CNC Routing

We have three CNC routers, each with its own limitations and capabilities.

CNC routing should be utilized when cutting 2d profiles, stepped topographies and 3d objects from materials such as wood and wood products, plastics and foam.

Community Designers

Are you a designer in our community who needs to use a CNC router?  Check out our Digital Fabrication Services.


Available Equipment and Machine Limitations


Shopsabre- Fab Lab

  • Maximum material size- 96”x 60”x 4” (foam up to 6″)
  • 3 Axis with additional Tangential Knife Cutting
  • 11 station automatic tool changer
  • Vacuum workholding
  • Best applications- Complex deep 3d surfacesDue to the large available z axis travel, thick, softer, materials such as foams, but it is suitable for all CNC routing applications.



Thermwood- A+A Woodshop

  • Maximum material size: 120”x 60”x 2”
  • 3 Axis of motion
  • 11 station automatic tool changer
  • Vacuum workholding
  • Best application: 2.5 axis milling. Due to the rigidity, bed size, vacuum fixturing and the tool changer, the Thermwood is best suited for cutting sheet goods such as plywood and mdf.



Shopbot Alpha- Fab Lab

  • Maximum material size- 96”x 48”x 3” (foam up to 4″)
  • 3 Axis with additional Rotary 4th axis
  • Manual tool changing
  • Mechanical workholding
  • Best applications- Complex deep 3d surfacesDue to the large available z axis travel, thick, softer, materials such as foams, any work requiring the use of the 4th axis.



Shopbot Desktop- Fab Lab

  • Maximum material size- 24”x 18”x 2”
  • 3 Axis of motion
  • Manual tool changing
  • Mechanical workholding
  • Best applications- Small objects, prototyping


Access Procedure

STEP 1: Attend an Orientation Session

Orientations are held throughout the semester (see calendar).  Orientations are necessary, and successful completion is required before access can be granted (no exceptions). Please plan accordingly; orientations are not conducted on a regular basis.  They occur mainly at the beginning of each semester, and individual sessions will not occur.


STEP 2: Design Something Amazing

Rhino will import geometry from most 2D and 3D software programs. Initial design can be done in many applications (Rhinoceros, AutoCad, Illustrator, SolidWorks, SketchUp, etc), but file must be finalized in Rhino. Make sure that your 3D model is a closed mesh or closed polysurface to ensure that it is “water tight.” Although profiling and pocketing applications can utilize surfaces, it is best that you always work with a 3d model. Be sure your lines meet exactly at endpoints and there are no duplicate, intersecting or overlapping lines. 3d machining requires a polygonal mesh, a surface or solid model. All files should be scaled to the actual size (output size) with units set to inches. File is to only include work to be cut.  All other information must be deleted, and model must be located in 0,0,0 position (x,y,z).


STEP 3: File Review

Before your part is cut, a technician will review the file with you. We will look for errors and suggest appropriate tooling and tool path creation. If your model contains complexities making it difficult to mill, the technician will advise you on methods to achieve the optimal outcome. If revision of your model needs to occur, an additional review meeting might be necessary. After the model is approved by the technician, the tool-paths need will be generated to program the machine to cut your part. To schedule a File review, use the following link 365 Bookings (see calendar below for existing appointments).

Once tool paths are set, the technician will “post process” your file. “Posting” creates a machine-readable text file (G-code), which is specific to the machine you will use and controls all machine operations (such as tool changes). Only technicians have the correct post-processor for our machine set-up: DO NOT post files on your own. Once your file has been posted, we will schedule a time for you to run your part on the CNC router. This generally does not occur immediately. We advise you to have your file reviewed several days (but 24-hour minimum is required) in advance of your desired cutting time. During peak usage, there could be long wait periods, so be sure to plan accordingly.

Material Preparation  Students must supply their own materials. If your material stock is glued up, be sure that it has had sufficient time to dry (24-hour minimum dry time). Use liberal amounts of glue that is spread evenly across the material to ensure complete adhesion when laminating materials. Use the appropriate glue for your material (do not use PVA on foam) because delamination during cutting will require job cancellation. Also please note your actual material thickness, as this may affect your RhinoCAM settings. Calipers are located in the Fab Lab to get the exact thickness of your material. For example, if using 3/4” plywood, it is likely the actual thickness ranges from 0.6875”- 0.78″. These exact dimensions must be used in RhinoCam.


STEP 4: Scheduled Machine Time

Material Set-Up and Operation

The processing of CNC jobs is at the sole discretion of Fab Lab staff: We will prioritize based on estimated cut time, staff workload and user preparation and availability. Having an appointment is not a guarantee of completion of work. Technicians will advise you on how best to secure your stock to the CNC bed and help you set the machine for your part. Users are responsible for observing the machine while in operation (entire cut duration). Please note that it is common for parts to take several hours to finish. All users are required to wear safety glasses while the machine is in operation; hearing protection also is recommended.


STEP 5: Clean Up

You are responsible for leaving the area in a clean condition. There is a dust collection system that will pick-up the majority of dust. When your part is completed, you should blow the majority of the chips off of the machine and sweep/vacuum the floor, putting off-cuts and scraps into the scrap bins or the dumpster. Cut large scraps down to rectangles for reuse. Do not leave large scraps in the router area. You may lose your privileges to use the CNC router if you are negligent in your clean-up responsibilities.


Enjoy your hard work, and please post your project photos to our Facebook page, UTK Fab Lab.



The Fab Lab is host to numerous workshops, lectures and orientations. During events, equipment usage may be limited. Please see calendar for available times for scheduling file review and machine use.

Fab Lab (Primary CNC)

A&A Bookings