Quote:
Originally Posted by pfreivald
Unless you add in the additional pressure regulator, you're extending at 120 psi anyway...so add ~75 lbs...
|
I'm sure as FrankJ mentioned, you mean that the cylinder is operating at running pressure, 60 psi (or less depending on your robot), not 120 or 75, but I say that the pressure inside the cylinder while the piston is moving is definitely Not that high.
What I mean is that the piston will begin moving immediately when the pressure on the pushing-side of it has exceeded the resistance-- friction loads, weight and if you have them, springs. The piston will continue to move at very low pressure staying just ahead of the friction and load until the time that the piston reaches then end of travel. Only then does any real pressure build up inside the cylinder on the 'up' side of the piston.
So if you have a pressure regulator between the valve and the piston, you'll be able to limit the pressure on the 'up' side of the piston to conserve air. Lots of it actually. You'll still need all of the pressure you can muster to lift the robot, so you can't put the regulator before the valve or anyplace that would limit the 'down' pressure.
So if you don't have springs to overcome, you'd be able to extend the lifting hook under very low pressure, like 5 psi (a 2.5" dia has 4.9 sq inches, at 5 psi is close to 25 lbs force)
Quote:
Originally Posted by pfreivald
As another idea, consider constant force springs that are already extended along the body of the cylinder, but don't lock in to the rod until it's fully extended-.
|
Yes, this is a very interesting idea too. Though I would rate it as 'difficult'. Of course there are teams that completely lifted the robot with springs that were already storing energy too (I saw 1619) So in this iteration, if you used an air cylinder, it would only need to get the hook up to the bar. Could be tiny.