Versatile Fingernail Gouge Grinding Jig
Note:
This Jig will aid the forming of a fingernail profile on a Spindle Gouge and a Bowl Gouge, it provides a greater ability to alter the bevel angle by both clamp head pivot and support arm adjustments.
Objective:
1. To make a Fingernail Gouge grinding Jig with greater Bevel Angle adjustment.

Reasons:
1. A need of an additional Jig to cover more diverse profiles, and explore a different techniques.


Design criteria:
1. To provide the equivalent function of the commercial units.
2. To do it with components/materials readily available in a wood shop.

Materials used:
1.  2 pieces of Beech of 20 X 20 X 300 mm section.                         Main Rails
2.  2 pieces of Beech of 20 X 20 X 150 mm section.                         Bench Guides
3.  1 piece of Beech of 45 X 55 X 20 mm section.                            Tool Clamp
4.  1 piece of Beech of 45 X 55 X 10 mm section.                            Tool Clamp
5.  1  piece of Beech of 20 X 20 X 150(130 finish) mm section.        Adjustable Pivot
6.  1 piece of Beech of 20 X 46 X 120 mm                                       Support Up-stand.  
7.  115 X 68 X 4 mm metal plate. (5mm Birch Ply as alternate)
8.  Coach Bolts, Nuts, Hex headed Bolts, Wing Nuts, Washers and Nuts to suit (6mm.)

Click on images for Better quality images (390 K each) should be printable to near scale dependant on users software.
Main Frame  Pivot 
   

 


Clamp  Assembly 
  Tool Support Clamp, Drilled to suit Tools, 12.7mm (1/2") is good for 13mm tools, a smaller width Vee Cut would allow wider tool shank size variation.
Basic Parts Complete Assembly
  The Original Components
Note Wide headed clamping bolt in centre of support rail. Original support post Pivot Socket
  Original High Support Pillar, more suited to larger Grinders.
  Original support post
Note pencil distance guide lines marked on side of support track for different gouges. Lower Pivot Point In Use
  The modified Base Pivot Point better suited to 6" grinder.
 
Some points on construction to note:

The dimensions are not super critical as the final angle of grind is dependant on user setup, the distance between the Pivot Rod Ball Centre and the Gouge Clamp Hole Centre suits a 6" grinder, I found that the original version with the support up-stand would be more suited to an 8" grinder, it causes too much natural contact pressure due to the tool weight when used with the 6" grinder.


To set up:

Fit Gouge to jig with approx 2 (50mm) protruding on Wheel side.

WITH GRINDER STATIONARY. Position and secure support slider arm and adjust clamp angle until the Gouge Bevel to be ground is sitting on the wheel at the desired angle.

Swing the pivot from side to side to check that the gouge remains in contact with the wheel.
Check that the jig does not foul grinder casing or guards.

Withdraw Gouge on pivot and switch on grinder.
Start with Gouge fully to one side and offer up to wheel, with hand on Gouge handle and a finger resting on top of Gouge near the handle side of jig clamp and with Light Pressure only, rock the jig from one side to the other until you have a continuous facet across the Bevel face of the Gouge.

More basic Fingernail Jig This Jig first appeared in UKWorkshop thread in Oct. 2006  

Page Revision date: February 20, 2011, 23.32 Hrs.