Quick release

[Kevin Sevcik]

I actually happened upon a ridiculously effective quick release based around an FP, a low ratio BaneBot planetary transmission, and a worm-wormgear set. With a servo with a cam to shift things. I can sketch something up in Inventor if you want to see how it'd work.

[Hastypickle]

Originally Posted by Kevin Sevcik

I actually happened upon a ridiculously effective quick release based around an FP, a low ratio BaneBot planetary transmission, and a worm-wormgear set. With a servo with a cam to shift things. I can sketch something up in Inventor if you want to see how it'd work.

Sure.
I was thinking maybe the pneumatic actuator could be used, but I don't know how much force that would be able to hold.

[EricH]

Originally Posted by Hastypickle

Sure.
I was thinking maybe the pneumatic actuator could be used, but I don't know how much force that would be able to hold.

If you design it right, it can hold a lot. I know that 330 fired a short-throw cylinder into a winch powered by 2 FPs back in 2004 to keep us on the bar. We never had a problem with it.

[KE5WGE]

1391 used a 1 inch pneumatic piston to hold back our launcher in overdrive. I think we had about 300lbs force held back by a simple lever actuated by the one inch piston.

Depending on the device you are trying to hold back, there are so many ways to do it with pre-made devices but I would recommend just throwing something together that does the job and that is simple and easy to make another one of at a competition.

[bhsrobotics1671]

Could you PM me or provide me with more information as to how this winch system worked? We are very interested in this type of design. Thanks!

[Chris Fultz]

Originally Posted by Hastypickle

Sure.
I was thinking maybe the pneumatic actuator could be used, but I don't know how much force that would be able to hold.

at 60 psi, a 3/4" diameter cylinder has 26.5 pounds of force in the extend direction and 23.5 in the retract direction. If that is not enough, you can step up to a larger diameter.

the equation is f=pa, or force = pressure x area.
for the example above, in the extend direction it is

f = 60 pounds / inch^2 x 3.14 (.375^2) = 26.49 pounds

for the retract, you have to subtract the area of the internal rod,
so the effective area is reduced (0.25 diameter = .125 radius)

f = 60 pounds / inch^2 x (3.14 (.375^2) - 3.14 (.125^2)) = 23.55 pounds.

Mod an Andymark Gen1 shifter, it has the release ability you're looking for as well as the ability to "wind up" whatever you're looking to build, if you do your design work right.

[qwertyuiop[]\]

you could just have a piston push all of the rope off of the open end of the reel.

[Dad1279]

Fishing reel? Motor to wind, servo to release.

[Aren_Hill]

http://www.chiefdelphi.com/media/photos/31538

http://www.chiefdelphi.com/media/photos/31539

you dont need pneumatics for quick releases....

[Chief Pride]

You could take a pipe, cut it in half and put it on a shaft, make a notch in one and and a reciprocating notch on the other, mount fasten the left side of the cut pipe to the shaft, use a pnuematic shaft to push the two pipes together while winding, then use the piston in the other direction to dislodge the pipe... If that makes sense.



Edit: 400th post.

[Team 135]

I would use a small pneumatic actuator that came in the kit. We used this on a prototype to hot swap the trailer and it worked great even under tension.

[Pneumaticsman]

We are thinking of using a winch as well. We are thinking of having a winch to pull some cable back, which loads tension on some surgical tubing. Once tensioned, we plan on releasing a "clutch" that will disengage the winch and release the tension in the surgical tubing, thus kicking the ball.

[Kevin Sevcik]

Originally Posted by Dad1279

Fishing reel? Motor to wind, servo to release.

Fishing reel releases tend to lock when under load. Some of them lock very effectively even under a light load. AndyMark Shifters and other dog or meshing shifters are going to exhibit some amount of locking under load as well, simply because more load means more friction on the meshing parts. They probably will still be shiftable, but it's never going to be as easy as when they're unloaded.