Before I could build the Thein Dust Separator I recently posted, I needed to come up with a router trammel. But, I couldn’t just leave the basic design alone. The original trammel was posted by Pitbull on Charles Neil’s “In the Workshop” ( c.f., http://www.freeforum101.com/charlesneil/viewtopic.php?p=11836&mforum=charlesneil#11836 ).
The first tweak was to construct the trammel body out of two ½” pieces of Baltic birch, instead of one ¾” thick piece of plywood. This increased the slide thickness from 3/8” to ½”, and the slide rails from 3/16” to ¼”. The second tweak was to use a brass pressure plate instead of the bare thread end of the tightening knob to lock the sliding trammel arm in place. (Photo 2) This eliminated the marring of the slide top and preserved the slide top for making minute adjustments. The third tweak was to add a Formica base to improve the friction resistance of the trammel base. (Photo 3) I also built it so the router could be aligned to the base with the use of a 30mm template guide (Photo 4), and made an optional sliding trammel arm that uses a Veritas Router Center Pivot (a mounting stud that eliminates the need to drill a pilot hole, Photo 5).
My tweaked version worked great and without any problems. The proof of its effectiveness can be seen in the Thein Separator it was used to construct. (C.f., http://lumberjocks.com/projects/102418 ) The only change I would make and suggest is to reduce the size of the base from 11-3/4” length to 8”. (Photo 6)
As always, comments (good, bad, critical or whatever) are greatly appreciated. Thanks for looking.