You can buy a commercial version of the measuring cube, posted on this site and downloaded over 2.5 million times, dishwasher safe, food-grade material, durable injection-molded plastic:
https://www.ebay.com/str/MeasuringCube

bakercube | USB and SD holder | plug saver | coins | juice squeezer | more...

Clamp A | Similar to a standard “spring” clamp | Size: regular | Height 145 mm (5.7”) | Clamp opening: 80 mm (3.2”) | Clamp reach: 52 mm (2”) | Smaller sizes: scale it down | Larger sizes: scale it up | Standard clamping strength: use a few rubber bands | Weaker clamping strength: use less rubber bands | Strong clamping strength: add some rubber bands | Extra strong: add even more bands.

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Clamp B | Similar to a standard “photo” clamp | Size: regular | Height 145 mm (5.7”) | Clamp opening: 76 mm (3”) | Clamp reach: 52 mm (2”) | Smaller sizes: scale it down | Larger sizes: scale it up | Standard clamping strength: use a few rubber bands | Weaker clamping strength: use less rubber bands | Strong clamping strength: add some rubber bands | Extra strong: add even more bands.

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We printed PLA at 0.2 mm layer, 70% infill or more (you do need strength for this one).

Supports: NONE (please don’t use any supports, they will fuse parts and the clamp will not work)

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The Clamps are protected by US patent pending.

Enjoy