Cutting Round Tenons on Chair Legs

The tenons on the front legs of our wood seat dining chairs come through the seat and are wedged — making the attractive and obviously strong “through-wedged mortise-and-tenon joint.”

The front legs of our chairs intersect the seat at an angle so the tenons and their shoulders are not parallel to the axis of the leg.  We cut the blank oversize so we can cut the angling and tapering leg out of it — but that is another story.  This is a story about cutting round tenons with square shoulders in a small shop.

We have three Newton, two spindle, horizontal boring machines made in Temple, Texas until about twenty years ago.  The machines were well-designed and well-built for making doweled face frames and other joints,  but “pocket screw” technology and foreign competition eliminated their market, and they closed — also another story.  Notice the foot pedals on these machines at one end of the shop.

One of these machines we have adapted to run a tenon cutter.  The adaption entailed, among other things, changing sheaves to turn the cutter at its optimal speed — much slower than boring bits and the Newtons were designed for.  As is common to most of our machines, we built fixtures to hold the various parts.

After producing the leg blanks to true dimension, we cut slightly oversize square tenons on them at the tablesaw, thereby reducing the wood that the tenon cutter must remove and creating square shoulders to fit against the seat bottoms.  In the photo below, you can see a “run” of legs, some show the square tenon (before), some show the round (after).

Will uses his leg muscles to maintain the proper feed rate of square tenon into round cutter — concentration and control are required.  Feed too slow and the wood burns and the cutter dulls; feed too fast and the machine stalls or the tenon is not accurate in diameter.

Photographing Furniture on a Backdrop

I have rarely been satisfied with the photographs of our furniture.  We try to capture the sculptural form and wood figure of the individual pieces isolated on a backdrop, and we try to capture the “presence” and utility of the furniture by shooting pieces or sets in a setting.  In the beginning, I hired acclaimed professionals, paying lots of money for mediocre results.  This motivated me to buy some equipment and do it myself.  For the last ten or twelve years, I have accepted my own work — accepted, though aware of the weaknesses.

This week, I broke through from reluctant acceptance to a certain satisfaction — and with some more practice and development, I might reach pride.  The breakthroughs came in lighting the piece and lighting the backdrop in a studio shoot of a Mitchell Trestle Table.

As before, I set up a “studio” in the living room, moving the furniture to the corners, hanging a backdrop from a long, wooden light fixture, and placing the flash stands.  I like the look of the furniture against a white backdrop, but this complicates things, gray or a color would be easier.  It is hard to keep that backdrop white in the photo.  Light bouncing off the furniture onto the backdrop will tint it — cherry tints pink, walnut tints lavender.  To cover the tint, it is necessary to overexpose the backdrop by adding a backlight flash or two.  Enough light to overexpose the backdrop will bounce back across the furniture, erasing the wood figure in areas and “wrapping around” to highlight the edges.  I have “accepted” a degree of tint in the backdrops and some wrapping around of the edges, and probably always will, but we figured out how to reduce both.

Another major hurdle is lighting the piece.  Furniture has nooks and crannies.  It is easy to get too much light in places and make “hot spots” and not get enough light in the shadows to show the wood.  Again, we figured out how to reduce both.

This is the first photo I took as a test.  As we had done many times, we set a flash on a side to “wash” the backdrop, a main flash for general exposure, and a subsidiary flash to light the shadows.  You can see pink in the backdrop and the almost loss of figure in the tabletop.  There are a number of photos on the website and in the catalog with these defects.

In preparation for this shoot, we painted some cardboard sheets flat black.  The next photos show the effects of holding the cardboard behind the table and lowering it to baffle the light.  The location of the backlight is different in these photos also.  We hung it flat against the backdrop aiming down.  You can see that the “glass-top” look has been eliminated, but there is not enough light on the top to show the wood.

So we worked with the main and the subsidiary lights.  We raised the main light and lowered the subsidiary, bouncing light from it off a reflector on the floor.  Another innovation: we hung a parachute cloth diffuser all along the right side of the table and backdrop instead of using a softbox as before.  This reduced hot spots and made a more even and pleasing light, without flattening the piece.  I have found that if the light is too soft, it removes dimension and any dramatic effect.  This photo is getting there.  It needs, among other light improvements, a cropping and the digital recreation of white above the table.

Changing to a wide-angle lens, I took a picture of the set-up.  You can see the parachute cloth to the right.  The main light is about 3 feet behind it and six feet high.

Notes:  The camera is a Canon Rebel xsi.  There is a ring flash on the camera at the tripod. The exposure is ISO100, F8 at 1/250.  The lens is a prime 50, 1:1.4; I can see distortion in even the very best zoom lens.  Furniture is architecture; the lines are important.  The lights are Alien Bees.  Seeing these results, we are going to build three sturdy, flat black panels (1/8” plywood laminated to a each side of a frame) that can support themselves in various ways.  I ordered another light to go behind the baffles.

Compressed Air Utility

The air compressor was down for maintenance for a day this week.  Aaron dug out the electric, 5-inch random orbit sander to sculpt and sand a rocker.  When done, he said, “I had forgotten how much easier our air sanders are to use.”  Sanding remains a grumbling chore, so we all need a reminder of how much better it is since we put in a compressor large enough to drive sanders.  They take a lot of air.

I took a photo of the electric sander Aaron had used and one of the air sanders.  The air sander is lighter, smaller, and has dust collection built it.  You hold the power of the compressor in one hand.

Aaron and I recalled the installation of the compressor.  I thought of the photos we took when we set it up.  In addition to placing the compressor and building a shed, we cut and threaded steel pipe by hand to build a loop around the shop with drops to machines and stations.  We created a utility — power generation with an infrastructure of distribution.

Bela Weeks’ First Carving

Bela wanted to carve something — her first carving.  The faceted, five-point star is a good relief for a lesson.  It is a simple, geometric shape with givens requiring precision:  the outline, the even depth and symmetry of the centerlines of all points, and flat planes from surface to centerline.  It calls for the mallet to get the depth and careful hands to true the facets.

She was intent.  She carved an fine star and made a proud grandfather.  Mrs. Snowden, her art teacher, got the star.

A Quick Walk Through the Shop

Yesterday, Austin took a series of photos with his phone while walking through the finishing room and shop.

Bent Laminated Braces

To accompany our rockers, we make a footstool that is 15″ high, right for use with the chairs.   The seats of the footstools are cut from 2″ thick stock, tenons are turned on the round legs, and the tenons are fit and wedged into holes bored in the seats.

www.garyweeks.com/harris_stool.htm

A patron requested a stool for playing cello of the same design, but built chair height of 18″.  It occurred to us that the extra length of the legs and the action of playing could be considerable stress on legs without stretchers.  We decided to make inconspicuous braces to truss and reinforce the legs.

We made parts as for a footstool with longer legs.  We turned the tenons on the legs first and inserted them in the stool to measure the angle the legs made with the seat.

Knowing the angle, we designed a form for pressing laminations of veneer.  The form is two sections, concave and convex.  Each section is a stack of plywood cut to the curve required and covered with aluminum sheet.  When describing the curve, the thickness of the final lamination must be accounted for — .45″ in this case.

We used a roller to spread glue on the eighteen pieces of veneer . . . quickly.

We lined up the forms and the stack of laminae in the press.

Clamped it tight.

We sawed braces from the bent stack, and sanded them to fit the groove we made in the legs.

Cello stool finished.

The Tapered Sliding Dovetail

. . . is the most finicky, persnickety, frustrating, and aggravating way I know to join a case.  It requires precision, patience, and painstaking beyond anything else we do.  We do it because the display of exacting craftsmanship and the strength of the cabinet is unsurpassed.

We still lose money at it.  But with this latest chest for drawers, assembled today, we have turned a corner — around exasperation and on the stretch to breakeven.

Among the hard things about it:

1. The panels of solid wood must be flat, square, and true to thickness, width, and length — within a very few thousandths.
2. The dovetail grooves across the panels must be true to depth and taper, again within a very few thousandths.  They must be square to the face, on layout, and in line with their mates at the front and back of the panels.
3. The dovetail pins on the ends of the panels must be mirror images of the grooves — yet smaller without being a hair too small.
4. A dovetail pin must slide into its groove and become tight along its entire length just as the faces of the panels line up.
5. A joint that slides and fits dry will be tight when glue swells the wood.

Among the new developments we made with this case:

1. We figured out a superior way to lay out the guide lines on the panels.
2. We tuned up the grooving fixture that guides the router across the panels.
3. We remade the tapered carriage that guides the panels over the router table.

The assembled case is interlocked, rock-solid rigid, and square.  You can’t shake it.