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titleMaterial strength of Acrylic (Plexiglas), PETG 3D printed plastics.

[1] Acrylic
Yield Strength: 64.8 - 83.4 MPa (Average value: 75.4 MPa)
Young’s Modulus: 2.76 - 3.30 GPa

Flexural Modulus: 2.96 - 3.30 GPa
Flexural Yield Strength: 98.0 - 125 MPa (Average value: 109 MPa)

[2] PETG
Yield Strength: 28.3 - 58.6 MPa
Young’s Modulus: 1.10 - 20.3 GPa (Average value of 2.65 GPa)

Flexural Modulus: 1.17 - 2.76 GPa
Flexural Yield Strength: 39.2 - 88.9 MPa (Average value of 69.5 MPa)

In short, Plexiglas is a strong enough viable alternative for the side walls of the cover.

Gel-coat
Protective finishing layer for composite surfaces.
Leaves a hard smooth surface good for sticking on adhesive.
Requires sanding and buffing for a smooth surface.
If painting the cover, apply gel-coat first then paint over it.

Source:
[1] http://www.matweb.com/search/datasheet.aspx?bassnum=O1303
[2] http://www.matweb.com/search/datasheet.aspx?matguid=4de1c85bb946406a86c52b688e3810d0

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Process Name

Details

Notes

Wet layup

  • Done by hand

  • Manual layering of fiberglass and resin onto both sides of foam core

  • Minimal equipment and tools required

  • Most inexpensive option and least amount of setup work required

Infusion

  • Vacuum bagging creates even pressure on the part

  • Nicer finish and stronger part than wet layup

  • Quite a bit of tools required

  • Requires mold (most likely)

  • Uses more resin

  • Good for parts of the cover where it bends and curves as the pressure from vacuum bagging keeps them in place

For the current cover design, a mix of both manufacturing processes is viable and is probably the best choice in terms of reducing time spent manufacturing and resources used.

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titleWaterproofing

Gasket for battery cover would be stamped out or cut out from a flat sheet of rubber to match the outline of where the cover would sit on the edges of the walls.
Neoprene is what is typically used for gaskets (synthetic rubber).


Gaskets could be manufactured by using die cutting, water-jet cutting, and laser-jet cutting.
Manufacturing could be potentially done in-house with a large enough laser cutter and a large sheet of rubber, or could potentially be made using a small blade slicing the rubber to the CADed shape.


For the seal to be effective, it should be one continuous piece that covers all openings and shall be compressed against the surface of the resting site and the cover so that small air gaps could be filled to prevent potential water from leaking.

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Assembly Detailing

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