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The trunnion assembly, in a manner of creating false studs, is a convenient method for making simple furniture. The dedicated guides allow an easy and precise realization!

Use a logging guide

Match holes and parts to assemble

If the principle of the trunnion is very simple, its realization is delicate: the holes must be perpendicular to the surfaces and coincide perfectly between parts to assemble. With the special guides, it becomes easy to "put the eyes in front of the holes", for a moderate cost, since the most expensive of the models presented does not reach 70 € (25 for the cheapest).
Better still, some allow the installation of invisible hinges or the drilling of shelving clutches. Only disadvantage, they know only the right angle. Few models are currently present on the consumer market, including three at Wolfcraft: two universal devices (the "4640" plastic and the "3750" metal) and a rule, widespread in DIY store. Virutex also offers one, available for sale by mail (HMDiffusion for example).

The preparation

The primary purpose of this type of assembly is the binding of panels, such as plywood, laminated or non-melamine agglomerates, glulam, etc. Surface preparation is therefore not an essential concern. But the songs must be square to stabilize the connection, otherwise glued or simply screwed.
The thickness of the material determines the diameter of the trunnions, usually 6, 8 and 10 mm. You must keep a minimum thickness of 3 mm on either side of the "peg", otherwise the wall, too thin, could break in case of lateral force. Thus, for a 12 mm thick piece, the diameter of the pin must not exceed 6 mm.

To limit the depth of the holes, the simplest is to use a special stop screwed on the drill. Otherwise, a piece of adhesive wound on the wick will serve as a reference. The depth of drilling in full panel is at least the diameter of the trunnion, and at most half of its length; Remember to take into account the centering point of the drill so as not to cross.
Side singing, it is necessary to avoid drilling too deep at the risk of making disappear the trunnion. The cumulative depth of the two holes must therefore correspond to the total length of the trunnion, with a margin of one millimeter to ensure the perfect contact of the two parts. When drilling in series, check regularly that the stop does not move: it is not uncommon for the screw to loosen!

Piercing on the edge

Except when the two pieces are pierced in the wake without moving the guide, the song is always prepared first. On long pieces, it is better to provide at least three pins to avoid any risk of sagging. As for the spacing, it can be 10 to 30 cm, depending on the constraints to which the piece is subjected. In the case of an end assembly, two to three pins are sufficient, depending on the width.
With the Wolfcraft Plastic Guide, the panel must be flanged to keep both hands available, one firmly holding the guide, the other the drill. A light machine is therefore recommended. The metal guide of the same mark immobilizes the parts on the bench, freeing both hands of the operator to hold the drill.

Reporter on the other room

The case of singing against singing or edge report is the simplest. Especially with the metal guide: each pair of holes is drilled in series without touching the device. But you have to realign the pieces for the next pair. The other device uses an adjustable bracket to adjust the depth. The face-to-edge trimming is therefore less precise, with in return a greater freedom of positioning.
The full panel report method is similar on both models. The rear of the guide has three notches corresponding to the three diameters. Two indexes molded on both sides allow the positioning of the device, according to the axis of the song (plastic model), or its edge (metal model).

Two more sophisticated devices

To make a complete set of furniture, it is better to acquire a specific system. This is the purpose of the Wolfcraft rule, designed for 32mm (and multiple) center hole drilling. 670 mm long, it is perfectly suited to the assembly of the walls of the boxes and also to the drilling of invisible hinge fasteners, adjustable shelving cleats and other drawer slides, thanks to the 5 mm cannons supplied.
The latest guide presented, Virutex brand, makes sense in a series of work. Its three drilling guns are positionable at will on a metal rod. Once arranged, they allow drilling on both edge and panel, constant spacing. Just locate the alignment of the holes to be drilled. Disadvantage, only the 8 mm trunnions can be used. A ø 5 mm barrel for cleats or screws is however provided.

Assembly and collage

The role of the trunnion guides is limited to the piercing stage. The process is then similar to that of any other assembly: gluing the trunnions and the song then put in press making sure squaring, or removable screwing. Remain the cases to which the guides do not answer: bonds not square, or face against face.
Two solutions are then possible. For an isolated assembly, the metal centering pins - sometimes sold with the guides - facilitate the transfer of holes from one part to the other. For a series job, it is better to make your own template in a plywood or chipboard drop.

Center the hole automatically

Center the hole automatically

The basic model allows, thanks to its lugs, to automatically center the drilling on the edges of the pieces. These must be perfectly erected while the unit is firmly stabilized.

Reporter on the face

Reporter on the face

To assemble near an edge, the transfer on the face is done with the positioning bracket. The trunnion engaged in the groove guides the groove, aligned with the drill pipe of corresponding diameter.

Metal model

Metal model

More sophisticated, the metal model is in two parts and simultaneously flanges the two pieces to the workbench. It is therefore imperative to align the ends of the latter with a square.

Drill holes in pairs

Drill holes in pairs

Holes are drilled in pairs, requiring movement of the device at each step. If this system does not center the holes mid-thickness, it guarantees squaring even with an imperfect song.

Reporter in full panel

Reporter in full panel

The principle of the full panel report is the same on both models. The trunnions are threaded onto the piece pierced on edge, flanged flat on the other. They serve as a benchmark to align the holes through molded notches at the back of the guide. An index on the edges of the apparatus allows the positioning in depth, according to the edge of the piece for one, and the axis of the holes for the other.

Locate the parts

Locate the parts

Once the visible faces are chosen, it is always prudent to locate the parts to avoid untimely inversions. Useless to use the conventional signs, simple letters are enough.

Use a drilling stop

Use a drilling stop

Always use a drill stop. With holes too deep, the trunnion would sink into the song, or lead to the other side. Not deep enough, they would make nesting impossible.

Glue a part of the trunnion

Glue a part of the trunnion

No need to glue the entire length of the trunnion, it is sufficient to dispose the glue so that the depression distributes it, thanks to the grooves. The other end is glued together with the song.

Use clear glue

Use clear glue

On the edge of the pieces, a trickle of glue is enough. An excess would not hold up better and would give you extra work. Prefer glues called "transparent", less visible in case of smudge.

Control the squareness

Control the squareness

As with any other type of connection, the pieces are clamped during the drying of the glue. Check the squareness: even if the assembly seems rigid, the trunnions always leave a little play.

Fit with a mallet

Fit with a mallet

If the nesting is recalcitrant, never hit the pieces brutally, let alone the hammer. Use a mallet and insert a martyr. If it is melamine, be sure to avoid splinters.

Use a Wolfcraft Rule

Use a Wolfcraft Rule

With its brackets and positioning brackets, the Wolfcraft rule can realize all the usual assemblies. Used flat, it also allows the drilling of holes in shelf cleats in series.

Guide opur kitchen elements

Guide opur kitchen elements

With the ruler, the center distance of the holes is always 32 mm. It can be used to install invisible hinges, making it the most suitable guide for mass production of kitchen elements.

Virutex Guide

Virutex Guide

The Virutex guide makes it possible to reproduce identically a sequence of holes. Its stem supports a series of suitably arranged sleeves and two flanges that retain the positioning according to the songs.

Screws and guns

Screws and guns

Each socket of the device comprises a screw reinforcing the locking on edge and a pair of guns; one allows the drilling on edge and full panel, the other the assembly at the edge of the room.


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