🌍CNC Topographical Carving Settings
Why Deep Cuts Matter: 3D topographical carvings look dramatically more impressive with thicker material and deeper cuts (2-3 inches). The added depth creates realistic shadows and dramatic relief that truly brings the landscape to life.
⚠️ The Challenge: Deep cuts require longer tool stick-out, increasing vibration and breakage risk—especially with smaller end mills. Proper feeds and speeds become critical for success.
Baltic Birch Plywood
Personally, I really like Baltic Birch Plywood as there are almost no air gaps between the layers. You can find this online in places like Woodworkers Source and similar sites. Or, you could just get it off Amazon. I have found that stacking 2-3 sheets works just fine when you glue them well with wood glue and some clamps for 24 hours.
⚠️ Important: Carving deep topographical maps requires longer tools so the collet doesn't crash into the workpiece. Here's a straightforward recipe sheet for 2″ deep carves using Baltic birch plywood.
📏 Tool Length: A 3″ long end mill is basically required for successful 2″ cuts, allowing for proper clearance and avoiding collet contact with the workpiece.
🪚Roughing Pass — 1/4″ Downcut
🔧 Tool Specifications
- • Solid Carbide 1/4" downcut end mill (3" overall length minimum)
- • Flute Length: At least 2.5" for deep carving clearance
- • Stick-out: Keep as short as possible while reaching full 2" depth
- • Collet Insertion: Insert fully, then back out 0.063" for thermal expansion
👉 Purpose: Removes bulk material quickly while leaving 0.01-0.02" stock for finishing pass.
Strategy: Flat end mills cut aggressively to establish basic terrain shape.
Pro Tip: Start conservative (80 in/min) and increase based on machine rigidity.
🎨Finishing Pass — 1/8″ Ball Nose
🎯 Ball Nose Advantages
- • 3D Contours: Ball nose creates smooth curved surfaces perfect for terrain
- • Any Angle: Rounded cutting edge works at all angles and slopes
- • Surface Quality: Eliminates scalloping for professional finish
- • Detail Resolution: 1/8" diameter captures fine topographical features
👉 Purpose: Refines surface to final precision and smoothness after roughing removes bulk material.
Strategy: Light finishing cuts with minimal deflection create professional topographic detail.
Critical: Avoid bit deflection by ensuring roughing left only minimal material to remove.
💡Critical Success Tips
Rigidity decreases by power of 3 as length increases. Every diameter reduction in stick-out doubles rigidity.
Roughing leaves 0.01–0.02″ material. Finishing pass removes this for precision surface.
Cutting depth should never exceed flute length or chips won't clear properly.
Deep cuts require excellent dust collection to prevent heat buildup and recutting.
Chatter indicates tool deflection. Reduce feed rate or stick-out length immediately.
Burning edges mean chips aren't clearing. Increase feed rate or improve evacuation.
Small end mills deflect easily. Conservative feeds prevent breakage on long stick-outs.
Ball nose stepover of 10% tool diameter (0.012") creates smooth topographic surfaces.