Cheap drill bit sharpeners

[Harry Bloomfield]

I bought one several years ago, couldn't make sense of how to set up drills, then bought a second one, hoping it might prove better - it wasn't. Using either one, the trailing edge is ground to be prouder than the leading edge, what am I doing wrong?
These are the cheap Powerfix type as sometimes sold in Lidl.

You put the bit in a reversible holder/clamp, but the instructions give no clue as to what angle to rotate the bit, in the holder that I could see and no helpful diagrams at all.

 

[Fred Blogs]

I've had four over the years. Two broke and the other two I sent back to amazon. They are just not accurate enough in the way that they hold the drill bits and the amount of movement in the plastic retainer parts to sharpen a drill bit properly. Bottom line is that they just do not work. I now just buy a new set of bits when my drill bits stop cutting.

 

[Brigadier]

I bought one several years ago, couldn't make sense of how to set up drills, then bought a second one, hoping it might prove better - it wasn't. Using either one, the trailing edge is ground to be prouder than the leading edge, what am I doing wrong?
These are the cheap Powerfix type as sometimes sold in Lidl.

You put the bit in a reversible holder/clamp, but the instructions give no clue as to what angle to rotate the bit, in the holder that I could see and no helpful diagrams at all.

Can you not just sharpen them, by hand, on a bench grinder?
Presuming you have a bench grinder, that is.

Effective, satisfying, and the bench grinder serves many other purposes than a drill bit sharpener does.

 

[Andy165]

Be aware that you can only use some of them for 20 minutes at a time. It's in the small print. Any longer and the motor burns out. Yes, I got carried away and did it.

 

[freddiemercurystwin]

Drill bits .... a consumable ..... so cheap why would anyone bother trying to sharpen them these days?

 

[blup]

I had one, absolutely useless. Hss steel for (small holes in) wood and bosch multi construction bits (which have decent carbide tips) for masonry/brick.

Blup

 

[Harry Bloomfield]

Can you not just sharpen them, by hand, on a bench grinder?
Presuming you have a bench grinder, that is.

Yes, I can, I have two bench grinders with four wheels and I know how to use them. I just wanted something a bit easier to use for touching up the tiny drill bits.

 

[Deleted member 174758]

Drill bits .... a consumable ..... so cheap why would anyone bother trying to sharpen them these days?

Sometimes you need to sharpen at an angle for different materials which aren't so easy to find locally off the shelf, e.g. plastics (standard jobber drills have 118 degree point - drills for stainless steel, etc are about 135 deg. and acrylic plastics are about 90 deg.)

 

[Harry Bloomfield]

Sometimes you need to sharpen at an angle for different materials which aren't so easy to find locally off the shelf, e.g. plastics (standard jobber drills have 118 degree point - drills for stainless steel, etc are about 135 deg. and acrylic plastics are about 90 deg.)

I used to be usually able to make a fair job of hand grinding a drill bit, but it needs regular practice to keep my hand in. Even so I would be struggling to reproduce those angles with any accuracy. As said - I'm fine sharpening the larger bits, but my eyes are just not good enough now for the smaller bits. I was hoping one of the machines might make it easier.

I grind my own lathe tool bits, using nothing more than an homemade chart of the silhouettes (try spelling that after a few pints) of all the angles, as a guide.

 

[Deleted member 174758]

I really don't think absolute accuracy is essential - but for plastics having a tighter angle makes a big difference, I find. Same goes for the pilot bits in drill/countersinks) which seem to work far better with a very pointed twist drill. I use a relatively cheap jig and a bench grinder when I regrind stuff, but sub 3mm it just isn't worth the effort as really small twist drills are so fragile (or maybe I'm just too cack handed?). I don't often bother with "regular" SDS bits (5.5, 6.5 an 7mm mainly) as they get bent so often (and in any case work supplies them) but I will touch up larger diameter, less often used bits because they are expensive

 

[jeds]

Cheap ones are useless. You need an expensive one - except the cost of an expensive one would cover a lifetime's worth of new drill bits.

 

[wobs]

I used to be able to sharpen bits by hand on a bench grinder far more satisfactorily , although it wasn't for really small bits, and usually over 10mm. Having a hole in the other end helped, as I could use a jig to check each edge was evenly ground down. Largest I used to do was 1 3/4", as that was the largest my lathe could handle. Smallest was probably 4mm, but guessing on that.

A skill I have mostly lost.