servo modification
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Hi,
In the different web pages I visited, servo modification includes replacing a
potentiometer by fixed resitors.
In the Robotics curriculum from Parallax, there don't tell to do it, and it's
obviously working very well.
What is the reason for this modification? Why is it working without doing it?
Thanks,
Nicolas
In the different web pages I visited, servo modification includes replacing a
potentiometer by fixed resitors.
In the Robotics curriculum from Parallax, there don't tell to do it, and it's
obviously working very well.
What is the reason for this modification? Why is it working without doing it?
Thanks,
Nicolas
Comments
well) you can leave the pot in and just pop the top of the servo to tweak
the pot by hand. One page suggests drilling a hole in the gear and slotting
the pot so you can insert a small screwdriver and turn the pot without
disassembly.
The advantage to this is that two identical servos modified with the same
fixed resistors may have different PULSOUT values for the neutral (stopped)
position. Leaving the pots intact lets you tweak them to match, which makes
the code easier.
The tricky part, if you chose to do it, is turning one motor around so it
runs backwards. This makes it easier to code stuff for a robot with servos
for driving the wheels because a value greater than the neutral value makes
either servo run forward, and a one smaller makes them run backwards.
Original Message
> In the different web pages I visited, servo modification includes
replacing a potentiometer by fixed resitors.
> In the Robotics curriculum from Parallax, there don't tell to do it, and
it's obviously working very well.
> What is the reason for this modification? Why is it working without doing
it?
>Hi,
>
>In the different web pages I visited, servo modification includes
>replacing a potentiometer by fixed resitors.
>In the Robotics curriculum from Parallax, there don't tell to do it, and
>it's obviously working very well.
>What is the reason for this modification? Why is it working without doing it?
>
>Thanks,
>
>Nicolas
This modification usually implies that you are going to make your servo work
in a continuous rotation mode. Note: Not all servo's can be easily converted.
With respect to the fixed resistors, I have found it much better to use a
small (1/4") pot turned so that the center position on the Transmitter's
stick corresponds to the modified servo in a "resting" state. Once the pot
is set, I leave it alone. The reason for this is that the fixed resistor
references usually tell you to use 2 resistors of equal value which would
theoretically point to a center or "resting" servo position, but I have found
this is not always true for some servo's. So much so that you could not
compensate with the Transmitters "trim" adjustments by their methodologies.
Beau Schwabe IC Mask Designer
National Semiconductor Wired Communications Division
500 Pinnacle Court, Suite 525 Mail Stop GA1 Norcross, GA 30071