Try This

Here's an easy fix. Go to an auto-parts store and buy a handful of l¿*-inch or !/¡-inch O-rings. Take a bit along to test the fit, so you get the right size. Roll an O-ring onto the shank of each bit you have. Roll it right up almost to the cutter. Leave it there. Whenever you chuck the bit. the O-ring will keep the shank from dropping too far into the collet. It won't be in contact with the armature shaft, and the collet will squeeze the full shank, not just the fillet.

A shank that's undersized more than 3 thousandths is probably too small to he gripped securely by a collet. If you have trouble with a particular bit, measure its shank with a micrometer or a dial caliper, as shown here. This bit is I thousandth under a half-inch in diameter.

causcs this at least as often as operator neglect does. Most designs use a wing nut to secure the base. Despite the nuts slightly elongated wings, it can be difficult to tighten because you simply can't get a good enough hold on it.

1 don't know what the solution to this is. Maybe you can replace the wing nut with a plastic knob of the proper thread. Fred suggests adding an extra washer under the wing nut and putting a drop of oil on the threads from time to time. You might just replace the wing nut with a hex nut and tighten it with a wrench.

Base-to-Motor Squareness

Another Haw that sometimes undercuts the precision of the router is a base that isn't perfectly square to the axis of the bit. It is a problem with both fixed-base and plunge routers. With edge-forming cuts it is seldom a discernible problem, and even with shallow grooving cuts it is of little practical consequence. But on a deep cut. it can be annoying if precision is your goal. You cut a mortise and tenon, and the assembled pieces won't lie flat.

How do you check your router? First check your collet for runout, as explained in "Router Maintenance" on page 43. To do this, you use a drill rod that is the conect size to tighten in the collet. After checking to ensure there's no appreciable runout, set a square against the router base and line up the blade with the rod.

The problem usually isn't with the base itself. The base is usually an aluminum casting. It's strong and rigid, and the bottom is flat. With some fixed-base routers, the base simply doesn't hold the motor square, and there doesn't seem to be a remedy. You need to be able to adjust the motor vertically to use the machine, so any shimming you do will last only until the next time you adjust the vertical height.

Try replacing the base. Get a new base, but before you actually buy it. see if it will solve the problem. If the new base won't solve the problem, there's no sense in buying

Your router's base must be square to the axis of the bit if you expect to make precise cuts. To check this,fit a drill rod in the collet and hold a square against the base beside the rod. This one looks pretty good.

it. If the problem is truly severe, you may have to replace the whole router.

With a plunge router, the problem is in the plunging mechanism. The rods may not be perpendicular to the base. Or. more likely, there's too much slop between the rods and the bores for them in the motor housing. A technician may be able to back out this slop, but 1 doubt it. Replacing the bearings that run on the rods may solve the problem. This is something you really should check either before you actually purchase the router or immediately after you buy it, so you can return it if there's a problem.

Setting an Edge Guide

In some router operations, you need to use an edge guide An edge guide may or may not be supplied with your router. Plunge routers of European and Asian origin seem to have pretty good edge guides as standard equipment. The American manufacturers have a need, for some reason, to charge extra for the edge guide, but what they supply isn't usually very good.

The edge guide is a sort of shoe that attaches to the router base. It hangs just below the base, and it can be adjusted from a position surrounding the bit to one about 8 to 10 inches away. The guide slides along the edge of the work and ensures that the router's cut is parallel to it.

The guides that are supplied with Elu, Bosch. Hitachi, and Ryobi plunge routers—these are ones I've used— are dandy. You make coarse adjustments by sliding the mounting rods back and forth in relation to the base. Then you make fine adjust-

WORK LOADS

merits with a vernier screw, which moves the guide itself in and out along the rods. These guides have fairly large plastic knobs, rather than wing nuts, to lock the rods and the guide in position. They are easy to adjust quite precisely, and they stay in position.

Most of the extra-cost guides I've tried are pretty dismal: The guide itself—the shoe—has a short contact surface, so it doesn't slide well along the work's edge. It lacks any son of fine adjustment. The locking system uses thumbscrews, which aren't particularly secure. Usually, the guide mounts on two rods. Each rod is "locked" in a hole in the router base with a setscrew. Then the guide itself is secured on the rods with setscrews. What happens with these babies is that the router vibration shimmies the so-called set-screws loose, and as you rout, the guide slips out the mounting rods. Instead of a straight cut. you get an arc. Yet another router-induced headache.

My advice? If a guide comes with your router, try it out. evaluate how well it works, and if you're satisfied, use it. The two essentials are that the guide must slide easily and that the setscrews must really set. If the guide fails on these points, toss it. If you have to pay extra, just make your own. The chapter "Dadoing and Grooving" has plans for a good guide you can make yourself. And in the chapter "Sliding Dovetail Joint."' you'll find a plan for making a fixture with two edge guides, so you can trap the workpiece between them.

Holding the Workpiece

A final and vital part of setting up for a cut is anchoring the workpiece. You don't want the work to shift or slide away from you as you feed the router. Not only can it screw up your cut and ruin the work, it can put you at risk.

There are so many different variables thai it's impossible to tell you how to clamp your work. In many situations, you simply have to clamp the work to a bench. Sometimes the clamps that secure a fence to the work can also secure the work.

Hand-held routing is full of these challenges: Holding the stock so you can move the router on it without having the router tip and wobble, without hitting clamps, without having to move the clamps three times in the course of a single pass, and so forth. To me, the challenge is finding a way to secure the work that allows me to complete a cut in one operation. I just hate to undamp, shift the work, and then rcclamp it just to complete a single cut.

Here are some examples of measures you might take.

• To slot a narrow workpiece, you may need to wedge it somehow between two wider boards that will provide additional bearing for the router.

• To rout an edge treatment on a circular or oval blank, you may try "dogging" it—pinching the work between a bench dog and the vise's dog—on a narrow workbench, so the maximum amount of edge is overhanging the bench. After routing as much of the edge as possible, one shift of the workpiece exposes the remaining uncut edge.

• Small workpicces can be set on a router pad. which is somewhat like a very stiff carpet pad or the pad used with a computer's mouse. The router pad has enough "bite" to keep the workpiece from shifting as you rout.

• Sheets of sandpaper glued back-to-back can be slipped between a workpiece and the workbench to keep the work from sliding around. This is an effective way to keep a

This edge guide, an accessory for Bosch's newest plunge routers, has all the features you should look for in a guide. The plastic wing nuts that seat against the mounting rods are easy on the hands and vibration-proof. Loosening the wing nuts on the guide allows you to dial in the exact setting you need with the fine-adjustment knob. It's easy to set precisely, and it won't work loose during use.

A router pad provides traction between a workpiece and a work surface, keeping the work from sliding around, even when you maneuver a working router across it. Tltis makes it a lot easier to rout the edges of small workpieces that are tough to clamp. The rubbery pad can he folded and cut with scissors (or the router bit or even the screw that seaircs the pilot bearing).

A router pad provides traction between a workpiece and a work surface, keeping the work from sliding around, even when you maneuver a working router across it. Tltis makes it a lot easier to rout the edges of small workpieces that are tough to clamp. The rubbery pad can he folded and cut with scissors (or the router bit or even the screw that seaircs the pilot bearing).

panel in place while you make a trammel-guided cut. for example.

• A clamp that secures a T-square to a workpiece can also secure the work-piece to the bench. It's a double-duty clamp.

• Hot-melt glue has enough strength to bond a template to a workpiece. or a workpiece to a bench. Yet it is too weak to resist a sharp mallet blow or a little prying with a chisel.

• A shop-made fixture with toggle clamps can expedite repetitive routing by making it easy to switch workpieces. Clamp or dog the fixture to a bench, then switch work by flipping the toggles open and closed.

WORK LOADS

Like every other power tool in your shop, the router does have limits. You do have to use some common sense in making a cut.

Just because your bit has a 1-inch-long cutting edge doesn't mean the router will make a 1-inch-decp cut in a single pass. Try it. Your router will probably tell you it's overloaded. It will start to bog down, losing speed sharply. If you persist, it will probably stall completely, maybe trip the circuit breaker, maybe bum up.

The conventional wisdom is that the router is a trimming machine. If you have a heavy cut to make, nibble at it: Make a sequence of light cuts. If you can make a rough cut on a table saw or band saw and remove a lot of the waste that way, do it.

The conventional rule of thumb is to cut about [A inch deep at each pass. This is safe and reasonable.

But as you get more experience in router work, you probably will come to view that rule of thumb as a little wimpy in many situations. If you arc using a sharp '/¿-inch-shank bit, even a l'/i-horscpower router can hog away more than V* inch of material. You have to listen to the router. Is it running free or starting to bog down? Is the bit whizzing through the wood, or is it chattering? Do you have to feed so slowly that the wood burns?

A plunge router's depth-stop system allows you to make a full-depth cut in sever al passes, each cutting progressively deeper. Using the turret stop allows you to control exactly how deep each pass arts.

Problem Solver

One of the most important things you can do to improve the accuracy of your router woodworking is to mill the working stock properly. The router is capable of incredible accuracy and precision, but it's usually dependent upon the surfaces and edges of the work-piece for guidance.

In hand-held operations, the router slides across the surface of the work. If the workpiece is bowed or twisted, if its surface is rough or rippled, the router won't be able to even them out. The cut may be of uneven depth; it may be choppy. When you're using a piloted hit, the pilot will telegraph any imperfections in the edge very visibly into the cut.

Make sure the stock is smooth, flat, and square.

A nick in the edge of the work is magnified by a piloted bit. If you bump the edge of a workpiece against a saw table or the like, plane the nick out before routing a profile.

The point of the rule is to get a good-quality cut without overtaxing the router and the bit. So consider the power of the router, the configuration of the bit, and even the hardness of the stock. Hard maple? Lighten up. Pine? Hog away. A '/«-inch straight bit? Take it easy, even if it's on a '/¿-inch shank.

Was this article helpful?

0 0
A Course In Wood Turning

A Course In Wood Turning

Ever wondered what wood turning is all about? Here are some invaluable information on how to make beautiful items out of wood! That one little strategy from A Course In Wood Turning that I implemented not only worked, but the results were completely astonishing. I had never seen anything like it! Now, keep in mind that I had tried a lot of other products up until this point. You name it, I probably tried it! That’s how desperate I was to improve my skills with wood turning.

Get My Free Ebook


Post a comment