Reaming morse taper sockets

The morse taper sockets on both of my lathes are filthy and appear to have some corrosion to boot. So I have just purchased an MT2 reamer and was about to start the job, when it occurred to me that I really did not know a lot about hand reaming, although I have done some parallel hand reaming with somewhat variable results!

OK, I must clean up the tapers as best I can, before starting. I also know that you need to cut meta,l rather than rub the flutes gently. So using a taper reamer, one should push and twist firmly I suppose? When bright metal is seen all over the tapered area, it is time to stop, However if one just stops after a positive push and turn, then one is likely to end up with 'steps' at the point that the flutes stop.

Should one then take the final cut by gently reducing the pressure on the tapered reamer to zero?

Sounds like a pretty dumb question, but most elementary texts seem to skip the basics, when it comes to using reamers.

Regards,

Andrew.

I would check that what you intend to ream is not hardend, if it is your reamer will not last long.

Mike

I would not use a reamer to clean out a taper. As Mike said it may be hard or could be just tough and you will end up snagging the reamer or at worse jamming it in. Make a wooden taper that will fit the taper, slit it through and use it to hold a piece of Scotchbrite or fine emery. Then using something to rotate it, or do it by hand and slide it in and out at the same time. Do the final passes with oil added.

The angle of a morse taper is a locking taper, i.e. it needs something to make the parts separate.

Hello Mike,

I don't expect to be doing this often. Once the tapers have been cleaned up, I intend them to stay that way. Prior owners have not done this, hence the difficulties.

If the reamer lasts to do 4 Morse taper sockets, then I care not if it is blunt at the end of the job. I would rate £3 to have each MT cleaned up to be money well spent.

However if you are saying that the reamer cannot do the job, because the tapers are likely to be too hard, then how would you do the job? Maybe using a tapered lap?

Howard,

Thanks for that suggestion, it does seem simpler than making up a lap. If the bore is corroded, it will take some time to shift that! Well worth while to do as you suggest, at least I will be able to see if I do have any significant rusting.

Thanks ,

Andrew.

Edited By Andrew Tinsley on 24/01/2017 21:19:34

Edited By Andrew Tinsley on 24/01/2017 21:20:17

The solution to removing gunge and a bit of rust is probably not a reamer. You may be better off with a wire brush, a bottle-brush type, and a little bit of gentle emery paper on the rust. At a pinch, you can take a piece of 3/8" wooden dowel, cut a 1" slot in one end with a hacksaw. Insert a strip of fine emery tape a few inches long into the slot and wind the emery tape around the the dowel. Insert into taper and spin it with an electric drill and make one or two passes up and down the taper, just enough to remove any rust and that's all.

After that, if there are burrs or dings that are preventing a good taper fit, a reamer might be given a light useage, just a turn or two to get rid of the burrs. Tread lightly. Do not push the reamer in hard or it will catch and leave a nice line burr all the way up the taper where it locks up. Remember, you do not want to ream the taper. The taper is fine. All you want to do is remove a couple of tiny burrs that are sticking up proud of the taper.

Proceed with gentle caution. Once you have stuffed the taper up, it's stuffed for good.

Thank you everyone,

Very good advice, which I will follow. I will keep the reamer until last and use it to remove any 'dings' that may be standing up (this being a last resort!)

I will in the near future, have to make several tapered bores. I intend to offset the topslide and bore a previously drilled hole to get the basic taper. I will have to use a taper reamer to finish the job, all this in mild steel. My previous question of how one finishes the reaming process is still unanswered and hopefully someone can tell me how to finish off the taper, to avoid potential steps left from the reamer?

As an aside, somewhere (probably Tracy Tools), I have seen advertised a drill to drill morse tapers. The mind boggled at this, suspecting an April fools joke. However I have to believe this is serious. So how does drilling compare to boring a taper. If the addled memory serves me right, the drills were not overly expensive.

Thanks again,

Andrew.

I use a 12 bore bronze bristle brush on a ramrod to clean my 2morse sockets. It goes right through my Myford headstock

Roy

Not that I've ever made a female MT but there is a bit in Geo. H Thomas's book Model Engineers Workshop Manual on how to use a Morse Taper reamer. I'll try to find it and post the relevant part.

Tubalcain has a couple of videos on YouTube of him making external and internal morse tapers using a taper turning attachment.

You can finish turn tapers so long as you can get a good finish that results in the parts mating correctly. Commercial tooling tapers are ground to finish because they have to conform to standard tolerances. Yes you can drill and ream tapers this is done on production machines with short tapers such as ball joint fittings. You have to decide what you want finish wise and produce something you are satisfied with. So long as the end result does what it needs to do why go to more expense. You also have to consider the machine available to produce the taper. A mini lathe may be short on bed length and tailstock travel to allow reaming, but may well allow it to be turned.

Me too,

Mike

Will I need a 4 bore to clean up a 4MT?

Could be a bit small, 2 bore might be better.

Mike

Mike and Roy: Me, too. And shotgun barrel cleaning fluid is pretty good at dissolving crud in morse tapers. But do get a proper bronze brush from a gun shop. A lot of so-called brass and bronze brushes sold in DIY outlets are, in reality, plated steel.

If you can get an MT2 reamer cutting by hand, you must have muscles like Popeye. It will clean up a socket of burrs and bumps, used with care, but don't expect to make the socket noticeably deeper.

Neil

I would use an MT2 socket and some carbide paste to start with, and lots of cleaning up paper etc.

I think the Morse taper drills you saw were most likely refering to a drill bit that has a Morse taper on the holding end so it fits straight into your tailstock without using a chuck. I have not come across a drill that will drill a tapered Morse hole, although they may be out there somewhere...

To get your topslide at the correct angle to turn an MT2 taper, you can set up an MT2 centre between centres in the lathe, then use a dial indicator mounted on the top slide to get the top slide angle just right (ie 0-0 reading over the full length.). To set up a centre between centres, you need an MT2 centre with a centre drill hole in the aft end. Then put a piece of round mild steel in the lathe chuck and centre drill a centre hole in it. Put another centre in the tailstock and hold the first centre between that centre and the drilled centre hole in the steel in the chuck. Use a solid centre in the tailstock for highest accuracy. Revolving centres always have slop in the bearings unless they are the very expensive ones.

Using a hand reamer to finish off with, hold reamer with a large tap wrench, with the tailstock centre guiding it in straight. Rotate the chuck by hand by putting the belts on the lowest speed and turning the countershaft pulley by hand. This gives a nice low gear ratio and makes turning easier.

I think the Morse taper drills you saw were most likely refering to a drill bit that has a Morse taper on the holding end

Not necessarily. Taper pin holes are initially drilled with a special tapered drill - these cut on the flutes & have the flutes notched to act as chip breakers. Drilling with these is slow & requires the drill to be retracted frequently to clear the chips (a parallel hole of the small end diameter of the taper drill is used before the tapered drill). I am pretty sure I have seen similar drills for drilling MT sockets, but can't find a reference to a supplier at the moment - a good, traditional, Engineer's Merchant should be able to advise.

Some graphite electrical parts we make at work are joined with MT sockets and pins - to generate the taper sockets we use a roughing reamer through a hole drilled slightly larger than the reamer small end diameter, then finish to size with a finishing reamer. The difference between the two reamers is that the rougher has chip breaker notches in the flutes & the finisher has continuous flutes.

The mention of using abrasives (paers, cloths or pastes) in precision taper sockets makes me shudder ! The most aggressive abrasive I would consider would be a very fine Scotchbrite pad.

Nigel B

They do exist, I have seen them for MT2, 3 & 4 and actually have a Drill that is Tapered for drilling MT3 sockets and is on a MT3 Shank, I think its Dormer.

They appear on the second hand stalls at the ME shows sometimes. Mine was unused as the Black oxide on the cutting edges was unmarked.

Steve