Easy CNC Guide 3D

Easy CNC Guide 3D

Easy CNC Guide 3D is a simple, modular set of 3D-printable parts that lets you quickly build a table-mounted router sled on two 25×25 mm steel profiles. This project is my own interpretation of a well-known guide concept you might have seen online (e.g., on Instagram or Kickstarter).

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🎯 What is Easy CNC Guide 3D for?

• Surfacing large s
  
  By running a router sled on two parallel 25×25 mm steel profiles, you can achieve perfectly flat, straight cuts over an entire tabletop or workbench—no expensive CNC machine required.

• Fast assembly & teardown
  
  All printed parts snap together in minutes, and you can disassemble the whole thing just as quickly for storage.

• Perfect for woodworking shops when you need to:

  • Flatten a tabletop
    
  • Sand large surfaces with a sheet of abrasive paper attached to a flat sled
    
  • Mill grooves or recesses in oversized s

Profile Compatibility

Easy CNC Guide 3D is designed around typical 25x25mm square tubes. The gaps in both the corner blocks and the bearing carriages are designed to allow the 25.0mm profile to fit snugly (up to about 25.3mm). If your tube is 25.2-25.3mm, simply lightly sand it with 120-180 grit sandpaper until it slides in without any play.

Note: You don’t have to limit yourself to steel – any 25x25mm tube will work, whether it’s aluminum or even square carbon fiber, as long as its actual width is between 25.0mm and about 25.3mm.

Bearing carriage and pin diameters

Each bearing carriage (both "slider" and "slider 2") can hold four or eight 608 bearings (total 22 × 8 × 7 mm). The bearing "pins" (locating pins) are designed in two diameters:

1. Ø 8.06 mm
   Fits bearings whose inner race measures about 8.06 mm (typical for some Chinese batches).

2. Ø 8.105 mm
   Fits bearings with a nominal inner race of 8 mm (or up to 8.10-8.12 mm in reality).

This allows you to press the bearings in tightly without any wobble, regardless of whether they are slightly below or slightly above 8.00 mm.

Simplysity (geometric) pin option

Before generating G-code, you can swap out the round pins for more square pins. To do this:

1. Load the carriage guide model into the slicer.

2. Replace the round pin part with the “Simplesity model.”

3. Slice as normal—the slicer will generate square pins that will grip the inner bearing ring even more securely.

This is especially useful if your 3D printer doesn’t produce perfectly round holes.

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Hex nut pockets in each carriage

Each bearing carriage contains four embedded hex nut pockets (one for each mounting screw). When you view the sliced ​​“section view” (see photos), you should see a small gap or recess where you can insert a 5mm hex nut during printing.

• Before printing, plan a pause point to insert these nuts.
• Make sure the printed blocks are aligned with each nut location so that the nut is securely captured when you resume printing. add blocker for nut pocket

Carriage Length Options

Two versions of the bearing carriage are available:

• 250mm long (“standard” carriage)
  Ideal for narrower setups or when you want two carriages closer together.

• 300mm long (“long” carriage)
  Designed for wider tables or when you need extra distance between carriages (e.g. on a larger machine).

To have a full Easy CNC Guide 3D setup, print the following:

• Connector × 6
• Footer × 6
• Right corner block × 2
• Left corner block × 2
• Runner carriage (8-bearing) × 2
• Small runner carriage (4-bearing) × 4
• Stoppers × 8
• er × 2
• Stopper screws × 8
• Corner screws × 8
• Runner screws × 4

Corner Post Feature: Flip-Over Height Adjustment

Each corner post (corner block) has a square hole at both the top and bottom. This allows you to flip the entire frame upside down if you need a higher carriage height:

1. Insert the profile into the bottom hole (standard orientation).
2. If you need extra clearance, flip the corner post 180° so the profile fits into the top hole—raising the whole sled assembly by one block height.
3. For intermediate heights, you can also insert a connector + footer stack between the corner block and profile.

This flip-over design lets you adjust clearance without redeg or adding extra spacers.