19-03-2011, 07:28 PM
(15-03-2011, 08:42 PM)Skidz Wrote:(15-03-2011, 08:30 PM)secant0give Wrote:(15-03-2011, 06:49 PM)Skidz Wrote:(14-03-2011, 06:52 PM)secant0give Wrote: I also found that they hunted a bit around the center and had a little back lash too. Now it's going to be Hitec 5085MGs instead
Hey Jason,
Maybe your servo had a broken tooth around neutral. I have had the same thing happen.
That's Interesting Dave I'll have to pull it apart and have a look now that it's out. What brand of servo was it that you had the broken tooth with? and what brand of servo are you currently using? I remember you showed me some nice ones on your rotor head a week or two back, they moved super smoothly, but I can't, for the life of me remember what name they went by.
New servo is now installed in the edge 540 and I'm still thinking of shifting the C of G aft a little more to get it right.
slowly slowly catchy monkey
I don't use the large servos like the larger planes are using. I had trouble with el-cheapo HK servos. They were Hextronic HXT somethings (blue case). Ok for some models but not ok in helicopter cyclic controls (on my learner 450 - not the 500 I fly at the field). The plastic teeth came free quite easily after a mishap. I fixed the rotor head only to end up cursing the servos. I had freeplay and "issues" around mid travel. Right where the gears were meshed at crunch time. The heli developed eratic behaviour until I realised it was jumping a tooth or three.
The servos I am using at present are Savox servos. The manufacturer of my heli (Align) relabel them as DS510 for the cyclic control and DS520 for the rudder (higher torque and faster) but they are Savox units. On the quality scale they are 3.5 stars from 5.0. They are plastic gears not metal. Plastic has a better mesh quality and much less freeplay than metal. Provided they are matched for the load, I am duly advised plastic is ok. When you get in to the stump pulling torque requirements, I guess metal gears are better. I put a lot of stress on the cyclic servos with the flybarless set-up due to the way things link together but the servos are just fine.
Here is a good link that readers might find useful: http://www.spartan-rc.com/resources/servodb/servo.php. It is customised towards helicopters but the information is excellent.
Dave
Thanks Dave !!!
“The knack of flying is learning how to throw your machine at the ground and miss.”
"When once you have tasted flight, you will forever walk the earth with your thoughts turned skyward, for there you have been, and there you will always long to return." ~Leonardo Da Vinci