I hope the jig device makes sense as presented. I am assuming you have the ability to read between the lines, but I'll try to clarify a bit. I
remember when I began using this because I had blown several catlinite pieces by missing ever so slightly with the bowl bore, and once you get it
perfect, you have to have them all this way or it's just no good. You wind up with a sloppy off center and oversized hole at the bowl bottom which is
unsightly and annoying.
There are two pieces of wood needed...one has the parallel bores and in these you insert
1) the exact drill you used to bore the draw tube-assuming you held exact tolerances with the drill- and 2) above that drill you have another tight
fitting tool, drill, whatever, just so they are stable.
The second piece gets a bore for the upper tool, and a tiny bore exactly centered on that bore, at right angles, or whatever angle you want to shape
the form to. This small hole must be precisely drilled in the center of the bore. Then you insert the starter drill, the tiny one, through the hole
you drilled, and when it is put together it looks like a rectangle, viewed from the side. You swivel the wood piece bearing the small drill until it
points dead center at the point of the bottom drill (which drill is to be inserted into the pipe). You must cement the top drill, or tool, at both
ends. The bore drill needs no cement. You cannot allow swiveling on the tool between/joined to the 2 pieces of wood, because those 2 wood pieces are
aligned to cause the small drill to always point at the must be locked down.
It sounds like a lot of fuss but really it's pointless to try to machine set up irregular things like stone etc.... This jig will give perfect results
but you should proceed slowly to prevent scarring the long draw bore bottom. Strictly finger drill that tiny hole, and take breaks to blow through it
until you strike, so you aren't going too deep. It is still possible to make mistakes in location of length (try to aim for the very point left by the
drill, or slightly beyond it).
You are going to be guessing at depth so keep a close watch. The centering should be perfect if you were patient with jig construction and pilot
drilling consistently with the small drill.
It would be a shame to miss after all that work.
I'd post images but I seem to be unable to figure it out. The image box won't accept the copy cursor. Maybe I need to shut my machine down, restart? I
have managed one image, and the procedure seems to not work anymore.
a reply to: skalla
edit on 27-4-2017 by TheWhiteKnight because: (no reason given)