Before dismantling my shaper I decided to do some more 90 degree reverse glue joint work.
I had some timber needing attention so I set it up again using method 2, cut the set up blocks from the single piece of timber.
From the initial eyball setup I made another two adjustments and it was again a perfect fit.
So bring on the 90 deg joint.
Keeping in mind I was just using the shaper cutter and not a bearing mounted bit this is the result I got.
This is the test cut after alignment, some where in there is a reverse glue joint cut, the precision is impressive.
This is the same test cut looking from the other end, the cut is just visible this time.
Here is another shot, same as picture 1 but with the joint deliberately off set to see the actual mating surfaces.
A point to note here on the vertical section there is a small rebate, this is due to using a shaper bit and not setting the fence at zero. Other wise this is where the bearing mounted cutter earns its bread.
Having a reasonable result with the 90 Degree I decided to go another step and try a 45 Degree joint.
Now the 45 Degree cutting was a breeze, simply a matter of clamping the material to the tee slide and passing it through.
However because the cutter has a high side and a low side although the joint worked perfectly again, using it this way resulted in a miss match in the material on the opposite sides of the inner 45 degree joint.
This in my mind was unacceptable so I binned the test cut.
I then examined a T&G cutter and upon checking the profiles the only difference between the two is that the T&G cutter has two parallel profiles either side of the tongue and groove cutter section, where as the reverse glue joint has an offset cutter surfaces either side of the T&G section.
This makes the T&G cutter suitable for 45 degree joints as opposed to the reverse glue joint cutter.
Using the reverse glue joint on edges be it at zero or 90 degree works well, and if you are using it table mounted you can set the fence so there is zero timber removal when doing the face, otherwise that’s why there is a bearing fitted to the bit
-- Regards Robert