CNC WORKPIECE HOLD

This is a hold-down for material to be shaped by a CNC mill.

Notes:
This hold down has been evaluated for several months with my own CNC machine and in a commercial operation with excellent results.
Filament material does not matter but I prefer PLA. Use 0.2-layer height. The octagonal rods may need a raft depending on your printer setting (I did not use a raft). Support material is not needed.
The hex rods fit very snug in the base (needs to be pounded in). The slider moves over the hex rods tightly. The washer is needed to keep the M4 bolt from backing out of the slider. The fixed block can be attached to the table were wanted in place of the adjustable hold-downs.
M4 hardware needed: M416 or eighteen bolt, M4 washer, M4 nut. Washer and bolt for attachment to the table varies with user.
The nut is held in place by a taped recess. When first assembled, the bolt should be fully tightened to sink the nut into the taper.
The clamp is strong because of the orientation of the laye