Drill bit sharpening / sharpener?

[gasket999]

Hi folks - confession time: I've never sharpened a drill bit in my life. I've used them until blunt and then chucked them.

I used to get large numbers of high end bits from work - chucked. Would have cost a fortune to buy privately.

Now I buy HSS and M35 Cobalt bits by the hundred from China - chuck them too.

So, time I learned something new and stopped being so wasteful.

I do have a bench grinder but am very tempted to buy a drill bit sharpener, given that I'm lazy and this seems quicker than sharpening them on a wheel.

Can anyone advise if the sharpeners you see in Machine Mart and the like are any good and if so could they advise a model/design to buy? Moving away from being a chuck-away wastrel I'd be keen to get a better quality machine in which the sharpening elements (stones?) of the tool either don't wear out or can be replaced.

Alternatively if they're a gimic and if learning to do it on a bench grinder is a better idea, just let me know.

Thank you.

 

[123hotchef]

quicker on a bench grinder practice and once u done a few its gets easier and you become even quicker.

 

[James1979]

Those gadgets suck. All the ones I have come across anyway. Even the better ones aren’t good and they have collets you need to use.

I have been doing it free hand since I was small (Dad was an engineer) and do it without thinking. It’s hard to describe but I would certainly show someone how to do it.

I would practice. Get someone to show you or watch YouTube. Some will be put on here shortly I imagine. Then practice more. Your bits are going to be slung anyway so nothing to lose. It is a skill well worth learning. Once you understand it, it saves you money and can get you out the sh1t. I’ve sharpened them on an angle grinder clamped to a bench in a push to get me out of a muddle.

 

[123hotchef]

Start with the bigger sizes first, I even sharpen my snapped drill bits! I normally wait until I have a bunch to sharpen and do them all at once unless I am drilling something and the bit appears blunt then I touch it up on the bench grinder

 

[Misterg]

Learning to (at least crudely) sharpen a drill bit is one of my covid19 lockdown achievements

I use my Aldi belt sander / linisher and am still astonished that I can do it. They aren't the super, multi-faceted drill points of an expert, but they cut steel very well. The more you do, the better you get. I've even gone as far as deliberately breaking a couple of bits and re-sharpening them to stub length drills. (One 7mm one which was subsequently used for drilling Hastelloy X which it did admirably.)

Give it a go.

 

[RWD3M]

I was shown how to sharpen a drill bit by hand (on a bench grinder obviously!) at school. I would have been 12 or 13 I think.

I did buy one of those sharpening tools, it's still in the box, unopened!

 

[James1979]

My Dad used to grind the ends flat so I had to do it from scratch. Was worth it in the end.

I was given a selection box of Chinese bits last month. They were useless and wouldn’t cut. I re ground them and they aren’t bad. Passable.

 

[Maker]

I was shown how to sharpen a drill bit by hand (on a bench grinder obviously!) at school. I would have been 12 or 13 I think

These days they'll show you a drill bit, say "This is what they used in ancient times", then teach you how to program a laser to cut your holes.

 

[DSR]

I've just bought a Drill Doctor after years of just sharpening them by hand. I'm OK with the bigger drills but anything below 4mm and I can barely see the drill let alone the point The DD does a good job but it's a bit slower and limited to 13mm (1/2") (19mm (3/4") if you buy the extra chuck). It's a bit slower than manually but I find it does give good results. Where it fails is that you don't get that good feeling of satisfaction of 'I sharpened this' that you do when manually sharpening.

 

[ronan]

Have a look at the modelmaking magazines and forums, a project for a lot of people is building a drill sharpener.

Drill & Lathe bit sharpener. - HomemadeTools.net

This combination drill and bit sharpener, happened back in the 80's when I acquired a green wheel [5 bucks], had this motor from a commercial sewing

www.homemadetools.net

 

[gaz1]

or buy or build your own quorn sharpener

Anyone into jigsaws?

Of the 3-D variety. Yesterday, overcome with guilt, I ventured into the far reaches of the cave to unearth the boxes containing the parts of my Quorn cutter/grinder. I'd forgotten [in my defence it's been a looong time since I clapped eyes on them :ashamed:] just how many there are. :o I've...

www.mig-welding.co.uk

Tool and Cutter Grinder Build

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homemade brooks and stent cutter grinder

it appears that i have bought a homemade brooks and stent cutter grinder from ebay This is a shop-made tool cutter-grinder described originally in a pair of articles by Derek Brooks in the English magazine Model Engineers' Workshop, No. 16 (April/May 1993), pp. 60-65, and No. 17 (June/July...

www.mig-welding.co.uk

 

[Rkweld]

This isn't bad but you are limited up to 6.5mm but will do down to 0.5mm. there is still need to know what you are doing to use one properly. I do most of mine on a bench grinder from 2ish mm upwards. Below 2mm they are tricky if you havent got a fine or diamond wheel. I think a reasonable one will set you back a few quid but might be less than you spend on drills to chuck away in the long run.

 

[MetalMonkey]

This type of machine is supposed to be pretty good and much better than the cheapy plastic things.
It's rebranded by everybody and their dog so you have to shop around to find out who does it cheapest

https://www.chronos.ltd.uk/product/pp-13c-expert-drill-sharpening-machine-3-13-mm/

Not tried one myself, I still sharpen the bigger ones on the bench grinder, and bin the small ones.

 

[tom2207]

once you get the knack its quicker to sharpen a drill bit that go for another.

 

[EM1L4]

How do you sharpen the multi angles on cobalt drills? (They appear multi angle to me) i gave it a go, seem pasable on HSS but on my cobalt drills they seem to have more than one angle and i’ve not had any success sharpening as you has to swap angles during sharpening

 

[Rkweld]

On the sharpener pictured above you set a cutting edge angle and clearance angle pass it across in both positions. If that makes sense!

 

[gasket999]

Thanks very much everyone - with no miracle solution, I'll get on youtube and start learning how to sharpen them on the grinding wheel.

 

[Lewis_RX8]

How do you sharpen the multi angles on cobalt drills? (They appear multi angle to me) i gave it a go, seem pasable on HSS but on my cobalt drills they seem to have more than one angle and i’ve not had any success sharpening as you has to swap angles during sharpening

At first i tried to copy these when grinding and get the chisel/split point to avoid need for a pilot drill but now i just grind one angle

So red is the second grind and blue is the first grind.

I am not an expert however i try to grind around the black bit and as shown in picture i grind it a bit further back while pushing the drill bit to give some relif for the swarf to come from but all in a single grind while changing the angle.

however factory grind the red grind goes all the way to the middle which i believe means you dont need a pilot drill and it can start itself whereas the blue grind itself just make a dull point but i always use a pilot drill so dont need my 14mm drill to move any metal from the center because of a pilot hole.

Heres a diagram off the web that may explain better

Hope that makes sense if not let me know

 

[Maker]

How do you sharpen the multi angles on cobalt drills? (They appear multi angle to me) i gave it a go, seem pasable on HSS but on my cobalt drills they seem to have more than one angle and i’ve not had any success sharpening as you has to swap angles during sharpening

That's either a four facet grind or web thinning, both are quite tricky to get right. Four facet you just grind the primary relief as you always would, then grind a secondary relief a bit steeper, the trick is getting all four planes to intersect at a point in the centre, it makes the drill less likely to wander. Web thinning you grind away a little of the web in front of the cutting edge so the actual cutting edge is longer, it comes closer to the centre of the drill so more material is cut and less is extruded by the web, you need a well dressed wheel with a sharp edge to do it. If you drill a pilot hole and then widen it with a bigger drill, there's no advantage to doing this.