Is it me or is it the drills I buy

[Pete.]

MG David at the bottom of this post is the feed and speed chart for drilling, that I have on the wall next to my drill press. It sounds like you are using far too much speed with your drills and if you are drilling thin material that will also heat up fast transferring heat to the bit. Slow your speed right down as per the chart.

I also recently made a very simple jig for sharpening drills bits on a bench grinder. Couldn't very well be simpler. Gives reasonable results for people like me who haven't done enough drill sharpening to consistantly grind nice points.

All I've done is milled a vee along the side of a block of scrap ally, slightly off-set from center. Then I milled a 2mm step in the block at 59 degrees (half of the 118 point) and milled a corner off at the same angle.

This is how you use it, just hold the drill bit tight in the vee with your fingers and run the stepped edge along your bench grinder tool rest.

The for the secondary relief you just tilt the block and slide the drill forward.

Here is the result - not perfect, but not bad either and drills quite nicely.

Drill speed chart.

 

[zzr1200]

I also recently made a very simple jig for sharpening drills bits on a bench grinder. Couldn't very well be simpler. Gives reasonable results for people like me who haven't done enough drill sharpening to consistantly grind nice points.

All I've done is milled a vee along the side of a block of scrap ally, slightly off-set from center. Then I milled a 2mm step in the block at 59 degrees (half of the 118 point) and milled a corner off at the same angle.

Pete, would you possibly consider making one for me, I can't shapen drills on a brench grinder to save my life, there would be some beer tokens for your trouble.

zzr

 

[Pete.]

Sure, I can do that, I have a couple of bits of the ally left. PM me your address.

 

[Norm]

Pete, that is really clever , I can't sharpen drills to save my life, I'll see if I can get one of those made unless you fancy making another
regards Norm

 

[darren817]

yeah the drills you are buying are cheap crap, have i missed though what ur drilling into, with hss you can easy drill 2" up hole straight off in carbon steel so why the step ups? double fired house brick?

 

[brightspark]

yeah the drills you are buying are cheap crap, have i missed though what ur drilling into, with hss you can easy drill 2" up hole straight off in carbon steel so why the step ups? double fired house brick?

do i take it u mean u drill a 2inch hole without putting a pilot drill though 1st take a look at the drill tip and u will see that it has a flat chissel across the tip . the larger the drill the larger the chissel .so efectively when u are drilling the chissel scrapes away the metal
and the harder u have to force it in small drills have a smaller chissel so will cut quite easy on the cutting tips without scraping . so using a pilot drill 1st will cut the center out then use the larger drill which will be cutting on the flutes not rubbing on the chisel

 

[PhillipM]

Use split point drills then

 

[brightspark]

Use split point drills then

still need pilot drills 1st if u dont want them to run off and also oveload the drill or lathe motor

 

[Pete.]

Not to mention a bunch of power and good workholding

 

[Sub-arc]

Nice job there Pete.

My tuppence here would be never quench a bit post sharpening.
And use a good cutting oil/paste. I use Rocol RTD oil and its deadly. Trefolex is a good paste, terrible wang of it though.

 

[PhillipM]

still need pilot drills 1st if u dont want them to run off and also oveload the drill or lathe motor

Split point don't tend to run off really though, better than a chisel point at any rate.

 

[keithski122]

If you're making holes for plug welding how about one of these:- http://www.cbsonline.co.uk/product/Power_Hole_Punch_Set_PWRP

 

[hiho9]

really good idea on the block

 

[bigtip]

i wish i had a mill....that looks like a handy tool.

even with cheap drills it's good to slow down the speed. my drill press is always on it's slowest speed, mostly as i can't be arsed to change the belt position but it cuts just fine anyway, i stand there with just the weight of my arm on the lever and wait...it doesn't take long. mind you drilling spot welds is not the easy life for drills.


but i second what many have said, you might as well buy some decent bits. forget about the colour that they make them, it's mostly ********. you drill for 2 seconds with a 'titanium' coated drill and the electroplated titanium is gone, then all you have left is a poor quality carbon steel bit.


i must admit i know 'f' all about split point drill bits but to me you got to start with a 3mm drill and maybe even less for hard spot welds. it's easier if you do and bigger holes have more chance of staying round in sheet metal.

 

[zzr1200]

Sure, I can do that, I have a couple of bits of the ally left. PM me your address.

Sorry for the very very late reply I have pm'ed you my address.

 

[mancavedweller]

I've had some cheap Chinese drills for about 13 years now and they are still going strong. The secret is keeping them cool (rpm). Admittedly most of my drilling is now done in my beloved pedestal drill but the principle is the same. I even have a coolant pump and flood the drill with coolant while running at low speed. I know not everyone has this setup but I'm just letting others know what allows me to use cheap drills.

On a sidenote, here in Australia, Bosch have some new "blue" drills. They have been designed for masonary and metal, and can drill hardened steel. I previously used ordinary masonary drills to drill hardened steel but these "blue" ones do it better, I use them only for drilling hardened steel and won't let them go near masonary.

 

[Browser]

I also recently made a very simple jig for sharpening drills bits on a bench grinder. Couldn't very well be simpler. Gives reasonable results for people like me who haven't done enough drill sharpening to consistantly grind nice points.

Nice jig design Pete, mind if I copy it?

I can remember one of the first things we had to learn in the apprentice school was drill sharpening, and if we got it wrong the instructor would just grind the end of the drill flat (taking about 5 seconds) and you had to start again! Didn't take me long to learn how to do it right

 

[Sanny]

2 part video on drill sharpening HERE. i found this very useful.

 

[ouchmyfinger]

drill dilemma

hey david, it may well not be the quality of drill your using but your technique of drill sharpening and/or thickness of metal you are drilling, drills work at there best when they are in total cutting contact with the metal i.e driliing a hole in a plate 1/2" thick shouldnt be a problem, drilling a hole in 22 gauge metal is a different ball game it can snag, catch, bite and hurt your wrist, its not actually cutting, its ripping small chunks, use gradually larger drills, pain in the butt, or a graduated conical drill not perfect but not too bad. good luck