GW8IZR Posted November 20, 2016 Share Posted November 20, 2016 In my view it depends what your asking, if your talking setting about a bit of metal with a battery drill, by hand you can centre punch, then angle the punch and hit it again, a few goes and you can have a mark that a small pilot drill at the right angle wont slip out of.. work up in sizes a bit at a time till the hole is big enough for the final drill size and go for it. On the other hand if I can, I put the job in the mill, use a milling cutter to create a flat at the right angle then swap the cutter for a drill.. treat as a normal hole. Proper machinists will have other and probably better ways. Quote Link to comment Share on other sites More sharing options...
HoSS Posted November 21, 2016 Share Posted November 21, 2016 11 hours ago, Troll Hunter said: Slightly off topic, so please move if inappropriate, but while we're talking about drilling and tapping how do members start to drill a hole that is intentionally at an angle to the work piece surface? Mike If the angle is near 90 end of things you can do it from a centre punched Mark. Ideally on a mill though Quote Link to comment Share on other sites More sharing options...
landroversforever Posted November 22, 2016 Share Posted November 22, 2016 If I'm machining something with a hole at an angle to the surface i'll 'spot face' it, which is as Paul say, just machining a flat for the hole as generally you will have a fastener that you will want to tighten down onto a flat surface. As for tapping with a battery drill, its OK but you have to be very careful about keeping it straight in the hole. Any wandering and you'll risk breaking the tap. I wouldn't use a drill for cleaning up threads as you never know the condition and doing it by hand lets you feel how its cutting. Tapping holes in the mill or lathe are my favourite method as this guarantees you'll keep the thread square, either when tapping with the machine (I only really do this with through holes), or manually with a sprung loaded centre in the back of the tap keeping it square. You can get specialist tapping heads for mills etc, but I've not used one; I also can't see the point unless you're doing production stuff in blind holes. Quote Link to comment Share on other sites More sharing options...
Peaklander Posted November 22, 2016 Author Share Posted November 22, 2016 5 hours ago, landroversforever said: or manually with a sprung loaded centre in the back of the tap keeping it square. Ross is that a special accessory or do you mean putting the tap through a suitable spring and pushing down on it with the tapping handle? Quote Link to comment Share on other sites More sharing options...
landroversforever Posted November 22, 2016 Share Posted November 22, 2016 It's one of these: https://www.google.co.uk/search?q=sprung+loaded+tapping+centre&safe=off&rlz=1CDGOYI_enGB600GB600&hl=en-GB&prmd=sniv&source=lnms&tbm=isch&sa=X&ved=0ahUKEwj4x5XIm73QAhWECCwKHcgPArYQ_AUICSgD&biw=375&bih=591#imgrc=RKeyTRmJ3IEy4M%3A it goes in the spindle of the machine and the spring loaded point fits in the tap to make sure it stays square. Does that make sense? Quote Link to comment Share on other sites More sharing options...
GW8IZR Posted November 22, 2016 Share Posted November 22, 2016 I was going to take a picture of mine but found this on the web which should help.. Quote Link to comment Share on other sites More sharing options...
landroversforever Posted November 23, 2016 Share Posted November 23, 2016 Same idea with the sprung loaded centre, but going by the angle on the above, they're using a scriber. Just to add, the angle on the pointed end of a tap will be the right angle to fit in the back of the tap if you haven't got a proper centre. Quote Link to comment Share on other sites More sharing options...
HoSS Posted November 23, 2016 Share Posted November 23, 2016 I usually put the tap in the lathe chuck directly, start the thread and then finish it in a vice. (leaving the slide loose, head stock out of gear and turn by hand) Quote Link to comment Share on other sites More sharing options...
vulcan bomber Posted November 24, 2016 Share Posted November 24, 2016 I much prefer tapping holes using a sleeve.... I made my set I use at work. it works on a similar principal as the center but is a snug fit on the outside of the tap, I grind a flat onto the shank of the tap to drive it. the perk is you get much more feel of the tap cutting with there being no spring loaded action. Quote Link to comment Share on other sites More sharing options...
landroversforever Posted November 24, 2016 Share Posted November 24, 2016 I'm curious as to how you think the spring loaded centre reduces feel? I still tap by hand, all the spring loaded action does is keep the centre in the back of the tap for longer before I have to move the tailstock or quill/knee? Quote Link to comment Share on other sites More sharing options...
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