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

Equipment

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

Orientation

First Steps

• Switch power on to both control and VFD (located on right side of the table)
• Visually inspect all sides of table to ensure nothing is in the way
• Verify the e-stop on the table and the pendant are not pressed

The Cycle Start Checklist

The Cycle Start checklist is your friend. Complete all steps before hitting Cycle Start

1. Locate the emergency stop

• Know where both e-stops are located (table and pendant) so you can react quickly if needed
• Test that you can reach them without looking away from the machine

2. Home your machine

• Establishes the machine's reference coordinate system
• Ensures accurate positioning and prevents out-of-range errors
• Must be done after every power cycle, emergency stop or pressing the stop button

3. Confirm Material Dimensions

• Verify your material size matches what's programmed in your toolpath
• Check for proper clearance around the entire cutting area
• Ensure material is flat and properly supported

4. Secure Workholding

• Confirm clamps, screws, or plastic nails are properly engaged
• Test that material cannot move during cutting operations
• Avoid placing workholding where it might interfere with the toolpath

5. Check router bit installation

• Verify the correct bit is installed for the current operation
• Ensure collet and nut are properly tightened
• Check that bit length matches your toolpath settings

6. Verify work coordinate offsets

• Set X, Y, and Z offset either manually, or with the z-probe
• Double-check Z-zero position relative to material surface
• Verify X and Y zeros match your intended starting position

7. Load G-Code and Preview Toolpath

• Open your file in Mach4 and use the preview function
• Watch for any unexpected movements or rapid moves
• Verify the toolpath matches your design intent

8. Review Mach 4 and G-Code

• Check that feed rates and spindle speeds are appropriate
• Make sure that any overrides are reset before running your next toolpath

9. Test Spindle

• Run the spindle briefly at your programmed RPM without cutting
• Listen for unusual noises or vibrations
• Verify spindle starts and stops correctly

10. Reinstall Dust Shoe

• Ensure dust shoe is properly seated around the collet
• Confirm vacuum hose is connected and clear
• Make sure blast gate is open, and other blast gates around the woodshop are closed

Software

To use the CNC router, you typically need software from two categories: CAD (Computer-Aided Design) for creating your project and CAM (Computer-Aided Manufacturing) for generating toolpaths. Some programs combine both into a single tool.

Software	Type	Cost	Best For / Description
FreeCAD	CAD	Free & Open-Source	Complex 3D parametric modeling. Steep learning curve but very powerful.
Inkscape	CAD	Free & Open-Source	2D vector designs (signs, profiles). Excellent for artistic projects.
Fusion 360	CAD & CAM	Free for Hobbyists	An all-in-one professional solution. Powerful but has a steeper learning curve.
Easel	CAD & CAM	Freemium	The easiest all-in-one web-based software to get started quickly. Good for beginners.
Carbide Create	CAM	Free / Paid	Easy-to-use 2D CAM software. Can import SVG and DXF files.
VCarve Pro	CAD & CAM	Paid (Makerspace Licensed)	Our primary, recommended software. Excellent for 2D, 2.5D, V-carving, and importing 3D models. User-friendly with powerful features.

Using Our Makerspace License: VCarve Pro

Our makerspace has a license for VCarve Pro, which is installed on all PCs in the Clean Room.

To get a license for running the Makerspace Client version of this software on your own PC, please attend an upcoming CAD/CAM for the CNC Router workshop.

For detailed instructions and tutorials on using VCarve Pro, please see the dedicated wiki page: VCarve.

Getting Started with Software

• For Beginners: If you are new to CNC, start with VCarve Pro on the shop computer. It has a more guided workflow and extensive built-in tutorials.
• For Simple 2D Projects: Inkscape (free) is excellent for creating or editing 2D designs, which can then be imported into VCarve Pro for toolpath generation.
• For Advanced 3D Modeling: If you want to design complex 3D parts at home, FreeCAD or the hobbyist version of Fusion 360 are powerful free options. You can then bring your model to the shop to be processed in VCarve Pro.

End Mills

End Mills are considered consumables - while we have them on hand for orientation, you need to provide your own afterwards.

An incredibly comprehensive guide on endmills can be found here:

Bit Types and Their Uses

Straight Bits (Up-cut)

• Pulls chips upward, good for through cuts
• Can cause tear-out on top surface
• Best for: cutting out parts, slots, dados

Straight Bits (Down-cut)

• Pushes chips downward, excellent top surface finish
• Can compress chips in slots
• Best for: top-quality edges, plywood, veneered materials

Compression Bits

• Combination of up-cut and down-cut geometry
• Clean edges on both top and bottom surfaces
• Best for: sheet goods, plywood, melamine

V-Carve Bits

• Create decorative V-shaped grooves
• Various angles available (60°, 90°, 120°)
• Best for: sign making, decorative carving, lettering

Ball Nose Bits

• Rounded tip creates smooth contours
• Ideal for 3D carving and curved surfaces
• Best for: 3D models, decorative carving, mold making

Spoilboard Surfacing Bits

• Large diameter with multiple flutes
• Designed specifically for flattening surfaces
• Best for: resurfacing spoilboard, facing lumber

Collets

• We have ER-20 collets for 1/8", 1/4", 1/2", and 3/8" shank end mills
  • DO NOT use end mills with metric sized shanks. If you need to, you can provide your own ER-20 collets with the appropriate shank diameter for your metric tool!
• 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 1× tool diameter. Going deeper will need you to reduce speed
  • Stepover - rule of thumb is 1/2 diameter for pocketing operations. Smaller stepovers 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
• How to Choose Feeds and Speeds
  • 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
  • The presets on VCarve will often be conservative. They will work, just not 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

Endmill recommendations

Cheap

Spetool: Amazon

High Quality

Amana Tools: Tools Today. The AMS-119 3 piece starter pack has several tools you'll be using a lot: AMS-119 Starter Pack

Local

• Woodcraft in Lexington - Sells Whiteside, Freud, and Amana
• Lowes / Menards / Home Depot - some V-carving and straight end mills available
  • DO NOT use end mills with guide bearings

Troubleshooting

Common Problems and Solutions

Machine won't move after turning on - toolhead stuck at endstop

• This happens when the machine was turned off with the toolhead parked against an endstop
• The endstop switch remains engaged on startup, preventing normal movement
• Solution:
  • In Mach4, go to the Jogging tab and enable the "Axis limit override" function
  • Carefully jog the toolhead away from the endstop in the correct direction (make sure you're moving it away from the limit switch)
  • Once clear of the endstop, disable the "Axis limit override" function
  • Then proceed with normal homing procedure

Router bit keeps breaking

• Check your feeds and speeds - you're likely pushing too hard
• Reduce depth per pass (try 1/2 tool diameter instead of full diameter)
• Ensure the bit is properly secured in the collet
• Check for runout in the spindle

Poor edge quality or burning

• Increase feed rate - you're moving too slow and burning the material
• Check for dull bit - replace if necessary
• Use climb cutting instead of conventional cutting
• Consider using a down-cut or compression bit

Material moves during cutting

• Improve workholding - add more clamps or screws
• Use tabs when cutting out parts completely
• Reduce cutting forces by using smaller stepover or shallower passes
• Check that your spoilboard is flat and properly supporting material

Machine makes strange noises

• STOP IMMEDIATELY and investigate
• Check for loose components or mechanical issues
• Verify nothing is interfering with the machine's movement
• Look for chip buildup around the bit or dust shoe

Cut depth is inconsistent

• Re-surface your spoilboard - it's likely not flat
• Check that your material is properly supported
• Verify Z-axis is properly calibrated and not slipping
• Ensure workholding isn't causing material to bow

Dust collection isn't working

• Check that blast gates are properly set (open at CNC, closed elsewhere)
• Look for clogs in the dust shoe or hose
• Verify vacuum system is running
• Clear any debris around the dust shoe seal

Machine won't home properly

• Check for obstructions in the machine's travel path
• Verify limit switches are functioning
• Ensure e-stops are released
• Check that all power is on (control and VFD)

G-code errors in Mach4

• Verify your file is saved in the correct format
• Check for special characters or unsupported commands
• Make sure you're using the correct post-processor from your CAD software
• Preview the toolpath to identify problematic sections