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danhoskin
02-24-2010, 02:59 PM
Hi,

I built a robot arm that has Hitec HS645MG servos on all three joints. The problem I am having is that I need a bit less play in the arms shoulder joint. The servo holds position well enough, but the gear lash allows for quite a bit of movement at the end of the arm. I am going to remake the arm using the 'Giant' scale servos, but does anyone here have any tips on how to reduce effective gear lash from and RC servo? My concern is that even with the larger scale servo I may still see an unacceptable amount of motion.

Thanks,
Dan Hoskin

DresnerRobotics
02-24-2010, 03:02 PM
It's going to be something you compete with even with higher end robotics actuators. Mechanically you could design a system using leverage so that the servo output shafts are not directly moving the arm axis....but that can convolute your arm design very quickly.

Clever thing I have seen implemented is the use of two servos in conjunction on a single joint, with them offset so that they fight against each other slightly to maintain position.

danhoskin
03-01-2010, 11:23 AM
That actually worked great, I'll post some pics once it is all assembled and running.
Thanks,
Dan Hoskin