How to trim a retract servo ?
09-06-2009, 03:47 PM
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How to trim a retract servo ?
Hi, i am having some issues with a P-51 retracts. I am actually using a GWS S136GM / 2BB but it can't be trimmed. It goes only to two only fixed positions. The mechanical fit that i have currently requires less travel to one side than the other. I am using a DX7 that allows to control the travel of the GEAR channel. But this servo can't be trimmed it has only two fixed positions. There is no room for a full size servo to replace it. I was wondering if someone knows of a retract servo that accepts trimming or travel adjust. Not sure if the JR RT88 does that. Does anyone knows ?
thx
thx
09-06-2009, 09:35 PM
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RE: How to trim a retract servo ?
The only proportional retract servo that I know of is the Airtronics 94739. It is no longer made, but it is a full size servo, so it probably wouldn't work for you anyway. You'll have to adjust the linkage in a way that gives you the travel you want on either side.
Jesse
Jesse
09-07-2009, 01:05 AM
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RE: How to trim a retract servo ?
Attach the pushrods at different positions on the output arm to get different throws. Further out toward the end of the arm = more throw. Closer in = less throw.
Terry in LP
Terry in LP
09-07-2009, 01:48 PM
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RE: How to trim a retract servo ?
Besides previous advices, I suggest a servo saver, in order to get some cushion effect at the end of the servo travel.
http://www3.towerhobbies.com/cgi-bin...?&I=LXD646&P=7
http://www3.towerhobbies.com/cgi-bin...?&I=LXD646&P=7
09-07-2009, 03:06 PM
#7
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RE: How to trim a retract servo ?
When I could not find an appropriate hole in the retract servo control wheel, I used the setup in the picture below. This allows the retract servo to move its normal amount but not move the pushrod quite as much. As that old saying goes, "Works good and lasts a long time."
09-09-2009, 08:52 PM
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RE: How to trim a retract servo ?
You should measure the travel required from stop to stop on the retract itself... then choose the two holes the same distance apart on the servo wheel. (Or drill them if required) If you use the "servo saver" method you might not engage the up or down locks.
