pic: 1625's shooter ready to fire

This is our shooter in “loaded” position. To fire the Fischer price would just rotate the large sprocket a little more and trip the mechanism over center.

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Wow. I have been waiting for these pics for a while now :smiley:

That is pretty innovative (but simple).

I like it.


1625 is awesome. Everyone on 1251’s scouting would like rave about you guys in Newton. I’m glad we got to play with instead of against you guys in Elims. Great robot this year, innovative,proven, and effective. Good luck at IRI to Aren and the rest of the 1625 crew.

Congratulations to the gang at 1625 on coming up with such a simple and elegant solution. Pretty much everyone from 1114 had the same reaction when we checked out your shooting mechanism in Chicago, “That’s so cool!”.

I like how the shooter has the words “Sucker Punch” on it.

Nice work 1625 on another fantastic robot.

Took me a while to figure out how it worked, glad you posted the second picture of it as well.:slight_smile:

Very simple, yet effective design. :smiley:

wow great design! took me a second to figure it out. never would have thought of that… I assume you have a pot or other sensor so you dont miss fire.

its got an ma3 absolute analog encoder on the other end of the shaft of the big sprocket to tell it where its at.

this mechanism never gave us a problem during the whole season, very easy to maintain

(also i came up with this linkage concept 4 years ago playing with legos…)

What is that giant heatsink on?

Pretty winnovative:)

Seriously though, that is one pretty awsome shooter.

err… how does it work?

I’m guessing the arm has freedom to move inside the half-circle?


the FP motor that steers the wheels, it actually helps for when the bots running for more than 2 minutes.

Leav, look at the next picture of our shooter and you’ll get a better idea how it works, its kinda tough to do with words.

We wanted to accomplish a punching mechanism without having any other actuation, as we’ve never used pneumatics once in our 4 years and another motor is more weight.

Are there any safety features on it?

it doesn’t move if we don’t tell it to, by leaving the anti-backdrive pins in the dewalt. And if it dry fires nothing goes flying. It only is able to shoot when in the correct firing position. besides that we just used our “don’t be stupid” policy and it hasn’t gotten anywhere near to harming anything

So if I were to bump the wheel when it is loaded it wouldn’t shoot?
You use a crab drive right?

you’d have to apply ALOT of downwards force on the linkage arms in order to fire it “accidentally”. And yes we’ve got a 2 speed swerve drive

okay, heres how this thing works. In this picture the shooter is currently ready to fire.
there are two linkages, one hinged to the puncher itself and one hinged to the large sprocket, then connected together. Currently the forward force of the surgical tubing is holding the linkage quite tightly against a catch on the face of the sprocket. In order to fire the large sprocket rotates, moving the hinge point of the rear linkage over center and therefore there is no catch to stop the puncher from flying forward, hence it flies forward.

this leaves the shooter in "unloaded position but both linkages fully outstretched.
The large sprocket then rotates the same direction it did to fire, drawing back the rear hinge point hence partially loading the shooter. Then once the hinge point 180deg from where it was the catch grabs the linkage and it does another 170deg rotation, to be back ready to fire.

i hope thats not to confusing, i managed to explain it to people in person but alot of talking with the hands was involved :rolleyes:

That shooter is very impressive. I watched you guys in some of your matches and I extremely impressed. I know this thread is about your shooter, but your drive train is incredibly cool as well. Do you have any pictures or CAD models that you can post of the drive train?

Here are a couple links of pics already posted:

Single Module

Corner of robot focusing on a module

So, from where we are looking, the sprocket rotates counter-clockwise, the metal semi-circle that is attached to the sprocket hooks the bolt connecting the two bars and draws them back?

That’s pretty neat. I like how this is all accomplished without pneumatics.