Mini servos on OMP 540
02-05-2004, 11:39 AM
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Mini servos on OMP 540
I was thinking about using GWS mini servos on my OMP 540 funfly. The servos are rated at 47 oz/in, which is about the same as other standard servos. I could save 2.5 oz using these servos. I figured someone maybe has already tried something like this and would like to benefit from your experience.
Thanks
Thanks
02-05-2004, 01:06 PM
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RE: Mini servos on OMP 540
I'd be careful about going too small on this plane. I'm not that familiar with the GWS servo you mentioned, but you need to make sure the geartrain is strong enough to stand up to the forces of 3D flying also. If you want to go small, you can try the Hitec 225s I've had them on my Edge for about 8 months and they've worked great. Plus, on 6V, they put out 67oz of torque. They weigh 1.1oz, so you'll still save a couple of ounces over standards.
Whatever you do, get the plane built. You'll love it!
Whatever you do, get the plane built. You'll love it!
02-05-2004, 01:14 PM
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RE: Mini servos on OMP 540
I have a buddy that put 225's on his omp... He's had no less that 9 failures........ They don't really hold up on a 40 sized bird if you're running extream throws.....
I'd stick with standards....
I'd stick with standards....
02-05-2004, 03:35 PM
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RE: Mini servos on OMP 540
I have hitec 225 metal gear minis on the rudder and elevator of my OMP edge and they are holding up fine. I would guess about 50 + or so hard 3d flights . I like them. Get the metal gear though, the plastics strip pretty easy
02-06-2004, 01:25 PM
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RE: Mini servos on OMP 540
All good points! If you go smaller than the standard size servo you absolutely must have metal gear servos or you will break those little gears. There simply isn't enough surface area on those gears to hold up to the given forces. I am using Hitec 85MG servos on my 47" OMP planes and they are on their second season now with no failures.
Mike
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Mike
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02-06-2004, 03:26 PM
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RE: Mini servos on OMP 540
The servo's in question were on Jess Rozman's OMP Edge 540. He was running Hitec HS 225's. They were the nylon geared version, but stripped gears where rarely the cause of failure....
Granted he 3D'd the snot of of this plane for untold gallons of fuel.... but I never saw him turf it... so all the wear on the servo's was flight induced...
Granted he 3D'd the snot of of this plane for untold gallons of fuel.... but I never saw him turf it... so all the wear on the servo's was flight induced...
02-06-2004, 08:21 PM
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RE: Mini servos on OMP 540
Paul, I am running the MG's. Never a gear strip, motors burn up. Hitec has always replaced no questions asked. I have 190 hours on my transmitter clock on said OMP. I have ball links on the control surfaces for bind free movement. My servos don't even hum at full deflection. I have been through 3 OS46fx's if that tells you anything.
Mike, gimme your OMP and let me give your servos the torture test.
Jess
Mike, gimme your OMP and let me give your servos the torture test.
Jess
02-10-2004, 02:27 AM
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RE: Mini servos on OMP 540
ORIGINAL: RCU-RCU
I flew mine hard all of last year with 225 MG's with no failures. I don't know how the nylon gears would hold up though, no experience with them. Now that I mentioned no failures.....Murphys law will come into play.....!
JW
I flew mine hard all of last year with 225 MG's with no failures. I don't know how the nylon gears would hold up though, no experience with them. Now that I mentioned no failures.....Murphys law will come into play.....!
JW
It is very possible the motors have less life on the 5 cell packs that I run. I have been trying to figure out why me and others trash so many 225 servo motors. This has also happened to other people at our field on their 40 size funflys. We all run 6 volts and major 3D throws. We burn a bunch of 3D juice also.
Jess
02-10-2004, 09:01 AM
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RE: Mini servos on OMP 540
Hey I bet that has lot to do with it. I run a 4 cell pack and never a failure. The servo motors should handle the 6v pack just fine but that's worth a question to Hitec about.
Mike
Mike
02-10-2004, 10:10 AM
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RE: Mini servos on OMP 540
ORIGINAL: AFSalmon
Hey I bet that has lot to do with it. I run a 4 cell pack and never a failure. The servo motors should handle the 6v pack just fine but that's worth a question to Hitec about.
Mike
Hey I bet that has lot to do with it. I run a 4 cell pack and never a failure. The servo motors should handle the 6v pack just fine but that's worth a question to Hitec about.
Mike
See the short thread [link=http://www.rcuniverse.com/forum/m_364132/mpage_1/key_/anchor/tm.htm#364135]here[/link].
I am very satisfied with Hitec servos. I have been using the 5945, 5245, in my Carden Cap and I use the 475HB on my funfly's now. No problems. The right servo for the job makes a difference.
By the way, Mike resolved all issues. I had the wrong e-mail adress.
Jess
02-10-2004, 02:08 PM
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RE: Mini servos on OMP 540
Hmmm. looked at that thread and Mike doesn't really give an explanation. He just says that they probably aren't suited for that application. As an engineer I find that hard to swallow as an excuse. Especially the failures of 225s being used as throttle servos! There is no way these should fail as throttle servos - heck that's almost no load! Based on the torque output of these servos it's simple to me: if the servo is supposed to deliver that much torque then it should be designed to handle that load. If the Hitec servos are rated at say 50 in-oz of torque but realistically they fail if repeatedly used at these loads then their specs are wrong and should be changed. Either that or the motors improved to match the rated output of the gear train.
This is really off this topic but worth the note. Sounds like the 225s have poor motors but a good gear train in my book.
mike
This is really off this topic but worth the note. Sounds like the 225s have poor motors but a good gear train in my book.
mike
02-11-2004, 11:49 PM
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RE: Mini servos on OMP 540
You guys are on to something! I burned up two 225's in a three week perios on the throttle of my 33% edge. (6 volt system) My little omp edge has a 225 on the throttle with a 4.8 pack no problems. Maybe the 6V is just too much for the 225?
02-12-2004, 12:17 PM
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RE: Mini servos on OMP 540
ORIGINAL: AFSalmon
Hmmm. looked at that thread and Mike doesn't really give an explanation. He just says that they probably aren't suited for that application. As an engineer I find that hard to swallow as an excuse. Especially the failures of 225s being used as throttle servos! There is no way these should fail as throttle servos - heck that's almost no load! Based on the torque output of these servos it's simple to me: if the servo is supposed to deliver that much torque then it should be designed to handle that load. If the Hitec servos are rated at say 50 in-oz of torque but realistically they fail if repeatedly used at these loads then their specs are wrong and should be changed. Either that or the motors improved to match the rated output of the gear train.
This is really off this topic but worth the note. Sounds like the 225s have poor motors but a good gear train in my book.
Hmmm. looked at that thread and Mike doesn't really give an explanation. He just says that they probably aren't suited for that application. As an engineer I find that hard to swallow as an excuse. Especially the failures of 225s being used as throttle servos! There is no way these should fail as throttle servos - heck that's almost no load! Based on the torque output of these servos it's simple to me: if the servo is supposed to deliver that much torque then it should be designed to handle that load. If the Hitec servos are rated at say 50 in-oz of torque but realistically they fail if repeatedly used at these loads then their specs are wrong and should be changed. Either that or the motors improved to match the rated output of the gear train.
This is really off this topic but worth the note. Sounds like the 225s have poor motors but a good gear train in my book.
Jess
