home made fingernail grinding jig

[Shay Vings]

I have made one of these from the various designs on the web. Basically it uses a 2inch wood block with a hole for the gouge and a dowel projecting at an angle from the base which pivots in a sliding arm. Geometrically, pretty much like the commercial product

It does produce a degree of side grind on my spindle and bowl gouges.

However, can someone enlighten me as to what adjustments to make to increase/decrease the amount of side grind for a given bevel angle?

As I see it, there are 4 variables:

1 protrusion of the gouge from the face of the block
2 distance between that gouge hole and the point at which the dowel leaves the block
3 the length of the dowel
4 the angle the dowel makes with the gouge axis (45 and 30 degrees in my case)

Which of these should I experiment with. I have tried meddling with all 4 but I just get more confused.

 

[BMac]

If you hold a gouge horizontally at 90 degrees to the grinding wheel that will give you the least swept back wing. As you lower the handle the wings will get longer so you probably need to adjust the length of the dowel or the distance the cup extends from the grinder.

Hope that made sense.

Brendan

 

[CHJ]

Can I add a little more confusion? the diameter of the grinding wheel and the distance of your pivot point from it.
The angle on the face of the tool will vary due to the curvature of the wheel.

There are so many variables concerned and the various jigs have recommended settings to achieve their designers version of any particular grind that it is very difficult to come up with any 'definitive advice'

The easiest way to learn is to hand grind a piece of scrap steel to your desired form, or obtain a set of 'Setting Samples' (Sorby?) and then adjust you own jig settings to achieve the desired form.