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10 Tips for Making Clean Cuts With Router Bits
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1.  If possible, use router bits with 1/2" shanks. Many routers come with interchangeable 1/4" and 1/2" collets, and many bits are available in both shank diameters. But you’re likely to get better stability and less vibration with 1/2" bits because of the increased shank mass – and that typically yields a smoother cut and longer cutter life.

A properly installed router bit

A properly installed router bit.

2. Make sure that the bit is properly installed in the router. Insert it until it bottoms out, then back it out about 1/16" to 1/8" and tighten the collet. If you don’t back it out, the collet might tighten at the rounded transition area between the cutter and the shank – meaning that it won’t be in full contact with the rest of the shank. This increases the risk that the bit could come loose while the router is running – a very dangerous scenario.

3 diamond hones for router bits Use diamond hones like these to keep your router bits sharp for a clean cut.

3.  Make sure that your bits are sharp, smooth and clean. Resin buildup and dull cutters lead to heat buildup, which will further dull the bit and produce a bad cut. Buildup can be removed with a product such as Rockler’s Pitch & Resin Remover (Item #39146), and bits can be given a touch-up
sharpening with diamond-coated sharpeners (Item #24663, for example). Also check for nicks in the bits’ cutting edges. It might be possible to remove small nicks with diamond sharpeners, but cutters with large nicks are best reground by a professional. For bits with guide bearings, make sure that the bearings can spin freely. If necessary, clean and lubricate with a product such as the PG2000 RouterBit Bearing Lube Pen (Item #31801).

router bit speed guideline chart These are guidelines only. Always follow the manufacturer's instructions.

4.  Watch your bit speed. Not all router bits can be run at the same speed. Larger router bits have more mass and therefore the potential to create greater vibration at high speeds. So, as illustrated in the above chart, the general rule is: the larger the bit’s diameter, the slower the speed. Manufacturers often specify maximum speeds for their router bits, and you should follow those recommendations. Even so, it’s important to remember that these are the top speeds for safe operation and are not necessarily the best speeds for every situation. Other factors include router horsepower (a less powerful router will slow down when it’s driving a large bit through a cut), feed rate, quality and condition of the bit and the machining properties of the wood being used.

dust collection options for routers Rockler offers a variety of dust collection solutions, including hoses and the Edge Routing Dust Port (Item #24991)

5. Clear the chips. Connect your router or table to a shop vac or dust-collection system to remove the waste material. If chips accumulate between the router plate and the workpiece (in handheld routing) or between the fence and the workpiece (in table-mounted routing), the cut will suffer.

large router bit Don't try to cut all the material away at once, especially with large, profile router bits.

6.  Make multiple light passes rather than one heavy cut. This is particularly important when working with bit profiles that remove a lot of material, but it also applies when routing dadoes or rabbets with a straight bit. Routers and bits aren’t made to hog out all the material at once, and you’ll get tearout and burning if you try. (The increased load also will dull bits quicker and perhaps even shorten the life of the router.) Instead, make two or three passes, increasing the depth of cut slightly each time. This can be especially beneficial when working with woods that tend to burn easily, such as cherry, or figured woods prone to tear-out. And if you’re using a flushtrim bit to rout a pattern or trim an edge, remove as much material as possible with a jigsaw or bandsaw first to decrease the burden on the bit.

7. Mind your feed rate. The feed rate is the speed at which the rotating bit is moved along the edge of the material (in handheld routing) or the edge of the material is moved across the rotating bit (in table routing). If you feed too fast, the bit will bog down, resulting in a rough cut. If you feed too slowly, you’ll wind up with burnishing or burn marks on the edges. Make practice cuts until you’re able to produce a smooth, consistent feed rate. This is especially important when working with long stock because of the need for hand-over-hand feeding. And try to keep the stock moving: Stops will cause burning.

rockler bench cookie for routers Keep your work in place while using your router with Rockler's bench cookie plus work grippers.

8.  If using a handheld router, make sure that the workpiece won’t shift during the cutting operation and that there’s proper clearance for the bit. Rockler’s Bench Cookie® Plus work grippers (Item #46902) make this simple and easy (without clamps), and optional risers (Item #35142) can be added if even more clearance is needed. If using a table-mounted router, make sure that the fence is set properly and that the work surface allows for a consistent feed rate. Also, use featherboards (Item #53677 for the table and #53685 for the fence) to make sure the stock remains tight against the fence and the table as it is passed across the bit.

how to use your router in the correct direction Use your router in the proper direction as shown above.

9.  Route in the right direction. In a handheld router, the bit spins clockwise with a great deal of speed and force. For maximum safety and control, move the router in a counter-clockwise direction when routing the outside edges of your stock. If you’re routing the inside edges of a frame, move the router in a clockwise direction. That way, the rotation of the bit helps keep it against the stock.

10.    When cutting a profile on all edges of a board, rout in the right order. Rout the end-grain edges first and then the long-grain edges. As the bit approaches a corner in end-grain routing, some of the wood typically splinters off. If the ends are shaped first, these areas of tear-out will be removed when the long-grain edges are routed. When cutting a profile only on the end-grain edge, or when shaping the ends of a rail in stile-and-rail constructions, add a backer board to the workpiece to eliminate tear-out.

Click here to view these tips for making clean cuts with your router bits in pdf form

posted on October 24, 2013 by Rockler
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16 thoughts on “10 Tips for Making Clean Cuts With Router Bits”

  • Bob Albers

    I have found that spraying the router bit with WD40 before using will limit if not eliminate pitch/resin/debris build-up on the bit. Furthermore after use, any debris on the bit can be remover easilly by hand (finger nail). It is then also helpful to again spray the bit with another dose of WD40.

  • Steve Douglas

    The problem with large router bits isn't mass- more mass will stabilize the bit- but speed. The cutter speed is proportional to the diameter (at the same rpm) so a 2" bit has a cutting speed 8 times that of a 1/4" bit. When doing edge cuts, a small bit is cutting nearly perpendicular to the edge, so is more likely to chip out- use the biggest bit you can. While when hand guiding a router it is usually necessary to feed into the rotation (they tend to skitter otherwise), it increases the likelihood of tearout. Feeding against the rotation usually requires a mechanical feeder, except for the lightest of cuts.

  • Henry Tennant

    I like Teflon spray a little better than WD40. I do not like to spray the WD40 inside my ship. I think it is what has been causing fish-eyes in some of my finishes. I could be wrong. But no silicone or oils sprayed, no fish-eyes.Thanks for the tips. Henry

  • Doug Sherman

    If you plan on applying a finish to your work, NEVER use silicon unless you are going to add it to the finish. Silicon always causes fish eyes with normal finish and it tends to cause crazing in the finish after a few years. This applies if you are trying to refinish a surface that has been sprayed with a silicon wax as well. Very consciencious use of a specially formulated silicon remover or completely stripping the old finish is the only way I know of to avoid fish eyes in new varnish or lacquer.

  • Salvador Ramos

    Love your stuff would love to learn ore about your router tips display all your 1/2 inch shanks

  • Lester Poteet

    I would also like information on a full set of large cut bits in 1/2 inch shaft.

  • David

    All my routers have 1/4" collets. Where can I find a collet adapter for 1/4" to 1/2" shanks?

  • John Mcconnell

    I'd prefer Teflon to WD40 spray. WD40 causes fish-eye everytime i use it

  • Ron

    Most commercial companies will lubricate the bits with beeswax if you are trimming laminate. I have also used it when working on extremely hard wood like walnut.

  • Carl Johnson

    I need to take off an 1-1/4 w by 1/8 deep strip off of the edge of some 1" plywood sheets. Would you have a router bit that would work? I'm not familiar with routers, yet.

  • Ken

    I think number 9 of these tips is backwards. I think it is clockwise on the outside, counter-clockwise on the inside.

  • sajib kar

    need autocad soft file,

  • Jim Archer Trumillwork inc.
    Jim Archer Trumillwork inc. June 11, 2015 at 4:26 pm

    Counterclockwise or clockwise that is the question on a router table you always approach right to left if you flip the router over that movement is counterclockwise on that edge it's not necessarily what appears to be the direction of the bit cut but the centrifical force that pulls your bearing or stop into the piece or object you're working on and gives you greater control and smoother cutsI have never used any chemicals Teflon WD 40 but I always put my bits into a good pitch cleaner for saw blades you let them soak briefly and clean them off

  • cindy griffin

    can you change the bearing to change the amount you take off.

  • doug

    i have a question what is the biggest cut you should take when making dadoes

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