VRev Final Design Review Presentation

Final Design Review

Team 2

Team Leader: German Garcia

Members: Daniel Rohwedder

Yongming Cao

Yi Lu

Landon Allen

Stephen Vullo

Team 2

Project Outline

● Wall climber must ascend a painted steel

door through a 48 inch section marked at the

top and bottom by black tape.

● Wall climber must return back down the door

to underneath the initial starting line.

● Wall climber must move autonomously.

Mechanism Review

Design: Wall Climbing Robot

Overall Plan

Subsystem 1: Chassis

Subsystem 2: Adhesion(magnet)

Subsystem 3: Drive

Subsystem 4: Power

Subsystem 5: Control


● Machined out of a 6”x4”x1/16” (150mm x 100mm x 1.60mm) sheet of 6061

T-6 aluminum bare sheet since it’s the most cost effective one in the

market.

● Using aluminum because it is lightweight and strong

● Approximate weight of chassis after machining = 20 grams going by

Solidworks

● Support and mount for the Arduino, 2 DC motors, power supply wires, and

magnet.

● All parts will be bolted to the chassis


Failure Stress AnalysisMax Shear within machine:

Yield Stress of 6061 Aluminum: 276MPa

Von Mises Stress

Subsystem 2: Adhesion


● BX082CS-N - K&J Magnet

● The magnet has two countersunk holes in it that are made for #6 screws.

● Chassis will have holes for the bolts and we will attach the magnet with the

nuts on the top side of the chassis.

● This will give us the ability to change the distance from the magnet to the

door if needed.

Top View: Bottom View:


Specifications

● Dimensions: 1 X .5 X 1/8 “(25 x 13 x 3 mm)

● Weight: 6.6 g (0.23 oz.)

● Pull Force: 41 N (9.2 lbs)

https://www.kjmagnetics.com/pdfs/BX082CS-N.pdf


● The magnet force

reduces

exponentially as

distance increases.

● For the required

8.9N of force, the

distance from the

wall needs to be 2.7

mm.

0

5

10

15

20

25

30

35

40

45

0 1 2 3 4 5 6

Fo

rce

(N

)Distance (mm)

Magnet Force


● The calculations of the necessary force needed to keep

the robot from sliding was calculated using a 2.0 factor

of safety on the mass.

● With 360 grams as the mass, the minimum magnet

force require before the robot slides is 8.9N.

Subsystem 3: Drive

Subsystem 3: Drive

Motor Specifications: http://www.pololu.com/product/2366/specs

Subsystem 3: Drive

Front wheels are 30 mm dia

Back wheels will be connected with a

common shaft and will be free spinning

Subsystem 3:Drive

● On the front wheels we are using what they call a

“sticky pad”. People use these in their cars to keeps

their phones from sliding.

● The coefficient of friction is 0.7.

● We will cut strips from a sheet and glue it around the

wheels with super glue.

Subsystem 3: Drive

Subsystem 3: Drive

Using 145 RPM, diameter of the front wheels,

.03 m, the linear speed of the motor will be .23

m/s

Subsystem 4: Power and Control


Power requirements for wall climber:

● Motor: 40mA at no load speed, 700mA at

stall torque so calculated at 370mA for

estimated torque and speed

● Arduino: .2mA (negligible to calculations)


● Power source is a cable that downsteps 110

volt wall output to 9v input for the Arduino

● Power cable will be soldered to inputs on the

Arduino board


● Current load from wall climber when runs

constantly:

● Standard current available from wall socket

is approximately 15 amps

● Average torque during acceleration

● Torque when the car runs constantly

● The total time to go up and down is

● The total energy consumption for the two

DC motors is


Wiring Diagrams and Routing


● The motors will attach in the M2 and M3 ports of the

motor shield.

● The power cable will be soldered directly to the arduino

board, on the Vin and Gnd ports, and will be routed

underneath the chassis. The wire will run straight

through the middle between the two rear wheels to

maintain balance.


● The speed of the DC motor will be controlled with PWM by

changing the duty cycle.

● The motor will be running at half of the maximum RPM, 128

Duty Cycle

● Once it is at the top of the door, the motor will run in the

opposite direction with the same RPM.

● Once the motor reaches the bottom of the door, the motor

will be stopped again will remain stationary.


Mass Breakdown

Crashworthiness

During testing a shock absorbing implement

will be placed below the test area to ensure

no damage to the wall climber during

development.

Manufacturability

Rapid Prototype:

Rear Wheel: 40mm Diameter -

Front Wheel: 30mm Diameter -

Machining

The chassis will be

machined using a

CNC

The shaft will me

machined

manually with

lathe and mill

Machining

Labor Cost

Cost for Parts and Manufacture

Budget

The total cost of

the whole project

will be $223.01

Conclusion



Subsystem 3: Drive


Future Plan● Ordering Parts

● Machining

● Assembly

● Testing

Questions?

VRev Final Design Review Presentation

Documents

Transcript of VRev Final Design Review Presentation