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Unread 16-02-2014, 09:46
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Paul Copioli Paul Copioli is offline
President, VEX Robotics, Inc.
FRC #3310 (Black Hawk Robotics)
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Re: Weird Behavior - Vex Pro Ball Shifters

Quote:
Originally Posted by DampRobot View Post
There's probably enough separation forces in the shifter that you need that extra pressure from the piston to keep it locked in gear.
In normal use, this is just not true. The ball shifter is set up such that when the shifter is in each position the balls are sitting on the flat area of the plunger. This means there is no separation force at all.

As some of the people using this as a pull back device, the normal force between the flat area of the plunger and the balls and the side of the ball pocket in the gear at high (externally applied) torque conditions, the plunger does not want to disengage.

The critical dimension on the layout drawing on the vexpro.com web site must be met if you are using your own gearbox.

Also, I have found that the SMC solenoids are not that happy at anything under 40 psi.
Paul
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In full disclosure I am the President of VEX Robotics, a division of Innovation First International.
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