Archive for the 'Routing' Category

From a pile of parts to a jig

Published on February 5, 2011 in Jigs and Fixtures and Routing. Closed Tags: , , , .

The parts, ready for assembly

Here’s the pile of parts, waiting to become a jig. That loop in the front is 1/4″ threaded rod that I bent into a semicircle and covered with vinyl tubing. It’ll help secure the router in place, along with the knob at the back of the picture (which threads into a hole on the side of the router casting).

I inserted the carriage bolts and drew them up to bite into the melamine, then secured them with nuts. Nuts and washers near the top of the bolts support the top plate which holds the router.

Setting the height

Here’s the jig with the router in place. I set that height gauge on the left to the distance between the table that will support the router jig and the centerline of the lathe spindle. Now, it’s a simple matter to adjust the nuts up and down on the bolts until a bit chucked in the router is at the spindle height, and the router is level. The digital protractor in the foreground helped with the leveling.

The jig at work, cutting a mortise

It’s time to try it out! Here you see it in place on a plywood table that’s mounted on the lathe ways. I’ve clamped stops to limit the width and depth of cut, and chucked a 1/8″ spiral bit into the router. The note, not yet fully carved, is held in place on the lathe.

Here’s a close-up of the action.

Here you can see details of what’s happening at the business end of the router. Once that mortise is cut, I can carve the rest of the note so the stem flows smoothly into the body, and make a “flag” that plugs into the mortise. See it in the next post.

Shop Tip: deepening a mortise

Published on September 26, 2010 in Routing. 4 Comments Tags: , .

A friend dropped by the shop with an interesting problem. The solution highlights a great use for a router.

Here is the face of the kitchen clock, along with the old and new clock mechanisms.

The clock mechanism for his kitchen clock had finally succumbed to time and kitchen grime, coming to a stop. It was time for action.

My friend bought a new clock mechanism he wanted to use in the old clock body. Unfortunately, the new mechanism had a shaft 1/4″ shorter than the old one’s, and that shaft had to project through the hole you see in the center of the clock body on the left, in order to mount the mechanism to the wood.

Here you see the clock mechanism mortise in the back of the clock body, along with the tool for making it deeper.

The 2″ square clock mechanism sits inside a mortise in the rear of the clock body. You can see it in the second picture. The problem was to neatly deepen the mortise by 1/4″. The solution was a router with a “pattern follower” bit.

A pattern follower bit is a straight bit with a bearing on the shaft, the same diameter as the bit itself. It’s like a flush trim bit, but the bearing is on the shaft of the bit instead of on the top. You can see one in the far corner of the mortise, and in the picture below.

Because the mortise already existed, I could use it as a template to cut deeper. I chucked a short pattern follower bit in a hand-held router and began cutting to final depth in the center of the old mortise, around the hole. This got the bit down far enough that its bearing would run against the existing mortise walls. Now it was just a matter of running the router clockwise around the mortise, deepening it right up to the old mortise walls. The edges were perfect, with no indication that I’d just cut the pocket deeper. Now, the new clock mechanism would fit easily.

Pattern follower and flush-trim router bits are very useful for duplicating shapes, and will probably find use in most woodworking shops. I have to admit that I don’t use a pattern follower bit often. But when I need it, nothing else will do the job.

Doorbell: finishing the motor housing

Published on September 9, 2010 in Bending, Jigs and Fixtures and Routing. 4 Comments Tags: , , .

I trimmed the top and bottom edges even on the bandsaw, using the bending form to establish a reference surface.

After the motor housing was laminated into its curved shape, it needed trimming on four sides. This took some cogitation, to develop a reference surface against which to square the cuts. Here was my thinking.

The most important thing was that the housing should appear to sit square on the motor, with its front (curved) surface vertical. That surface was hard to use as a reference, but the inside of the curve (which was parallel to the outside) was easy. All I had to do was put the housing back on the bending form and press it against the curved nose. Then, if I spaced the form away from the fence and pushed it through the bandsaw blade, I’d cut an edge that would be square to the curved nose, as in the photo.

Trimming the ends of the curved housing was easy, again using the bending form.

Once one edge was done, I just flipped the form over and ran the trimmed edge against the fence to trim the opposite edge. The form supported the “U” shape, which otherwise would have chattered up and down as it grabbed and released the blade.

The next step was to trim the open ends of the “U”, square to the edges and even with each other. Here again, the bending form made things easy. I used a square to mark a line across the width of the form at the right distance from the curved end, and set the bandsaw fence so the blade would cut at the line. Then I pressed the square end of the form against the fence and cut first one side, then the other. They came out square and even. (Note—this worked because my form was wide enough to stay square to the fence. If it was narrow, I’d have used a sled or miter gauge to keep it square during the cut.)

The resaw blade was still on the bandsaw, and I resawed a 1/4″ thick slice of the same Honduran Mahogany used for the sides of the motor housing and glued it onto the top edge of the “U”. I glued it with the grain running along the sides of the “U” because it will expand and contract with changes in humidity, slightly flexing the walls of the “U”. If I’d glued it across the “U”, sooner or later its seasonal movement would have broken the glue bond.

Once the glue dried, I trimmed it within 1/8″ of the housing sides with the bandsaw, then used a flush-trim router bit in my router table to bring its edges flush. In this operation the bit runs against the grain for half the cut, potentially yielding a torn out surface. What I did was to use a normal cut (moving the piece against the rotation of the bit) for the right side of the cut, then use a climb cut (moving the piece with the bit’s rotation) for the left side. This way, the cut was always supported by fibers beneath it. It took several light passes, but the final cut was just about perfect, only requiring light scraping with a card scraper to produce clean, flush edges.

I sanded all surfaces to #180, then finished them with the same gel polyurethane varnish I used on the rest of the cabinet.

Next, the installation and lessons of the project.

Doorbell: Finishing up the feature panel

Published on August 23, 2010 in Finishing and Routing. Closed Tags: , .

Here's the feature panel, all inlaid and with the lines flushed to the surface, ready to finish.

I probably should have added these pics to the previous post. The first pic is of the panel after all the grooves have been cut and filled with cherry veneer slices. I leveled them and sanded the whole panel, then pre-finished it with shellac before adding the frame. I did this because the frame projects out a little from the surface of the panel, and it’s easier to rub out something that doesn’t have those little “walls” to stop your hand on each stroke.

Here's the panel wearing its mahogany frame.

The second picture shows the panel wearing its mahogany frame. The frame was moulded from flat stock with a router, using the same techniques as the larger mouldings I blogged about earlier. I masked the edges of the panel before gluing on the frame pieces, then finished them with shellac and rubbed them out to a satin finish with 0000 steel wool and wax.

Doorbell: Making the feature panel

Published on August 20, 2010 in Routing and Uncategorized. Closed Tags: , .

The most eye-catching feature of this project is a panel veneered with curly maple veneer, with a cherry cross-hatch pattern inlaid over it. I blogged back on June 22nd about having to bleach the maple veneer because it arrived too red. Here’s how I did the inlay.

I vacuum bag veneered the maple onto one side of an MDF panel, and put a backer veneer on the other side. Then I sealed the maple veneer with a coat of shellac. Once the panel was ready to work on, I wanted to create a pattern that referenced the floor where the project would be installed. That floor is 20″ limestone squares, separated by 1/4″ grout lines. I scaled down by a factor of ten, and wanted to produce 2″ diamonds in a pattern, separated by .025″ lines of inlaid cherry.

Here you see the special router base screwed onto my Dremel tool. In front is a router guide.

The essential tools came from Stewart McDonald Co. They included a very precise fixed router base, shown attached to the Dremel tool at left; and a six-pack of .030″ straight router bits (I needed several because they break easily). With these tools, I could route a line just wide enough to accept the thickness of a sheet of cherry veneer.

Next, I attached a sacrificial hardboard sheet to a straightedge and cut it off with the router bit in the Dremel tool. You see the results in the first photo. This would tell me exactly where the bit was going to cut. Finally, I cut a 2″ spacer from another piece of hardboard.

Here the Dremel "router" is ready to cut a .030" inlay channel, once a new bit is inserted. The black strips are shims to let me cut to final depth in three passes.

I made the first cut on one corner of the panel at 45º. Then it was a simple matter to run a stop up to the straightedge, remove same, drop in my 2″ spacer, and re-clamp the straightedge for the next pass.

Actually, it wasn’t quite that simple, because the router bit wasn’t stout enough to cut to final depth in one pass. So I cut a couple of plastic shims from a .012″ thick sheet. On the first pass, I stacked both pieces under the router base. Next pass, I removed one. Finally, I made a pass with no shims to get sufficient depth.

When I reached the end of the panel, I ripped my cherry veneer into roughly 1/8″ strips with a newly-sharpened paper cutter, and glued them in place. After the glue set, I leveled them with a hand plane before making the intersecting cuts.

When the inlay was complete, I leveled everything carefully with a sharp plane and card scrapers, sanded and vacuumed the surface, and applied five coats of shellac. After a few days, I rubbed out the surface with 0000 steel wool and wax.

Doorbell: making trim moulding

Published on August 10, 2010 in Routing. 4 Comments Tags: .

I thought six bits had promising profiles. Here you see the shape each makes, and how it contributes to a moulding.

I wanted moulding above and below the fluted trim pieces which make up the sides of the case, so I pulled out the most promising router bits and cut sample profiles to consider.

I needed two mouldings: one about an inch tall, and the second about 2″ tall. The picture at left shows how I combined the shapes made by two of the bits to create the 1″ moulding.

The lower moulding (next photo down) used the broad curve from the same (top left) router bit to shape its lowest part, followed by a straight section and a small bead from the bit on the top right.

The bottom component is from the same router bit used above. The top bead is from this bit.

The point is, you’re not restricted to store-bought mouldings for your projects. In fact, it’s often difficult to incorporate them into something. First, they’re rarely made from a matching wood. Even if it’s nominally the same species as the rest of your project, differences from tree to tree may keep it from matching. But often you can’t find the shape you want in the right wood at all. Second, you have to plan around the available mouldings. If you make your own, you can pick a piece of this profile, a piece of that, and combine them into something that’s just the size you need. I don’t have a large number of profile bits, but I can combine them to make an incredible number of shapes.