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View Full Version : Is it possible to modify a drill to be an end mill?



HankMcSpank
29-04-2010, 12:03 PM
Just wondering if it's possible to grind a bog standard drill down to make a flat end mill.

I only need the end mill to cut acrylic, but I need some odd diameter sizes that are (seemingly) only available as drill bits - so that got me thinking....when is an end mill a drill & vice versa!

So for the purposes of cutting acrylic...is turning a drill bit into an end mill do-able?

keith.russell30@googlemai
29-04-2010, 01:28 PM
Yep, It sure is, if you have access to a book called the Amateurs Lathe by L.H.Sparey, it tells you how. As far as I recall, you must grind the drill flat, and the allow some backing off on
the trailing side. And to avoid snatching, it might be advisable to just take the "hook" from the cutting edge by means of an oil stone, this will alter the cutting rake, and make the drill less prone to snatch. As there is no offset in the centre of the drill -as for example in a slot drill.- you may not be able to take plunge cuts. Well worth a try, but practice on some old stuff first.. Hope this can help

Keith

i2i
29-04-2010, 02:49 PM
a dremel with some cutting discs is a very usefull tool for shaping the end geometry of drills, and you can get the all important clearance groove with it.

HankMcSpank
29-04-2010, 03:35 PM
a dremel with some cutting discs is a very usefull tool for shaping the end geometry of drills, and you can get the all important clearance groove with it.

Well I have a Dremel (actually a Proxxon but same thing). I also have a minilathe...so I was initially thinking to secure the drill bit in my lathe's collet chuck & attacking it at an angle with my Proxxon (bestowed with a cutting disc) mounted on the crosslide

i2i
29-04-2010, 03:51 PM
you could mark off the chuck in degrees to give an idea where to go to.