Thread: Rescueing old drill bits

Oi,

What about Pictures.

I have one of those and would love a copy of the destructions. The originals got oil on them and are unreadable. Mine was a Paulco.

Could I PM you and you send a scanned copy or some cclose up Photographs.

Cheers

Brian

G'day Sheddie,

Can you do a photo tut on this maybe?

I've got a similar gizmo, but no intructions, so I just resort to freehand on the A&A 8".

G'day guys, I'll transcribe the instructions and post them here somewhere. You can print 'em out then.
Will do it tonight. Also will post some pics.
Cheers

Ok guys heres the scanned instructions for the General Tool Company Drill Sharpening Attachment I'm not sure if the Paulco model is the same though.
Hope it helps. Next post a bit i did.

I've set the Drill Sharpening Attachment at the side of my grinding wheel because the face of the wheel has a curved edge on one side. Plus it lets me see what is happening to the bit. This is one of the 1/2" bits I did. As you can see the cutting edge is nice and clean.
The instructions say that some bits need the heel ground by hand to give a point/heel clearance. I've discovered this applies to 3/8" / 9.5mm amd 10mm bits. Ity must be the geometry of the combinatioin of the angle 59deg, the size of the bit and the travel of the attachment. However, once the major cutting edge is ground it is a simple matter to grind the heel by hand. It seems important to ensure the the bit, if sharpened for general use (timber, mdf and plastics) at 59deg, protrudes past the lip rest only 50% of the diameter of the bit. I tried at 49% but drilling hardwood was rough ( alot of chatter even the cutting edges were identical and there was adequate heel clearance. Sharpening with this is very easy but makes me even more in awe of those who can do it freehand. Ignore the angle of the edges in the pic. The bit is just sitting in the attachment so I can picture it clearly. When grinding the cutting edge is lined up central to the attachment.

G'day Shedland,

Thanks for putting the pics and instructions up, now I just have to work it all out and see if I can sharpen using the whatsyacallit.

Thanks for posting, Sheddy


Cheers..............Sean

I like my Drill Doctor, so simple even I can use it .

I got this for nix and I like a challenge.

Bah, your all doing it the hard way , easier to do it by hand

Originally Posted by djstimber

Bah, your all doing it the hard way , easier to do it by hand

And then some , once you master sharpening by hand you do a far better , quicker and easier job

yes, but I'm sure you'd need a steady hand and a good eye. I have neither.

Sharpening by hand is quicker if you continually practice it, but you still need gauges for checking your angles.

Hand sharpening is something that once you've learn the principle it's easy to pick up again but you have to be taught the correct method in the first place. Its a two directional movement of lifting the bit against the wheel at the correct angle while rotating the bit at the same time to produce the back clearance.

As a first year apprentice in the company's in-house training centre we were all taught how to sharpen a drill so that when drilling copper you got a small "copper hat" swarf as the drill completed its cut. Without this copper hat we were unable to progress to the next point of instruction. I managed this skill in a couple of days and f%%K knows how many drill holes on scrap bus bars. Others took near on a week to be successful.

Thanks Shedie