True moving speed of AX-12
True moving speed of AX-12
by planius
Mon Aug 29, 2011 1:56 am
Hi,
the AX-12 manual states 2 what seem to me contradicting claims regarding the AX-12 moving speed:
1. In the technical data the speed is given as 0.2s/60deg @ 9.6V, which equates to 50rpm
2. Under the moving speed entry in the control table the maximum value of 1023 (0x3FF) is stated as equating to 114rpm
I am more inclined to trust the technical data, but what does that mean for altering the moving speed? Has anyone done any measurements when altering the moving speed in the control table?
Thanks
Peter
the AX-12 manual states 2 what seem to me contradicting claims regarding the AX-12 moving speed:
1. In the technical data the speed is given as 0.2s/60deg @ 9.6V, which equates to 50rpm
2. Under the moving speed entry in the control table the maximum value of 1023 (0x3FF) is stated as equating to 114rpm
I am more inclined to trust the technical data, but what does that mean for altering the moving speed? Has anyone done any measurements when altering the moving speed in the control table?
Thanks
Peter
by PedroR
Mon Aug 29, 2011 5:49 pm
Hi Planius
You are likelly looking at specs at different voltages.
Because of the way servos are built (using a DC motor and the surrounding circuitry), you may find that if you apply 12V you'll get a faster movement compared to applying only 9.6V.
I believe 9.6V is the "default" voltage for the Comprehensive considering its battery pack.
The PREMIUM Kit for example uses a 3 cell LiPo, offering a little over 12V when fully charged.
There is no official data regarding AX-12 specs at different voltages. however it is common that, by increasing the voltage on this type of servos, you encounter an increase in speed and torque. (just make sure you stay within the values that can be supported by both the DC motor and the gearset to prevent any damage).
Regards
Pedro
You are likelly looking at specs at different voltages.
Because of the way servos are built (using a DC motor and the surrounding circuitry), you may find that if you apply 12V you'll get a faster movement compared to applying only 9.6V.
I believe 9.6V is the "default" voltage for the Comprehensive considering its battery pack.
The PREMIUM Kit for example uses a 3 cell LiPo, offering a little over 12V when fully charged.
There is no official data regarding AX-12 specs at different voltages. however it is common that, by increasing the voltage on this type of servos, you encounter an increase in speed and torque. (just make sure you stay within the values that can be supported by both the DC motor and the gearset to prevent any damage).
Regards
Pedro
by Fritzoid
Mon Aug 29, 2011 6:49 pm
Planius,
The AX-12 manual says that the no load moving speed is 59 rpm at 12V. That's the number I use. It's similar to your quote of 50 rpm at 9.6V.
Just ignore the 114 number you see in the description for the speed value in the control table. All the manuals (AX, DX EX and RX) use the same number, 114rpm, for this description. They can't all be the right. I think Robotis is just being lazy here!
The AX-12 manual says that the no load moving speed is 59 rpm at 12V. That's the number I use. It's similar to your quote of 50 rpm at 9.6V.
Just ignore the 114 number you see in the description for the speed value in the control table. All the manuals (AX, DX EX and RX) use the same number, 114rpm, for this description. They can't all be the right. I think Robotis is just being lazy here!
by planius
Sat Sep 03, 2011 1:56 am
Finally got a reply from Robotis as well:
Thank you for your patience with us, Planius.
#1 is correct. As for #2, it is noted max 114RPM to explain the units (0~1023) for all our DXLs.
Thus, if it is noted 300, it works under 33.3RPM, but even if it exceeds the max RPM for the AX12,
there will be no change in speed.
If you refer to the manual. it states as below :
Notes: Please check the maximum rpm of relevant model in Joint Mode. Even if the motor is set to more than maximum rpm, it cannot generate the torque more than the maximum rpm.
http://support.robotis.com/en/product/d ... Address_20
Thank you for your patience with us, Planius.
#1 is correct. As for #2, it is noted max 114RPM to explain the units (0~1023) for all our DXLs.
Thus, if it is noted 300, it works under 33.3RPM, but even if it exceeds the max RPM for the AX12,
there will be no change in speed.
If you refer to the manual. it states as below :
Notes: Please check the maximum rpm of relevant model in Joint Mode. Even if the motor is set to more than maximum rpm, it cannot generate the torque more than the maximum rpm.
http://support.robotis.com/en/product/d ... Address_20