Workholding Options

Securing your material to your Mill One’s bed is a crucial part of CNC milling. Here’s a couple of workholding options you can use!

Double Sided Carpet Tape

Double sided carpet tape is one of the fastest and easiest options for securing your material and can be found in most hardware and department stores. Carpet tape is surprisingly sticky, and works best when applied to large, flat objects. Using carpet tape can help you avoid the need for workholding tabs because the part which is being milled is held onto the bed surface by the carpet tape.


  • Ensure surfaces are clean before applying carpet tape.
  • Press firmly on your material to ensure both surfaces are adhered properly.
  • Water will often cause the tape to loosen its hold on the tape. Keep this in mind if you are using coolant.


Clamps like the 2 inch C clamp shown in the picture are simple and easy to use. Clamps of all shapes and sizes can be found in hardware stores and you can even find small, inexpensive ones in your local dollar store.


  • Ensure that the router will not run into the clamps. You can make sure by moving your router to the outer dimensions of the part you are making.
  • Securing material on one side can sometimes cause the material to lift up on one side. Double check that the bottom of the material is flat before milling
  • If you need to cut a part out of the material, you can use a combination of clamps and double sided carpet tape to secure your piece. Otherwise, make sure to use workholding tabs in your part.


Vises come in all shapes and sizes, for hundreds of applications. Because of it’s parallel facing jaws, a vice is perfect for holding square or rectangular items, but can be used to hold just about anything. Vises offer extremely high clamping forces, which are needed when milling tough materials. A low profile 4 inch cast iron drill press vise like the one shown below works well for firmly holding materials.


  • Tall vises will decrease the height that the Z axis can travel. Make sure to pick a suitable vise which allows for enough clearance.
  •  Ensure the jaws of the vise are not in the way during the milling operation.

Hot Glue

Recommended by Nathan C.

Hot glue is a great workholding option for both flat and irregularly shaped materials. When properly used, it offers a higher degree of strength than carpet tape while eliminating the need for workholding tabs. Parts can be removed from the bed with a paint scraper or peeled off by hand. Using hot glue can sometimes be somewhat tricky, as you must apply an even layer of glue to keep the workpiece level with the bed and secure the piece before the glue cools. With some practice however, hot glue offers a quick, cheap, and effective workholding option.


  • Hot glue will sometimes take chunks out of your material, especially with foam and wood. You can prevent damaging your work by applying glue strategically in areas that are not cosmetically important or used in thin layers which are easy to peel off.
  • Hot glue hardens faster on metals (due to their high thermal conductivity) compared to other materials like plastic and wood. When using metals, apply glue to a non metallic wasteboard secured on the bed and place the material on top to secure it so that the glue has a chance to stick to both surfaces.

Other Workholding Options

Here are some other workholding options suggested by the Sienci Mill One user community.

  • Screws to hold materials to a wasteboad (recommended by Jim F.)
  • Machining wax (recommended by Huayi G.)
  • T slot tracks (recommended by James M.)

Let us know which workholding method you prefer! And if you have any suggestions for holding methods that we haven’t yet discussed feel free to let us know at so that we can tell the world!