Servo not reaching full travel

[ruijc]

Hi skimask,

i'm using a 16F628A.

With your new code the servo moves all the way up to the new red marks ( as showned in pic # 2 ).

It is still not at it's fisical limit but i think that probably these are the electronic limits of the servo.

.

[skimask]

Hi skimask,
i'm using a 16F628A.
With your new code the servo moves all the way up to the new red marks ( as showned in pic # 2 ).
It is still not at it's fisical limit but i think that probably these are the electronic limits of the servo.
.

Could be the electronic limit thing saving the servo and the gears themselves. Maybe get your hands on an older analog type (i.e. S148) and see what happens.

Also, you said that your center isn't quite right. Could be because you're using the internal oscillator and it's not quite on spec. Datasheet says you could have up to about 5% slop on that (Table 17-5).

[Acetronics2]

Hi,

Just remember this is a DIGITAL Servo, and digital servos have "software" programmed travel limits ...

from the Datasheet ...

<< This digital servo cannot be used with the following * AM *
transmitters as the servo neutral signal is: 1310us).
CONQUEST AM, FG Series (T4FG, T5FGK,T6FG, T6FGK, T7FGK), New Terratop,
T3EGX, T3PGE, T2NL, T2LGX, T2FR, T2PK series.

***** Do not use digital servos with older AM systems *****
>>

Some brands, like hitec, sell the programming box to trim your own parameters ( travel, speed ... etc.)

They also can recognize a valid signal frame ...

so, shortly said, they do not allow you to make "uncontrolled things" ...

Once more reading the servo DATASHEET could have helped !!! ...

Alain

[ruijc]

Acetronics,

true about that...

BUT

If it wasnt for skimask i woudnt be able to get that extra travel


PS. - do you have the link for the s3152 datasheet ?
.

[mister_e]

http://www.gpdealera.com/cgi-bin/wga...pgm?I=FUTM0311

[ruijc]

Thanks mister_e,

" the neutral is at 1310ms " ... weird

.

[Acetronics2]

Thanks mister_e,

" the neutral is at 1310ms " ... weird

.

Nooooooooooooo,

Those OLD systems HAD a 1310 µs neutral ... from Robbe ( German brand ); Lextronic ( French brand ) and Multiplex had a 1.65 ms neutral, KRAFT ( US ) had a 1.70 or 1.80 ms neutral ...

Now, it's 1500µs for Everyone !!!

Alain

[Acetronics2]

Hi, Ruijc

Having tortured ( also build and modified ...) dozens of servos ...

I can tell you EVEN Analog ones do not meet your requirements , as the linear response of futaba analog servos is only about 1/2 of the physical range ...

for the full mechanical travel of a S3001, I've measured the pulse width from 200 µs ( full left ) to 2500µs ( full right ) with an awful ( LOL ) non-linearity between 200 and 800 µs ...

Now ... Digital. " a 1.3 ms neutral won't work... " ... as classical travel is +/- 0.5 ms
that means roughly only .9 to 2.1ms range will be accepted by the digital "amplifier" ... or will give a proportionnal output.


STOP DREAMING this servo will NEVER REACH ITS PHYSICAL LIMITS !!! otherwise, that would mean you can burn the output stage of the amp ...


Skimask's lines permit you to measure the input range of your servo ... cause exploring from 100 to 2900 µS.
You're then sure you've seen ALL the travel your servo gan give ... no need to try to get more, unless modifying the servo amp factory settings !!!

Alain