What is the difference between the “intake mechanism” tab and the “linear mechanism” tab. I get the same travel times but the current draw is a LOT LOWER on the linear tab.
I am trying to use it for our winch.
To calculate a winch, you would use the Linear Mechanism tab. The Intake Mechanism tab is for calculating intakes used to pick up spherical objects from the floor.
THANKS It will go a lot faster now
I don’t completely understand. Why would the intake calcs show a much higher amp draw?
Drag load =/ Applied load
ok no big math guy here I read your post as Drag load equals divided by Applied load. You really lost me there.
Linear mechanism tab is the way to go. Note that you have to account for any increase in pulley diameter (due to rope wrapping increasing the effective diameter of the pulley) manually when setting up the calculations.
You can also use the rotary mechanism tab but then you have to calculate the number of rotations required to climb.
Drag load is not the same as applied load, that is why your seeing an amperage difference.
I think Eric meant the not-equal-to symbol, =/= he just forgot that second =.
ok please explain the difference
Yes. The linear and rotary tabs produce the same current draw. The intake tab shows a much higher current draw. I guess that is what I am having a difficult time digesting. Can someone explain this to me please? Examples of each would be nice. Thanks
The intake tab is for calculations for a conveyor sliding/rolling a game piece and the linear motion tab is for a winch moving a linear mechanism.
The linear tab uses load applied directly to the winch and the intake tab uses drag load of the game piece. It doubles the drag load number for the calculations. Maybe to account for the fact that a rolling game piece is moving half as fast as the conveyor? Maybe for safety factor? I’m not exactly sure.
OK I get what you are saying but it DOUBLES the current draw and I would think a rolling game piece would reduce the current draw.
It could be assuming you’re attempting to lift the object rather than just draw it in (IE, an intake that feeds up into a hopper or something). Perhaps in addition to loosing 50% of the speed of the roller, you also loose 50% of the torque?
I suspect sticking a 150lb ball into an intake roller is going to present some different results than using that same roller to winch up a 150lb robot, whatever the case may be.
If you want the correct answer to the question of what that tab assumes, I suspect you might have better luck PMing JVN.
A rolling game piece would have the same current draw for a given drag load (assuming “drag load” equals the load on the entire intake system, not just “one side”), but half the speed.
For a winch use the linear tab. It is designed specifically for that use case.
Digging into the formula, I forgot to divide by 2 in the intake version. I’m applying the load torque using the diameter instead of the radius of the pulley as the lever arm. I will upload a new version to fix this glitch.
Sorry for the confusion!
-John
Thanks John