Thread: Some observations on the Tormek drill bit sharpener

Can't safely put my money on either, look forward to the result.

The factory grind from a reputable manufacturer such as Dormer, Suttons etc would be the finish to aim for. I think they as machine tool manufacturers have been doing it a bit longer that Tormek. My take on it if I have read your post correctly.

I tend to agree MMini but having seen the video results from the Tormek I must say that it has something going for it..

Truth is, the point of your drill shouldn't have to be doing any material removal, with the exception of pilot hole drills which are small enough to overcome the problem. I hand sharpen any drill bits I've got (1/16"-1/2" usually) and aim for a finish similar to those found on a standard twist drill - not a viper bit or anything like that, just clean and simple. The most important things are getting the cutting edges even and symmetrical, using a sharp and well dressed wheel to leave a good finish and getting your relief angles correct. I use these same drills to drill all manner of materials from wood to 4130 and stainless without any trouble. The important thing to remember is to use pilot holes so that the cutting edges of the bit are doing the work, not the tip.

I could well be wrong in my outlook, but it's worked well for me.

Tom.

I'm a fan of pilot holes too Durdge.but that really doesn't throw any more light on the question.

Just watched the video on youtube showing the workings of the DBS. As far as the best "sharp" drill bit goes there is, what seems to me, no difference between the Tormek system and a conventional grind. What defines the "sharpness" is the angle of that primary facet. Too shallow and you don't have enough relief to cut effectively without a lot of force; too steep and the edge is not durable. Whether by hand or in a jig like this, the relief angle can be controlled. The only purpose of the second facet and the needle point serves is to avoid wandering on starting the hole. I've used the Sutton viper bits which are essentially the same grind and found them to be less durable when drilling tough materials as there is less material supporting the cutting edge. They tend to have a more aggressive nature when drilling softer materials as the main facet on a conventional grind also serves as a bearing surface and controls the aggressiveness of cut to an extent.

I'll try reproducing the Tormek grind by hand and see if it's difficult enough to justify a few hundred dollar jig.

My opinions thus far are based primarily on personal experience, so I can't claim what I say as fact, in case anyone wants to jump on me for something.

Originally Posted by Durdge39

I'll try reproducing the Tormek grind by hand and see if it's difficult enough to justify a few hundred dollar jig.

My opinions thus far are based primarily on personal experience, so I can't claim what I say as fact, in case anyone wants to jump on me for something.

These jigs are for people who do not have the necessary skills to sharpen drills, we are not all toolmakers.
It is the same with all types of jigs that are used they help people get the repeatability .

Some are more expensive that others and give varying results.

A bit of topic but interesting none the less. I used to work with a tool maker who used a jewellers loupe to sharpen number drills.

Originally Posted by artme

The Tormek is used to produce four FLAT facets and a true point.

Which method produces the best "sharp" drill; the Tormek or the original factory grind.?

About 100 years ago when I was in my final year of my engineering degree, I must have been away on the day the GOOD thesis subjects were handed out because I ended up being given a thesis on measuring drill points ... yup, just the point! It was part of a much bigger project on drill point efficiency, duration of cutting life, temp, pilot hole vs no pilot hole etc etc and so a very accurate measurement was required on drill points. My memory of the bigger project was that the "tormek" type of point was by far the most efficient BUT the Australian manufacturer (P&N ?) who sponsored the whole project, didn't proceed with that advice as their automated grinders couldn't be adjusted to grind the 2 facets. Also the 'tormek' single point was better than the traditional chisel point at starting the hole both with and without a pilot hole. ALL drill point geometry results in an ammount of deformation before cutting starts and the 'tormek' point required much less deformation than the traditional chisel point without a pilot hole AND better alignment than the chisel point (= accuracy) WITH a pilot hole.

fletty

Originally Posted by fletty

About 100 years ago when I was in my final year of my engineering degree, I must have been away on the day the GOOD thesis subjects were handed out because I ended up being given a thesis on measuring drill points ... yup, just the point! It was part of a much bigger project on drill point efficiency, duration of cutting life, temp, pilot hole vs no pilot hole etc etc and so a very accurate measurement was required on drill points. My memory of the bigger project was that the "tormek" type of point was by far the most efficient BUT the Australian manufacturer (P&N ?) who sponsored the whole project, didn't proceed with that advice as their automated grinders couldn't be adjusted to grind the 2 facets. Also the 'tormek' single point was better than the traditional chisel point at starting the hole both with and without a pilot hole. ALL drill point geometry results in an ammount of deformation before cutting starts and the 'tormek' point required much less deformation than the traditional chisel point without a pilot hole AND better alignment than the chisel point (= accuracy) WITH a pilot hole.

fletty

Would make an interesting read.

I just found this little gem fine bit of engineering/machine now how.

Drill Sharpening

Most interesting Fletty. I can't say I expected those results, but thankyou! What I don't understand is why manufacturers haven't adopted this grind as the standard over the years, both here and overseas. Perhaps durability or some other variable makes the conventional grind still favourable? Surely pure cost could not be the determining factor after this length of time.

As a follow up to my last post, I did try replicating the Tormek style by hand and found it to be no more hassle than a regular grind, it just takes another few seconds to shape the secondary relief facets. Going on what Fletty says I'll try using this grind at work and see if it does make a difference in day to day activities.

Good topics like this get the brain juices flowing!

Tom.

Well' all of this - particularly a reading of Ray's excellentence - puts my ideas on the scrap heap!!

Won't even bother to give it another thought