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The CNC Wood Routing Handbook – A Beginners Guide

CNC Routing Wood - CNC Tooling Shop

CNC routing unlocks a world of wood cutting possibilities. Each species brings its own personality to the machine table: softwoods that carve like butter, hardwoods that fight back with stubborn grain, and engineered boards that demand a careful balance of speed, tooling, and technique. A successful project isn’t just about uploading a file and pressing go. It’s about understanding how maple chips under pressure, why birch loves a sharp bit, and what makes walnut smoke when feeds and speeds aren’t dialed in. Mastering those nuances turns a CNC router from a generic cutter into a precision instrument that respects the nature of every board it touches.

Router Bits

First off, let’s dive into some of the most common wood cutting bits:

  • Compression Bits: Made with both an upcut and downcut portion in order to minimize material fraying
  • Downcut Spirals: Great for profiles (when not cutting all the way through)
  • Upcut Spirals: Great when fraying is not an issue and chip removal is important
  • Bradpoint Drills: For creating partial holes for dowel pins
  • Through-Hole Drills: For drilling holes completely through wood
  • V-Grooves: For beveling edges or engraving designs

Feeds / Speeds

There could be an article written on the feeds/speeds for each type of wood, so I’ll provide some basics. Feel free to reach out to me for further information, recommendations, and tips/tricks.

Compression Bits are your most common tools for cutting wood. They are specifically designed to eliminate fraying, increase feed rates, and extend tool life. The 3/8″ Compression tool is the most common, so here are a few feeds/speeds by material that I would recommend (assuming that you are using an industrial CNC router) with a 3/8″ Compression. My most sold 3/8″ compression bits are XC2023 and mortise version XC2023-M. If you need a coated version (for longer tool life or laminated wood), then the 60-124MC is great.

MaterialFeed RateSpindle SpeedPer Pass
Solid Wood450-550 IPM18,000 RPM3/4″ or less
HPL / HDF500-600 IPM18,000 RPM3/4″ or less
MDF550-620 IPM18,000 RPM3/4″ or less
Plywood550-650 IPM18,000 RPM3/4″ or less
Melamine600-700 IPM18,000 RPM3/4″ or less

Now that you see the different feed rates that are needed for each wood material, I’m sure that you can imagine how much they will change as we get into upcuts, downcuts, drills, and v-grooves. Again, feel free to reach out if you’d like me to go through your entire project or operation. As long as you get tools through me, I’m happy to help.

One last note that I’d like to make on feeds and speeds is that drilling operations act very different. Drills, whether brad point or through-hole drills are plunging, not cutting side to side. Because of this, low RPM’s are VERY important. The same way you start a fire in the woods by spinning a stick in place, this can happen on your CNC router bed. I’ve seen it happen and helped CNC operators work through the mess of repairing their burned machine. Common feeds and speeds for drilling holes is often in the range of 4,000 – 8,000 RPM at a plunge rate of 100-200 IPM. Pecking motions in and out of the wood can also help remove chips and in turn heat buildup.

Left-Hand vs. Right-Hand Tooling

Left-hand versus right-hand tooling matters far more in CNC wood routing than most newcomers expect. Hardwood fibers behave like tiny stubborn soldiers, and the direction your bit spins determines whether you’re slicing them cleanly or going against the grain and in turn removing chunks of material. Right-hand tools dominate the industry, spinning clockwise to pair with the standard router motor rotation while evacuating chips efficiently upward or downward depending on flute geometry.

Left-handed tools sneak into hardwood routing for several smart, practical reasons, almost like the secret agents of the tool rack. Hardwood likes to fight back, and sometimes flipping the cutting forces is the only way to keep the peace. A standard right-hand bit may try to lift the work off the table or peel grain in the wrong direction, while a left-hand bit pushes the part down instead, keeping clamps and vacuum hold-downs happy. Some setups also need chips traveling the opposite direction for cleaner extraction, cooler cutting, and less scorching on wood that already resents heat. When machining both sides of a component or working in mirrored operations, left-hand tools keep edge quality consistent where the grain would otherwise splinter. They’re not common, though when hardwood starts misbehaving, a left-hand spiral suddenly becomes the hero.

Material Hold-down

Vacuum hold-down is crucial when CNC routing wood. It’s like giving your material an invisible bear hug so the router can hog out large amounts of material quickly. Vacuum tables spread suction across the entire sheet, perfect for large panels and nested projects. Vacuum cups, on the other hand, elevate smaller parts or projects needs side profiles (like doors), gripping specific areas with concentrated force so edges, profiles, and pockets stay crisp without tabs or tape. Hardwood can be slippery and determined to wander when cutting forces ramp up, so choosing between a full vacuum table and precision cups depends on part size, surface area, and how dramatic that wood plans to be during machining. A stable hold means cleaner cuts, safer routing, and no surprise airborne souvenirs. Here are a few materials that you can use as a sacrificial board “Spoilboard” on a vacuum table that will allow air to flow through and assist material hold-down.

  • Standard MDF (Mill both the top and bottom layer before using)
  • LDF (more porous equals more airflow)
  • Ultralight MDF (even more porous equals more airflow)

Mastering the art of CNC wood routing isn’t just about knowing your machine, it’s about understanding the character and behavior of every board that lands on the table. From selecting the right bit geometry to dialing in feeds and speeds that respect the density of each species, every choice influences the outcome. Vacuum hold-down keeps parts grounded, while the often-overlooked balance between left- and right-hand tooling ensures grain and chip flow stay on your side. Once these fundamentals click, your CNC router becomes less of a power tool and more of a creative partner, transforming raw wood into precise, polished work worthy of its natural origins.

15% OFF CNC Router Bits

Greg Smolka

Greg Smolka (Author)

CNC Tooling & Applications Manager

Here to help with tooling recommendations (bits, knives, collets, tool holders, maintenance kits, torque stations, etc.) and applications (feeds/speeds, tips/tricks, # of passes, etc.).

Contact Infogreg@cnctoolingshop.com | (616) 502-7277 | LinkedIn

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Why are my CNC bits breaking?

Why Your CNC Bits Are Breaking

Every so often, I’m asked the question “Why are my CNC bits breaking?” and then the process of elimination begins. There are an array of issues that could be causing this to happen. Here are the most common:

  1. Incorrect feed/speed
  2. Dull bit
  3. Bad vacuum/hold-down
  4. Debris in collet/tool holder
  5. Bad collet

Incorrect Feed Rate & Spindle Speed

First off, the feed rate and spindle speed are often the culprit. Bits can break at too high or too low of both the feed rate and spindle speed. It’s important to find the correct mix of feeds/speeds that meets your material and quality requirements. The easiest solution for this is to send an email to tooling@cnctoolingshop.com. On a daily basis, I’m troubleshooting and offering starting points on how to cut a specific material for my customers.

Dull Bit

Most operators know this, but a dull CNC bit is far more likely to break than a new sharp one. Instead of the dull bit cutting through the material, the pressure is pushing through it until it no longer can. In this case, a smaller diameter tool will break before a larger one will. Pay attention to the cut quality and sound coming from the tool when a new tool is cutting vs. a used one. This way you can spot a dull tool before it breaks or sacrifices too much quality.

Poor Vacuum/Hold-Down

Bad material hold-down can very easily break a bit. Vibration or material movement is the enemy. The hold-down could be bad because of vacuum problems or even a vacuum not suitable for your machine, lack of milling the spoil board, vacuum pressure leaking out the side of material, etc. Do whatever you have to do to keep material held in place. Some people use double-sided tape, down-spiral bits, vacuum cups, or vacuum enhancers to further decrease movement. Again, do everything in your power to keep material held in place.

Debris In Collet/Tool Holder

If tool holders and collets are not properly cleaned, debris can build up and cause the tool holder to be off balance. When your CNC machine is cutting material out of balance, you face a decrease in tool life, spindle life, and cut quality. This can easily be a reason why your bits are breaking. Remember that collets and tools holders are consumables and should be replaced in a reasonable time-frame. See a recent article, I wrote, with more detail on tooling maintenance HERE.

Bad Collet

Like I mentioned above, collets are consumables. Depending on use, collets have a 90 day life. When you break a bit near the collet, they should also be replaced because they can damage the collet to where it no longer holds a bit correctly. Think of a collet as a spring. If a spring is compacted together for 90 straight days, it will no longer be the spring it once was. Therefore, your CNC bits are not being held as tight and balanced as they need to be. Find collets on our webstore HERE


Greg Smolka

Greg Smolka (Author)

CNC Tooling & Application Manager

Here to help with tooling recommendations (bits, knives, collets, tool holders, maintenance kits, torque stations, etc.) and cutting recommendations (feeds/speeds, tips/tricks, # of passes, etc.).

Contact Infogreg@cnctoolingshop.com