Don't bother trying to fix DS620 slop!

[Snaaakeey]

Thought I'd post about this topic as I havent seen anything perticular bout it and I would like to give other members the heads up before they spend £50 for nothing.

I have had 300 odd flight on my Align DS620 servos and the slop is now quite bad. I can grab the swash plate with the servos set to hold 0 pitch and move it about 2mm up and down! Not unexpected from Align servos after this length of service! So as part of a general service I went on the hunt for all components with slop so No1 on my list was new servos or new gear sets! It seemed a waste to chuck the 3 ds620s as 300 flight isnt really alot and except for the slop they work perfectly. Well I swapped them all out and it made no difference at all to the play! The motor output shaft as a small gear on it which is not included in the gear set kits and I think this may be where the play comes from or its inside the motor itself.

The long of the short of it is dont bother! just buy 3 new servos ( Great for Align who probably designed it this way so they can get a higher turn over)

So I'm £50 down but you dont have to be!

Does anyone know if they are all like this or are some makes truly serviceable?

Cheers

[SaneAdam]

Outrage Torq have zero slop. You could jump up and down on the servo arms and they wouldn't move an inch!!!

[Snaaakeey]

Outrage Torq have zero slop. You could jump up and down on the servo arms and they wouldn't move an inch!!!

Is this after long service or new?

My MKS bls980/990 servos are the same as your torqs but they have 50 flights.

[SaneAdam]

Mine are relatively new. But use should not effect the holding power?! Aslong as they have not been crashed

Im a bit confused... maybe i got the wrong end of the stick. Your asking about better servo's than the 620's, yet you have a set of MKS?! So you know that better servo's perform better?

The Aligns have that slop right from the off, it is not something that develops... not I'm my experience anyway

[LaurenceGough]

Can't you just fly 'em anyway? Replacing servos just for a little bit of slop seems very extreme. People say the Futaba BLS are slop free, well just as like most servos they have low slop to start with but they quickly all get sloppy, mine are but it still flys great.

[Snaaakeey]

I have always been told you should keep slop to a minimum ( This is a fb head) My MKS servos are on a fbl head. The DS620 were fine for about 20 flights then they started to get a bit baggy. Im probably not good enough to tell if servo slop effects flight performance. The Heli in question still hands well but I do notice quite large altitude changes and bobbing in high wind (more than transitional lift from wind)) I presume from the play in the blades pitch as it can jiggle abit 1 or 2 degs. When the head is loaded up in a manover it seems fine but the transition from upright to inverted in a piroflip and back again to upright seems to be getting vey choppy and hard to hold in one place. I presume fbl helis mask most interactions but they suggest in their manuals minimal play as well.

[scallybert]

Can't you just fly 'em anyway?

That's kind of the $1M dollar question, isn't it ? ie How much difference will it make ?

[...]but they quickly all get sloppy, mine are but it still flys great.

So I guess the answer is 'less than we might think'...

One thing that bothers me about sloppy servos is that it affects the accuracy of set-up; or you take a mid-point, or take the lash out in one direction. It seems a shame when (some) FBL heads are pretty much slop free.

Another is that if the servo is sloppy enough, the motor might end up hunting like crazy. (The feedback pot is on the output shaft, so a small movement on that might mean the motor has to take up all the lash in one direction; then do the same in the other direction and so on.)

The amount of slop in unused Align servos [DS410M/DS415M] seems to vary a lot. Maybe the tolerances of the gears isn't good.

[dani_r]

Are you using DS620s on your swash all round??

[Snaaakeey]

Are you using DS620s on your swash all round??

Yep. My 6hv as done nearly 2 year on them. Not a problem is it? ds620s are designed for 600 sized helis.

[Snaaakeey]

That's kind of the $1M dollar question, isn't it ? ie How much difference will it make ?


So I guess the answer is 'less than we might think'...

One thing that bothers me about sloppy servos is that it affects the accuracy of set-up; or you take a mid-point, or take the lash out in one direction. It seems a shame when (some) FBL heads are pretty much slop free.

Another is that if the servo is sloppy enough, the motor might end up hunting like crazy. (The feedback pot is on the output shaft, so a small movement on that might mean the motor has to take up all the lash in one direction; then do the same in the other direction and so on.)

The amount of slop in unused Align servos [DS410M/DS415M] seems to vary a lot. Maybe the tolerances of the gears isn't good.

Interesting stuff!

I think F3C guys would find the slop unacceptable. 3d probably not so much.

[dani_r]

Yep. My 6hv as done nearly 2 year on them. Not a problem is it? ds620s are designed for 600 sized helis.

I'm sure it's fine. The 620 is a tail servo normally, with the 610 for the swash. I have heard of folks using the tail servos on the swash before though

[SaneAdam]

I thought the 620 was a tail servo also?!

[dani_r]

I thought the 620 was a tail servo also?!

The 620 is traditionally a tail servo

[Snaaakeey]

I thought the 620 was a tail servo also?!

Ds650 is the tail servo. The 620 and the 610 are similar. 620 is slightly faster with less torque and the 610 is the other way around. different tooth count on the gear sets i guess. (Im off to double check. That would be embarrassing if I have been flyin tail sersos on cyclic!)

[SaneAdam]

To be fair i just read some blurb that said they could be used on swash or tail