JR 8611 servo play, flutter?

[TonyThomasian]

When i give up or down elevator on my comp-arf and let go of the stick, only one of the elevator half fludders. this happens only when i LET go of the stick. Or is it from the comp-arf elevator play? It does it very fast, but very little up and down movement. It looks like its flyable.?.?.?
thanx

[EddieWeeks]

I think that is because the stick on the transmiter is bouncing back and forth
after you let it go

[TonyThomasian]

I know thats not it, because only one half of the elevator does that, and it doesnt "fling" up and down a couple of times, it fludders very fast and doesnt stop untill i give it full up or down movement then gradually "push or pull" the stick back to center stick position.

[SUPERFLYJAY]

FLUDDER ????

[Biff]

9611?

[ShortBus]

I had a Futaba S3001 do that....It was in a profile on the aileron. It would flutter up and down until I moved the servo.

Some of the teeth on the gears were stripped.

[Shawn Berkheimer]

	Quote: Originally Posted by TonyThomasian
	When i give up or down elevator on my comp-arf and let go of the stick, only one of the elevator half fludders. this happens only when i LET go of the stick. Or is it from the comp-arf elevator play? It does it very fast, but very little up and down movement. It looks like its flyable.?.?.? thanx

JR digital servos are notorious for that. What has happened is that the gears and pot have some wear. You will notice that it will do it worse on a fully charged battery. With flight loads it will not do it and it will also not fail. You can send it to JR and they will rebuild the servo. I don't recall the price but it is better than a new servo. In some cases I have heard of them doing it at no charge. I have about 6 of them doing the same thing. I hope to get another 2 contests on them and then send them in for rebuild.


Shawn

[casey g]

i just sent in 4 ds 811 same thange.
the weired thange is they only had 13 flights on them so jr said send them in

[slowroller]

I had the same problem with one of my JR servos I replaced the servo extention lead and problem went away. A couple of weeks ago a flying buddie had a similar problem and I suggested to replace the extention and guess what it went away....

[Shawn Berkheimer]

	Quote: Originally Posted by slowroller
	I had the same problem with one of my JR servos I replaced the servo extention lead and problem went away. A couple of weeks ago a flying buddie had a similar problem and I suggested to replace the extention and guess what it went away....

That could happen with inferior brands of extentions. Personally I don't use extentions, I cut and solder all my leads to the exact length I need. For elevator in the fuse I have custom made extentions of the exact length and for ailerons I plug the servo leads directly into the matchbox. The idea is to limit the number of connecters to bare minimum. I usually practice twice a week 6 flights each session. Thats 24 times through the sequence with some fooling around thrown in per week. Thats alot of wear and tear on the servos.

Shawn

[madmax]

...modified thread title to reflect proper model #.

[airborneSGT]

I have to say that soldering your leads to the exact length aint a bad idea. I have done the same myself in the past. Doing so can take away several failure points.

JR must get a lot of 8611A's sent in from the 1/8th scale buggy guys. Most of the guys switch to those after trashing about everything else.

Makes me wonder if JR wont release a TG gear set for the 8611A's.

[soarhi23]

Shawn has said it best I think, as to my use of these 8611's, I have had this happen on servos stright out of the box!!!! Its, not been a problem and I'm sure JR is trying to fix the issue, but I can assure you that these servos are going to stand the test of time. But, the guy that changed his servo ext. and had this correct his problem, that was news too me! If you could please send the info on what ext. your using and the ones that your not cause of the issue, thanks!!!! And remember""""""KEEP'em LOW""""""""!!!!!!!!!

[rede2fly]

most likely he switched to a heavy duty ext, they are bigger wire or lower guage wire alowing more power to the servo. long wire = resistance = jitter or flutter. digital servos take more power to opperate than non digital. i personaly wont use standard servo extensions, not on anything that i want to keep flying.

[KrisW]

	Quote: Originally Posted by rede2fly
	most likely he switched to a heavy duty ext, they are bigger wire or lower guage wire alowing more power to the servo. long wire = resistance = jitter or flutter. digital servos take more power to opperate than non digital. i personaly wont use standard servo extensions, not on anything that i want to keep flying.

The current drop across even a 48" extension is negligible, even with 24 gauge wire instead of the HD 22 or 20 gauge wire setups. High amperage loads near the wires max capability of 5-6 amps would still supply the servo with proper voltage. A better suspect would be the pins and connectors themselves, since this is where about 90% of your power loss occurs in extensions.

If you look at the wire gauge for the servo itself. . guess what?? It's 24 gauge, even on 8611's and HiTec 5955's My Seiko PS-050 uses 20-22 gauge, but it is capable of 1200-1600 ounces of torque and pulls 8-10 amps with ease.

28 gauge LD extensions should be avoided, however, since they can only handle about 1 amp of current.

As for the 8611 Elevator "Fludder". . . typical JR ultra-tight deadband and sloppy geartrain scenario. They have ALL been doing this since JR introduced the 8411. You'd think that in 4-5 years JR would have finally gotten the problem solved. But, JR has failed to address the problem, along with the excessive geartrain wear problems. . so I refuse to use JR servos anymore. At $115/servo, they should never "fludder", wobble, and the wear characteristics should be a LOT better.

To stop the "fludder". . . take a large rubber band and hook it around the control horn of the surface, then anchor the other end someplace on the stabilizer that will allow the rubber band to pre-load the surface and provide tension on the control rods. This will help prevent the servo from overshooting center, and make things smooth out. It was THE fix for 8411's when they first came out. . and will still work today on the 8611's.