I would disagree with the absolute (will not) would prefer something like 'may not'.Hello there
This is one of the BEST Explanations I've read in a long while on WHY a CENTRE DRILL will not lead to a very precise and accurate Drilled Hole.
Much appreciate the Post
Thanks again for the input
My question of you, and them, would be : how much is enough?I disagree - with everything
Alexander Pope and echoing Juvenal much earlier said:-
A little learning is a dangerous thing
The more that one learns, the less one knows.My question of you, and them, would be : how much is enough?
(Yes I agree with the sentiment but quoted too often leads too many to not want to learn and that is very negative for the system and its longevity!)
(the answer that is most likely would be "You can't learn enough" which is also true)
Hi Richard,Wait a miniute. I am too old to learn! But it is always helpful to know about these spotting drills. I never knew about them till I lookt them up because of all your posts. I thimpfk I have never owned one of these drill bits. Maybe I 'll get a couple to test out. Even so, I am still incapable of learning.
Hi Ken, Surely you mean a "Bell Bottomed" hole !It's a trick you need to be careful with - it not only drills bigger but continues to drill bigger and bigger the deeper you go.
Years ago I was production drilling Ø7mm holes prior to a 7mm hexagon wobbly broach - we needed to drill Ø7.05 - on one occasion we overdid it and by the end of the 11mm deep hole the bore was so bell-mouthed that the hexagon vanished - the result an expensive warranty return from VW when the hex drives stripped on assembly.
I couldn't believe the Ø7 hole had bell-mouthed to Ø8 in just 11mm - of course the damn thing passed all the Go / No-Go gauges - you could only see the error if you sectioned it.