Oak Joinery

[Kenneth Larson]

Joineryis a part of woodworking that involves joining pieces of wood, engineered lumber, or synthetic substitutes (such as laminate), to produce more complex items. Some woodworking joints employ mechanical fasteners, bindings, or adhesives, while others use only wood elements (such as dowels or plain mortise and tenon fittings).

Many traditional wood joinery techniques use the distinctive material properties of wood, often without resorting to mechanical fasteners or adhesives. While every culture of woodworking has a joinery tradition, wood joinery techniques have been especially well-documented, and are celebrated, in the Indian, Chinese, European, and Japanese traditions. Because of the physical existence of Indian and Egyptian examples, we know that furniture from the first several dynasties show the use of complex joints, like the Dovetail, over 5,000 years ago. This tradition continued to other later Western styles. The 18th-century writer Diderot included over 90 detailed illustrations of wood joints for building structures alone, in his comprehensive encyclopedia published in 1765.[2] While Western techniques focused on concealment of joinery, the Eastern societies, though later, did not attempt to "hide" their joints. The Japanese and Chinese traditions in particular required the use of hundreds of types of joints. The reason was that nails and glues used did not stand up well to the vastly fluctuating temperatures and humid weather conditions in most of Central and South-East Asia.[3] As well, the highly resinous woods used in traditional Chinese furniture do not glue well, even if they are cleaned with solvents and attached using modern glues.

As the trade modernized new developments have evolved to help speed, simplify, or improve joinery. Alongside the integration of different glue formulations, newer mechanical joinery techniques include "biscuit" and "domino" joints, and pocket screw joinery.

This must be taken into account when joining wood parts together, otherwise the joint is destined to fail. Gluing boards with the grain running perpendicular to each other is often the reason for split boards, or broken joints. Some furniture from the 18th century, while made by master craftsmen, did not take this into account. The result is a masterful work that may suffer from broken bracket feet, which was often attached with a glued block, which ran perpendicular to the base pieces. The glue blocks were fastened with both glue and nails, resulting in unequal expansion and contraction between the pieces. This was also the cause of splitting of wide boards, which were commonly available and used during that period.

In modern woodworking it is even more critical, as heating and air conditioning causes more severe respiration demands between the environment and the wood's interior fibers. All woodworking joints must take these changes into account, and allow for the resulting movement.[4] Each wood species has a general respiration rate; a generally-assumed time length for acclimating a board to its locale is 1 year per inch of thickness. In preparing raw wood for eventual usage as furniture or structures, one must account for uneven respiration and changes in the wood's dimensions, as well as cracking or checking.[5][6]

Wood is stronger when stressed along the grain (longitudinally) than it is when stressed across the grain (radially and tangentially). Wood is a natural composite material; parallel strands of cellulose fibers are held together by a lignin binder. These long chains of fibers make the wood exceptionally strong by resisting stress and spreading the load over the length of the board. Furthermore, cellulose is tougher than lignin, a fact demonstrated by the relative ease with which wood can be split along the grain compared to across it.

Different species of wood have different strength levels, and the exact strength may vary from sample to sample. Species also may differ on their length, density and parallelism of their cellulose strands.

Timber expands and contracts in response to humidity, usually much less so longitudinally than in the radial and tangential directions. As tracheophytes, trees have lignified tissues which transport resources such as water, minerals and photosynthetic products up and down the plant. While lumber from a harvested tree is no longer alive, these tissues still absorb and expel water causing swelling and shrinkage of the wood in kind with change in humidity.[7] When the dimensional stability of the wood is paramount, quarter-sawn or rift-sawn lumber is preferred because its grain pattern is consistent and thus reacts less to humidity.

All reinforcements using wood as the introduced spanning material make use of the item's cellulose fibers to resist breakage. Biscuits or dominos may provide only slight strength improvement while still forming a strong alignment guide for the joint's pieces.[9]

A joiner is an artisan and tradesperson who builds things by joining pieces of wood, particularly lighter and more ornamental work than that done by a carpenter, including furniture and the "fittings" of a house, ship, etc.[16] Joiners may work in a workshop, because the formation of various joints is made easier by the use of non-portable, powered machinery, or on job site. A joiner usually produces items such as interior and exterior doors, windows, stairs, tables, bookshelves, cabinets, furniture, etc. In shipbuilding a marine joiner may work with materials other than wood such as linoleum, fibreglass, hardware, and gaskets.[17]

The terms joinery and joiner are in common use in Canada, UK, Australia, and New Zealand. The term is not in common use in America, although the main trade union for American carpenters is called the United Brotherhood of Carpenters and Joiners of America.

In the UK, an apprentice of wood occupations could choose to study bench joinery or site carpentry and joinery. Bench joinery is the preparation, setting out, and manufacture of joinery components while site carpentry and joinery focus on the installation of the joinery components, and on the setting out and fabrication of timber elements used in construction.

In the history of technology in Europe, joinery was the medieval development of frame and panel construction, as a means of coping with timber's movement owing to moisture changes. Framed panel construction was utilised in furniture making. The development of joinery gave rise to "joyners", a group of woodworkers distinct from the carpenters and arkwrights (arks were an intermediate stage between a carpenter's boarded chest and a framed chest).

The original sense of joinery is only distantly related to the modern practice of woodworking joints, which are the work of carpenters. This new technique developed over several centuries and joiners started making more complex furniture and panelled rooms. Cabinetmaking became its own distinct furniture-making trade too, so joiners (under that name) became more associated with the room panelling trade.

I understand that the Shapeoko has some amount of Y axis overhang off the front of the machine which might be usable. The idea is that I will have a pair of T tracks on the front vertical face of my table end, I could clamp work in a vertical orientation and use that overhang to cut fingers.

Unless you are planning on making joints all the time, t will be in the way or at least restricting access during normal operations;

You may need to move the machine for servicing so it could become an issue if it is attached vertically to your tracks;

You may want access from the front to put things under your table/enclosure and the tracks may be in the way.

One thing you may want to consider is tiling. You may want to have a trap door at the back of the enclosure to have a work piece extend behind. Tiling makes it possible to mill pieces larger than your bed by sliding them on the work surface.

You may also want an access door on the left side to access your controller without moving the Shapeoko. Other things to consider are dust collection (the noisiest part of operation) and you need to get the vacuum tube in without impeding movement, ventilation, lighting, access to the components for servicing and cleaning. If you ever want to upgrade to HDZ,you would also need to consider the height above the gantry.

I just used some random clamps in the model from the sketchup 3d model library.

The basic idea being that I can clamp to the front, with the rails recessed into the hardwood edging that I intend to use on the table. This is just a mock up. The top skins on the torsion box will not extend to the edge of the table.

I am wondering if you clamp only at the top, will the momentum of a long piece make it difficult to keep it properly perpendicular? The clamping is system is attached to the torsion box, not the shapeoko frame so any movement of the Shapeoko on the torsion box would mess up the alignment. It would not take much misalignment to mess up the joinery.

Thanks for sharing this @TravisGood Do you have any more details other than the video? I can see whats going on here but just wondering if the spindle mount has been modified at all and what all is going on there. I found the JointCAM website and there are a few posts on the forums about jigs but nothing to the degree of finish as the one in the video.

Also I fully intend to anchor the shapeoko to the table so that it cannot slide around. As I learned with my 3d printer, stability and rigidity go a long way towards accuracy. It goes for a lot of things actually. If you put more weight on a telescope than it is designed to carry then your accuracy will suffer as the mount struggles to maintain tracking.

Btw, the major challenge with the fixture was securing a tight fit on a platform that could not stick out beyond the front of the SO3 very far and use up the extra Y. If I were to do it again I might have considered using thinner alum. Also is the rigidity of the platform where we tapped 1/4-20 holes in the front of the SO3 and also the table that it was sitting on. That thing was not going anywhere. Here are some pics detailing the design and some interesting cuts inspired by Mirock. ArrownhoopJoinery.jpg642577 44.5 KB VertFix.jpg832803 180 KB

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