Work Holding, Clamps, and Jigs
Work holding
In general, no hard metal hold downs are safe for the CNC, like screws or metal clamps, because of the risk of ejecting shrapnel out into the shop.
Strategies
Brass screws and composite nails may be used, and are available in the shop. Be sure to remove them after use!
- Brass screws are good for attaching from the top (easier) or bottom (if the top surface must be preserved) and provide the best overall strength and reliability.
- Composite nails are quick to attach into waste material from above.
Cam and wedge clamps work well and can be easily customized for stock that has square edges. Several are available near the machine.
- Great for work without waste material, engraving, and repeat setups.
- It's better to make a block that fits just right rather than use too many pieces in one direction, or the assembly may buckle outward.
- Avoid too much upward pressure by using a down-cut endmill or making shallow passes with standard up-cut endmills and engraving tools.
Wooden peg based "7"-shaped hold fasts and clamps may be used on the grid of holes in the spoilboard, but still take care to avoid when programming.
- Great for holding fragile work, pieces that cannot easily be held from the sides or below, and for projects which need to resist more upward forces.
- Steel holdfasts may not be used.
Files
We can always cut more clamps and jigs! If you make something for the CNC, consider sharing models or drawings here.
Corner jigs and clamps: CNC Workholding Clamps + Jigs.f3d