Cabinet Assembly Options
Traditional assembly still makes sense for small shops that neither build a lot of boxes nor own a CNC. The investment is minimal. It involves little more than a glue bottle and a few clamps. Everything is milled manually on a table saw, a router table, or with a portable router and a straightedge. The joints are all dry-fitted and tweaked, glue is applied, and then clamping takes forever and usually requires a second pair of hands. Each assembly needs to be checked for square, and the clamps then need to stay in place for a long time, if not overnight.
Labels such as RTA (ready to assemble) or KD (knock-down) don’t apply here. These boxes are built, and they stay built. There’s no flatpack and they’re transported to the job fully assembled. The only hardware is the odd screw driven in a spot where it will never be seen.
A step up from dadoes and glue is to add biscuits or dowels to help with alignment and add some strength. The slots or holes are manually cut or drilled one at a time, and the process still requires glue, clamps, and lots of diagonal measurements for square.
If a woodworker has lots of time and is on a tight budget, this is still a perfectly viable option, but it doesn’t need to be. There are lots of other cabinet assembly options.
Biscuits and boxes
Liestal is a town of about 15,000 inhabitants that was first settled during the Roman Empire. It sits on the road between a bridge over the Rhine at Basel, and the Gotthard Pass. The bridge joins Germany and Switzerland, and the pass is one of two ways to travel through the Alps from southern Switzerland to the north, and on into Germany.
Hermann Steiner opened a woodshop in Liestal back in 1944, in the waning days of World War II. Twelve years later, he invented the Lamello biscuit joining system to join parts that were cut from the new material, chipboard.
Biscuits have come a long way since then. Today, the Lamello P-System is distributed in the U.S. by Colonial Saw (csaw.com) through locations in California and Massachusetts. The system consists of the Zeta P2 profile biscuit joiner and a variety of connectors that let a woodshop make fast connections (permanent or detachable) in solid wood, plywood, MDF, particleboard, plastics, and solid surface material. There is also a CNC version of the cutter for higher volume and faster-paced cabinet assembly. The ‘biscuit’ still has the same football-shaped profile that it has had for more than 60 years, but the edges on P-System biscuits have a small ridge along either side of each curved outer edge. The carbide tips on the circular blade are a little bit wider than the saw plate is thick. The blade enters the wood, goes full depth, and then moves up and down before returning to center and exiting the wood. The result is a curved T-slot that gives this generation of Lamello biscuits unparalleled strength and hold. The biscuit halves either snap together, or they can be drawn together mechanically by turning an Allen wrench.
There’s a new connector from Lamello called Cabineo, and it was designed for cabinet shops that use nested-based CNC routers. The toolpath is machined with a standard, straight-shank router bit without a tool change. The connectors are simply tapped into the routed pocket, and they can then be used to join cabinet components together by screwing into a mating 5mm shelf pin hole. Delivering nearly 200 lbs. of clamping force, Cabineo can be covered with decorative caps, or cabinet parts can be inverted to hide the connector. And because there is no pin or stud required with Cabineo, all components may be shipped to the jobsite as a true flat-pack, RTA solution.
McFeely’s (mcfeelys.com) is familiar to most woodworkers for its screws and fasteners, but a large section of its catalog includes various RTA and KD connectors, primarily from the Australian manufacturer Striplox. There are invisible plates that are screwed individually to surfaces, and then snapped together, or others that are used with a standard 4” biscuit joiner. The connectors come in many different shapes and sizes and are intended for cabinet and furniture assemblies that need to be disassembled for shipment and reassembled on the jobsite.
Cabinotch is a unique cross between a clever, hardware-free cabinet assembly system and an outsourcing supplier. Based on a patented interlocking joint, the Kentucky manufacturer delivers a top-quality, all-wood, custom-sized cabinet that includes the face frame, sides, backs, bottoms, tops, and shelves. The woodshop finishes the parts and assembles the cases using a simple click-and-lock method.
Mortises, dovetails and dowels
Based on its floating wooden tenon system, Festool (festoolusa.com) has created a family of mechanical connectors for cabinets that slip into mortises that have been milled with a Domino DF 500 tool. There are two types of corner connections for right-angled assembly, and two center panel connectors for edge-to-edge assembly. The Domino connectors make KD joinery simple and stable, and allow a woodshop to easily assemble, separate, and reassemble cabinets.
Hoffman USA (hoffmann-usa.com) has adopted a different approach. The company manufactures polymer and wooden dovetail keys, and it supplies several machines that accurately mill keyways for them in stiles and rails, picture moldings, face frames, mitered cabinet doors, angled cabinet, range hoods, and more. For example, the PP2-NCF is an automatic dovetail routing machine that is equipped with two high-speed router motors to process two workpieces simultaneously.
Castaly (castalymachine.com) has added two new CNC dovetail machines with different pre-programmed production profiles. Model CM-600NC includes modules for English, French blind, and threading dovetail joints. Model CM-700NC has three extra modules for English One and English Two dovetail joints, and parallel indent straight cut finger joints.
The Mod-eez connector system from Knapp Connectors was specifically designed with RTA furniture, case goods and cabinetry in mind. It’s designed around clips that are made of spring steel. A clip is set into a routed groove in one of the two wooden parts and screwed in place so that it is just below the surface. A single screw with a double head is screwed into the second wooden part. There’s a tapered slot in the spring clip, and when the second part is tapped with a mallet it slides down the taper and pulls the joint tight.
The new Cam5000 is the strongest cam yet from Titus Cabinet Hardware (titusplus.com) and it was designed for simple cabinet assembly. Basically, one of three different metal dowels is installed in one cabinet panel, and a small rotating cam is installed in the other. The cam is simply rotated with a Phillips head screwdriver to pull the parts together and lock them.
Zipbolt (zipbolt.com.au) also offers a cam-operated system, FastFit, for drawing parts together during assembly.
Last year, the Irish manufacturer OVVO (ovvotech.com) announced that its connector system would be available in North America through Richelieu Hardware. The system has won several prestigious awards in Europe and offers a quick-connect and disconnect system that can be used by one-man shops with a drill press or PantoRouter, or by large shops with CNC equipment. It works on boards from 1/2” thickness on up, and it delivers an invisible, affordable cabinet connection system that doesn’t require tools, screws or glues on the jobsite. OVVO (that’s two Vs, not a W) is available in a range of sizes, with permanent and releasable options.
Lockdowel (lockdowel.com) is based in Davidson, N.C. and produces fasteners that simply snap into routed slots. The system eliminates glue, screws or staples, and is fast to assemble or disassemble. Simply slide parts out of the routed slots and reassemble them elsewhere as needed. The catalog includes drawer slide and hinge options, and the entire system is designed for lean manufacturing.
One of the simplest and most effective cabinet assembly options is the elegant and unique FastenLink dowel (fastenlink.com). The pending patent design includes a plastic dowel that has a groove cut into the tip that creates a shoulder. That profile slides into a tapered groove cut into the wood, called the ramp. The groove guides the FastenLink dowel until it clicks into the locked position.
Screws and pockets
There are times when screws are the best choice for assembling cabinets, especially when the screw has been specifically designed for that purpose. Cabinet assembly screws from Deerwood Fasteners (deerwood.com) are a good example. The company offers a flat top surface head that’s designed to sit flush with the surface and is available in Phillips, square or combo drive recesses. It also comes with or without type-17 self-drill cutter points. There are flat heads with nibs that are added under the head to aid in countersinking and locking the screw in place, and trim head screws that can be used discreetly to attach moldings and trim to cabinets. And Deerwood’s round washer head screws have a semi-elliptical top surface with a built-in washer to provide a larger bearing surface.
The Aura line of screws from Screw Products (screw-products.com) has an aesthetically pleasing mushroom head that is shaped to look well in cabinetry and furniture. The large diameter head of the fastener ensures increased holding power.
Castle USA (castleusa.com) also specializes in screws. The company’s flagship pocket screw is an engineering marvel designed to work perfectly with its low-angle pocket holes. The cheese-head top is supported by an angled fillet for strength, and the Torx (star) drive gives the woodworker extra grip and avoids bit slippage and stripping.
The familiar pocket hole cabinet assembly system from Kreg Tool Co. (kregtool.com) got a huge upgrade last year with the introduction of the 720PRO Pocket-Hole Jig. It automatically changes clamping and hole alignment for different thicknesses of wood from 1/2″ to 1-1/2″ thick.
Ritter Machinery in Holland, Mich. (rittermachinery.com) makes a family of four foot-operated, stand-alone pocket hole machines, available with single or double spindles. They are designed for high production of face frames and five-part door frames.
LignoLoc (beck-fastening.com) is the first collated wooden nail system where the nails are made of wood. That means shops building cabinets and furniture on CNCs don’t need to worry about the bit slicing through a metal fastener. The shootable wooden nail is perfect for use in timber construction, too. The nails are made from central European beech from sustainable FSC certified forests. Due to their mechanical properties, the nails can be shot into wood and wood-based materials without pre-drilling, using a specially developed Fasco pneumatic nailer.
Raptor Nails and Staples (raptornails.com) also offers a safe way to nail down parts during CNC operations and casework assembly. The company’s plastic composite nails hold parts tight while the glue cures, and they are safe to use around expensive cutters and blades.
A search for cabinet connectors on the Häfele America website (hafele.com) yields an astonishing 266 results. The company has developed several systems such as Rafix, Minifix, and the Ixconnect SC spreading connector. There are so many choices for specific needs that a woodworker might want to spend a little time working through the online catalog.
Hardware Resources (hardwareresources.com) also offers a selection of cabinet connectors including a metal cam and double bolt metal dowel system for joining 16mm and 19mm panels.
Cabinet assembly solutions from Hettich America (hettich.com) include Rastex, Megalock and VB eccentric connecting fittings, plus some block connectors. The Rostrino dowel and socket system is a detachable connecting fitting with catch springs that provides easy installation and removal. The Rastex system offers numerous metal dowl and socket options including three for angled connections.
Outwater Plastics (outwater.com) has a wide selection of cam and pin casework connectors including several drop-on outriggers in various sizes and materials.
Bainbridge Mfg. (bainbridgemfg.com) carries a good selection of plastic corner braces for surface mounted panel connections.
For shops looking for a fast way to attach face frames to boxes, the Blind Stapler (blindstapler.com) is a pneumatic staple gun that eliminates the need for pocket screws, nails or putty. It doesn’t leave a mark, so cabinets can be pre-finished before assembly. It allows a narrow crown staple to be shot in diagonally for maximum grab without popping out through the front.
For casework requiring traditional mortise-and-tenon joinery, the PantoRouter from Woodcraft Solutions (pantorouter.com) has just added a set of segmented templates to create 154 sizes of round-end mortise and tenons, and 77 sizes of square-end tenons.
Another ingenious machine, the Multi-Router, is back in production thanks to Woodpeckers (woodpeck.com). The 3-axis manual control machine was very popular a couple of decades ago, and the new and improved version now has integrated dust collection, improved vertical micro-adjustment, and tighter tolerances.
This article was originally published in the September 2022 issue.