Design Process: 2012 Shooters

[Billfred]

2815's process pales in comparison to all of the above.

Like everyone else, we looked at the game at Kickoff and said "Okay, so we're building a 6WD turreted shooter. Done." Smaller elements like whether we wanted to be able to slot-load were discussed and contemplated.

It was midway through Week 3 where some showstopping CAD delays caused us to reassess our plans. The question was now "What will get us out of this funk?"

We thought of fender campers, but a moment's inspiration led to our dual-headed shooter, carefully measured so that it would in line with the hoops as long as our back bumper touched the player station wall (because what are you going to do, push us more into the wall?). We figured that even if the idea was crap, we could pull it off and put on a forward- or rearward-facing shooter.

At first, our attempts at prototyping the shooter centered around going up a straight 45-degree angle; we prototyped this with square tubing and corrugated plastic from some scrapped signs at work. We realized that we needed something with a little more curve to the surface to make the ball travel better, which led us to Lexan...and what holding it? A run to Ace led me to 1/2" EMT electrical conduit. At $2 for 10 feet, I figured we had nothing to lose. (I was frequently sent on parts runs, since I didn't have to supervise the kids and was willing to float some money and get reimbursed.)

Sure enough, the EMT bends nicely, is easy to work with, and is dirt cheap. (Expect to see more of it on future Los Pollos Locos machines.) We used flat aluminum strips to fine-tune the amount of squish the ramps gave us--we would bow the ramps out more, and the lexan pulled the aluminum back in to about right.

The early shots were promising, even giving us hope for threes. We weren't at a level of sophistication (let alone time) to go into a custom gearbox, so it was a F-P motor in an AM Planetary, through a CIMple Box (good looking out, 1398), then sped back up to the shooter with a chain run. It was bootleg, but it shot!

At Peachtree, we swapped out the wedgetop for a wide piece of roughtop (black, of course) that covered both wheels as a tandem. The extra contact patch seemed to improve our shots, and we did respectably. By Palmetto, parts had arrived to let us add a second AM Planetary (this one running their 9015 motor). The extra oomph made us even more reliable, to the point of hanging a banner when combined with some luck from the backup line.

By Championship, we attempted to speed it up even more through changing the sprocket on the gearbox to be bigger (there wasn't much room to go smaller on the axle). We hit a three on the practice field, but not with enough reliability to go with it. That we didn't make elims was a disappointment (when isn't it?), but understandable.

We do intend to redo the gearbox before SCRIW, and we may yet improve on it. Some next steps for this shooter could include:

-Switching to bearings on the shooter axle for less friction (we used bronze bushings out of familiarity, cost, and space reasons)
-Building a custom gearbox to accommodate more motors and faster gearing (we could add an ungodly number of motors under the rules--one more F-P, one more AndyMark, two or three more BaneBots, and even the Denso motors if we got fancy).
-Some method of rangefinding to enable us to dial in shots from further away than the fender (all of ours were within an inch or so of touching it). We experimented briefly with ultrasonic sensors, but couldn't find a way to get a clean reading with the bumpers.