The Surfacing Platform

The concept of the platform is this: The workpiece rests between two level tracks. A double-rail carriage that supports the router spans the tracks. The carriage is designed so the router can slide from one track to the other. And the carriage can slide from one end of the tracks to the other.

To plane a board, you set it between the tracks, with the router in its carriage at one comer. Then you slide the carriage along the tracks, routing a strip as wide its the bit from one end of the board to the other. Move the router in its carriage an increment, and slide the carriage back, widening the machined strip. Just keep moving the router and sliding the carriage. It's a methodical, even tedious, operation, but it gets the job done.

The platform consists of a base with two sides—the tracks. One side is fixed (though it is easily removed). The second side adjusts, as Surfac-itgjjatform and Carriage makes clear. The base must be flat—plywood, panicleboard, and MDF arc good materials for it. The sides must be straight and true. A straight-grained hardwood makes durable, as well as smooth-sliding, tracks. The carriage consists of two rails and two guides cut from the same stock as the sides

The real key to getting flat stock with parallel faces from the platform is accuracy in the platform itself Each side must be straight with par-

The surfacing platform has two parts: a base with tracks and a carriage for the router. You set the material to be surfaced on the base between the tracks, and you set the router that's to do the surfacing in the carriage. Work your way across the stock in a series ofback-and-forth passes, smoothing and flattening it. The setup is useful for surfacing badly twisted boards, end grain (as here), and material with particularly gnarled grain.

The surfacing platform has two parts: a base with tracks and a carriage for the router. You set the material to be surfaced on the base between the tracks, and you set the router that's to do the surfacing in the carriage. Work your way across the stock in a series ofback-and-forth passes, smoothing and flattening it. The setup is useful for surfacing badly twisted boards, end grain (as here), and material with particularly gnarled grain.

CUTTING LIST

Piece

Number

Thickness

Width

Length

Material

Base

1

W

19ft"

42"

Plywood

Sides

2

1W

42"

Hardwood

Carriage rails

2

1V*"

2"

20"

Hardwood

Carriage guides

2

11/«"

2"

lOVi"

Hardwood

Spacers*

2

vr

12"

42"

Plywood

Spacers*

2

K"

12"

42"

Plywood

Spacers*

2

Va"

12"

42"

6 pes. M®" x 3" flathcad stove bolts

4 pes. V" X 3" carriage bolts

'Optional

Insulating Radiant Heat Basement Slab

V*'«S* FLATUEAD STOVE BOLT

PLATFORM PLANE PROBLEM STOCK WITH YOUR ROUTIR

- AND TUIS SURFACING PLATFORM AND

CARRIAGE

V*'«S* FLATUEAD STOVE BOLT

PLATFORM PLANE PROBLEM STOCK WITH YOUR ROUTIR

- AND TUIS SURFACING PLATFORM AND

CARRIAGE

allel edges, and the sides must he of identical height. If one side is even l/u inch higher than the other, whatever you machine in the platform will have a slight taper across its faces. This important caveat aside, the platform is easy to make.

1. Cut the pans to the sizes specified by the Cutting List. You don't have to cut the spacers, but depending on the stock you are starting with and its final thickness, it may be handy to have several spacers to boost it up in the platform.

2. Position the sides 3 inches from the edges of the base and clamp them Drill the mounting-screw holes through them. (For the adjustable side, these holes will serve as the starting points for the slots.) Countersink the holes for the fixed side. With a Forstner bit, slightly coun-icrbore the holes on the sides, so the T-nuts will be slightly recessed. Drive the T-nuts into place.

3. Use a router and straight bit to extend 5-inch-long slots from the mounting holes for the adjustable side. I used a T-square to guide the router, and 1 eyeballed the length of the cut. which isn't thai critical. After the slots are cut through, use a V-groovc bit to "countersink" each slot.

4. Bolt the sides to the base, and make sure the bolt ends don't extend above the sides' top edges (they shouldn't even be flush). They'w got to be below the surface for the carriage to slide easily.

5. With the platform done, turn to the carriage. Cut a %-inch by V-»-inch rabbet into each rail. Mark and rout the 2'/Mnch-long slots for the adjusting bolts that secure the guides to the rails. These are easiest to cut on a router table.

6. Assemble the carriage, bolting the guides to the rails.

An optional part of the rig is a square baseplate. Some routers, plungers particularly, have a flat edge or two on their bases. But most are round, and the round ones, we've found, tend to rock on the carriage. The solution is a square or rectangular baseplate. I've found surfacing is a job where a good view of the bit and the workpiece is important. Clear acrylic or polycarbonate thus might be your best choice.

Using the platform and carriage is not difficult. The workpiece has to be about 4 to 6 inchcs shorter than the platform, of course, so the bit can move off the edge of the work without the carriage tumbling off the ends of the tracks. (You may even want to tack stops to the ends of the tracks to prevent this from happening accidentally.)

Trapping the stock may be the hardest part. To avoid gouging the sides, you should set them so there's about a half-inch of space between each side and the workpiece. Center the workpiece. then tap wedges between stock and sides to keep it from shifting.

Four-quarter stock will probably have to be elevated so the bit can reach it. and anything thinner than

Warped and oddly shaped material, such as this disk cut from the base of a cypress trunk, is a challenge to set in the platform, but the effort can save it from the wood-stove. At those spots where the stock curls up off the base, slide shims under it. The goal is to steady the stock. Then drive wedges between the stock and the sides, as here, to keep it from shifting.

that surely will need a lift into the router bit's range. You should be able to mix and match the different spacers listed in the Cutting List to put even the thinnest stock where you need it. Keep your roll of double-sided carpet tape handy if you arc concerned that either the workpiece or the spacers will shift.

The most troublesome stock to position for machining is warped stuff. Yet this is stock that's best reserved for router thickncssing. If it's warped enough, it can be the devil to joint flat so you can feed it through the planer. And if you plane it without flattening one face, you'll get a smooth but still warped board— smooth because the planer's feed rollers will press it flat while it's in the machine, warped because it'll be warped when the pressure of the rollers is off. So if you can plant the board and use the router to plane one face flat, you can plane the second face in the planer or in the router thickncssing rig.

What you need to do is set the warped stock in your platform, and shim the comers as necessary so it doesn't rock, like shimming cabinets to level them during installation. Try to set the board so you can get a

^BITDRAWER

The best bit to use for surfacing is designed chiefly for hollowing out compartments in a tray. It's called a dish cutter. The one shown is from CMT.

What makes the dish cutter ideal for surfacing? The cutting edges arc radiused at the bottom of the bit. This gives you a nice radius inside a recess, but it also means you don't have a hard edge between adjacent passes.

CMT offers the dish cutter in several sizes, in both Winch- and Vnnch-shank configurations. The one in the photo has a cutting diameter of VA inchcs, which means you cut a broader swath than with a '/i-inch or Winch straight bit. Because of the radiused edges, you do have to overlap passes a bit more than if you were using a 1 Winch bottom-cleaning bit. But the latter bit tends to leave ridges between sweeps.

The CMT bit is also available with a bearing on the shank, which allows you to use it with a template.

flat surfacc with minimal stock removal. When the board is set, tap those wedges in place, so it doesn't shift. Then you're ready to set up the router.

Set the carriage in place and adjust the guides. Chuck the bit. set the depth of cut to remove no more than '/k to Mf inch from the high spots, and place the router in the carriage. Then rout.

The conventional wisdom seems to be diat you must make your sweeps in the direction that the grain runs. In our experience, that doesn't seem to be the case. Sweeping back and

Because the cutter isn't addressing the entire width of the material in a single pass, it's natural to have some indications of ov erlap. In the job shown—surfacing cypress end grain—the quality of the initial pass is affected also by the extremely soft, punky character of the wood. The feed rate also has an impact; rough tracks suggest that the router was moved too quickly.

forth across the board doesn't yield a lesser finish than coursing from end to end. As Fred points out, the router bit's cutting edges don't sweep the surface in the same way that planer and jointer cutters do. Cut across the grain or against the grain on one of these machines, and you will have a choppy finish. But with the router, however you move the router itself, the bit is addressing the wood with the same motion. It is just this difference in cutting action that enables the router to plane curly mapb and other twisted-grain woods.

Be methodical, however. Whcth-

eryou work backand forthorendto end, be an automaton. Sweep on one axis, then click over a notch in the other. Sweep, then click over. Sweep, then click over.

After a first pass over the enure surface, make as many additional passes as necessary to flatten the board. Then make a final skim cut to make the surface as smooth 23 you can get it with the router. Scraping and sanding will then remove any remaining tracks or swirl marks

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Woodworking Tools and Installation Tips

Woodworking Tools and Installation Tips

There are a lot of things that either needs to be repaired, or put together when youre a homeowner. If youre a new homeowner, and have just gotten out of apartment style living, you might want to take this list with you to the hardware store. From remolding jobs to putting together furniture you can use these 5 power tools to get your stuff together. Dont forget too that youll need a few extra tools for other jobs around the house.

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