Rolltop Desk

Tedswoodworking Plans

16.000 Woodworking Plans and Projects

Get Instant Access

Part II

Now that the lower desk has been completed, we turn our attention to the rolltop section. The construction of the end panels with tambour grooves is the most difficult part of the entire project, but any woodworker with moderate skill should be able to do a creditable job if care is used in laying out, cutting, and squaring up the rolltop unit.

A method has been worked out that will enable the builder to perform all operations with a table saw, router, and hand tools. Certain operations can be done on the shaper and those who have access to this machine will, no doubt, put it to good use.

The framed end panels are tackled first. Referring to Figure 1, you will see that the end panels consist of four frame parts, A. B, C, and E. surrounding a raised panel D, First cut stiles A and rails C and B. Enlarge the grid pattern of Figure 2 and prepare a template for cutting the double curve of rails E from %" stock.

All four frame parts must be grooved to hold the beveled edges of the raised panel D. The straight pieces will present no problem, but the curved rail is somewhat of a challenge because the tight radius of the inside curves precludes the use of a router. The grooving can be done with a shaper or with a centuries-old hand tool called a scratch stock.

The scratch stock shown in Figure 3 can be quickly made from scrap hardwood. A blade is ground from an old scraper or saw blade. File the

The Top cutting edge square and burnish a burr on the edge. The blade does the grooving by scraping rather than by cutting.

Insert the blade to take a light cut and clamp it. Push forward, repeating strokes until the blade no longer removes material, then set the blade for a deeper cut. Continue until a depth of %" has been achieved (Figure 4).

When the end-panel rails and stiles have been grooved, lay out %" dowel-pin locations for joining them. At the top joint, between B and E, care should be exercised so that positioning of the dowels does not interfere with the tambour groove.

Assemble the frames temporarily with slightly loose dowels and check for squareness and wellfitted joints. Lay the frames over a glued-up panel that is to be beveled, and use a sharp pencil to scribe a line around the inside edges of the frame.

Cut panel D larger all around than the pencil line to allow for fit in the frame grooves. Use a compass and straightedge to mark this cutting line, then jigsaw the panel to shape and sand the edges to remove any bumps or slight irregularities.

Beveling of the three straight edges to form a raised center panel is a routine table-saw operation. The curved portion can be beveled by hand once you've cut a clean lip to start the bevel. One way to do this is by cutting a template from hard-board or plywood. This template, which is shown as B on Figure 2, is clamped to the panel. A router with a %'' O.D. pilot-bushing attachment and a straight bit is run along the edge of the template and cuts the lip to a depth of Xe" (Figures 5 and 6). Don't forget that panels D are mirror images of each other, and not identical.

After running this groove, use a plane to remove most of the waste down to a feathered edge. Finish off the curved bevel with a chisel, file, and sandpaper.

The entire end panel can now be finish sanded and glued together with short dowel pins, Follow the same procedures for building the other end

FlG. £ PATTELRMS OJTTirsJG E RAIL

5>ipe \aew PETTAIL A TÁMK^UK SOaP

ATTA/XMEMT

USíMíi fóVTBR^tfuPT 0O6WNG Tí fin»* UT ON f**JEL (ff J

-\ tamsoor strsps must r»6>s under ¡y ^xov rail. vomich stop's, u ft 13af.

-\ tamsoor strsps must r»6>s under ¡y ^xov rail. vomich stop's, u ft 13af.

UFT BAC tracks

ON AT

Each end

UFT BAC tracks

ON AT

Each end

panel, but don't forget that the panels are left and right mirror images.

The tambour-tracking groove, which is %" wide \ %" deep, is routed into each end panel, again using a template and a router with %" pilot bushing. A single template is used and reversed for the alternate end panel. Thus slight irregularities in one groove will be transferred and will correspond on the opposite groove.

Again referring to Figure 2, enlarge the grid pattern and cut template A. cutting as accurately as possible and sanding until all curves are smooth and continuous, without bumps or depressions. Make reference marks on the template so it can be positioned identically on cach end panel.

It's best to screw the template to the work-piece. This saves a lot of fussing with clamps, and the screw holes can be filled later. Consider fastening the template to a piece of scrap and making a trial run or two to get the feel of running the router around the curves.

When fastening the template to the end panel, note that the groove you are going to rout does not exactly parallel the outside edge of the curved rail E, but veers away so that the tambour will clear the stop rail across the front of the rolltop case (Figures 2 and 7).

After routing the first groove, remove the template and, using the reference marks, locate it on the other end panel for the other groove. When the grooves have been routed to a depth of sand them smooth with a small sanding block, then seal them with a thinned shellac and a thin coat of wax.

Having completed the end panels, we can proceed to the construction of the framed back panel shown in Figure 8. Follow the same general procedures as used for the framed panels that make up the base of the desk (see Part I of the project). The back is fastened between and flush with the ends using % "-square cleats and screws. Square up the assembly and tack a strip across the bottom near the front edges to hold it square.

The top piece, which is % x I2A x 49", is attached to the end back panels with IK" #10 flat-headed screws, counterbored and covered with flush wood plugs.

The pigeonhole case (Figures 9 and 10) is constructed separately and inserted as a unit. It should be a good sliding fit between the end panels. Use dadoes and rabbets to attach the various partitions and shelves. The upright dividers at each end are cut from K" plywood and shaped with a jigsaw. All drawers are constructed with stock. The drawer fronts are of W stock and fitted flush. Drawer bottoms are %" or K" plywood.

The back of the pigeonhole case conceals the tambour when it is in the up or open position. Cut the case back from %" plywood and apply a veneer that matches the rest of the desk to the side facing front. The back is rabbeted into a % x 2 x 4414'" rail fitted into notches in the case uprights.

When the case is completed, place the roiltop assembly on a flat surface and insert the pigeonhole unit. Later, this can be fastened with small finishing nails driven into the end panels.

Thirty tambour strips are required, but you may have to rip fifty to get enough good ones. The strips are dimensioned as shown in Detail A. A saw-blade angle of 12 to 14 degrees will provide the relief angles on each strip so they can travel through the S curve. Rip the strips to a rough length of about 47 They will be trimmed later to finish length as determined by your measurements from one groove bottom to the other.

Because of intrinsic tensions in the ripping stock, you may find that many strips will warp immediately, or after a couple of days. A small degree of lateral warp is acceptable as this will be removed in a jig that holds the strips flat and square while the canvas is glued in place.

Figure 11 shows such a jig. Use a half sheet of particle board for the base, which should be cut to 31" high x 51" long. Fasten two rabbeted strips to the base, then add a back stop strip as shown. Slide the sanded tambour strips into the jig face side down. Then slide in a stop strip and fasten another strip 4" further down. Cut wedges and tap them into place between the last two strips. Make wedges just tight enough to close the gaps between the tambour strips. Tap ail the strips until they are flat against the base.

The canvas backing can be secured at art supply shops. For the original desk denim was used, but artist's canvas of about 10 ounces in weight is good. The canvas is cut to a height of 24i4" and a length of 44%". The finished tambour strips should measure 46%" in overall length, and when the shoulders are cut the distance between shoul

Tambour &UJIM& Jt&

ders is 45%". If the width of your rolltop assembly is slightly off, you will have to adjust tambour length accordingly after attaching the canvas.

The canvas is fastened in from the points where shoulders will be cut on the strips. Allow a 2" overhang beyond the first tambour strip, which will be fastened to the lifting bar (Figure

Working a section of about four strips at a time, apply Titebond glue and lay the canvas along guidelines penciled on the tambour strips. Do not allow the glue to drip between the strips. Use a roller or veneer hammer to smooth the canvas and spread the glue.

Allow the tambour to dry for 24 hours before removing it from the jig. The tambour can now be trimmed at each end to a finish length of 46%*. The shoulders on the strip ends can be cut with a router and a damped guide strip (as shown in Detail A).

Make the lift bar according to the specifications given in the Bill of Materials. Cut a strip of X" stock to fasten the 2" tail of canvas to the lift bar using countersunk flat-headed screws screwed through the strip and canvas and into the bar (Figure 7). Note that the bar is fitted with ^«"-diameter dowel pins at each end to enable it to track in the grooves.

The tambour can now be fitted into its grooves. A bit of sanding at the ends of the tongues may be necessary. The strip shoulders should not rub along the end rails because that will eventually cause unsightly marks that are visible when the desk is open. When the tambour tracks easily, remove it and apply a finish, taking care to keep it off the canvas.

The rolltop section is joined to the desk with ^"-diameter x 2J4"-long dowel pins. These pins are permanently glued to parts C (Figure 1) and D (Figure 8) of the rolltop and fit into (but are not glued into) corresponding holes in the desk top. This method makes for easy removal and replacement of the rolltop unit. Seven dowel pins are required to join the desk and rolltop. Dowel-pin holes in both units are drilled to ^"-diameter x IK" deep.

The rolltop lock model itL31 was obtained from the Wise Company (see p. 244 for the ad dress). It is of brass and iron construction, furnished with two keys and a trap-door catch. Screw holes are bored and countersunk for =4 screws. The matching escutcheon, model #E22. is made of gauge brass. Drill and mortise the desk top and lift bar as required for installation. Also select an appropriate lock and escutcheon for the kneehole drawer.

Choosing a final finish will depend upon the type of wood used for the desk as well as individual taste; however, it should be done with patience and care. Sand thoroughly, making sure to remove all tool marks.

The original walnut desk was finished with four coats of Deft clear wood finish, with light sanding after the second and fourth coats. For the final coat, a can of Deft spray was used, leaving a fine finish free from brush marks.

BILL OF MATERIALS—DESK TOP

Pes.

Key Req'd

T

w

L

Back (Figure 8; I req'd1

A 2

r

2!4*

1414

B 3

2W

10"

C 1

214"

41"

D 1

214"

41"

E 4

w

8 %"

10"

End Panels (Figure 1; 2 req'd)

A 2

214"

1414

B 2

254"

9"

C 2

214*

24"

D 2

10"

24)4'

E 2

614"

24"

Top (Figures 1 and 8)

1

x*

1214"

49"

Tambours

30

%'

4714'

Lift Bar

1

2%"

45 W

Was this article helpful?

0 0
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.

Get My Free Ebook


Responses

  • lete idris
    Are tambours grooved at ends of rolltop?
    7 years ago

Post a comment