RIScov.pag

Horizontal Boring Jig

M

Y BORING JIG,WHICHuses a^1 ⁄ 2 -in. portable drill, is similar to a
conventional horizontal-boring machine except that the table
moves rather than the drill. The jig consists of a base, a hinged drill
platform, and a sliding table.
Make the base and sliding table from^3 ⁄ 4 -in. hardwood plywood.
The drill platform should be extra stiff, so laminate two pieces of^1 ⁄ 2 -in.
plywood to give a 1-in.-thick platform. Spindle elevation is adjusted
by raising or lowering the hinged drill platform. Install a piano hinge
on one edge and two or three bolts with wing nuts for adjustment on
the other edge. If adjustment is needed over a wide range (say, 3 in.),
some sort of pivoting arrangement would be required for the adjust-
ment bolts.
Most^1 ⁄ 2 -in. drills have a threaded handle socket on the top or side
that accept standard^3 ⁄ 4 -in. threaded pipe. Secure the drill to the plat-
form with a short piece of threaded pipe and a standard floor flange.

CHAPTER FIVE

Sliding

table

Moveable

fence

Guide

Bolt and

wing nuts

Rail

Pipe

and

flange

Hinged

drilled

platform