How to Cut a Bowl and Tray on the CNC: Bit Setup Steps
By Premium CNC & Router Bits for Precision Cutting | Published: 2026-11-03
Category: How-to Guides
Set up a CNC bowl and tray bit for clean, ridge-free cuts. Step-by-step guidance on corner radius, feed direction, and bearing use for tray routing.
Quick answer
Use a bowl and tray bit with a flat bottom to clear the tray floor in shallow, overlapping passes, then switch to a bearing-guided pass for juice grooves. Match the corner radius to the fillet you want and keep the bit moving to avoid burn marks.
Why corner radius and bit style change your setup
The corner radius sets the fillet where the tray wall meets the floor. A 1/4-inch radius leaves a tighter inside corner, while a 3/16-inch radius gives a slightly sharper transition. Neither is better; pick the one that matches your design and the look you want.
A spiral bowl and tray bit clears chips more aggressively than a straight-flute bit, which helps in deep tray pockets. The trade-off is that spiral bits can leave a slightly different floor finish, so test your stepover on scrap before committing to the final tray.
When a bearing helps and when it gets in the way
A bearing-guided bowl bit is useful for routing juice grooves around a charcuterie board because the bearing follows a template and keeps the groove at a consistent distance from the edge. For freehand CNC pocketing, the bearing can interfere with the collet clearance or the dust shoe, so many users remove it or choose a non-bearing version.
If your tray design has a template-routed groove, plan the bearing pass after the main pocket is cut. If you are cutting a deep bowl with no template, a non-bearing bit gives you more Z-axis freedom.
Step-by-step CNC bowl and tray bit setup
- Choose the bit by corner radius and depth: Pick a 1/4-inch radius bit for a softer inside fillet or a 3/16-inch radius for a tighter corner. For deep trays, choose a bit with enough cutting length, such as the 1-3/4-inch length on the triple-flute spiral model. Check that the bit’s cut length exceeds your deepest pass before you program the toolpath.
- Set RPM and feed rate for the bit: Start at the bit maker’s recommended RPM when listed; the AstraHP-coated 1-1/4-inch bit lists 14,000 RPM. Keep the feed steady so the bit stays engaged and does not dwell in one spot. If you see burn marks, increase feed or reduce RPM slightly rather than pushing deeper passes.
- Program overlapping passes for a flat floor: Use a stepover of about 40–60% of the cutting diameter and cut in shallow depth increments. A flat-bottom bowl bit is designed to avoid ridges, but too large a stepover can still leave visible scallops. Run a test pocket on scrap with your planned stepover before cutting the final tray.
- Use the bearing with a template for juice grooves: For a charcuterie board groove, install the bearing and collar, secure a template, and route the groove in one continuous pass at a consistent depth. Keep the bearing in contact with the template and avoid tilting the router. Test the bearing fit on the template before routing the actual board; a loose template causes a wavy groove.
- Clear chips and check the floor between passes: Pause between depth passes to vacuum chips from the pocket. A triple-flute spiral bit clears chips well, but packed chips can still cause the bit to rub and leave marks. If the floor looks fuzzy, take a light finishing pass at full depth rather than sanding heavily later.
Bits that fit this workflow
- 1-1/4″ Bowl & Tray Bit w/Bearing x 1/4″ Corner Radius x 1/2″ Shank – Whiteside 1376B: 1-1/4-inch cutting diameter, 1/4-inch corner radius, 1/2-inch shank, and a bearing for template work. The bearing makes it a practical choice for juice grooves on charcuterie boards, while the 1/4-inch radius softens the tray floor edge.
1-1/4″ Bowl & Tray Bit w/Bearing x 1/4″ Corner Radius x 1/2″ Shank – Whiteside 1376B - 1-1/4″ Bowl & Tray Router Bit x 1/4″ Corner Radius x 1/2″ Shank – Whiteside 1376 (AstraHP Coated): AstraHP-coated 1-1/4-inch bowl and tray bit with 1/4-inch corner radius and a recommended RPM of 14,000. The coating can help with wear resistance, and the stated RPM gives you a starting point for your router or spindle speed.
1-1/4″ Bowl & Tray Router Bit x 1/4″ Corner Radius x 1/2″ Shank – Whiteside 1376 (AstraHP Coated) - 3/4″ Triple Flute Spiral Bowl & Tray Bit – 3/16″ Corner Radius – 1/2″ Shank – 540-BT750 (AstraHP Coated): 3/4-inch triple-flute spiral bowl and tray bit with 3/16-inch corner radius and 1-3/4-inch cutting length. The longer cutting length and triple flutes suit deeper tray pockets where chip clearance matters more than a tight corner radius.
