Killer Bees

Team 33

2017 Design

Buzz Xxii

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Robot Design

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Strategy The Killer Bees spend the first days of the build season

making a functional objective list. We rank these objectives in categories of yes,

maybe, and no based on how important of a priority the task is for our robot to

complete during a match. We keep this list present during the entire season to

make sure we remember the most important tasks to us for our robot to

complete.

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Prototyping During week 1 of build season, we make a list of

prototypes to build. This year we decided we needed to

make a one and a two-wheeled shooter, a fuel storage

device, a floor collector for fuel, floor collector for gear, and a hanging system.

We divided the team into separate hives to work on each subsystem’s prototype.

Gear Collector Initially, we tried out four ideas: two pneumatic claw variations (one of which was inspired by

our 2015 Recycle Rush robot), a sandwich-like slide track prototype, and a roller intake. The

roller intake is the design we choose with a 6° HDPE ramp. It proved to be the fastest, most

efficient, easiest to align, and most compact choice of the available design options.

Hanger We did a short drum and a full-length drum prototype. Both prototypes use

the hook Velcro epoxied onto a shaft. The short drum was a 2” diameter, the

second iteration was a ½” hex shaft with Velcro flaps. We saw that these flaps

helped to grab the strap better. The full-length version was a 3/4” hex drum

with the Velcro flaps. These full-length drums proved to be the most efficient

when lining up to hang by winding backwards to snag the hanging material

and winch the robot to pull upwards.

Fuel Collector We did three iterations of fuel collection devices. We initially tried rubber

bands on 48 tooth sprockets but it expanded too much so we sleeved it.

Then we did a test with surgical tubing but we still had expanding issues.

Next, we tested a sleeve of fabric that helped the expansion but it became

off centered easily. Finally, we prototyped a ½” rod with a surgical tubing

wrap floating and it worked great because it was light-weight, minimal

packaging, and gripping fuel.

Fuel Shooter

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We prototyped both a double-wheel shooter and a single-wheel

shooter, both to shoot fuel into the high goal at a 70% accuracy and

15 balls per second. The single-wheel shooter started with 2”

AndyMark stealth wheels which was replaced with 65 durometer

conveyor wheel then full drum 65 durometers then they made a full

drum of 65 durometer wheels. The two-wheel shooter’s first iteration had 2 axles with 2.5”

Colson wheels to create two drum-like rollers, and was then changed to 2.5” PVC drums. The

third iteration used four axles of 2.5” PVC drums, as the wheels had more variability. We ended

up choosing the single wheeled shooter with 35 durometers because it had better repeatability

than the double wheeled shooter.

Ball Management We tested a prototype of urethane rubber belts but we encountered a dead space between

every belt so we developed a belt comb to keep the belts in place. We tried different speeds

and tensions with the belts. From the testing, we found that belts should run as fast as possible

and a little loose but not enough to walk.

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CAD and Fabrication

The CAD and Fabrication Process begins with the CAD

drawings. Each student or pair of students receives a

detailed drawing of a part, designed in Autodesk Inventor Professional. To provide

extra care for every part, each student uses the mentality of measure twice, cut

once. After fabrication of the part is complete, each part must be approved by a

mentor. If the part is good and meets the demands, then it will be placed into a

designated robot bin for assembly. If the part does not meet satisfactory levels,

then the student will work with a mentor to adjust the part to meet demands.

Assembly

We make two robots: one practice and one competition. The robots are

assembled from parts made in the fabrication process. They are all labeled and

wrapped in their CAD render, which facilitates assembly. Mentors assist students

to clear up any questions. After we make the parts, we assemble parts into

subsystems from CAD model assembly drawings.

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Chassis 1/10” versatube frame 26” x 28” Two 3.25” caster wheels and two 3.25” traction

wheels 25 pitch chain placed inside tube for chain retention and neatness Gearbox

geared for 15ft/sec 6 mini CIM drive Pneumatic fittings for cooling

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Hopper/Cage Wall Extends hopper to 35” total when fuel collector is

pushed out Two 4lbs constant force springs Motivated by fuel collector Allows the robot to hold over 100 balls

Fuel collector

Main structure 1” x 2” x 1/2” box with 775pro with 3:1 versaplanetary gearbox

reduction 1/2” hex shaft with gum rubber 1” x 1” x 1/2” box with 1”x 1/2” bar 1” x 1/2” box 1.35” aluminum bar Delrin pivot mounts

1/2” floating roller with surgical tubing Ball guides of HDPE 1/4” wheeled guides

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Shooter

Shooter 1/8” aluminum sheet metal water jetted

parts Four 4” x 1.875” 35 durometer polyurethane wheels Three 775pro motors 5:1 pulley reduction for the flywheel Lightweight standoff structure 1/16” Rigid Hood aluminum 3.5” x 12.5”

Vertical feeder 775pro with 3:1 pulley reduction Three 1” OD aluminum tube 1.25” OD surgical tubing

Floor Conveyor feeder 775pro with a 5:1 versaplanetary Three 32” urethane belts Two 1” aluminum rollers HDPE belt comb

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Gear collector Main structure 25” x 6” deep angled throat Independently actuated polycarbonate tongue with

6° from floor to collect gear 40° polycarbonate pieces on edge to center gear in throat Twelve 2” rubber compliant wheels across opening Aluminum 1/2” cam to stop tongue from back driving Run by 775pro and Two Bag motors Ten 1” polycarbonate flaps to stop the spring from penetrating the

collector

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Divider wall 1/2” x 1/2” x 1/8” aluminum box 24” x 17” frame 1/16” polycarbonate spring shield

Rope Climber 100:1 versaplanetary reduction on a single 775pro motor 24”x 1/2" hex shaft 21” x 1/2" x 1/2” hex tubing 2” flanged Velcro flaps 1/2” ratcheting wrench

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Programming Labview based, 5 Main stages

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Initialization

o Set up sensors and motors to be used later

Input Processing

o Read sensors and joystick, translate to usable units HMI/Auton

o Use Inputs data to translate into what the machine wants to do

Control

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o Figures out how the machine should do what it wants to do

Output Processing

o Gives the commands to the motors so the machine does

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Electrical 2 SICK proximity sensors – Detect Gear once in the

arm

NavX inertial measurement unit – For use in determining the heading of the robot during autonomous routines, also used in ensuring the heading is constant during teleop when driver pushes a button

Magnetic position encoder – Measure the speed of the flywheel for our shooter

2 Quadrature optical encoders – To determine the distance the robot traveled during autonomous

2 Potentiometers – To determine the position of the gear arm and the gear arm tongue for PID control

Pneumatics Two 10” pistons which deploy the fuel intake and extend the hopper

simultaneously

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SPONSORS Fiat Chrysler Automotive is the seventh-largest automaker in the world, designs, engineers, and manufacturers. They sell passenger cars, light commercial cars, components, and production systems worldwide. Innovation First International (IFI) was first started with producing the electronics for autonomous parts for ground robotics, then started to be a leader in educational and competitive robotics products. They have become a growing developer of consumer robotics toys. Hubbard Spring started in 1905 with leaf springs and harrow teeth, and have now come to produce a variety of parts, from standard to custom parts for many different industries, including, aerospace, automotive, agriculture, and medical. TI Automotive is a global automotive industry that produce award-winning, industry-leading automotive fluid systems. They have provided technology to vehicles around the world for almost 100 years. Elite Fencing is a manufacturer of superior quality ornamental aluminum fencing, railing, pool fences, and gates and has been since 1986. Their staff has over 40 years of experience in this business. They have stellar customer service and superior products.

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OUTREACH

RoboZone In 2015, we launched RoboZone, a weekly television show featuring Michigan

FRC competitions. Viewed on the same state-wide network as the Detroit Tigers,

a Major-League Baseball team, the show brings FRC to homes and businesses.

Advertisers are expecting 1.8 million

impressions/viewers in 2017. In its

rookie year, RoboZone was honored

with an Emmy® award.

FIRST Badges We lead a statewide project, FIRSTBadges.com, with the Michigan Department of

Education. This innovative micro-credential program demonstrates a student's

STEM skills acquired in FIRST for future employers and college applications. We

design the badge icons and field test the badge requirements. Digital badge topics

include Communication, Marketing,

Leadership, Electronics, Engineering Design,

and Machining. There are currently 47 teams

participating, with over 100 student badges

awarded.

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Diversity Challenging traditional gender roles, we run an annual All

Girls FRC tournament with teams 68, 2834, and 469 each year for the last 4 years.

We set up a scholarship fund for team participants, awarding $12,000 in

scholarships financed by concession stand profits.

It is a great opportunity for girls to make friends

with other girls who have an interest in STEM as

well as learn how to speak up, delegate, and lead

others in robot repairs. These experiences inspire

students to deepen their interest in STEM careers

and dream beyond traditional gender roles. Because of the single gender

tournaments, 2 of the attending teams implemented an All Girls Tournament in

their communities (Indiana and West Michigan).

Community In past years, we recorded many service hours fundraising and participating in

one-time events. In 2013, we changed the focus of our outreach efforts to provide

sustained opportunities to an underserved population at the Baldwin Center, a

local soup kitchen and community center. We

provide STEM activities in summer and fall programs

for 75+ at-risk students. Our plans for 2017 include

continuing these activities for the summer and fall

programs and starting FIRST teams at the center.

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OCCRA Each fall, we run a competitive STEM program to

emphasize FIRST values and provide teams with a pre-

season challenge. OCCRA is a partnership of local

educational agencies, high schools, and corporate

sponsors. Featuring FRC-size robots that can only be

fabricated with simple tools and limited mentor assistance,

we compete with and against 30 local high schools. Our

mentors run the events, impacting 10,000+ students in the

15 years of OCCRA.

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Contact Us

Website: www.killerbees33.com

Twitter: @FRC33

Facebook: https://www.facebook.com/killerbees33/

Email: 33killerbees@gmail.com