Getting the most out of a drill grinding jig, or Perfect twist drills every time

[RayW]

The son of a late friend has asked my help in sorting out, and selling off, unwanted items from his fathers workshop. I was interested to come across this thread as amongst the items to be sold are two drill sharpening jigs, one by Spiralux (the silver one in the photos), which looks identical to the one at the beginning of this thread, and the other is by Reliance.

[Graham Meek]

Hi Ray,

Thanks for posting the photographs, the first picture has solved a mystery as to why I had to put a 7.5 degree wedge under my Far-Eastern clone. The clone copy missed out this vital Spiralux addition to the base. The Spiralux would however benefit from fitting the adjustable eccentric to control the drill off-set. The Reliance jig on the other hand is a much better design.

My best regards
Gray,

[Graham Meek]

Following on from the publication of the article I have received a query concerning the amount to be removed from the drill location vee in order to get the end of the vee in-line with the centre of rotation. As this was something I had not come across in the course of writing the article I thought it would be wise to make this problem known. When the "query" jig was set at 59 degrees the amount to remove was 13 mm, which is far too much. The amount to be removed should be no more than about 3 mm, I have attached a photograph showing the amount removed from my own jig.

When the "query" jig was reset to 49 degrees the end of the vee was near enough in-line with the axis rotation not to worry about. Upon closer inspection of this jig, the drill angle scale was found to be off-set on the die casting compared to the "clone" that I have. It is this off-set that I believe is the problem. It does however mean the base will need a different angle on the wedge in order to re-establish the correct drill point angle.

I must thank Art for bringing this to my attention.

My best regards
Gray,