Tahmazo servos jittering?

[Cycross]

Hi all,

I just got 2 ts49s and found them to behave jittery around the centre. I keep hearing the motor often wind for about a sec more or so, after some movement of the sticks and centering.

I tested them under no load conditions and with other servos and rxs. Still they are the only one which makes the 'center hunting' motor noise.

Does anyone here have similar experiences with the tahmazo servos and shed some light on this?

Thank you for your replies.

on the other hand, the blue arrow servos were smooth and precise IMHO. Thanks Mack!

[PhiBeR]

Hi Cycross,

did a little search for you..
http://www.daddyhobby.com/forum/show...hlight=tahmazo

Someone has got same problem with theses exact same servo too!
Suggest u read up the thread and go ask Johnny to fix it if anything wrong!

Cheers!

[Cycross]

Thanks

Ahh... Thanks PhiBeR!

Seems like from the thread's final post, MicroHeli-Nut found at the end it's not the servos that caused it. But he didn't say the real reason though.

Probably really got to go exchange them liao.

[MicroHeli-Nut]

Heh.... well, the only reason johnny gave was that that's because they were seeking centres... The odd part is when the servos are under loading, all jittering goes away

[Cycross]

MicroHeli-Nut, I just sent you a pm to ask about it. haha...

Thanks guys for your help and assistance!

It's kinda strange though. I mean, if no load it can't center properly, under load how would it even hold center better?

I did feel that they consume quite some power for operation comparatively. It drained my rx batt dead after some time. when I placed back other servos, there was still enough to drive them slower. Put back the tahmazo and no movement. I wonder if it's because of the higher torque motor.

[MicroHeli-Nut]

No Cycross, that's the problem. When i first bought the servos..... It didn't occur to me that they drained a lot of juice. But trust me, they are just about as strong as the bigger micro servos..... But when u think about it, it only makes sense that they'll drain more juice, --> smaller and more torque....... The jitter is probably also due to higher torque with less resolution.. check the speed..... not very high rite?

For da price, TS-49 is only for serious weight saving hardcore xiao xiao pple like Uncle Loyn aka Walking Workshop. The TS-54s give much more resolution ( much smoother)at about the same amount of torque ... at $10 cheaper! Plus.. when u do the weighing, the weight diff bet TS-49 and TS-54 not that big because of the wires.... That said , tahmazos is brought in from Korea by a local company. So quality control should be not bad....

I've only had my TS-54 slip on me in a freak accident which i still have yet to find the reason to....

My verdict is this.... If u need super resolution and smoothness, go for Futabas.... however, realise that they are a tad slower than servos like Hitecs, SG-50......

Correct me if I'm wrong. I've no admin rights, so i cant boot u outta this board if i buay song! hahahahahah

[Cycross]

In fact I think you are right on...higher torque with less resolution

Anyway, if not for the specific need for the slim profile cum higher torque, I would have gone for other servos already.

and yup. they are not fast.

Also, it seems that they have two different packing for the ts49s. Mine was showing only 1.1kg/cm 4.8V instead of 1.2kg/cm on the pack. I called up and they say it's the same. Email tahmazo to ask and no reply also. Duh.

[Cycross]

Final update on this:
Managed to exchange the servos at SHS after demoing the inability to center properly to them. New servos working fine.
Thanks all!

[MicroHeli-Nut]

Found a mod to clean up this jittering problem... I cleaned the potentiometer and the jitter's are mostly gone! Smoother also.....

[MicroHeli-Nut]

Hey Presto.

Well,
I might have posted this on this thread to death liao, but i feel I should be a bit more responsible when it comes to these products. I feel that i might have misinformed a lot of people with regards to this matter.

Some of you might have saw that i was fuming when my ts-49s apparently were going off trim in mid-flight and when i powered up on a certain funfly last year.. as a result i'm currently on HS-55s.... yar.. they work beautifully without the centering problems the older models used to have.

Well, because of the interest in building the SPAD Coros and lightening my H2 to reach 330grams.,... I ripped them apart again... Here's what i found:

1) I had not removed cleaning fluid/ degreaser after i just mindlessly poured them on the TS-49s... this led to the servos going off trim on that funfly.....

2) The gear lash on the gear train is not optimal for the first gear from the motor.... I applied walt's HS-50 gear-lash mod to fix up all of the Ts-49s.... Presto.... all the nonsense off centre issues were gone.... the problem was due to the motor slipping on the first drive gear which caused the potentiometer to keep searching for the center.....

Okay... as of now.. still more testing... but i find with walt's mod they are working smoother.... I still have not got the "servo arm locked in max endpoints" position problems that i've experience whenever shifting the cyclic stick up and down furiously for 100 times.......

Are servos suppose to heat up when u work them very fast with no load?

[MicroHeli-Nut]

Also,
if the servos are drawing a lot of current and the motors are heating up real fast will it help to use thicker gauge servo wires or do i have to increase wire motor size...?

[Cycross]

Hi,
I concur with you that your advice 2) works for me too. I unwittingly did it when one of my exchanged servos act up on me again....so I opened it up blah blah blah....

now it works like a charm.

I do not have a heating problem so far. (not much usage to tell)

[MicroHeli-Nut]

Ah.. baptism by fire.... finally another believer.....

[PhiBeR]

Seriously, given the many jittering problems reported with tis servo, even at rcflying..

And that the hs-55s are only $26 per pop now.
Doesn't it make sense to ditch the tahmazos and go for the hs-55s?

Just my 50cents..

[MicroHeli-Nut]

I have both......

But for the size and weight difference i get it's definitely worth it compared to the HS-55.... if it's the HS-50 also need to do mod...... but the 49s pack more punch....

I'm not saying they are better.... I have been adviced against putting them back in by HZM... but i decided to give it a shot.... 3g lighter for each servo... i save 9g....