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Mechanics and Construction => Mechanics and Construction => Topic started by: Rebelgium on March 18, 2008, 01:29:40 PM

Title: hitec servo maximum angle
Post by: Rebelgium on March 18, 2008, 01:29:40 PM
What is the maximum angle the Hitec HS422 and 322 ? And why is it so damn hard to find this info? :-\
For futuba servo's it's just in the datasheets, but for Hitec it's not that clear... It sais "45 /ONE SIDE PULSE TRAVELING 400usec"

here's a link to a Hitec datasheet:
http://www.robotwinkel.nl/pdf/Manuals/Servo_Drivers/hs422.pdf

Title: Re: hitec servo maximum angle
Post by: airman00 on March 18, 2008, 02:05:35 PM
Luckily for you I have both of those servos. They go 90 degrees per direction
Title: Re: hitec servo maximum angle
Post by: Rebelgium on March 18, 2008, 02:08:52 PM
Quote
90 degrees per direction
so that's 180 total?
Title: Re: hitec servo maximum angle
Post by: pomprocker on March 18, 2008, 04:59:26 PM
I looked it up for you:

http://www.servocity.com/html/hs-422_super_sport_.html (http://www.servocity.com/html/hs-422_super_sport_.html)
(http://www.servocity.com/assets/images/90_Servo_Angle_Schematic.jpg)


http://www.servocity.com/html/hs-322hd_standard_deluxe.html (http://www.servocity.com/html/hs-322hd_standard_deluxe.html)
(http://www.servocity.com/assets/images/90_Servo_Angle_Schematic.jpg)

Title: Re: hitec servo maximum angle
Post by: airman00 on March 18, 2008, 05:05:01 PM
I looked it up for you:

http://www.servocity.com/html/hs-422_super_sport_.html (http://www.servocity.com/html/hs-422_super_sport_.html)
(http://www.servocity.com/assets/images/90_Servo_Angle_Schematic.jpg)


http://www.servocity.com/html/hs-322hd_standard_deluxe.html (http://www.servocity.com/html/hs-322hd_standard_deluxe.html)
(http://www.servocity.com/assets/images/90_Servo_Angle_Schematic.jpg)



thats what it says on the website , but in actuality it is not 45 degrees but 90 degrees per way

180 total, yes
Title: Re: hitec servo maximum angle
Post by: pomprocker on March 18, 2008, 05:31:18 PM
for which servo? we should do them a service and contact them in their error.
Title: Re: hitec servo maximum angle
Post by: paulstreats on March 18, 2008, 05:57:04 PM
They already know. Its down to the precision of the pot on the board. It has a decent enough precision through the 45 degree angles to pretty much guarantee your precision, but using them at 90 degree angles cant guarantee their precision. I noticed this with pots, they seem to have a sweet spot area where they return an exact value, but too far near the high or low end and the output jumps between 2 or 3 values
Title: Re: hitec servo maximum angle
Post by: benji on March 19, 2008, 09:18:24 AM
do you mean that making the servos turn to more than +45 -45 makes unprecies motions?
i did expirement with this servo and here is what i precisely got

-90 == 0.69 ms
0  ==  1.515 ms
+90 == 2.385 ms

and as you can see it doesnt make a perfectly  straight line equation, i dunno whats wrong
Title: Re: hitec servo maximum angle
Post by: Admin on March 23, 2008, 03:40:36 PM
http://www.societyofrobots.com/robotforum/index.php?topic=2379.0
Title: Re: hitec servo maximum angle
Post by: benji on March 24, 2008, 12:23:02 PM
you just need to expirement with your own servos,,
here is what you have to do
give known pwms and write down the angles you get,then try to find the function of angle=function(pwm);
if you really wanna get precise you wont get a straight line equation