|Project by kiefer||posted 01-22-2015 10:04 PM||5943 views||59 times favorited||26 comments|
Always wanted to make one but never took the time so this morning while I was waiting for a glue up to dry I made two .
I took a few pictures along the way and thought I share them .
I used 3/8” Baltic birch plywood for this because it is nice and stable .
Here is the simple layout two perpendicular lines and a part circle with a french curve finish to the 1” hole that will be the first to drill.
A piece of 3/4” MDF clamped to the drill press table and tight to the fence and the centre finder hole mark aligned .
The 1” hole drilled through the work piece and almost through the MDF .
The mdf shifted over and a 1” dowel wrapped with some packing tape to fit tight .
The work piece is aligned with the mark for the metal dowel ( cut of 1/4” carrige bolt which is a tight fit )the mdf piece is reclamped to the table and the two holes for the dowel are drilled ,first one from the top and the second after flipping the work piece and indexing it on the dowel again ,makes for nice and accurate placement of the holes
Next I cut along the centreline and just removed the line which I thought would give me an accurate location when marking out for centre .
Next a little cutting on the band saw and sanding on the disc sander to make everything smooth .
I also cut an seven degree angle on the outside which is a common angle that will come in handy for wedgesETC . this can alsobe used as a 90 DEG. square in addition to a centre finder.
I looked around the shop for a very accurate round object and thought the alignment disc that I use to align my table saw is likely the most accurate I have and used it to prove out both centre finders by measuring from the edge of the centre finder to the edge of the 5/8” arbor hole and the distance is 5/16” so I guess this is right on and luck was with me .Woks on squares and rectangles also just engage the pins on one corner and and aline the opposit corner with the edge then do the same on the next corner and you have the centre .
In the last picture I used it as a 90 DEG. square and derw the lines to quarter the board and also drew a seven degree line along the top of the board .
All in all a very quick and useful tool and no reason to use a ruler for these markings .
IHOPE I EXPLAINED IT WELL ENOUGH ?
Thanks looking in .