Need Specific Help Regarding Mathematics and Motor Choice of Arm

[MAXOFLIFE]

Originally Posted by EricH

I'll answer on the 8 boxes. For each gear pair in the gear train, the driving gear is the one that is GIVING the power to the next one. Each driven gear is receiving the power. If you have 3 gears, all in line, 1, 2, and 3, gear #1 is driving only, gear #2 is driving (#3) and driven (by #1), and gear #3 is driven only. If you are only using 1-2 reductions, set anything that's left to 1:1 ratio.

So, let's see if I read your setup properly: Two 10:1 reductions followed by a 4.67:1 reduction (the 18:84 change), with two mini-CIMs going into it. Then a 2.5'-3' arm, lifting 10 lb... I think that will work, maybe a tad overpowered but more is better than less in this case.

Originally Posted by Knufire

There's 8 red boxes (4 pairs) so you can do up to a 4 stage gearbox in the calculator. More often than not you'll only have a 2 or 3 stage gearbox, so you can leave the last set at 1:1.

Looking at the calculator, it seems like you plan on putting the miniCIM in a Versaplanetary with two 10:1 stages, and then an 18T gear on the output of the Versaplanetary driving an 84T gear connected to the arm. If this is the case, you have filled the calculator out correctly for this scenario.

If the scenario I said above was indeed correct, I'd caution you to maybe switch to a less powerful motor. The miniCIM is overkill for this application, which isn't in itself bad, but it also exceeds the load rating for a 100:1 Versaplanetary. You can find the load rating guide here: http://content.vexrobotics.com/vexpr...s-20151221.pdf

Thank you! If we continued with this design, would switching to 1 miniCIM be more efficient? Also, how does the belt system in our design play into the math for calculations?