Hmmm... Lots of views with no replies.
Maybe I need to be more direct:
When selecting stepper motors and pulley ratios to drive a heavy BP type knee at 20-30ipm...
1) Is the statement; "It is optimal to use a constant wattage/variable voltage power source as opposed to a fixed voltage power source", borne out from a real-world perspective?
2) Does 25% make sense as a reasonable estimate for knee mechanism power transmission efficiency? (See original post) Should I be according more to friction forces in the ways?
3) I have calculated the time it should take from rest to achieve maximum speeds of 20ips and 30ips given the table weight and estimated forces applied to it from 3 different approaches (using inertia&momentum, using a free body diagram with F=ma, and using Newton's motion equations).
I keep getting the same answers of around less than 1/10th of a second!?
I'm not entirely sure that makes any kind of intuitive sense?
I would be much obliged if one of you mechanical engineers could check my calculations.
Thanks for any and all help!