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

Electronic servo reversing...

Old 12-23-2002, 07:05 PM
  #1  
cap10fan
Senior Member
Thread Starter
My Feedback: (13)
 
Join Date: Dec 2002
Location: Columbus, OH
Posts: 135
Likes: 0
Received 1 Like on 1 Post
Default Electronic servo reversing...

I have seen several references to using a servo reverser for things like split elevators and the like.

I have always positioned the servos so the output arms are opposite each other (i.e. one push rod on the left side of a servo and the other on the right side of the other servo) and plugged them into a standard Y connector. I also do this with aileron servos.

Can this cause damage to the Rx/servos? Is there reason to use an electronic servo reverser?

Thanks and happy holidays to all!
Old 12-23-2002, 08:02 PM
  #2  
Ernie Misner
 
Ernie Misner's Avatar
 
Join Date: Jul 2002
Location: Tacoma, WA
Posts: 5,037
Likes: 0
Received 0 Likes on 0 Posts
Default Re: Electronic servo reversing...

Originally posted by cap10fan
I have seen several references to using a servo reverser for things like split elevators and the like.

I have always positioned the servos so the output arms are opposite each other (i.e. one push rod on the left side of a servo and the other on the right side of the other servo) and plugged them into a standard Y connector. I also do this with aileron servos.

Can this cause damage to the Rx/servos? Is there reason to use an electronic servo reverser?

Thanks and happy holidays to all!
The reason to use a servo reverser would be if there was no way to set things up with the output arms opposite from each other. I don't think the Y connector could possibly cause any damage. How could it?

Happy Holidays!

Ernie
Old 12-23-2002, 08:18 PM
  #3  
cap10fan
Senior Member
Thread Starter
My Feedback: (13)
 
Join Date: Dec 2002
Location: Columbus, OH
Posts: 135
Likes: 0
Received 1 Like on 1 Post
Default Electronic servo reversing...

I didn't think it would cause damage, I was just wondering why all the reference to servo reversers. Now I know. I just haven't found the "right" plane I guess..

Thanks and happy holidays!
Old 12-23-2002, 11:21 PM
  #4  
avinut
Member
My Feedback: (2)
 
Join Date: Aug 2002
Location: Slaughter, LA
Posts: 90
Likes: 0
Received 0 Likes on 0 Posts
Default Electronic servo reversing...

Thats interesting cap10fan. When I do that the elevator halves work opposite. If two servos are placed with the output shaft at the forward end, for example, with one arm pointing left and the other right, The left one moves forward when the right one moves rearward. Thats why you reverse one of them. Nothing wrong with using a Y connector though. Yeah , it works fine for ailerons because they work in opposition.
Old 12-23-2002, 11:29 PM
  #5  
DeadSticker
Senior Member
My Feedback: (18)
 
DeadSticker's Avatar
 
Join Date: Oct 2002
Location: Farmington, MO
Posts: 928
Likes: 0
Received 0 Likes on 0 Posts
Default Electronic servo reversing...

If I need them to be reversed and I can't position the arms opposite, I just bust open the servo, un-solder the 2 outside wires on the pot and reverse them, then reverse the wires on the motor. Works like a charm!! I don't think I could bring myself to use an electronic servo reverser....just one more thing to go bad. I also mirrored the ele channel on my radio, but I didn't like how you could only trim one (the master) ele. Then having to make opposite ail trim to counter act the trim on the ele! Big pain.......
Old 12-24-2002, 04:05 AM
  #6  
cap10fan
Senior Member
Thread Starter
My Feedback: (13)
 
Join Date: Dec 2002
Location: Columbus, OH
Posts: 135
Likes: 0
Received 1 Like on 1 Post
Default Electronic servo reversing...

avinut,

I place one output shaft towards the front of the fuse and the other towards the rear.

I am using this method on my GP spacewalker, and an Ultimate Bipe.
Old 12-24-2002, 06:47 PM
  #7  
avinut
Member
My Feedback: (2)
 
Join Date: Aug 2002
Location: Slaughter, LA
Posts: 90
Likes: 0
Received 0 Likes on 0 Posts
Default Electronic servo reversing...

Regardless of the position of the servos, if the output arms point in opposite directions the servos will act opposite to one another.
Cap10fan you must have the servo arms pointing in the same direction huh? For a symetrical arrangement I mount the servos in the same direction side by side then cross the pushrods going back for a better shot at the exit hole. This DOES, however,require that one servo be reversed. I never considered it a problem since reversing one takes about 15 minutes.
Old 12-24-2002, 08:38 PM
  #8  
cap10fan
Senior Member
Thread Starter
My Feedback: (13)
 
Join Date: Dec 2002
Location: Columbus, OH
Posts: 135
Likes: 0
Received 1 Like on 1 Post
Default Electronic servo reversing...

Avinut,

You got me thinking, so I had to go down to the basement laboratory and open the beast up.

I have the output arms mounted on the same side of the servos, with one towards the nose and the other towards the tail.

Should have looked first. Menory is not what it used to be. D**n dope....

Now that Deadsticker has taught me to reverse them in the case, it is a non-issue. Thanks Deadsticker.

The two servos on the left are my elevator servos, the pushrods cross in the tail.
Attached Thumbnails Click image for larger version

Name:	42852_21760.jpg
Views:	9
Size:	23.5 KB
ID:	26677  
Old 12-24-2002, 11:31 PM
  #9  
avinut
Member
My Feedback: (2)
 
Join Date: Aug 2002
Location: Slaughter, LA
Posts: 90
Likes: 0
Received 0 Likes on 0 Posts
Default Electronic servo reversing...

OK now I am with you. Gotta admit you had me going for awhile. On my mentioned method my elevator would be the two outside servos on your mounting plate with arms pointed outward for max separation and crossed pushrods for good exit angle. Like you say, reversing ain't a big deal and now you know why some of us do it.
Old 12-30-2002, 04:01 AM
  #10  
DeadSticker
Senior Member
My Feedback: (18)
 
DeadSticker's Avatar
 
Join Date: Oct 2002
Location: Farmington, MO
Posts: 928
Likes: 0
Received 0 Likes on 0 Posts
Default Electronic servo reversing...

No prb cap10fan. I was in the same boat and was looking into just buying one of the reversing y's. Then I got to thinking about it and figured switch the pos and neg on the pot then reverse them on the motor, should reverse the servo....and it worked!! Kinda like when you rewire an old guitar and the volume is backwards, reverse the wires.
Old 12-30-2002, 02:00 PM
  #11  
BillHarris
Senior Member
 
BillHarris's Avatar
 
Join Date: Dec 2002
Location: Jasper, AL
Posts: 837
Likes: 0
Received 0 Likes on 0 Posts
Default Electronic servo reversing...

As we discussed eariler, it is "better" to position the servos of rewire and reverse on servo than to use an electronic reverser.

A servo reverser works this way: the servo position is determined by the pulse width from the RX (and TX). For the sake of argument, a 1.0millisecond pulse is center, a 0.5 ms pulse is left and a 2.0 ms pulse is right.
An electronic reverser contains a timing circuit that reads the .5 ms pulse and makes it 2.0 ms, and does not chane the 1.0ms "centered" pulse. And operates proportionally between .5 and 2.0 ms. This changes left to right and leaves center unchanged.

The problem: both the TX and the RX are "times" by crystal-controlled clocks which are very stable with respect to temperature. The timer in the reverser is clocked by a resistor-capacitor circuit, which is inherently not as temperature stable as a crystal. So it drifts a bit with temperature changes.

And, although quite reliable, it does add complication and the potential for failure.

My 2c.

--Bill

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 -

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.