Basic descriptions of various types of tenoning machinery and their capabilities. November 13, 2008

Reprinted with permission from MLS Machinery, Inc.

Mortisers and some single end tenoners can be used in door and window manufacturing. This mortiser puts a non-round hole into the edge or top of a piece of wood; it can be square or oblong. Example, this type of hole is basically used for part of the locking mechanisms of a door, or for construction holes in the bottom rails of some chairs or for construction of a frame style door. It will put a non-round hole (mortise - female) into a part when a non-round part (tenon - male) is needed. They are often stronger in certain construction applications than a plain round hole. Example, early American style solid wood chairs, that have a piece of wood going between the legs (1) to give support to the chair and (2) to use as a footrest.

Some mortisers will do a square or oblong hole without rounded corners and others will do rounded corners. Note the difference between a mortise (female) and a tenon (male). The mortise will always be on the flat surface of the part; the tenon will always be on the end of the part. Manufacturers who need to do multiple holes, example garage doors, use a multiple slot or oscillating mortiser which might have six or seven of these slot mortisers on one machine producing six or seven holes at a time. The square type hole is made with an oscillating mortiser which can be a single or multiple head configuration as discussed above. The cutter or cutters go back and forwards (oscillate) all the time in the wood to a pre-determined size. The part will be put on a table and held down by clamps. The table moves slowly forward into the oscillating cutter/cutters to a predetermined depth; once reached, the table will retract. Some of these machines today are now C.N.C. (computer numerically controlled) which will automatically calculate where the hole or holes should be, how wide, long and deep they should be.

In the case of oblong holes with rounded corners, they work on the same basis except that the cutter itself would be circular instead of oblong therefore leaving rounded corners.

Chain mortisers are also still used. Basically these machines use a chain that is the tool which has numerous cutters on it. The machine almost looks like a conventional drill press with a handle that is pulled down, which in turn plunges the chain into the part that is clamped to the table. The width of the chain will determine the width and length of the mortised hole.

Single End Tenoners are basically a double end tenoners with only one side of the machine as per the example in Edgebanders single and double sided. A part to be worked on is put on a table which is usually manually fed through the machine, numerous cutters, saws shaper heads, etc. operating at the same time will do various operations to the edge of the piece depending on the application. There can be one head, two heads and sometimes up to six heads doing different jobs to the edge of a piece of wood as it passes through each cutter. The first head could be a cut off, just to cut to length; the next head could be a scoring blade that will leave no rough edges; the next head could be a top tenoning head which will put a groove in the top of the part; then a bottom tenoning head to put in the bottom groove; and various other heads doing other specific jobs at the same time. Used either in the panel industry for edge work on a panel, or can be used for the solid wood industry for doing certain parts, as an example a door tenon that has to fit into the mortise as described previously. This type of machine makes square or oblong tenons.

Single sided round end tenoners are for making round tenons.
(Similar to the chucker) In this case the machine only has one circular cutter that turns around the part that has been placed and held down on a fixed table. The cutter, which is round, keeps rotating on an accentric bushing that is pre-set to a pre-determined shape until complete. These machines will make round tenons, not circular, to fit the non round but rounded corner mortise discussed above.

Double end tenoners are just extensions of single end tenoners as they are double sided machines. Doing two sides at once, as in double sided edgebanders, they have a chain drive on both sides of the machine. The operator places the part onto the chain and it takes the piece through the machine. The part can either be a solid wood piece, for example, a rail which can be as narrow as 1" x 1" or a panel. Certain operations will be done to the ends of these parts as they pass the different heads. In the panel industry, it could be used for squaring up a door or any other part before certain other operations have to be done to the panel. The double end tenoner could put a groove into the panel or a shape on the edge or a tenon for chair parts. These machines will do repetitive work so all parts are exactly the same as each other when edge work or two sides of a part (be it solid or panel) are required.

The chain normally has attached to it in some form, a part called "dogs" which push the piece through the machine so that the part rests against these metal "dogs". When the double end tenoner is properly set up, the "dogs" travel at 90 to the fence being perfectly lined up on both chains on both sides. Some of these machines are very sophisticated and complicated, and could have possibly up to 15 heads on each side. Traditionally, however, three, four and five heads on each side is most common. In most cases, the configuration would be: first a scoring head, just to pre-score so that the piece on the underside does not chip; the second head is a hogging head, which would cut the part down to size and square it and hog off excess material; and the third head could be a tenoning head or a universal head (universal heads in any machine will tilt through 90 to 180 plane). These heads will all be for different operations and can cut the part from different angles, top, bottom and at 45. These types of machines could also have jumping heads to do "blind" cuts, that is cuts that do not go all the way through the panel, or corner rounding heads for table tops for office furniture. In certain large companies, two double end tenoners can be placed in line with each other with a panel turner so that all four sides of the material can be worked on in one pass. Normally used for squaring the panel. Some of these machines might have top driven pressures which will allow the part to be fed behind the "dog" instead of in front of it, which becomes relevant if long pieces are needed to go through these machines. Some of these machines might also have jump routing or some type of drilling attachment. Some newer more expensive machines are being made with C.N.C. controls to speed the set up of the machine as these machines often take long to set up.

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