swagman
Established Member
To make the motorised awl sharpener you 1st need a small motor. The one I used was a small wattage motor off a disused scroll saw.
Next thing is the abrasive mold that is glued to the end of the motor shaft. The outer cup for the abrasive mixture is a spare nylon bush out of a bench mounted sharpening stone pack.
This was lightly glued to a piece of board to stop the mixture from running out of the bottom.
Prior to filling the mold with abrasive mixture a drill bit needs to be selected that matches the diameter & shape of the awl tip. The tapered drill bits used to bore and countersink holes prior to fitting wood screws are ideal. They normally come with an adjustable collar which needs to be removed. Fit the bit into a pedestal drill ready for use.
The abrasive mixture is a 50/50 mix of Loctite and powder gathered from a soft Japanese Water Stone. This is mixed together well until it becomes a thick paste. The past is then poured into the mold till full. Scrape the top of the mix off to form a flat surface.
The abrasive mix sets within 2 or 3 minutes. You will feel the mix self heating prior to hardening.
As soon as the mix hardens, mark a center hole across the top face. Now drill the hole down to 3/4 mold depth. You need to do this stage reasonably quickly as the mix will continue to gain hardness the longer its left.
Now to fitting the abrasive cup to the end of the motor shaft. Roughen the end of the shaft with medium wet and dry, then clean surface with paint thinners. Mark a center point on the shaft.
Remove the bottom board from the mold. Apply a good amount of adhesive glue to the bottom of the mold and press over the center mark on the motor shaft. I chose to use Cyanoacrylate Quick Set for its adhering strength, but something similar like Araldite should suffice.
Now here is the fun bit. As the adhesive glue starts to tack, push the awl tip into the hole that was drilled. To find the exact center, start the motor up, and use the awl to guide you to the right position.The mold should then spin smoothly around the awl tip. Turn motor off and give adhesive adequate time to fully harden.
When in normal use, the awl tip tends to heat up during sharpening.To reduce this friction heating, dip the awl tip in Machine Cutting Lubricant before starting up the motor.
I hope I have covered all the important stuff.
Good Luck.
swagman.
