non-pneumatic "kicking" mechanism

[Stephen of REX]

A simple swing arm attached to a CIM does wonders. Not to mention that the strength is variable, because you can change the speed that the hammer swings at. Think croquet.

[DonRotolo]

The spinning wheel is out (good thing, too). Now we have a more conventional 'leg' powered by latex tubing, reset with pneumatics.

[Ether]

Originally Posted by Stephen of REX

A simple swing arm attached to a CIM does wonders. Not to mention that the strength is variable, because you can change the speed that the hammer swings at.

Mind posting a video ?


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[lynca]

Originally Posted by Ether

Mind posting a video ?


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The team from Chile posted a good toughbox kicker video.

http://www.chiefdelphi.com/forums/sh...d.php?p=911126

[kgzak]

Originally Posted by Stephen of REX

A simple swing arm attached to a CIM does wonders. Not to mention that the strength is variable, because you can change the speed that the hammer swings at. Think croquet.

We are doing something close to that except the CIM spins a wheel that is not directly connected to the kicker. The kicker is pretty much a wheel with a foot sticking off of it. when we put the CIM wheel against the kicker wheel the kicker spins forward and kicks the ball. The wheel is then retracted by a spring.

[Simpsonator]

Don't wanna give too much away, but we will be using a sort of bell crank mounted to a large wheel to retract our kicker, and surgical tubing to snap forward

[ratdude747]

we are using surgical tubing w/ a window motor and clutch. however, the clutch part is a mess. that is all i will say...

[MrForbes]

Originally Posted by ratdude747

the clutch part is a mess. that is all i will say...

heh....it's not an easy thing to design and build.

I'll let you know if we ever get ours working

[Vikesrock]

We will be using a crossbow type linear device powered by surgical tubing. The front carriage with the kicker will be pulled back by a second carriage on a lead screw. Releasing a latch will separate the carriages and the kicker will fire.

[RRLedford]

Since the only arrangement of elements with any structural integrity is the triangle, and since it is more efficient (less material) to apply and direct force via tension ---

Our kicker is an aluminum triangle "pendulum" made of tee-slot channel with gusset plates at corners and a "toe" on low corner for ball contact. Triangle's top corner clamps to 5/8 axle through ball bearings. At low corner of triangle is attached a 1500lb test 1/8 x 1/4 synthetic cable that runs through forward mounted pulley which turns cable rearward, toward bank of bungee cords, pre-tensioned to ~50LBS. Rear corner of triangle has strong travel stop cord attached to solid frame anchor point. It stops the kick at end of travel, and it sustains the minimum pretension force on bungees.

On its path rearward to the bungee group, the kicker cable passes through a winder plate that is driven by a geared down CIM motor to ~12RPM. Winder rotates 0-180 degrees in just over 2 seconds to shorten tension cable up to 12", depending on desired kick strength (bungee tension rises to ~120Lbs at max.). Kick is triggered by instant disengagement of winder cable from the winder plate using 2" of pneumatic cylinder piston travel to actuate the disengagement. The kick can be triggered at any point in the wind up cycle from 0-180 degrees. The trigger design is a very simple medieval-type concept and there are no other masses accelerated during kick, except the kicker & cable, and that is all I can say about it.

We are waiting to finish the gear box setup for the winder to confirm what level of wind torque it can hold while motor is de-energized. If de-energized motor allows winder to UN-wind, another system will be needed maintain the wind up tension/torque while waiting for the right moment to launch a kick.
Will confirm results of gearbox test when finished.

So far, our kicker has consistently placed shots within a 30" dia. circle at 35+ feet. We still need to "possess" balls well enough to maintain this level of accuracy during match play, and this remains the bigger challenge. We do expect to be able to consistently score two or more goals from far end in autonomous mode.
-RRLedford

[sloteera]

Here you can see our kicker.

http://www.chiefdelphi.com/forums/sh...highlight=1860

Without pneumatic systems. Only a CIM motor with gear box!!

[Matt382]

Our kicker is powered by surgical tubing right now, but for competition we will find something stronger. We pulll it back with a window motor, and we have this sort of locking ratcheting mechanism which we will release with another window motor. Our range is looking to be around 40 feet, but it's variable on how far back we wind up the kicker.

[Chris is me]

Originally Posted by Matt382

Our kicker is powered by surgical tubing right now, but for competition we will find something stronger. We pulll it back with a window motor, and we have this sort of locking ratcheting mechanism which we will release with another window motor. Our range is looking to be around 40 feet, but it's variable on how far back we wind up the kicker.

You won't get much stronger than surgical tubing, but if you're looking for more repeatability, bungee cord exchanges a little force for more consistency.

[Ether]

Originally Posted by Chris is me

... if you're looking for more repeatability, bungee cord exchanges a little force for more consistency.

Hi Chris,

I was wondering if you read this somewhere or if your team discovered it by testing.

Thanks.


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[Chris is me]

Originally Posted by Ether

Hi Chris,

I was wondering if you read this somewhere or if your team discovered it by testing.

Thanks.

I have read on Delphi that the spring constant of surgical tubing is very temperature-dependent. I've also heard from others' testing (at this time I don't remember who) that their surgical tubing powered prototype had issues with consistency.