Hi,
I am building a system that includes a part where the servo (LSS ST1) needs to go limp when told to.
That part lifts up another part, and then lets it go free to fall, by going limp.
I have starter to learn how to control the servo and the ‘limp’ command (#0L) does nothing. The wheel does not rotate freely.
All other commands I have tried do work.
Do I not understand correctly what ‘limp’ is in this context ?
Or is there a requirement before I do that ?
Thanks for any information
Hi,
Dpi again, answering its own question.
Limp it is indeed, but due to the gearbox, you need lever to move the shaft !
Not what I wanted, but it makes sense (no mechanical action to free the wheel from the gearbox)
Forgive the beginner
Dpi
@dpi Welcome to the RobotShop Community. You understand correctly, and assuming the other commands work, you have the ID and command structure correct (you include a carriage return after?). After you send the command, can you do a Q command to check the servo’s status?
Note that even in limp mode, the motor is still connected to the internal gears which create some resistance to motion and counter-torque. In limp mode, the motor is simply not powered and won’t try to resist.
Hi,
As part of my system (it is not a ‘robot’), I needed to rotate a horizontal tube, with some weight attached to it, until that weight is on top of the tube, and then ‘release it’ so the tube is free to rotate due to the weight, until it is down.
I understood that ‘limp’ did not allow that (due to the resistance from the gear, as you say).
So I did it another way: I placed a ‘hook’ on the tube that is attached, with a string, to another rotating tube (attached to the servo).
I ‘lift’ by rotating that second tube, wrapping the string around as it goes, pulling on the hook.
To let go, I rotate the other way at full speed, leaving the string loose and, therefore, the other tube too.
It works well enough (the servo is slower than gravity, so I had to thicken the tube to increase the diameter and the speed).
If you need a faster servo (though less torque), the HS1 can rotate at up to 100rpm, whereas the ST1 is limited to around 60rpm.
The only difference between the two is the gear ratio.
