TIGERBOT MECHANICAL DESIGN

Kyle Backer (EE), Jeremy Jensen (ME), Matthew DeCapua (EE), Eric Walkama (ME), Mike Thomas (EE),

Jonathan Cormier (CE), John Seybold (CE)

Overview 2 DOF in Head

4 DOF/Arm

1 DOF in Torso

6 DOF/ Leg

CHECKLIST

Spec. # Importance Source Function Specification (metric)

S1 3 CN9 F1-F4,F7 20"-36" tall

S2 1 CN10 F1-F7 Carry 25% of own weight

S3 2 CN11 F5,F6 DOF per arm

S4 3 CN11 F1, F2, F3 DOF per leg

S5 2 CN11 F4, F1 DOF Torso

S6 3 CN12 F13 Head turn up/down -45 degress to 90 degrees

S7 3 CN12 F13 Head turn 90 degrees left/right

S8 2 CN11 F1 torso bends 90 degrees down

S9 2 CN11 F4 Torso turns 45%

S10 2 CN11 F1-F7 Human proportionality

S11 1 CN13 F1-F3, F5 Servos from the market

BODY DIMENSIONS

~25.5” Tall (feet to shoulder)

10” Shoulder Width2.5” Torso Width

Custom Servo Brackets4 Simple brackets for

multiple servo mounting orientations◦Side mount◦Bottom mount◦Large “C” bracket

Single plane dual axis rotation

◦Shoulder Rotation

Side Mount

Bottom Mount

Large “C”

Shoulder Rotation

LINKS & BRACKET INTEGRATION

Simple Aluminum rods, ¼”

Cut to length Height adjustability

Very cheap (~$7 per 6ft) Integrates into standard

servo brackets.Simple 6-32x1/2” machine screws for assembly

Custom Brackets

Store bought Brackets

Arm Assembly

HIP DESIGN Ball Bearing

◦ Axial and Radial Loads

◦ Low rotation friction

◦ Ball Bearings are cheap

Reduce stress on servo horn◦ Increased hip

Stiffness

-Green Rotation-Gray Static

TORQUE REQUIREMENTS

(cos(ϴ))+g1(L1/2)(cos(ϴ))

T2=(g2)(L2/2)(cos(ϴ))+(L2)(g3)

T3~0

T1

T2

T3

Squat

T3

F

Leg Lift

Push up

F/2 F/2

Te Te

TORQUE RESULTS

ROBOARD SERVO SPECS• Standard size digital servo• Torque @7.4V: 35.0 kg-cm/486.0 oz-in• Speed: 0.11 sec/60º• Voltage: 6 to 7.4V • Weight: 70g

leg lift (1 leg) Squat (2 leg)

Torque at Hip Ankle Knee

MAX (lb-in) 14.44402961 18.74911 18.73543

(oz-in) 231.1044738 299.9858 299.7669

FS 2.076982726 1.600076 1.601244

Elbow TorqueF (lbs) 5.118229269in-lb 16.53188054oz-in 264.5100886FS 1.837359031

weight (lbs)

foot (ALL) 1.4708Lower Leg Links 0.0415Knee servo 0.1543Knee C-Bracket 0.0300Knee bottom Bracket 0.0100TOTAL KNEE JOINT 0.1943Upper leg Links 0.0377Hip C-bracket 0.0300Hip servos 0.4630Hip Brackets 0.0522TOTAL HIP JOINT (1 side) 0.5451TOTAL ABOVE HIP (2 sides) 5.6574 8.2165Hip plate 0.1100Hip components 0.1500Torso plate bottom 0.1000Torso plate top 0.2100Torso servo 0.1543Torso links 0.6509Other torso weight 1.2000Shoulder servos 0.3086shoulder brackets 0.0522upper arm C-bracket 0.0300Upper arm servo 0.1543upper arm links 0.0188upper arm brackets 0.0500elbow servo 0.1543lower arm C-bracket 0.0300lower arm links 0.0377lower arm bracket 0.0100Neck 0.3000TOTAL BODY 10.2365 2.5591

Stress Analysis Bottom Bracket

Stress Hip/Shoulder Bracket

Stress Analysis Elbow Bracket

Stress Analysis Leg Assembly

Deformation Leg Assembly

Mechanical System RisksBreaking on fall

◦Easily and cheaply replaceable frameInsufficient torque

◦Adjustable height Wire routing

◦Open skeleton design, adjustable chest volume

Boards shorting◦Large board spacing, easy addition of

insulation layer in chest

Mechanical BOM  Part Name Manufacturer

Manufacturer Part #

Distributor Distributor Part # Web LocationQuantity Needed

Unit Price Total Price Status Comments

Mechanical

Roboard Rs-1270 servos

Roboard RS-1270 Robot Shop RB-Boa-12

http://www.robotshop.com/

productinfo.aspx?pc=RB-Boa-

12&lang=en-US

21 $73.60 $1,545.60   already ordered 2

Lynxmotion Pan and Tilt Kit / Aluminium

Lynxmotion BPT-KT Robot Shop RB-Lyn-74

http://www.robotshop.com/

productinfo.aspx?pc=RB-Lyn-

74&lang=en-US

1 $35.99 $35.99    

Lynxmotion Aluminum "C" Servo Bracket with Ball Bearings Two Pack

ASB-09

Lynxmotion ASB-09 Robot Shop RB-Lyn-101

http://www.robotshop.com/

lynxmotion-servo-bracket-asb-09-

3.html

10 $12.90 $64.50  2 per pack, already

ordered 1 pack

Multipurpose Aluminum (Alloy 6061) 1/4"

Diameter X 6' LengthMcMaster 8974K31 McMaster 8974K31

http://www.mcmaster.com/#standard-aluminum-

rods/=g4e66o

1 $6.08 $6.08   6' lengths

Multipurpose Aluminum (Alloy 6061) 1/2"

Diameter X 6' LengthMcMaster 8974K33 McMaster 8974K33

http://www.mcmaster.com/#standard-aluminum-

rods/=g4e7wt

1 $15.01 $15.01   6' lengths

Electric Panel Round Nut Zinc-Plated Steel, 5/8"-27 NS, 3/4" OD,

1/8" H

McMaster 91843A123 McMaster 91843A123 http://www.mcmaster.com/#electrical-panel-and-conduit-fittings-nuts/=g4e9p4

1 $2.63 $2.63    

Multipurpose Aluminum (Alloy 6061) .080"

Thick, 6" X 48"McMaster 89015K83 McMaster 89015K83 http://www.mcmaster.

com/#standard-aluminum-sheets/=g4ehep

1 $30.64 $30.64   feet and brackets

Steel Ball Bearing Flanged Open for 5/8" Shaft Dia, 1-1/2" OD,

31/64" W

McMaster 6383K247 McMaster 6383K247

http://www.mcmaster.com/#standard-ball-and-

roller-bearings/=g4eoxi

1 $7.84 $7.84    

Multipurpose Aluminum (Alloy 6061) .125" Thick, 12" X 12"

McMaster 89015K18 McMaster 89015K18

http://www.mcmaster.com/#standard-aluminum-

sheets/=g4ehep

1 $28.02 $28.02  top and bottom of

torso

Machine Screws (6-32x1/2)

McMaster 91772A148 McMaster 91772A148

http://www.mcmaster.com/

#machine-screw-fasteners/=g4eqg2

1 $5.14 $5.14   pack of 100

Ball Bearing with Flange - 3mm ID (pair)

Lynxmotion BB-03 Robot Shop RB-Lyn-317

http://www.robotshop.com/

productinfo.aspx?pc=RB-Lyn-

317&lang=en-US

3 $4.95 $14.85  2/pack, for custom

brackets

Multipurpose Aluminum (Alloy 6061) .080" Thick, 12" X 24"

McMaster 89015K26 McMaster 89015K26

http://www.mcmaster.com/#standard-aluminum-

sheets/=g4euow

1 $33.36 $33.36   chest plates

  Totals   $1,789.66