Peg Shaper Prototype

This adjustable peg shaper works on the principle of a 45 degree angle for the peg size adjusting bolts, to ensure that the corners that hold the peg are always the corners of a square, no matter what the size.
The size of the peg is determined by marking on the taper tool in pencil, the required diameter of the peg at the collar, putting the taper tool in the jig and adjusting the holding corners to a snug fit on the taper tool, then insert the peg and when shaved to the collar the size will be identical.
For each reduction in diameter of the peg the size of the "square" is reduced with the adjusting screws and if required the blade protrusion is also readjusted.
The original cutter was a Stanley blade that had the corners ground off to give a 2" width to match the jig, the depth of cut can be very precisely adjusted by reducing the tension on the blade securing arm, adjusting the blade screws to give the required blade protrusion and then re-tensioning the securing arm.
With the initial setting of the blade towards the top of the peg diameter the double bevelled Stanly blade had a strong tendency to dig in and gouge a section out of the peg, this was solved by setting the blade to touch the peg at the 3 o'clock position, similar to the cutting position on a metalwork lathe.
However, in practice the very thin Stanley double bevel blade chipped, so the double bevel was ground off & replaced with a single bevel. This stopped the blade chipping but the Stanley blade was still a bit thin and has enough flex to want to dig in as the peg diameter reduces.
The blade has since been replaced with a thicker one made from part of a power hacksaw blade, with a single bevel, and has a lesser tendency to dig in.
The main bar and angle are made from 2" x 3/8" flat steel (can be thinner) and the peg holding corners are 2" long and cut from 1" x 1/8" square tubing, which has to be cut to a 30:1 taper to match the taper tool.
When securing the fixed corner section to the main bar (by welding or screwing) the smaller end has to be shimmed up 0.847mm (0.034") to make the top line parallel to the main bar and conversely the adjustable section has to have the bottom line parallel to the main bar, thus having the adjusting bolts fixed on the taper angle.

Sketch showing the 45 degree angle required and 1:30 tapers on the peg holding corners.

Top view showing taper tool inserted.

Side view.

Another side view angle

New peg, taper tool & two pegs shaved to match taper tool angle.

This page was last updated  on 07 April 2004