RC Radios, Transmitters, Receivers, Servos, gyros Discussion all about rc radios, transmitters, receivers, servos, etc.

JR 8411 different centering

Reply

Old 08-13-2003, 01:26 AM
  #1  
ChixwithTrix
Senior Member
Thread Starter
My Feedback: (8)
 
ChixwithTrix's Avatar
 
Join Date: Apr 2002
Location: Austin, TX
Posts: 394
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default JR 8411 different centering

I have one JR 8411 on each elevator half of my Patty, but both servo's centering is different and I cannot get the elevator halves to match. I only have a 7 channel reciever in it and both servos do not have their own channel where I can change the settings on them with the radio. What can I do to get my elevator halves to match with these servos?
ChixwithTrix is offline  
Reply With Quote
Old 08-13-2003, 01:36 AM
  #2  
bob_nj
My Feedback: (62)
 
Join Date: Dec 2001
Location: Vineland, NJ
Posts: 3,850
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default JR 8411 different centering

Not sure if this will help, but sometimes repositioning the arm, or trying different arms helps. Just as all servos are not created equal, the arms tend to be different too? Are you using metal arms, and can you send a picture? Are the linkages equal? Are you using a "Y"? Are the elevators equal at say 1/3 - 1/2 and full deflection? So many questions...
bob_nj is offline  
Reply With Quote
Old 08-13-2003, 01:53 AM
  #3  
ChixwithTrix
Senior Member
Thread Starter
My Feedback: (8)
 
ChixwithTrix's Avatar
 
Join Date: Apr 2002
Location: Austin, TX
Posts: 394
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default JR 8411 different centering

Ill go get a pic of the whole setup to answer ur ?s
ChixwithTrix is offline  
Reply With Quote
Old 08-13-2003, 02:42 AM
  #4  
ChixwithTrix
Senior Member
Thread Starter
My Feedback: (8)
 
ChixwithTrix's Avatar
 
Join Date: Apr 2002
Location: Austin, TX
Posts: 394
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default JR 8411 different centering

Here is a pic of the elevators at neutral
Attached Thumbnails Click image for larger version

Name:	101283_7104.jpg
Views:	4
Size:	42.9 KB
ID:	57397  
ChixwithTrix is offline  
Reply With Quote
Old 08-13-2003, 02:46 AM
  #5  
ChixwithTrix
Senior Member
Thread Starter
My Feedback: (8)
 
ChixwithTrix's Avatar
 
Join Date: Apr 2002
Location: Austin, TX
Posts: 394
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default JR 8411 different centering

The elevators deflected down...

see how the right elevator half is just a slight bit higher...? Its hard to tell in these pics the differences
Attached Thumbnails Click image for larger version

Name:	101285_7104.jpg
Views:	9
Size:	40.2 KB
ID:	57398  
ChixwithTrix is offline  
Reply With Quote
Old 08-13-2003, 02:51 AM
  #6  
ChixwithTrix
Senior Member
Thread Starter
My Feedback: (8)
 
ChixwithTrix's Avatar
 
Join Date: Apr 2002
Location: Austin, TX
Posts: 394
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default JR 8411 different centering

here are the arms positions at neutral. I have tried to put the arms in different grooves...but still wont match.
If u use the white monocote line for reference you can see the different postitions at neutral
Attached Thumbnails Click image for larger version

Name:	101286_7104.jpg
Views:	4
Size:	46.2 KB
ID:	57399  
ChixwithTrix is offline  
Reply With Quote
Old 08-13-2003, 02:53 AM
  #7  
ChixwithTrix
Senior Member
Thread Starter
My Feedback: (8)
 
ChixwithTrix's Avatar
 
Join Date: Apr 2002
Location: Austin, TX
Posts: 394
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default JR 8411 different centering

The right arm wont go as low as the left when deflected down
Attached Thumbnails Click image for larger version

Name:	101287_7104.jpg
Views:	4
Size:	44.5 KB
ID:	57400  
ChixwithTrix is offline  
Reply With Quote
Old 08-13-2003, 02:53 AM
  #8  
RCP57
My Feedback: (25)
 
Join Date: Mar 2002
Location: Cypress, TX
Posts: 406
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default JR 8411 different centering

It looks like your using a Y harness to operate both servos on one channel. I would try a MatchBox. It will allow you to adjust the “Center” position, and allow you to adjust the “end point” for each servo in each direction. This should solve the problem.
RCP57 is offline  
Reply With Quote
Old 08-13-2003, 02:54 AM
  #9  
ChixwithTrix
Senior Member
Thread Starter
My Feedback: (8)
 
ChixwithTrix's Avatar
 
Join Date: Apr 2002
Location: Austin, TX
Posts: 394
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default JR 8411 different centering

Its really hard to see a difference in this pic but the right servo arm goes higher when deflected up
Attached Thumbnails Click image for larger version

Name:	101288_7104.jpg
Views:	4
Size:	44.0 KB
ID:	57401  
ChixwithTrix is offline  
Reply With Quote
Old 08-13-2003, 02:57 AM
  #10  
ChixwithTrix
Senior Member
Thread Starter
My Feedback: (8)
 
ChixwithTrix's Avatar
 
Join Date: Apr 2002
Location: Austin, TX
Posts: 394
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default JR 8411 different centering

Yes I am...I was really hoping I wouldn't have to buy a matchbox...is there any other way? Or any different matching product?
ChixwithTrix is offline  
Reply With Quote
Old 08-13-2003, 03:07 AM
  #11  
RCP57
My Feedback: (25)
 
Join Date: Mar 2002
Location: Cypress, TX
Posts: 406
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default JR 8411 different centering

The only other way is to use two separate channels and create a mix. However, when you use two separate channels the servos will move at slightly different speeds. Unless your using a 10X where you can slow down one servo there is no other way to slow down the faster servo. The servos are running at the same speed, it’s the delay input to the channels that make the servo speed different. The MatchBox is the best solution.
RCP57 is offline  
Reply With Quote
Old 08-14-2003, 01:02 AM
  #12  
RJConnet
Senior Member
 
Join Date: Jan 2002
Location: OR
Posts: 680
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default JR 8411 different centering

Chix,

I have run into this problem several times, it looks from the pictures like you are using Dubro arms on your servos. I find that by using the four arm pieces that I can usually find a position that will allow the neutrals to be very close, then I just cut off the unused arms. The ideal of course is to have the servo arms at 90 degrees to the long axis of the servo at neutral but if they are close you can play with your sub-trim and end-point adjustments to get equal throw up and down. Just play around with it a little bit and see what you can come up with.

RJ
RJConnet is offline  
Reply With Quote
Old 08-14-2003, 01:58 AM
  #13  
mglavin
My Feedback: (31)
 
Join Date: Nov 2001
Location: Elverta, CA
Posts: 5,295
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default JR 8411 different centering

Matchboxes or Smartflys Equalizer or the like will solve the problem. Stay away from anything other than a standard HD wye or a JR amplified wye if they suit your application and you use JR equipment.

You maybe able to find another servo on your model that is not in the same predicament, i.e. the ailerons that centers similar to another, the idea being that if the NEWLY found servo meets your needs the aileron channel can be dialed in with sub-trim independently with any other servo.

Your problem is common place, long before the Matchbox type goodies were available I often had to cherry pick my servos from a large group to find suitable partners for them. I have since moved to programmable servos.
mglavin is offline  
Reply With Quote

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