Hello Everyone.
Team 3132 (The Thunder Down Under) are in the Process of designing the Kicker/Shooter for this years competition. One of the most popular options from the team is to disengage the motors and doing so release the trigger to shoot the ball.
The Question is, how we can disengage the motors in a way to minimise the damage involve with the gears? Also, if there is any other way to disengage the motors, please reply to the post.
Thanks.
Hello Chuku,
One way of disengaging a motor or gearing system is by using a dog gear that is attached to the shaft in a way that it spins with the shaft and the gear that it engages to does not. It is what is used in the AndyMark shifting gear boxes, as well as manual transmissions in cars.
To better understand your situation, how are you “cocking” you kicking mechanism. Knowing this may help people better answer you question. Not knowing how the motor acts upon the shooter makes is somewhat difficult to give you an answer on how to detach it from the device.
Ivey
head over to andymark and take look at at the 2 speed alot of team mod one to make a clutch
By far the easiest way I know of is to purchase an any-mark shiftable transmission and remove the “high” gear, so that when you shift it simply goes into freewheel. This will, however, require a pneumatic cylinder.
The other posts are likely the best way to do it, but if you are working on a narrow budget you can use spider couplers and a pneumatic to achieve similar results. Costs 30 bucks instead of a few hundred, but only can engage at lower speeds
i would just buy the parts the dog, shaft , and one gear
Depending on how you’re winding up your kicking mechanism, you could use a cam. Basically, a cam is shaped like a snail shell looking at it sideways. You wind it around so the smallest radius part of the cam contacts a shaft (known as the cam follower), and by rotating the cam, it pushes on the shaft more and more. Then, when it reaches the point of highest radius, it suddenly drops off, releasing the kicker.
The advantages of this kind of design is that it’s very simple to build, and relatively hard to break, while the main caveat is that you pretty much only have one kicking power setting.
I have been trying to determine the answer to the exact same problem. We used a winch on our 2008 robot that worked really well. Here is a video of the winch engaging. Look at about 2:20 mark for the winch engagement. http://www.youtube.com/user/Broncobots1987#p/u/38/pIV7yEc4xD0
I have been looking for some good pictures of the winch but cannot find any. We basically used a dog drive with a pneumatic release however we had a latch that would engage the arm. If you look at the video and there is a part that looks like an upside down coat hanger. There was a bolt that stuck out of it with two bushings on it and a set of hooks drove over the bushings then the winch was shut off and the dog drive was dis-engaged. Then the lock was actuated by a 3/4" pneumatic cylinder. We were waay too concerned about the shock load back into the transmission from disengaging the winch roll under load. We were drawing nearly 150 lbs with that robot.
Our team have been kicking around an idea of using a very similar idea for this years shooters with a little less monkey motion that was in that winch. We are hoping that we can accomplish a simpler method of the winch this year and be able to vary the power. I will not give away the whole idea but think about how you could use a ratchet and pawl to accomplish this task. I think this will allow the load to be removed from the gearbox to hopefully limit the damage. (fingers crossed)
You can use a bicycle freewheel to wind up to 179 degrees and then, when ready to shoot, you jog the winder a couple more degrees to fire off your kick. The freewheel will spin ahead for 180 degrees, and end up in a position ready to go for starting the next wind up cycle. You just have to swing a big enough diameter 180 degree arc to get enough pull on the bungees or latex tubing. Freewheels can’t take much side torque though so keep plane of tension as close to plane of freewheel balls as possible. Good luck.
-RRLedford
You might try thinking of it as:
How can we disengage the kicker from the motor?
This really sparked some creative thoughts in our group when a mentor brought this up.