Drilling on a taper

[WolfieParticipant @wolfie]

[WolfieParticipant @wolfie]

I have some bar which has been turned to a taper at one end. I now need to drill into this. How do I hold the work to present the taper to the drill?

[Ian PParticipant @ianp]

Youv'e done it again Wolfie!

Please give some indication of which way you want to drill into this taper, axially, radially, 90 degrees to taper surface? also material and hole size would clarify things.

Ian

[Michael GilliganParticipant @michaelgilligan61133]

Presuming that you want to cross-drill for a pin …

 

Best bet is to find, or make, the matching female taper and use that as a jig.

Failing that … set it up very carefully in the Mill, and use a Slot-Drill to spot a nice flat face before you try drilling.

MichaelG.

Edited By Michael Gilligan on 21/07/2012 08:52:15

[WolfieParticipant @wolfie]

Well presenting the taper to the drill kinda assumes that I want to drill into it at the normal 90º.

Its mild steel and 6mm

[Ian PParticipant @ianp]

Wolfie

I wasn't trying to be clever, I just was unsure what direction you wanted to drill the hole.

A hole normal to the taper is easier than one at right angles to the axis as the drill has less tendency to run off, its more or less like cross drilling a parallel shaft. One way might be to put the taper in a vee block mounted at an angle (say clamped in the machine vise). You could use the steel rule trick to find the centreline. Start off with a spotting drill and you might not even need to centrepunch.

Ian

[WolfieParticipant @wolfie]

"One way might be to put the taper in a vee block mounted at an angle"

Thats the idea I was looking for! Ta

I didn't know there was another way of drilling it

[Michael GilliganParticipant @michaelgilligan61133]

If it's important that the hole is on the centre-line, then what I suggested earlier is worth doing.

… spot the location with a slot-drill or a 3-flute cutter, before you commit to drilling.

This gives you one last chance to get the centering right, and it presents a flat surface to the drill.

… it only takes a little longer.

MichaelG.

[WolfieParticipant @wolfie]

Thanks all it worked a treat.

Borrowed a V block, put taper in and mounted it in milling vice. Started hole with centredrill.

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