What to Look for in a Woodworking Router

The wood router is essential among cabinet-making tools because it adds decorative contour that improves and defines the final appearance of your woodworking project. Used suitably, this tool is to the woodworker what a fine paintbrush is to an artist. It's all in the details. The router is a multi-purpose woodworking tool that can be used for a variety of tasks including rabbeting and making dado grooves.

There are four, basic varieties of wood routers on the market today: laminate trimmers, lightweight or low-powered routers in the 7/8 to 1 1/2 HP range, medium-powered routers in the 11/2 to 2 1/4 HP range and high-powered routers in the 3 to 4 HP range. Each has its use and I have owned all of them at the same time. The laminate trimmers do what their name implies as well as other light-weight tasks such as making hinge mortises. They are only suitable for small router bits but they are easily maneuverable and fit nicely right in your palm.

If you need more horsepower but still like the ease of a lightweight router, the 7/8 to 1 1/2 HP routers will do a fine job of revolving router bits up to 1/2" radius round-over bits. Every woodworking shop should have one of these available for bench-top jobs. They are a bit small for router table use. 2 1/2 HP woodworking routers have enough power to operate large router bits through hardwood and yet they are still light enough to be handy as bench-top wood routers. While any wood router over 2 HP can be used in a router table, I prefer the high powered ones for that application because there is no need to worry about how heavy they are and you might as well have as much power handy as you might want. Most, but not all, of these larger routers are plunge routers. The high horsepower is essential to plunge large bits deep into hardwood to make mortises and the like.

If I could only purchase only one wood router, it would be the 2 1/4 HP variety because it is light enough for most bench-top work and can also be used in a router table. If I could afford two routers, I would probably have a 7/8 to 1 1/2 HP machine for bench-top work and a 3 - 4 HP wood router under my router table. I don’t like repeatedly mounting and dismounting routers under my router table, so having a lighter wood router on hand near the bench when required really speeds things up.

I’d like to make a few suggestions about routers. First, I suggest you consider using only high-quality carbide-tipped router bits in these woodworking tools whenever possible. They can be re-sharpened many times and they typically don’t burn up and load up if they are kept sharp. High-speed steel bits don’t last long, they are not worth sharpening and they dull quickly, burning your work piece as they soon load up and turn black. Sometimes, however, the bit profile you need may only be available in a high speed steel bit:  This is the exception rather than the rule.

Second, as hand-held power woodworking tools, heavy and/or top-heavy routers are hard to manage. Not only will you be trying to control them all day, they tend to wobble easily which can often ruin a cut or leave an incomplete cut. If a smaller, low-profile wood router could have spun that bit, then that is the tool you should have been using. On the other hand, an under-powered wood router will not do a good job and may not even be safe. Also, be sure to check the weight of any wood router you may be comparing, if it is to be hand-held. Heavy woodworking tools are demanding and ungainly to use all day long. A pound or two less can make a big change.

Third, consider how you will be stabilizing the wood router while it is cutting. Are the handles comfortable enough for continuous use? Do the shape and material of the handles let you direct the  router properly? Some of these woodworking tools are also manufactured with “D” handles (at extra cost) which may give you better control and feel. One wood router from Milwaukee even has a padded grip around the exterior of the router base. One hand goes on the rubber grip while the other goes on a conventional knob.

Fourth, if your wood router is in the 2 1/4 HP range, you will want it to have a variable speed feature, especially if you are considering using large bits like raised panel bits. You will need to run these large bits a bit more slowly. They will stay cooler and cut better at a lower speed. On the other hand, you will get smoother cuts with small bits of you keep the speed high. No matter what RPM you choose, you will want your wood router to be able to sustain that speed at all times, no matter how hard you push it. Electronic speed control allows your wood router to offset heavy loads by automatically adding a enough amount of extra power to keep your router rotating at the same speed it was before the cut commenced.

Fifth, (and this is a safety consideration) try to buy a router that has “soft” start-up. This would not be a needed feature in stationary woodworking tools but is an important safety device in a hand-held  router. Historically, routers have had only one speed (high) and when you turn them on, they spin up quickly. The gyroscopic force of that can pop a spinning wood router right out of your control. A soft start-up power tool steadily increases its speed from zero to full, thus preventing most of the gyroscopic effect.

Sixth, if you are going to be switching bits all the time, consider what procedures you will have to go through to complete that task. Some  routers have a shaft lock button so you only need one hand to press the button and one wrench to turn the collet nut. I’m kind of comfortable with the two-wrench style. I usually take the router motor completely out of its base, lay it on its side on the table, putting one wrench on the flat part of the shaft and the other wrench on the collet nut. If I am loosening the collet nut, I will first lower the shaft wrench to the table top and then push down towards the bench with the wrench that’s on the collet nut. If I am tightening the collet nut, I will put the collet nut wrench down to the table top and then push down against that with the shaft wrench on the flat part of the shaft.

If you’ve used routers at all, you must have discovered that when you are loosening a collet nut, you will feel resistance at the start of the turn of the wrench and then it will turn freely for a while before resisting the wrench one more time. The first resistance comes from loosening the nut itself. The nut then unscrews a bit down the thread and then it begins to push against the collet, releasing it from the shaft of the router bit. When you are tightening a bit into a wood router, you will feel resistance only once as you squeeze the collet around the shaft of the bit while turning the nut as far as it will go.

Some people like to change router bits with the wood router upside down on the table with the two wrenches sticking out to the side. In this case, the technique is to position the wrenches so that you can squeeze their handles together with one hand to loosen, or tighten, the collet nut. For these people, some manufacturers make routers with flat tops. If find this way to be a bit clumsier than laying the wood router down on the bench: There is less leverage in case of a stuck bit.

Seventh, router bits come in three shank sizes, 1/4", 3/8” and 1/2". The half-inch shank bits are only slightly more expensive than the quarter-inch ones and yet, they give you a distinct advantage. With a larger diameter shank and a larger diameter collet, there is much less chance of slippage under heavy loads. Consider buying only 1/2" shank bits, especially if you are turning large cutters.

Eighth, some routers offer “above router table” height adjustment capability. This is usually accomplished by sticking a hex T-wrench into a hole provided. It’s difficult to adjust the height of a wood router accurately from underneath a router table while on your knees, fighting gravity. An even more elegant solution is to purchase a router lift for your router table.

Ninth, there are three types of wood router bases: Conventional, spiral and plunge. In a conventional fixed base, the router motor just slides straight up and down in the base and is clamped into position. The spiral-type base has an adjustment ring that turns in a spiral groove cut into the outside of the router motor casing, thus raising or lowering the router motor relative to the base. A plunge router base clamps onto the router motor and then pushes the wood router and router bit down unto the work piece from above. Some routers are offered in kits containing two or more varieties of bases so that you only need to buy one router motor for a variety of uses. Tenth, some of these woodworking tools gauge and control their fine depth-of-cut with a spiral ring while others utilize a geared shaft attached to a calibration knob. All routers have a means of making rough height adjustments by operating the lever or cam that locks the router motor into the base. Once adjusted to a location close to the final position, the fine depth-of-cut adjustments can be made in increments as small as 1/64 of an inch and, in the case of one router reviewed here, 1/128th of an inch.

Eleventh,  motor amperage is usually a better indicator of motor power in woodworking tools than stated horsepower. All 2 1/4 HP routers claim to develop 2 1/4" HP but their amperage (electrical power used) varies from 11 to 13 amps.

Twelfth, and finally, there are some less important (to me) but nice features offered on some, but not all, of these woodworking tools including: The availability of a 3/8” collet, an automatic motor power lock-off during bit-changing, a carrying case, a clear plastic sub-base for better viewing, a detachable cord set, a dust proof switch, a  switch that can be located left or right for the comfort and convenience of the operator, oval, rubber-molded handles, self-releasing collets and a way to fine adjust the sub-base so that it is exactly centered around the bit shaft.

The capability to center the sub-base means nothing if you are only using ball bearing router buts but if you are using router guides mounted around the bit shaft, it is very important that the bit shaft be centered within the guide. If your bit is not perfectly centered when using template guides, your cut will travel from side to side as you turn the router around while cutting. Since the guide is mounted to the sub-base, the hole on the center of the sub-base must be concentric with the router bit shaft.

Bob GillespieWoodworker

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©  2010 Robert M. Gillespie, Jr.