JR 8411 different centering
08-13-2003, 01:26 AM
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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?
08-13-2003, 01:36 AM
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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...
08-13-2003, 02:46 AM
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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
see how the right elevator half is just a slight bit higher...? Its hard to tell in these pics the differences
08-13-2003, 02:51 AM
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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
If u use the white monocote line for reference you can see the different postitions at neutral
08-13-2003, 02:53 AM
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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.
08-13-2003, 02:57 AM
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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?
08-13-2003, 03:07 AM
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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.
08-14-2003, 01:02 AM
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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
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
08-14-2003, 01:58 AM
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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.
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.
