Spektrum DS821 Sevos Junk or good
 

Well i purchased 4 DS821 Servos of RCU'Market place and got three due to one being damaged before shipping from being dropped. the the 3 i get one has the spline busted were it meets the case dont know if it happend beforee shipping or in shipping but wondering if there junk. I plan to use 2 of the good ones i have in a extra 330 for the elevators but i'm reconsidering now since seeing the spline busted at the case on the one.

So whats your opion? are they good servos are are they junk like the servo that come with the DX6 i think these come with a DX7? But i know the servo i got with my DX6 were junk whats up with spektrum i dont understand why they cant make a good quality servo to go along with there radio systems.

The DS821 Servo has black plastic spline shaft what kind of material is this? it sure isn't nylon looks like some kinda Chinese Pot plastic. Ok its cheap Malaysia plastic since thats were there made.

RE: Spektrum DS821 Sevos Junk or good
 

G'day Mate,
They are JR servos, I have 4 of them in my Katana with OS 160FX, 2 on elevators, & 2 on ailerons, the servos are strong, accurate & reliable, just like any JR servo I have used, but DON'T use any type of locking liquid in the screw that hold the servo arm, it will wreck the plastic, there is no need to anyway, the screw won't come loose.

RE: Spektrum DS821 Sevos Junk or good
 

I plan to use them in my extra 330L gasser for the elevator. But wasnt to sure they would stand up to the torsional forces on the elevator. thanks for the input Alan maybe some poeple wil chime in and give there 2 cents too.

RE: Spektrum DS821 Sevos Junk or good
 

Wow I cant imagine using them on anything that big. JR warns against using them on any airplane over 120 size.

Most of the helicopter people wont touch them because of the issues with the output shafts shearing off.

RE: Spektrum DS821 Sevos Junk or good
 

This is exactlyy why i wasn't going to use them on that plane due to the Spline shaft shearing off or breaking. I have other applications were i can use them there is alot of forces On the elevator. I guess i better just get some MG servos that are good quality if i Don't want A crash. I'll just put these in something else.

The Extra is a 28% plane and weighs about 12 to 15 lbs. Has a gfi 45I engine in it and i crashed it due to CHeap servos being put in it. And got a deal on these DS821 Servos Which I'm not impressed with so far.

RE: Spektrum DS821 Sevos Junk or good
 

The DS821 servos I own have been great! I use them in five planes (40 & 60 size), and they suit my purposes very well. They are inexpensive, quick, powerful, accurate, and dependable.

All of the DS821 failures I have heard about were due to either using them in situations they were not designed for, or from the use of Loctite that broke down the plastic. I WILL NOT use them in planes larger than 120 size, or in glow helis larger than 30 size, because they weren't designed for that. For my large planes, I am using metal geared servos designed for that application.

I am switching over another four planes (90 & 60 size this time) to DS-821 servos this winter! :)

RE: Spektrum DS821 Sevos Junk or good
 

The servos are good -
the intended application is as noted for setups -really with std length arms and definately not heavy surfaces
The inertia on a hard thmp down will possibly shear them
Why?
depending on the servo - you get white rather soft nylon or filled nylon (all colors) or metal.
Most earlier JR servos used plain nylon gears and the usual failure was the next to or next to next to last gear .
The bright white filled outputs and the black outputs are filled plastic and harder and ---more brittle--- Great servos but adding a 1.5 " arm and a ball joint on top of that is a recipe for disaster -if a shock load is introduced
If you fancy youself as a hard flying 3D type avoid plastic gear trains on any thing over -say 8-10 lbs-- any brands -

RE: Spektrum DS821 Sevos Junk or good
 

I have used them and will continue to do so, but only on certain applications and with a longer screw to hold the servo arm on (one that goes deeper into the output shaft). I have and will use them on sport style aircraft up to 90-120 size, but not on something with a high control surface loading such as 3D. Also I will not use them on any heli. But other then those restrictions I have used them and have had no problems or issues.

RE: Spektrum DS821 Sevos Junk or good
 

I'm sure there good servos for the right application. But i wont risk putting them onmy gasser. have to go with metal gears. But for smaller aircraft i'm sure they will be perfect.:)

And i can see buy the poll that there are more positives then nagatives so that is good. Poll will end tommarrow. Thanks everyone for the input on these servos appriciate it.;)

RE: Spektrum DS821 Sevos Junk or good
 

Ok i broke down And put the DS821 Servos in my Extra 330L on the elevator. these are suppose to be new servos. I have an airtronics RX in the plane that the servos are connected to it is a PCM modulation. radio is on PCM1. Now i'm wondering if i need to get a different RX Due to the flucuation that is noticed. the Radio is on and the RX is on and the servo will Move back and forth flucuate very slightlt and the other one jitters. is normal for digital servos? or are the servos just junk and basically i got Screwed again and purchase some worn out junk.

Not saying that the servos are junk if they are new but these obviously are used or i need to use a different RX.

Video of my frustrating problem

http://www.youtube.com/watch?v=XO9ULwKkvzs

RE: Spektrum DS821 Sevos Junk or good
 

For what it's worth. No not EVER, NO NEVER, under NO CONDITIONS use a Y reverser!

RE: Spektrum DS821 Sevos Junk or good
 

linkadrip

Sounds like they are just looking for center. If this is gas, you would be wise to replace with MG, unless your just flying circles. I say 645's if your on a budget, 5645 if you want digital, or if you have to have jr, try the 126's

RE: Spektrum DS821 Sevos Junk or good
 

Hi hobbyaire,

I am trying to relate your advice to this nearly three year old thread.

I also was looking for any reasons given by the five fellow that voted for those servos to be junk.

Zor

Edited by Zor to correct spelling of the word "hread" to "thread"

RE: Spektrum DS821 Sevos Junk or good
 

Use a 3/8" screw to attach the servo arm to the shaft. The ones they came with are too short to fill the inside of the shaft and some shfts broke of below the screw. A #4 x 3/8" sheet metal screw should do as the threads are the same.

RE: Spektrum DS821 Sevos Junk or good
 

I haven't had any problems with the current crop!

RE: Spektrum DS821 Sevos Junk or good
 

The video on this link is private. I wonder for who.
What is the point of linking a public forum to a video that is private ?

Zor

RE: Spektrum DS821 Sevos Junk or good
 

Considering the post is 5 years old, Zor, what does it matter?

Andy

RE: Spektrum DS821 Sevos Junk or good
 

Andy, do not feed the bears.

RE: Spektrum DS821 Sevos Junk or good
 

There are no Bears in Zorasic Park.

RE: Spektrum DS821 Sevos Junk or good
 

Andy,

The DS821 is still being sold here and I have no reason to believe it is any different.

I am using 8 of them and have had no prolem with them.

Zor

RE: Spektrum DS821 Sevos Junk or good
 

I'm using 4 of them on the ailerons of a Midwest Super Stinker with a Moki 1.35 and no problems.

RE: Spektrum DS821 Sevos Junk or good
 

I've never had any problems with the DS821 servos, despite the regular abuse they get in a 3D spad plane. The tail servos are even exposed to the exhaust glop, and they still work fine.
https://www.youtube.com/watch?v=g0bHsnIMfUI

RE: Spektrum DS821 Sevos Junk or good
 

Then why act like there's some big conspiracy behind a video being private? Maybe he pulled it down because HE realized his problem and resolved it.

Don't try to deflect.

DS821's are great servos. I have a bunch of them myself, no problems.

My answer above was based solely on your normal "there's a conspiracy" attitude.

Sorry for feeding him again, guys :(

Andy

RE: Spektrum DS821 Sevos Junk or good
 

I think I have about 6 or 8 of these servos, no issues at all.

Doug

RE: Spektrum DS821 Sevos Junk or good
 

Andy,

I never suspected any conspiracy.
I was just surprised of a link to a site that said it is private.
I saw that for the first time in a forum.

Now your false accusations really makes me wonder and perhaps some readers also wonder.
It seems to me that private messges or private sites are not linked to a public forum.

Zor.