A Partridge in a Pear Tree? Or specsavers for Rob or Drill doctor for Aplletree?
Anyway more testing:
3,2 mm pop rivet drill (IXCY or something...) really nice drills I buy them 10/20 pcs boxes...helix about 26 degrees, pint angle about 118. Align it on -1 mark, sharpen and split. Unbelievably perfect. See the picture. It did drill well and in size (that I could measure).
Then with great trepidation I choose Alpen Forte 6,5 mm slow helix 35 degree model that had served well but had one edge chipped. Align it to -1 notch and sharppening looked about right. No need to split, original split was close. Drilled well.
I thought that I have now it pretty much sorted and choose old traditional form English made Dormer 10,0 mm drill that had corners chipped. It has been sharpened by shop at one point. Chissel angle was about 60 degrees, point angle about 116 degrees and helsix close to 30 degrees, nothing exotic.
Aligned it exactly at 118 degree mark, sharpening took ages close to 30 rounds, but looked pretty much ok in the end. Chissel angle close to 45 degrees. Splitting just about touched it. But the drill worked fine. But probably would not be big tamale on startting the hole.
Starting to think: Does anybody knows what angle the drill lip should be set at the chuck vs. helix? Starting to think that optical setting could be more likely to hit the spot?
Pekka
* Regarding facetting and rough grinding at the begining....I'm not the only one. Looks like DD is a bit prone to resonance, least when wheel is new, but works with a fim grip.
http://www.hobby-machinist.com/threads/any-tips-for-using-the-drill-doctor-x750.4282/