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A CNC-Milled Isogrid Aluminum Skateboard

By Titans of CNC, for aerospace-grade ollies

By Rain Noe - April 3, 2023

in Digital Fabrication

An isogrid is a structure made from a solid metal sheet that has had triangular portions machined out of one face, leaving a thin skin on one side, and a triangular lattice on the other side.

Image: NASA

Invented by McDonnell Douglas, the technique is too expensive and impractical for mass production, but is prized within aerospace, as it yields solid, stiff but lightweight parts.

Image: NASA

As an experiment Titans of CNC, the manufacturer and CNC educational institution, created an isogrid-style skateboard from a 50-pound slab of 6061 aluminum. Resident machinist Barry Setzer started by measuring a standard laminated skateboard deck, transferred the dimensions to Solidworks, then figured out how much material he'd have to remove for the aluminum piece to match the weight of the 3.4-pound laminated one. (In other words, if machined solid, the aluminum deck would weigh 15 pounds, so 11.6 pounds had to go. Enter the isogrid.)

Setzer then ran the design through Mastercam, then CNC-machined it into reality on a BVM 5700 vertical machining center, a high-end machine manufactured by DN Solutions.

Technically speaking, sure, it's not a classic isogrid in that both faces have been removed. But the end result is beautiful:

Impressively, they even machined in the "grip tape" to provide traction for the skater:

Part of the "fun," of course, was working out the hold-down for the milling process: How do you cut the part loose at the end without destroying it? Obviously they figured it out:

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Ryan G

a year ago

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Technically, it’s still isogrid just with no face sheet. There’s also a ton of designs in the consumer side with isogrid, many injection molded parts have an isogrid on the B side of the part. The other main aerospace grid style is orthogrid. Orthogrid can be stronger in certain directions but unlike isogrid, it needs a face sheet to carry shear, otherwise the orthogrid would collapse (like a cardboard wine box insert).

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Dan Lewis

a year ago

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Ok, fun exercise, but if weight only gets back to the weight of a plywood deck it"s really kind of a serious time waste. No improvement.

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Ryan Cee

a year ago

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This is a cool design, but it could easily be forged on a line press resulting in a far stronger piece, the production would be a lot faster and cheaper, and result in a lot less material waste. Making the dies for it though... slightly less cheap.

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