250mm Multirotor Arm
This multirotor arm was designed as a replacement for a ZMR-250 and it's variants. This is version 6 of the design. When printed as described in the Print Settings section, I found that the durability of version 6 is much improved over previous versions.
This mount was designed for motors that use 3mm screws. M3x6 screws (3mm diameter by 6mm long) should work for most motors, but that recommendation is based on the motors that I've mounted to the arm. If you are planning on using this multirtor arm, please make sure you don't use a screw that is too long or your motors could be ruined.