Cleaning up Morse tapers

[Andrew TinsleyParticipant @andrewtinsley63637]

I purchased a large quantity of Morse taper drills, for a modest sum. The drill sections are all fine, even sharp!

However, some of the MTs have had a hard life and have the usual dents and dings on them. Having cleaned up my MT sockets on the lathe, I am loathe to use some of the worst offending drills in them.

Can I simply put them in a three jaw chuck and set up the top slide with a DTI and get the correct angle (obviously on a good example!). Then I could take the merest smidgen of a cut to remove anything that rises above the MT taper surface? I don't intend to do anything but clean up the high spots.

It sounds fine to me, so what have I missed, nothing seems to be as simple as it appears!

Andrew.

[Andrew TinsleyParticipant @andrewtinsley63637]

[RainbowsParticipant @rainbows]

I would be tempted to glue sand paper to a flat steel bar and just run it over the tang till clean. Depends how bad the dings are. With a cutting tool you have to worry about run out, the sandpaper would cut relative to the surface if that makes sense.

[Bob StevensonParticipant @bobstevenson13909]

probably a bit too hard to turn with ordinary cutting tools(?) …why not make a simple tube type holder with the right taper on the inside and then they can be used in a normal drill chuck. I have a large number of MT 1 drill bits that go back to the dark ages and this has worked very well for me for many years.

Any damage or 'dings' on the shanks can be carefully removed by 'polishing' with a small diamond hone such as an Eze-Lap.

[Brian WoodParticipant @brianwood45127]

Andrew,

Don't worry about the dents, smooth off the raised material with a nice fine file and the tapers will fit well enough to do all you might want from them.

Regards Brian

[Rick Kirkland 1Participant @rickkirkland1]

Don’t worry about them being too hard to turn. They’re not.

[Nicholas FarrParticipant @nicholasfarr14254]

Hi Andrew, I agree with Brian on this one. Chances of getting them to run dead true in a three jaw are slim, I would think. No need to be heavy handed with the file, just hold the drill in one hand and steady it on a block of wood if need be and file with the other hand twisting the drill as and when needed. Done loads like it, no need to remove any shallow areas.

Regards Nick.

Edited By Nicholas Farr on 14/09/2017 17:00:08

[Andrew TinsleyParticipant @andrewtinsley63637]

Thanks everyone. I was a bit wary of "sanding" or filing down any raised portion, but I suppose that as long as one is fairly gentle then the raised portions would be easy to get rid of without compromising the taper unduly.

I am not in the least bothered about the dents, it is the raised portion surrounding the dents that bothered me!

Thanks again,

Andrew.

[mark smith 20Participant @marksmith20]

Ive used fine diamond stones for the same sort of thing ,also on my south bend lathe spindle when i first got ,as it had a few raised dings caused by metal particles getting in  where the plain bearings run.

Edited By mark smith 20 on 14/09/2017 19:02:49

[Ian S CParticipant @iansc]

Drill tangs are quite soft, and can be turned down with a HSS tool, I'v converted a good many into parallel shank drills.

ian S C

[mark costello 1Participant @markcostello1]

I bought a boat load of MT drills at auction cheap because no one wanted the turned down shanks. They are turned down for only about 1", the rest of the taper is left intact. I don't particularly like it but it works. I would never do it to a good drill.

[Andrew TinsleyParticipant @andrewtinsley63637]

Hello Ian,

Some of the drills have indeed been turned down, but a god awful finish, looks more like tramlines! I would not mind skimming them to get a decent surface for the chuck to grip! So how did you turn down your drills and keep concentricity? Clock it up in a 4 jaw?

Andrew.

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