CNC Router

General Information

The CNC machine can be found inside the Wood Shop. When using any equipment in the woodshop, make sure to wear all proper safety equipment.

If you have any issues with Wood Shop equipment, the slack channels associated with this space include: #general, #shop-cnc, and #shop-wood

Orientation

The order of this document is to give some basic information of what will happen in the woodshop during the training. This orientation assumes that they have gone through our general space orientation.

This page will include video and textual links to supplement our CNC orientation, as well as the CAD / CAM instructionals we occasionally host. This is not a replacement to our orientation.

Do not operate any power equipment if you are under the influence of anything, in a hurry, are tired, or are not feeling well.

Inspect the equipment before using it.

General Safety Rules of the Woodshop

Attire
- Avoid loose clothes and hair
- Remove rings
- Wear close-toed shoes
- Don't wear gloves when operating power tools
Wear Safety Glasses
Wear respiratory protection when appropriate
Wear hearing protection for loud equipment or extended use
Keep floors clean, clear, and dry
- Keep extension cords off of the floor when not in use
Don't throw oily rags in the trash can
Store finishes in the yellow cabinet
Don't eat and drink around power tools
Be aware of people around you when using equipment, and don't approach others while they are using equipment

Equipment

CNC Router

AvidCNC Pro60120 platform, with 3 HP Plug and Play Spindle / VFD System

Work Area:
- X: 61-3/8“ (1559 mm)
- Y: 124-1/4” (3156 mm)
- Z: 8“ (203 mm) - minus spoil board thickness
Footprint:
- Width: 78-3/4” (2000 mm)
- Length: 141“ (3582 mm)
- Height: 77-1/2” (1970 mm)
- Weight: 708 lbs (321 kg)
Cutting Speed:
- 500 IPM (NEMA 34 version)
Rapid Speed:
- 1000 IPM (NEMA 34 version)
Drive System:
- X/Y: PRO Rack and Pinion
- Z: Precision Ballscrew
Resolution:
- X/Y: 0.0005” (0.0127 mm)
- Z: 0.0002” (0.005 mm)
Repeatability: +/- 0.002” (0.05 mm)
Accuracy: +/- 0.005” (0.127 mm) or better

Getting Cleared to Use the CNC Router

Attend scheduled CNC orientation
Successfully complete checkoff project
1. “Check off” involves getting your name on the CNC Operator Board, located above the CNC tool cabinet
2. This involves designing and machining a personalized nameplate that can be installed on said operator board
  1. 9×2“ max, any wood, any post processing
  2. Any software that creates gcode to be used on the AvidCNC router is fine
    1. Fusion 360, vCarve both have AvidCNC post processors for their output
    2. Easel's generic gcode output works fine. Verify speed control is set to automatic (and put in your spindle speed there)
    3. Mach 3 post processors in other design software should work fine as well. This is where “previewing your gcode” before running it comes into play
    4. Output in inches, not mm / cm
  3. We strongly recommend beginners use vCarve's “Avalon” tutorial to quickly get up to speed on basic design and camming for this project

Software for design (CAD) and gcode creation (CAM)

vCarve - we have a makerspace license for this, and it can be installed on any machine running Windows. Great for 2d / 2.5d projects. Their training library is extensive
Fusion 360- multiplatform, cloud based storage, great for both cnc routing as well as 3d printing. Free license for personal use
Carbide Create- free, simple, multi platform. Very similar to Easel, just not cloud-based. Has a pro license for certain features like 3d carving, but its free license is far more capable and less problematic than Easel has become

End Mills

Size

We have collets for 1/8”, 1/4“, 1/2”, and 3/8“ shank end mills
- DO NOT use end mills with metric sized shanks
Bigger shanks are better! Shanks often are larger than the cutting diameter
- Keep in mind how deep you plan to cut as well. Even when the shank matches cutting diameter, you shouldn't be rubbing it against what you just cut
Less is more when it comes to cutting lengths. They deflect less, and you can increase your feed rate

Feeds and Speeds

Feed rate: How fast the machine is pushing the end mill around the cutting area
Speed rate: How fast the spindle is turning the end mill
Other factors that affect your cutting ability:
- Depth per pass - most feed and speed guides assume a depth of 1xtool diameter. Going deeper will need you to reduce speed
- Stepover - rule of thumb is 1/2 diameter for pocketing operations. Smaller stepovers can can improve surface finish, while increasing machining time
- Chip load - how much material you're actually removing per flute, per revolution. Feeds and speeds can be increased or decreased while maintaining this ratio. Keeping within spec can prolong the life of your end mill
What Settings Do I Use?
- Consult the manufacturer recommended feeds and speeds for the end mill you've selected. That is not necessarily the hardest you can push that tool - these are starting points, and this turns into an art over a science, quickly
- I will often use settings from another manufacturer for a similar, cheaper tool from Amazon. If tool diameters / lengths / geometry / number of flutes match, this will often work fine