DS 8411 Question.....
 

Has anybody ever had a JR DS8411 just completely freeze (lock up). It is under no power, just me trying to freely spin the gear train.......Crazy, i have never seen this. It allowed me to move the servo only one direction until it hit it's limit and now it is completely locked out (will not move at all.....Thanks in advance...

RE: DS 8411 Question.....
 

What happens when you plug it in and power it up?

RE: DS 8411 Question.....
 

Didnt want to do it on my good battery/receiver setup so this weekend i was going to put it on a spare receiver/batt setup and see. I just cant imagine it will be good if i am unable to move it by hand. I have owned many 8411's before and all other models of their high power servos and have never seen this.

I do however, recall back in the day that the 8411 was under a lot of heat for bad gear train slop, but that was only after much use.........

RE: DS 8411 Question.....
 

Would need to know if this is a completely new servo or whether it has been used for a while. Was it involved in a crash or subjected to any shocks. I have one of these servos and I am able to move the the servo with the arm attached freely, although I try to resist the temptation of doing so. I mostly test it when its plugged in.

RE: DS 8411 Question.....
 

I would pull the top off and inspect the gear train before I plugged it in. If there are teeth missing on one of the gears or there is trash in the gears that are blocking rotation, powering it up and having it try and center is not going to do it any good...

Bob

RE: DS 8411 Question.....
 

Hey Bob, that is what i am thinking has happened. The servo is used, and as far as i know it has never been shocked......We shall see.. I am going to inspect under the cover tonight..

RE: DS 8411 Question.....
 

I presume the movement was free before it locked? Coreless motor servos can have the motor go bad and tighten before locking completely. The servo is very tight to turn, like driving a dynamo.

Dw

RE: DS 8411 Question.....
 

Nick,
I had an 8611A work completely fine one sunday, then 2 weeks later after being stored in the trailer it would lock up and or make a horrible grinding noise. Come to find out, one tooth of the only plastic gear in the gear train has broken free and would jam between two metal gears on occassion.

RE: DS 8411 Question.....
 

All gears looked good......nothing i could see. Then powered it up and it is still locked....strange. Off to HH it goes..

RE: DS 8411 Question.....
 

Nick,
After you determine the cause of the servo malfunction I would return it to Horizon for service or replacement.
My jet partner recently sent in all the DS 8411s off his CAFEurosport to Horizon and they repaired them at No Charge. I had a similar experience withsome high end JR servosfrom a couple of used jets that were purchased a while ago. Just include a nice, couteous letter to Horizon's customer service department and they should repair and/or replace the servos at No Charge.

Art ARRO

RE: DS 8411 Question.....
 

Thanks Art, yeah i have sent stuff in to HH before and have had nothing but good service. The servo will head off next Monday......

RE: DS 8411 Question.....
 

I had one of those... in the first Viperjet U-boat! [&o]

RE: DS 8411 Question.....
 

Ha Nick hope you and the family are doing well. I had one lock up because I was useing A123's with out regulators. It was a old servo. Dan

RE: DS 8411 Question.....
 

Even a bent tooth will lock up a gear train. The nearer the bent tooth is to the motor the easier it is to be locked up.

RE: DS 8411 Question.....
 

Make sure the pockets the gear pins sit into are not damaged. The gears could move to one side under load and lock when going the other way.

RE: DS 8411 Question.....
 

Just wanted to say that I got the servo back today and want to send a huge THANKS to Horizon Hobby and staff! They found a "top case pivot point" worn and swapped it out for no charge!! That is customer service right there, and that is why I have stayed JR all these years..

RE: DS 8411 Question.....
 

I have seen this happen before on servos, always wondered why the better more expensive servos have not addressed this area better. A simple hole in the plastic case is all that keeps the pin in place and once it wears like above your gear train locks up.

You have 15-25kg high power servos relying on a pin going into a plastic hole, servos of this power should be using alum cases.