I kinda like the idea somebody had of using a drill-stop. You can find them at the hardware store, like a really big thick washer, with a hex set-screw.
Just take the Aixiz module with you and find one that's nice and snug.
I wound up using a thick bronze metric flange bearing, but they're probably harder to find.
For my TEC project I just bought a surplus aluminum bar and spent half an hour cutting a cube off it with a jigsaw, then drilled it to fit an Aixiz.