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Screw length for Machined Aluminum Bracket for 37D mm Metal Gearmotors

The product page for the 30:1 Metal Gearmotor 37Dx68L mm 12V says twice that mounting screws must not screw into the motor more than 3mm. However, the Machined Aluminum Bracket for 37D mm Metal Gearmotors comes with 8mm screws, which protrude 4.4mm through the bracket (according to the drawings). Will using these screws cause damage to the motor? I would assume not because they’re both made by Pololu. However, I thought it safest to double-check because the motor’s product page seems quite insistent about the 3mm maximum depth.

Note: I arrived at the 4.4mm number by subtracting the thickness of the bracket (6.5mm - 2.9mm = 3.6mm) from the screw length (8mm). I also confirmed this number by measuring the protruding screw with a ruler (length is ~4mm).


That warning on the product page is based on the 3mm threaded depth of the mounting hole, and our recommendations to not exceed that are intended to maintain a decent safety margin. It is possible to use longer screws, but that increases the risk of permanently damaging something if you slightly misjudge the length. The screws we include with our brackets will always be safe to use with their corresponding gearmotors, even if they extend beyond the 3mm threaded depth of the mounting holes.

- Patrick

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