Drill Sharpeners

[gus]

"Old fashion hand grinding of twist drills is not that difficult to pickup. There are many YouTube videos on twist drill grinding. I was taught drill grinding in Trade School.
__________________
Gus,the Happy Boat-Fisherman and Happy Machinist.
(Jack of all Trades and Master of None)"

^^^^^ What 'e said.
Every 16-year-old first-year apprentice can sharpen a drill bit correctly. It is not a difficult skill to learn. Perhaps easier to learn firsthand from someone else rather that out of a book or off a video, but still not rocket science.

It may be helpful to get a drill gauge, a piece of sheet metal with the angle of the required cutting edge cut into it, with small graduations to help you get the two cutting edges equal length.

You can always have a try at sharpening a few larger drills then post pics on here and some of the old hands can give you advice on how you are doing. The closest you can get to firsthand one-on-one instruction.

For drill under about 2mm or 1/16", they can be sharpened easily on a simple oil stone on the bench. There are various drawings available on the net for small, easy to make fixtures that you clamp the drill into and then rub the whole block up an ddown your oil stone to sharpen the small drill to a four facet point.

The number one shortfall I see with beginners sharpening drills is not grinding enough clearance onto the surface behind the cutting edge. This is the number one barrier to easy drilling. No clearance, no cutting. Just rubbing on the flat face.
So it pays to grind a bit of extra clearance on the "land" like the below pic at angle B


Here is all you need to get started on grinding your own.

Hi Hopper,

The drill bits issued to us from the Trade School tool counter were in a bad shape. Instructor passed and saw Gus shaking his head at a 1/2'' drill ,walked over and asked if I would like to learn drill grinding. After two sessions and dozen attempts,I was pretty good or rather passable. From there, it became my job to grind worn drills. I did not pick web thinning till later life. After trade school,I went on to study Mechanical Engineering and from there did not do any serious machining.

 

[Tin Falcon]

For those who are interested I am attaching the link to the Tormek DB22 sharpening jig manual.. FYI I am using mine on a german engineered Scheppach 2500 that is about half the cost of a tormek. Reading it it may seem complicated. But one you understand the steps it goes quite easily and does not take long to sharpen a drill. And lot of good sharpening advice.

Tormek DB-22 Manual .pdf
Tin

 

[mcostello]

These were not CNC machines, all Brown and Sharp Automatics. The skill is worth developing as it aids in other areas, such as tool bit grinding.

 

[kiwi2]

Hi All,
Thanks for all the helpful comments. It's a shame that the Hafco model I was looking at seems to have received the thumbs down - at a bit over $100 it would have been worth it if it worked.
I think at some stage I'll try to get my head around the four facet method and see if I can come up with a jig for the Eccentric Engineering sharpening system.
Regards,
Alan C.

 

[Wizard69]

Hi All,
Thanks for all the helpful comments. It's a shame that the Hafco model I was looking at seems to have received the thumbs down - at a bit over $100 it would have been worth it if it worked.
I think at some stage I'll try to get my head around the four facet method and see if I can come up with a jig for the Eccentric Engineering sharpening system.
Regards,
Alan C.

If you look around there are a couple, maybe more, sites with sections focused four and six facet grinds. Ultimately what would be a good idea is to build a tool grinder of some sort. There are lots of options that have been developed by the model engineering community.

 

[Tin Falcon]

If you google 4 facet drill sharpener you will find lots of pics.

This site has lots of info the grinder was a build in the Home Shop machinist mag.

http://www.gadgetbuilder.com/DrillSharp.html
You may also want to look at harold halls page.

http://www.homews.co.uk/page354.html

And here is a simple jig that is basically hand sharpening but is based on the 4 facet method.
Looks easy!!

http://madmodder.net/index.php?topic=6480.0

tin

 

[kiwi2]

Thanks for the links Tin. Do you know what the primary and secondary angles are for a 4 facet drill? I think I can see how to use the Eccentric Engineering sharpening system to sharpen twist drills. It's already set up to grind 2 different relief angles.
Regards,
Alan C.

 

[Tin Falcon]

The several links have good diagrams . Do not remember off hand IIRC primary is the cutting angle secondary is relief.
Tin

 

[XD351]

Have a look at Harold Halls website - homews.co.uk .
He has some good info on drill sharpening especially four facet .
Primary angle is 8 - 10 deg secondary around 25 deg but will need to be adjusted to get the chisel edges to line up correctly as you will see from Harold 's website.

It still pays to be able to sharpen drills freehand though as there will come a time where you just want to touch up a drill and don't want to stuff around setting up a grinding jig .
If you look around on ebay or similar and pick up some old cheap drills to use for test subjects say 3/8 (10mm) 5/16 (8mm) and 1/4 (6mm) then arm yourself with with a little knowledge you may find it is easier than you think .
You don't need fancy gauges for tip angles just use two hex nuts clamped together this gives 120 deg which is close enough to 118 deg to get you by.
If you check your work against a new drill you can compare tip and relief angles etc and make adjustments .
If you mount up some scrap aluminium in your drill press or mill and try your newly ground bit you can see if both flutes are cutting etc .
I never worry if the hole is a little oversize as i never rely on any drill to size a hole accurately , if i want dead on size and perfectly round i either drill then bore or drill and ream .
The worst thing is if a drill is incorrectly sharpened it will tend to drill triangle shaped holes and it would be just a case of inspecting and regrinding the offending flute .

 

[goldstar31]

I think that I have found a Reliance drill jig. I probably got it with a heap of other stuff- and promptly forgot it existed.
What remains of my memory, there was once one attached to a Quorn T&C in Model Engineer- but no more.

Despite finding loads of waffle, I cannot find that anyone a set of proper instructions for it. Can anyone help please?

A note is necessary as mine has a welded 'stop' which was done by 'A.N. Other'

Thank you

Norman

 

[goldstar31]

Since Charles Lamont's kind offer of assistance, I have come across yet another jig. This time it seems that it could be made in the home workshop out of bits of aluminium etc.

Meantime, I have a date in HongKong - for Dinner and then onto Fiji.

Can't say that life at 86 is boring:hDe:

Cheers and thanks

Norman