Go Back  RCU Forums > RC Airplanes > Giant Scale Aircraft - 3D & Aerobatic
Reload this Page >

87" Yak Rudder hinge pins broke

Notices
Giant Scale Aircraft - 3D & Aerobatic Discuss all your 3D & Aerobatic giant scale airplanes right here!

87" Yak Rudder hinge pins broke

Old 04-21-2007, 01:06 PM
  #1  
JoeAirPort
Thread Starter
My Feedback: (41)
 
JoeAirPort's Avatar
 
Join Date: Aug 2003
Location: Milwaukee, WI
Posts: 10,259
Likes: 0
Received 0 Likes on 0 Posts
Default 87" Yak Rudder hinge pins broke

I have the Ultra RC 87 inch Yak with about 2 gallons of flights on her. Awesome plane. The problem is, I think, the sloppy geared 8611 combined with a huge rudder. It vibrates back and forth pretty fast at center. I tried tightening the cables. It made it better but the cables have to be really tight and I never liked that (you can feel the tightness at center moving it by hand). Then after a few flights it started to vibrate again. Well after about 20 flights the top two hinges sheared the music wire hinge pins. I wonder if this thing is fluttering up there and I don't notice it? Maybe I need a new servo, perhaps a 5955. If you say that the cables being too tight broke the hinge pins, why only the top two? The cables are closer to the bottom ones.

All I need to do is put new music wire in the top two hinges and the hinges should be fine (unless the bottom two are wearing also). But as many of you well know, I may be ignoring a more serious problem by simply replacing the hinge pins.

Your thoughts and ideas are appreciated.
Old 04-21-2007, 01:39 PM
  #2  
closetguy
My Feedback: (13)
 
Join Date: Jul 2004
Location: berlin hts, OH
Posts: 1,462
Likes: 0
Received 0 Likes on 0 Posts
Default RE: 87" Yak Rudder hinge pins broke

Joe
FWIW i have the same plane,i never like the looks of those hinges that was suppied with the kit,i used robart pin hinges,never had one come lose yet using Titebond wood glue. and i agree with you GREAT flying plane,Extreme Flight design a nice one here!
ENJOY!
Old 04-21-2007, 02:33 PM
  #3  
xtdsm
Senior Member
 
Join Date: Apr 2006
Location: , BC, UNITED ARAB EMIRATES
Posts: 118
Likes: 0
Received 0 Likes on 0 Posts
Default RE: 87" Yak Rudder hinge pins broke

I have the same plane and never had a problem with the hinges it comes with, I have a freind who had a similar problem, the wires just slipped out, all the he did was put new wires and bent them from both ends so they won't come out again.

good luck

Ahmed
Old 04-21-2007, 02:47 PM
  #4  
rcblimppro
Senior Member
 
rcblimppro's Avatar
 
Join Date: Feb 2003
Location: San Jose, CA
Posts: 514
Likes: 0
Received 0 Likes on 0 Posts
Default RE: 87" Yak Rudder hinge pins broke

I think that it is a high frequency vibration that has caused this. can you tell what engine/prop combo you have and the method you use to balance your props.


Shawn
Old 04-21-2007, 09:13 PM
  #5  
JoeAirPort
Thread Starter
My Feedback: (41)
 
JoeAirPort's Avatar
 
Join Date: Aug 2003
Location: Milwaukee, WI
Posts: 10,259
Likes: 0
Received 0 Likes on 0 Posts
Default RE: 87" Yak Rudder hinge pins broke

It did it in my basement shop when I first powerd it up...from the get go...no engine running. I have seen a rudder do this on another plane as well (Funtana 40, push pull). I might try another servo. Not sure what caused the pins to shear. Maybe the vibration got worse in flight. The hinge glue job is fine...it's just the pins that sheared.

Engine is ZDZ 50 NG, prop was precision balanced both the hub and tips. I agree that the engine can cause the rudder to vibrate back and forth even worse but this one does it with the engine off.

Thanks
Old 04-21-2007, 10:09 PM
  #6  
Tired Old Man
Senior Member
My Feedback: (1)
 
Join Date: Feb 2002
Location: Valley Springs, CA
Posts: 18,602
Likes: 0
Received 3 Likes on 3 Posts
Default RE: 87" Yak Rudder hinge pins broke

Shawn,

You know that high speed jitter you have with the 8611's on the one surface of your Extra? I had the same condition happening with a new 8611 on the rudder of my Edge. It happened so much and so fast that it broke the Gorilla Glue joints around the hinge points on the vertical stab. For me that lends a little credance to the allegation of the servo hunting on this persons Yak breaking the hinges.

That jitter (I was informed) is caused by the servo attempting to find center after the gears have worn too much. They start bouncing like crazy. The "story" is that the linkages are being improperly set up, causing the servo gears to undercut the teeth on the adjacent gear. Don't know how that applies to servos in the first couple of flights though. Mine was new also. I asked JR if they had any plans to change gear material and was told the 8611 is just great as is

I just placed a reservation on 5 Hitec 5955's with Wild Hare for my next plane....
Old 04-21-2007, 10:37 PM
  #7  
JoeAirPort
Thread Starter
My Feedback: (41)
 
JoeAirPort's Avatar
 
Join Date: Aug 2003
Location: Milwaukee, WI
Posts: 10,259
Likes: 0
Received 0 Likes on 0 Posts
Default RE: 87" Yak Rudder hinge pins broke

I think I will try a 5955. Otherwise it will just happen again and maybe next time I won't be fixing just the hinges.

Old 04-23-2007, 10:41 PM
  #8  
crazyjoseph
Senior Member
My Feedback: (3)
 
Join Date: Aug 2004
Location: Glenwood Springs, CO
Posts: 150
Likes: 0
Received 0 Likes on 0 Posts
Default RE: 87" Yak Rudder hinge pins broke

I had the same thing happen on a 30 % sd yak w/ jr 8611.
Old 04-24-2007, 10:37 AM
  #9  
rcblimppro
Senior Member
 
rcblimppro's Avatar
 
Join Date: Feb 2003
Location: San Jose, CA
Posts: 514
Likes: 0
Received 0 Likes on 0 Posts
Default RE: 87" Yak Rudder hinge pins broke


ORIGINAL: Silversurfer

Shawn,

You know that high speed jitter you have with the 8611's on the one surface of your Extra? I had the same condition happening with a new 8611 on the rudder of my Edge. It happened so much and so fast that it broke the Gorilla Glue joints around the hinge points on the vertical stab. For me that lends a little credance to the allegation of the servo hunting on this persons Yak breaking the hinges.

That jitter (I was informed) is caused by the servo attempting to find center after the gears have worn too much. They start bouncing like crazy. The "story" is that the linkages are being improperly set up, causing the servo gears to undercut the teeth on the adjacent gear. Don't know how that applies to servos in the first couple of flights though. Mine was new also. I asked JR if they had any plans to change gear material and was told the 8611 is just great as is

I just placed a reservation on 5 Hitec 5955's with Wild Hare for my next plane....

Pat I suppose I can see that happening. Was yours a pull pull or a push pull? I got the same story about improper setup from JR service when I sent them 4 8611 servos. We had quite a lengthy chat and I had explained to him that they were in my IMAC 40% Extra and what my current standings were in the points. He then agreed to send them back free of charge.

Last week I was having an issue with a customers R2000 receiver not being able to lock on to a TX. It would scan but not lock. I called JR service. The first thing from them was I did not have the TX set to S PCM. I told him that I did and that the TX was verified on my own equipment using a 950RX. I asked if it made any difference that I was using a Power Expander and was proptly asked what a Power Expander is. All I can say is that there looks as is there was a changing of the gaurd over at JR service and it is really shaking my confidence in them.

As far as servos go their official stance is that we should not use a ratio less than 1.5 to 1. in other words 1' servo arm with 1.5" control arm. I told him that in the real world that is not going to happen, guys are going to want more throw than that. The guy I had on the phone did admit he has been with Horizon about 1 year.


Joe so that I understand, are you having the same servo jittering? Is your setup pupp pull or push pull?


Shawn
Old 04-24-2007, 11:19 AM
  #10  
Tired Old Man
Senior Member
My Feedback: (1)
 
Join Date: Feb 2002
Location: Valley Springs, CA
Posts: 18,602
Likes: 0
Received 3 Likes on 3 Posts
Default RE: 87" Yak Rudder hinge pins broke

Shawn,

Mine was a push pull single servo surface. It doesn't get much simpler than that. Arrangement was 1-1/[email protected] to 1-3/[email protected] with no radical angles. Surface mounted ball links on SWB arms with true RCL-70 linkage at the rudder horn. No binds or side loads anywhere. Never could get rid of the issue, and same as yours, could smack the surface to quiet the servo down. Not a good thing.

I've got an e-mail from another user that sent ten 8611's in for repair after well less than a year of use. Too much slop in the gear trains was the reason for sending them in. They tried to charge him about $35.00 apiece to repair the gear trains since the wear was part of "normal wear" and not warranty covered. After an animated conversation that noted there were far less than 100 flights on the servos they relented and took care of it, but that was enough to shake the customers confidence in the warranty coverage. He sold them all when they were returned and changed manufacturers.
Old 04-25-2007, 08:56 AM
  #11  
juanes1969
Senior Member
 
Join Date: May 2005
Location: Comayaguela, HONDURAS
Posts: 409
Likes: 0
Received 0 Likes on 0 Posts
Default RE: 87" Yak Rudder hinge pins broke

It`s incredible how these JR8611s wear off their gears. I have a Wild Hare YAK, for those of you that know this plane, it is a very small plane (too small in theory) for the 8611s. I had two 8611s one on each elevator, and just after 27 flights the servo on the right elev. started to show signs of wear in the gears. It did not hold it`s center, there was a lot of play in the servo arm!
My little YAK has now over 100 fights with Hitec 5985s and there is no problem with those in any way.
I still have the two 8611, it just makes me mad to have paid $115 for them.

John
Old 04-25-2007, 10:21 PM
  #12  
JoeAirPort
Thread Starter
My Feedback: (41)
 
JoeAirPort's Avatar
 
Join Date: Aug 2003
Location: Milwaukee, WI
Posts: 10,259
Likes: 0
Received 0 Likes on 0 Posts
Default RE: 87" Yak Rudder hinge pins broke


ORIGINAL: rcblimppro

Joe so that I understand, are you having the same servo jittering? Is your setup pull pull or push pull?

Shawn
Shawn, it's pull pull. I put a 5955 in there and the problem is totally gone. I'm done with JR. It's Hitec for me from now on. They took good care of me with the one service issue I ever had. A few years back I had a (4) 635 karbonite gear failure, was not even 100% their fault. I repaired the CAP232, they gave me 4 brand new 5645 MG servos..free. And those babies worked great for three years. These 5955TG are awesome servos. Got one on the rudder of my 30% Edge too. Never a single rudder issue on that plane.



Old 04-25-2007, 10:26 PM
  #13  
Josey Wales
Senior Member
My Feedback: (61)
 
Josey Wales's Avatar
 
Join Date: Jul 2003
Location: **, NJ
Posts: 4,741
Likes: 0
Received 0 Likes on 0 Posts
Default RE: 87" Yak Rudder hinge pins broke

Good decision Joe...Get a programmer too...its well worth the money...
Old 04-26-2007, 07:21 AM
  #14  
JoeAirPort
Thread Starter
My Feedback: (41)
 
JoeAirPort's Avatar
 
Join Date: Aug 2003
Location: Milwaukee, WI
Posts: 10,259
Likes: 0
Received 0 Likes on 0 Posts
Default RE: 87" Yak Rudder hinge pins broke

Yeah I like those programmers. Used them plenty. A friend of mine has one that I use but I really need my own.

BTW, the local hobby store had some .039" music wire that worked great to replace my rudder hinge pins. Now with this 5955 I won't have to tighten the crap out of the cables so the hinge pins won't sheer.

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

Copyright © 2022 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.