Router Tips

[DrewKaree]

From Woodcraft's website:


Choosing The Right Router

Author Patrick Spielman, writing in The Art of the Router; Award-Winning Designs, states that in addition to the choice between fixed base and plunge type routers, there is also the choice between 1/4" and 1/2" maximum collet size capacities. A broader selection of bits is available with 1/2" shanks rather than 1/4". But for certain light jobs, light routers are preferred because of their lightweight and ease of operation with one hand. As a general rule, the deeper the inside opening or overall length of the collet the better. Good collets also have more lineal splits to grab the bit more uniformly around the shank. And, collets should be made of tempered, hardened steel. Test them with a file. If it makes a cut, the collet is not tempered, but it is soft which is not good.

Large routers up to 3.5 HP are available for industrial/continuous use. Spindle locks and self-releasing collets (pulls the bit out as the nut is loosened) are nice features, but not found on all routers.

The switch should operate easily and, preferably, from the handle or it should be located within reach without needing to remove the hand from the knob or handle.

The design of the base offers more design choices. Some are not completely round but have combined straight and circular edges. This may allow for working closer to a vertical obstruction. It may also make following a straight edge easier. Meanwhile, large round bases have more surface area supporting the router and can bridge large openings. It is important to consider whether there is a provision for interchanging various styles of sub-bases. For general shop use, it is also important that the base have sufficiently threaded sockets that allow safely mounting the router inverted for table use.

The depth of cut adjustment and locking clamp should be quick and easy to operate with a fine adjustment provision. A plunge router intended for use in a router table should be equipped with a depth control knob for easy adjustment or this accessory should be available.

Other important features include overall quality construction, good bearings, durable brushes, and new electricals such as soft starts and the variable speed option. Also check the availability and mounting convenience of template guides, edge guides and the adaptability of the router as a power source for other machinelike accessories such as router lathes, carving machines, or other special router driven joinery devices.

Safety Tips

When you lose control of a router, whether totally or just a little, it's the workpiece that most often gets messed up. Now and again, you'll chip or break a bit. And if you're really unlucky, you will get hurt. Keep this in mind: Most router bits rotate at a speed in excess of 20,000 rpm. When something goes wrong -- a grab, a dig, a jolt to the machine, bad things happen fast. I have had my fingernails trimmed mighty close by a dovetail bit before I knew what happened.

Router safety is essentially a matter of controlling the router and securing the workpiece (and vice versa on the router table). Safety considerations are therefore intimately related to the quality of the cut. The safest routing technique will by and large yield the best finished surface.

Here are some tips to help you produce the quickest, smoothest and safest cuts with a router.

Some bits bite back.  Not all router bits are created equal. Some are far less capable of handling the stresses of cutting wood and will break easily. Some are prone to other problems, such as burning or catching in the cut. Recognizing bits that need particular care will help you keep them from biting you and your work.

Long, thin bits are fragile: Thin bits with cutting-edge lengths that are more than three times longer than their diameters are easily stressed and broken. Some of the thinnest bits are milled into their shank, making them even more fragile. This 3/8-in.-dia. bit has less than 1/16 in. of steel between the flutes. Cut in 1/8-in. increments or less with these bits.

Trapped bits need precise guidance: Some bit designs, such as dovetail bits and T-slot cutters, trap the bit in the work. The slightest wavering in the cut will mess up the workpiece. These bits should be used only with jigs and fences to guide them.

Dovetail and T-slot bits also break easily. They are designed to cut while fully engaged in the workpiece, which is the most stressful kind of cut for any router bit. Most of the cutting is done at the ends of the flutes where their diameter is at a maximum. However, most of the stress is concentrated where the shank and the flutes meet, which is the thinnest part of the bit. To make matters worse, some of these cutters are ground into the shank. Just take things easy, and don't force the cut. For long T-slots and sliding dovetails, I pre-plow with a straight bit.

Many other kinds of bits cut in such a way that you can't lift the router straight up and off the workpiece freely. These bits include cope-and-stick cutters, glue- and finger-joint bits, bull-nose bits and some profile bits. To be used successfully, they should be treated as trapped bits.

Spiral bits can be unpredictable: Spiral up-shear and down-shear bits can produce impeccable surfaces. The cutting edges travel in a spiral motion and are always engaged in the work, unlike ordinary straight bits. Up-shear bits send the chips into your face, and down shears send the chips into your socks. Large spiral-ground down-shear bits have one nasty feature: If the bit catches in the work, it will pick the router up and out of the cut. I almost lost my grip on a router with a down-shear bit that suddenly climbed up the work. Down shears are too unpredictable for this woodworker, especially on end grain. If you use them, cut very lightly, or use them in a router table with a power feed.

• Read your owner's list
• Make sure that you have selected the proper bit. Check the type, shank strength, cutting length and diameter, and sharpness of the bit.
• Make sure that the router horsepower and speed is appropriately matched to the material, the intended depth of cut, and the size of the bit selected.
• Always disconnect the power when changing bits, servicing the router, or mounting attachments.
• Make sure that all bits, attachments, clamps, and locking devices are secured before starting the router.
• Make sure that the on-off switch is off before connecting the power.
• Dress properly. Wear eye-, hearing-, and dust protection devices, and either short-sleeve shirts or long-sleeve shirts with rolled-up cuffs. Wear a shop apron or tight clothing. Make sure that your hair, jewelry, etc., will not become entangled with any moving parts of the router.
• Keep children and observers at a safe distance.
• Make certain that all workpieces are securely clamped and will not shift during routing.
• Always grip the tool tightly, especially when starting up the router; when you have to resist the initial motor torque. Keep both hands on the knobs or handle, or use a foot switch when the job requires a "third hand".
• Be especially cautious when routing small pieces. Make test cuts in solid unchecked stock of a safe size.
• Be absolutely certain that the bit is not in contact with the workpiece and that no part of it will strike the wood when you are turning on the power.
• Develop the habit of turning off the router immediately after you have switched it on. As the motor starts to coast down, use your eyes, ears, and sense of touch to detect any unfamiliar conditions or irregularities.
• Always shut the power off immediately at the first sign of any unfamiliar noise or vibration. Always be aware of the feeling in the handles and the "hum" (that can even be heard through hearing protectors) that indicates the router is operating properly.
• Do not operate electric routers in moist, wet areas or damp environments.
• Do not use mounted abrasives, carving burrs, drills, or other non-routing tools and cutters in routers just because they have shanks that are the same size as your router's collet.
• If the router or work tends to ride upwards and requires extra pressure to feed, turn off the power immediately. This indicates the bit is dull, it is slipping out of the collet, or just that you have selected the wrong bit design.
• Don't force-feed the router or work in any situation.
• Do not try to increase the bit's depth of cut by inserting less of the shank in the collet. Most bits should have at least 3/4 of their shank length inserted into the collet.
• Always feed the hand-held router into the work in the correct direction, against the bit rotation. In router table use, feed the workpiece in the direction that is also against the bit rotation.
• Maintain your router equipment diligently. Replace worn parts, discard worn-out and poor bits, and check the router periodically.

[Crazy Cooter]

• Do not try to increase the bit's depth of cut by inserting less of the shank in the collet. Most ALL bits should have at least 3/4 of their shank length inserted into the collet.
  

Having worked in a woodshop with newb's, I thought this needed extra attention.  Besides not unplugging the thing when changing bits, this is the #1 mistake they made.  Adjust the router people, not the bit itself.  I've witnessed bits come out of routers twice.  If they had hit anyone... Even I could have been grossed out.  Unless I ran over yelling "snake bite!" and tried removing the bit with my teeth... Heheh, you never know with me.  You just never know.

[chasmosis]

not sure if this is the right place to ask this but since it's a router specific thread...

I've recently purchased a router (sears) and a pack of bits (MLCS).  The bits have a soft plastic/rubber/whatever coating on them.  Do I need to remove the coating or will the first use of the bit take care of that for me?  If I need to do it - whats the best way?

Thanks.

[Crazy Cooter]

You should be able to just pick it off with your fingers.  It's there to help prevent rust until it's sold and to keep the edge sharp if they came loose and hit each other during shipping.

[DrewKaree]

If it don't wanna come off, or if you're askeered to gouge your fingers up in case it comes off and cuts you, take a razor blade and work it under an edge from the shank OUTWARDS.  If you have hooked-end blades, you can just pull them into the material and it'll split 'er right open. 

That's GENERALLY a good sign that you purchased decent bits, as well, although not foolproof!