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. #ImportanceSourceFunction Specification (metric) S13CN9F1-F4,F720"-36" tall S21CN10F1-F7Carry 25% of own weight S32CN11F5,F6DOF per arm S43CN11F1, F2, F3DOF per leg S52CN11F4, F1DOF Torso S63CN12F13Head turn up/down -45 degress to 90 degrees S73CN12F13Head turn 90 degrees left/right S82CN11F1torso bends 90 degrees down S92CN11F4Torso turns 45% S102CN11F1-F7Human proportionality S111CN13F1-F3, F5Servos from the market
BODY DIMENSIONS ~25.5” Tall (feet to shoulder) 10” Shoulder Width 2.5” Torso Width
Custom Servo Brackets 4 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 T1 T2 T3 Squat T3 F Leg Lift Push up F/2 Te
TORQUE RESULTS ROBOARD SERVO SPECS Standard size digital servo 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 HipAnkleKnee MAX (lb-in) (oz-in) FS Elbow Torque F (lbs) in-lb oz-in FS weight (lbs) foot (ALL) Lower Leg Links Knee servo Knee C-Bracket Knee bottom Bracket TOTAL KNEE JOINT Upper leg Links Hip C-bracket Hip servos Hip Brackets TOTAL HIP JOINT (1 side) TOTAL ABOVE HIP (2 sides) Hip plate Hip components Torso plate bottom Torso plate top Torso servo Torso links Other torso weight Shoulder servos shoulder brackets upper arm C-bracket Upper arm servo upper arm links upper arm brackets elbow servo lower arm C-bracket lower arm links lower arm bracket Neck TOTAL BODY
Stress Analysis Bottom Bracket
Stress Hip/Shoulder Bracket
Stress Analysis Elbow Bracket
Stress Analysis Leg Assembly
Deformation Leg Assembly
Mechanical System Risks Breaking on fall ◦Easily and cheaply replaceable frame Insufficient 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 NameManufacturer Manufacturer Part # DistributorDistributor Part #Web Location Quantity Needed Unit PriceTotal PriceStatusComments Mechanical Roboard Rs-1270 servos RoboardRS-1270Robot ShopRB-Boa-12 x?pc=RB-Boa- 12&lang=en-US 21$73.60$1, already ordered 2 Lynxmotion Pan and Tilt Kit / Aluminium LynxmotionBPT-KTRobot ShopRB-Lyn-74 x?pc=RB-Lyn- 74&lang=en-US 1$35.99 Lynxmotion Aluminum "C" Servo Bracket with Ball Bearings Two Pack ASB-09 LynxmotionASB-09Robot ShopRB-Lyn servo-bracket-asb html 10$12.90$ per pack, already ordered 1 pack Multipurpose Aluminum (Alloy 6061) 1/4" Diameter X 6' Length McMaster8974K31McMaster8974K31 com/#standard- aluminum- rods/=g4e66o 1$6.08 6' lengths Multipurpose Aluminum (Alloy 6061) 1/2" Diameter X 6' Length McMaster8974K33McMaster8974K33 com/#standard- aluminum- rods/=g4e7wt 1$ ' lengths Electric Panel Round Nut Zinc-Plated Steel, 5/8"-27 NS, 3/4" OD, 1/8" H McMaster91843A123McMaster91843A123 com/#electrical- panel-and-conduit- fittings-nuts/=g4e9p4 1$2.63 Multipurpose Aluminum (Alloy 6061).080" Thick, 6" X 48" McMaster89015K83McMaster89015K83 com/#standard- aluminum- sheets/=g4ehep 1$30.64 feet and brackets Steel Ball Bearing Flanged Open for 5/8" Shaft Dia, 1-1/2" OD, 31/64" W McMaster6383K247McMaster6383K247 com/#standard-ball- and-roller- bearings/=g4eoxi 1$7.84 Multipurpose Aluminum (Alloy 6061).125" Thick, 12" X 12" McMaster89015K18McMaster89015K18 com/#standard- aluminum- sheets/=g4ehep 1$28.02 top and bottom of torso Machine Screws (6- 32x1/2) McMaster91772A148McMaster91772A148 com/#machine- screw- fasteners/=g4eqg2 1$5.14 pack of 100 Ball Bearing with Flange - 3mm ID (pair) LynxmotionBB-03Robot ShopRB-Lyn x?pc=RB-Lyn- 317&lang=en-US 3$4.95$ /pack, for custom brackets Multipurpose Aluminum (Alloy 6061).080" Thick, 12" X 24" McMaster89015K26McMaster89015K26 com/#standard- aluminum- sheets/=g4euow 1$33.36 chest plates Totals $1,789.66