: 70
Joined: 4/17/2008
From: redmond, OR, USA
Status: offline 		i am flying mine with stock flybar no weights just the rubber peice one hole out on both servos. works good. yo ustill have to go easy with stick inputs if you jam it hard you get clack.

(in reply to snobelt)
       Post #: 12

RE: CX2 servo linkage - 7/10/2008 12:26:59 AM