Drill bit sharpening

I,ve tried that one Vic, OK on drills down to about 3/16th,but the wheel gets a groove in it and then u/s.The prob. doing it by hand is that no matter how good you are there is only one cutting edge thats doing the work,unless your lucky.My father left me loads of drills all much better than the Chinese rubbish.I,ve been looking for a good well made drill sharpener for sometime.
 
nedmin said:
I,ve tried that one Vic, OK on drills down to about 3/16th,but the wheel gets a groove in it and then u/s.
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I think that a basic problem with this type of sharpener is that the the small stone is running much too slowly. This makes the stone cut "soft" with the resultant slow grinding action and heavy wear, but maybe OK for occasional use.
For the size shown, a speed of 8 or 9000 rpm would be nearer the mark, ie. way above the speed of a diy drill.
 
Buy a bench grinder Vic.......

.....such as this on e-bay, which has a very useful linisher attachment good for wood chisels and plane irons as well. http://cgi.ebay.co.uk/Clarke-240vol...Home_Garden_PowerTools_SM&hash=item4aa7202e98

Those gadgets are really no substitute for a bench grinder with a fine to medium grit wheel and when sharpening drill bits even they soon get a groove round them and the wheel needs dressing. How much more a baby wheel in one of those gadgets?

To keep the wheel in good condition, invest in a dressing tool, the single point are the best for a bench grinder, consisting of an industrial diamond brazed onto a bit of round bar. Simply put the thing on the rest and roll it across the face of a spining wheel with the ball of your thumb - it cuts the wheels nice and straight avoiding chatter and vibration in use. Similar to this: http://cgi.ebay.co.uk/DIAMOND-DRESS...530?pt=LH_DefaultDomain_0&hash=item414c9e4eda

Mine was made for me so you'll have to hunt for one.

As for drill bits, clearance clearance clearance is the phrase, the proudest part is the angled cutting edge and the rest of the drill curves back away from that cutting edge to allow clearance for swarf to get clear of the cut.
 
VicS said:
I have loads of drill bits. Apart from the metric ones which I have bought most were my father's and are all getting a bit blunt.

I cannot sharpen them by hand and was wondering if this is any good

Click the picture to open the webpage

Anybody own or tried one?

.
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I have the same problem and I would appreciate very much a functioning device. In particular I appreciate the helical movement of this object but what puzzles me is how the drill floats midway... I cannot believe that the drill is held by the shaft!
The short movie and the pictures seem to cleverly overlook the issue.

Daniel
 
I have an Eclipse device that avoids the problem of worn grinding wheels (which is why I have avoided the pictured kit) by using abrasive paper. The jig holds the drill at the correct angle and you run it up and down a sheet of wet & dry. The eccentric back wheels produce the back angle. After honing up one face, you turn the drill and do the other. It is not great for badly worn drills, which need a grind stone, but ace for ones that have lost their edge. Or new ones that benefit from a quick hone on fine paper.
It is not made any more but turns up on fleabay fairly often. Had mine for 25yrs plus, best value ever. Good up to 13mm.
 
I was taught as an apprentice to sharpen drills and still can, but if slight damaged or needing cutting back a long way like some well used masonry drills use a sharpening gadget. Mine is an old Plasplugs one & still is OK. It is horses for courses, if you look at the cost of bigger masonry drills then the cost of an occasional stone is well worth while. I used to run a computer cabling co. & resharpening masonry drills was needed reasonably often.
 
tr7v8 said:
I was taught as an apprentice to sharpen drills and still can, but if slight damaged or needing cutting back a long way like some well used masonry drills use a sharpening gadget. Mine is an old Plasplugs one & still is OK. It is horses for courses, if you look at the cost of bigger masonry drills then the cost of an occasional stone is well worth while. I used to run a computer cabling co. & resharpening masonry drills was needed reasonably often.
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masonary / conctete = SDS bits use then & bin em after 1000s of holes
 
Despite a lifetime in engineering, I must own up to the shame of a real blind spot when it comes to sharpening drills!

I have one of those Axminster ones which does work, but is a bit of a pain - especially on small bits. I've also tried the drill-mounted ones with limited success.

I got my dad a "Drill Doctor" like this:

http://cgi.ebay.co.uk/DAREX-DRILL-D...532?pt=LH_DefaultDomain_0&hash=item255fc28904

some years ago and that works very well. It's pretty much idiot-proof. It was a 240 volt one though, and these seem to be 110V. I haven't been able to find 240V versions in the UK recently.
 
Hi Vic, I used to have a similar machine made by Martek. Worked ok, if a bit fiddly, but the wheels soon wore out, and I can't find replacements. Since then I've been doing it by eye, on a wheel, and it gets better with practice. You can't do too much harm. After all anything is going to be better than a blunt drill. There's some great vids on You-tube, can't do links like the cleverer folk, but look for a series of three by a guy called Tubal Cain. V.informative ands occasionally v.amusing.

Sparkie
 
To digress a little from this subject,How are small drill bits maufactured? I presume that they are ground ,but how does it work?
 
jamesmar said:
To digress a little from this subject,How are small drill bits maufactured? I presume that they are ground ,but how does it work?
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Good quality HSS twist drills are ground from solid on automatic grinding machines. This webpage gives some idea of the method, as it advertises a new single machine process. http://www.manufacturingtalk.com/news/anc/anc105.html

I suspect that cheap drills may be forged with only the business end ground, but have not seen the process.
 
When I was in the motor trade, many years ago, there were no machines like the one in the OP. Drills were always done by hand. The correct angle can be compared against 2 adjoining faces on any standard nut, and the leading (cutting) edge should always be higher than the trailing edge by a couple of degrees.
Helpful I hope.
 
Thanks for the replies.

Maybe I'll give one a try. £15 is not a mint of money to forfeit if turns out to be as useless as some have suggested but I might find it as useful as others have done. If I start with the large drills and work down to the smaller ones it should overcome the problem of the wheel wearing.

I don't have a bench grinder so hand grinding is not really an option. I do have the facility to spin a grinding wheel on the lathe but it may not be fast enough for this purpose.

Some good info on Youtube videos from tubalcain .. Thanks ... I must watch the ones on lathe tool grinding .. I don't have much of a clue about that.
 
VicS said:
Thanks for the replies.

Maybe I'll give one a try. £15 is not a mint of money to forfeit if turns out to be as useless as some have suggested but I might find it as useful as others have done. If I start with the large drills and work down to the smaller ones it should overcome the problem of the wheel wearing.

I don't have a bench grinder so hand grinding is not really an option. I do have the facility to spin a grinding wheel on the lathe but it may not be fast enough for this purpose.

Some good info on Youtube videos from tubalcain .. Thanks ... I must watch the ones on lathe tool grinding .. I don't have much of a clue about that.
Click to expand...
Bit of fred drift, out in Egypt desert, Zeit Bay, winter time, colder than a witches tit. We had set up an onshore facility to process oil from the offshore platform. The workshop had a brand new lathe but the dip **** engineer in charge of procuring supplies had screwed up on buying lathe tools, anyway the drill rig needed a left hand thread strainer to screw on the end of the drill string, could we make one, hmmm says I let me see what I can do. We had some Ridgid pipe threaders, I got one of the removable thread cutters, put it in a vice and snapped a piece off. I then got a cold chisel, ground it so that I could braze the piece in to a slot on the end. Then I ground the end to the required shape to cut a thread. A skill I learned as an apprentice. I then heated the whole lot up and let it cool gently, then I polished it till it was bright, I then warmed the "tool" till the and watched the colours "flow" to the end intil it turned blue, again another skill learned as an apprentice, I then plunged it in to oil to quench it.
It worked beautifully, the tool cut like a son of a bitch, in fact I made several which did the job until we got some proper ones.
The rig was most impressed, make a tool AND cut left hand threads!
Stu
 
VicS said:
...
I don't have a bench grinder so hand grinding is not really an option. I do have the facility to spin a grinding wheel on the lathe but it may not be fast enough for this purpose.

....
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I'd do all I could to keep grinding dust away from the bed of the lathe and its slideways, to be honest.
 
I use em and chuck em.

Scientist me, not trained in grinding drills, but they are so cheap there isn't much point trying.

Good for those that can, but in our disposable times with chep Chinese rubbish consumables there isn't much point I'm afraid, mores the pity.
 
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