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Mechanical Design Specifications

A project log for 2021 HDP Dream Team: EJA

Learn more about Team EJA's intelligent buoy, and how their solution will help the global fight against ghost gear.

ekEK 09/18/2020 at 18:540 Comments

The Eja ropeless gear system consists of three parts: Release Mechanism, Intelligent Buoy, and Onboard Gateway. Here are the mechanical design specifications for each, also available as a pdf here.

Release Mechanism

3D viewer: https://a360.co/3msDSha

Files: https://github.com/RobotGrrl/Hackaday-CXL/tree/master/Design/release_mechanism

Length

52.9 cm

Width

39.0 cm

Height

32.9 cm

Approximate Weight

15 lbs / 6.8 kg (including ballast)

Materials

0.375 in HDPE base, PLA 3D printed pieces

Max Depth

TBD

Eja Bill of Materials - Release Mechanism



Last Updated: Sept. 18, 2020



All fasteners for prototype are zinc-plated steel



Item

Qty

Cost (USD)


McMaster Part #

Source

Notes

M6 x 16 mm

32

3.32


90128A263



M6 x 25 mm

30

3.97


90128A265



M6 Washer

50

2.15


98688A116



M6 Hex Nut

62

1.61


90591A151



M3 x 10 mm

12

1.70


95263A134



M3 x 16 mm

12

2.11


95263A158



M3 Washer

28

0.96


98688A112



M3 Hex Nut

24

0.56


90591A250



Magnets N52 (large)

5

4.85


5862K116



TOTAL MECH COMPONENTS

21.22












0.375 in Natural HDPE 24 x 48 in

0.5

42.50



eplastics - San Diego

Cost / in^2 = 0.04

1 kg 3D Printer Filament PLA

2

57.98



Amazon


Misc. rope, cord, carabiner

1

5.00



Random


10 lbs Dumbbell

1

7.00



Canadian Tire


Spool holder

1

1.00





TOTAL MATERIALS

113.48












CNC machine time

20

20



DesignLab

1 / min

3D printer time

1200

60



EK's 3D printer

0.05 / min

Injection moulding time

0

0





Assembly time

90

22.5



EK

15 / h

TOTAL MACHINE TIME

102.5












GRAND TOTAL

237.20






Parametric Design

Here are the values used for parametric design


Intelligent Buoy

3D viewer: https://a360.co/3hJjc0R

Github: https://github.com/RobotGrrl/Hackaday-CXL/tree/master/Design/intelligent_buoy

Diameter

9.3 cm

Height

20.8 cm

Approximate Weight

500 g

Materials

Polycarbonate (‘Tritan’), PLA 3D printed pieces, Neodynium magnets, FR4 circuit board for structural strength

Waterproof Rating

Waterproof*

*Further testing is needed to determine depth

Eja Bill of Materials - Intelligent Buoy B



Last Updated: Sept. 18, 2020



All fasteners for prototype are zinc-plated steel



Item

Qty

Cost (USD)


McMaster Part #

Source

Notes

M2.5 x 8 mm

4

0.54


90128A184



M2.5 x 6 mm

14

1.85


90128A183



M2.5 Washer

4

0.13


98688A111



M2.5 Hex Nut

8

0.18


90591A270



M3 x 10 mm

4

0.57


95263A134



M3 Washer

0

0.00


98688A112



M3 Hex Nut

4

0.09


90591A250



Magnets N52 (small)

4

3.04


5862K103



Magnets N52 (large)

5

4.85


5862K116



TOTAL MECH COMPONENTS

11.24












Nalgene 1L wide mouth enclosure

1

20.00



SportChek


1 kg 3D Printer Filament PLA

0.25

7.25



Amazon


Misc. glue, wires

1

1.50



Random


TOTAL MATERIALS

28.75












3D printer time

60

3



EK's 3D printer

0.05 / min

Injection moulding time

0

0





Assembly time

20

5



EK

15 / h

TOTAL MACHINE TIME

8












GRAND TOTAL

47.99






Onboard Gateway

3D viewer: https://a360.co/32DGUHE

Files: https://github.com/RobotGrrl/Hackaday-CXL/tree/master/Design/onboard_gateway

Length

15.6 cm

Width

8.5 cm

Height

6.3 cm

Approximate Weight

300 g

Materials

PLA 3D printed pieces

Waterproof Rating

Not waterproof

Eja Bill of Materials - Onboard Gateway



Last Updated: Sept. 18, 2020



All fasteners for prototype are zinc-plated steel



Item

Qty

Cost (USD)


McMaster Part #

Source

Notes

M2.5 x 8 mm

8

1.07


90128A184



M2.5 x 6 mm

0

0.00


90128A183



M2.5 Washer

0

0.00


98688A111



M2.5 Hex Nut

8

0.18


90591A270



M3 x 10 mm

4

0.57


95263A134



M3 Washer

0

0.00


98688A112



M3 Hex Nut

4

0.09


90591A250



TOTAL MECH COMPONENTS

1.91












1 kg 3D Printer Filament PLA

0.75

21.74



Amazon


TOTAL MATERIALS

21.74












3D printer time

180

9



EK's 3D printer

0.05 / min

Injection moulding time

0

0





Assembly time

10

2.5



EK

15 / h

TOTAL MACHINE TIME

11.5












GRAND TOTAL

35.15





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