I’m building a wrist for a large robot arm and would like to get your feedback. I’m wondering what you all think the pro’s and con’s would be of a wrist using two 5990’s for Pan and Tilt versus using two 5745 giant scale servos. The Pan and Tilt mechanism used for the 5990’s would be the one from Servo City (servocity.com/html/spt200_pan___tilt_system.html) that has ball bearing support.
I haven’t weighed the hand, but I’d guess it’s probably 2-3 pounds.
I suppose this debate could come down to what you think is better–the smaller scale higher powered servos or the larger slightly less powerful (but maybe able to keep it going longer) servos.
Thoughts?
I’d go with the 5990, which has more torque and built in overload protection, plus it will actually fit… that pan tilt is designed for standard servos.
I would only use that pan/tilt setup for the 5990’s. I figured I’d either build my own pan/tilt brackets or use the larger servo brackets Lynxmotion sells for the 5645 configuration. I was under the impression the 5645’s had thermal shutdown (according to this site anyway servocity.com/html/hs-5745mg_digital_1_4_scale.html). But maybe it’s wrong? Can anyone confirm or deny?
Thanks for the feedback!
That site is notoriously unreliable for specs… they just copy/paste.
I don’t see any mention of thermal shutdown from my info from Hitec for anything except HSR-xxxx servos. 
coallen you have used both 5645 and 5745 in your post. Not sure which one you really mean.
Sorry for the confusion, I meant 5745. I didn’t see anything in the hitec specs for this servo having thermal shutdown either, but then I also didn’t see anything in the 5990 hitec specs stating thermal shutdown (unless I missed it?). But I know the 5990 has thermal shutdown, so I wasn’t sure about the 5745 (since the servo city site says it does have it). Do you know one way or the other for certain?
Also, any thoughts as to whether the 5990 or the 5745 would be better for the application I have in mind? Would both be equally able to operate at 60-80% of their max torque for equal amounts of time? Or would the bigger one be better at operating heavy loads for sustained periods of time?
I will inquire with Hitec concerning the thermal shutdown. The gear driven devices are fine, but they will slow down the response of the servo. It’s up to you if this speed slowdown is acceptable for your application. I’ve never used them so I can’t tell you which method would be better for you.
