[Rob]

Hi,

That sounds like a pretty heavy arm...depending on the length you are going to have to do ALOT of reduction to get the FP motor into acceptable range. I hope that you have 2 FP motors available to use.

The AM planetary is probably a good start, I have never used it but I think it is supposed to reduce the FP to about the same free RPM as a small CIM (approx 5500 RPM).

One area you might consider is already attached to the motor: the plastic FP gearbox. Consider these possible advantages: They are free, very light and reasonably simple to interface with and mount. Another "advantage" that many dont consider when doing an arm application is that they are pretty inefficient...What you say, how is that an advantage? They are hard to backdrive. If you have 2 of them on your arm the amount of force required to backdrive might be more than the torque on your arm joint from the weight of your arm. This is a huge advantage because your arm can then hold position without applying power to the motors and sparing you from smelling a stalled FP burning up. If you gear your arm right they will always be at high RPM when moving and not need any power to hold position (although with a 30-40 pound arm that may not be the case).

Just something you may want to consider. Best of luck!

RAZ