What weight tolerances on the Z arm should we respect? notice my language choice as I often “abuse” my variables 
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The holding torque looks to be 4.4Lb I should be fine with less than 450G of additional weight but then there are a number of other items contributing, cabling, arm extrusion,stepper, utm etc…
- for the arm
- the tool / 3 magnets
debating to mount above the UTM or engineer a tool w custom pinouts…