Drivetrain Question

[AlexH]

simplest and safest way to prevent unwanted actuation of the ram is to physically lock the ram in the extended or retracted position with a pin or something

[JamesCH95]

Originally Posted by AlexH

simplest and safest way to prevent unwanted actuation of the ram is to physically lock the ram in the extended or retracted position with a pin or something

Please explain how that would work procedurally.

[1502]

I didn't mention that we would have dual disk brakes that would engage for a few seconds after an error to stop the drive.

My thought was to create a gearbox that only had one speed and a spring return cylinder that disengages the motor. Two of the wheels would have our disk braking system from above.

[AlexH]

Originally Posted by JamesCH95

Please explain how that would work procedurally.

what i meant was something that works in the same manner as how the pin that holds the receiver and insert ends of a trailer hitch together except used to lock something in place and keep it from rotating.

another idea is you could put a piece of "c" channel that is smaller than the clevis over the ram's rod to physically jam it and keep it from retracting.

[JamesCH95]

Originally Posted by AlexH

what i meant was something that works in the same manner as how the pin that holds the receiver and insert ends of a trailer hitch together except used to lock something in place and keep it from rotating.

another idea is you could put a piece of "c" channel that is smaller than the clevis over the ram's rod to physically jam it and keep it from retracting.

The issue with this is that it relies on a human-in-the-loop to function. My opinion is that safety equipment on a robot cart and similar devices should not rely on human involvement. If someone forgets to install the pin, or student A thinks "student B did it" and student B thinks "student A did it" then you have a situation that is exceedingly dangerous as those around it are assuming the piston is locked out when in fact it is not.

[techhelpbb]

One could make a latch system that works like a automotive jack stand.

As you extend the piston to lift the cart it would ratchet it's way down and then prevent reverse movement without manual intervention. In fact they make small cheap automotive jack stands one could probably tweak for this purpose.

[tr6scott]

If you are going wth pneumatics or brakes, just use spring loaded cyclinder or mechanism that deploys the brakes in an unenergized state. Use a single solenoid, to retract/release the brake when under electric control. loss of power, loss of pneumatics will deploy brakes.

Look up rail cars, trailer brakes, they use air pressure to release the brakes. Lose the air pressure and the rail car stops, not continuing down the tracks...