This might be a dumb question, but I have to ask …
The gripper on the Lynx6 uses a very small servo. When I go to pick something up, is it OK to drive the servo to the fully closed position or should I try to figure out a position that is just closed enough to pick up the object? In other words, once the servo stalls does it really matter what position it is trying to reach? I don’t want to burn it out.
Clearly if it does not matter then I only need to use fully open and fully closed servo angles (which are NOT +/-90 – I think they are closer to +/- 35 for the Lynx6).
The servo on the gripper is a micro servo, with correspondingly “micro” gears inside. With most of the micro servos I have encountered, it is entirely possible to strip the gearing with its own power if you try to drive it against an unyielding object.
In other words: don’t try to drive it beyond the physical limit of what your object will allow, or you will potentially be buying a lot of replacement gearsets in the future.
If you don’t want to worry about how hard you grasp an object, first get the arm working, and then work on adding some sort of pressure-sensitive grip to it, so that your controller will know when it’s grabbing something firmly enough to pick it up, but not firmly enough to strip out the geartrain.
I like to relate hobby robot arms to real peoples arms. You wouldn’t want to grip an object while squeezing as hard as you could, right? Of course not. You’re hand would get tired and you could strain your muscles. Servos are the same, they can overheat or break a gear if commanded to hold on too tightly.
The RIOS program has the ability to close the gripper servo while monitoring a digital or analog input. If you modify the gripper to include a switch or analog pressure sensor RIOS will automatially stop the gripper when the switch closes, or the sensor reaches a preset threshold. Hope this helps! Jim
You’re hand would get tired and you could strain your muscles. Servos are the same, they can overheat or break a gear if commanded to hold on too tightly.