Thread: Best way to clean up taper?

If you had a picture it would help to assess the problem.
Kryn

Attachment 289107

Brett, my thoughts would be that the spindle should be hard, so it is possible that the rough surface is pick up from other spindles that have been mounted in there. Perhaps check the spindle with a file and if it is hard, try gently filing, reaming or using abrasive to remove the extra material.

Michael

Originally Posted by KBs PensNmore

If you had a picture it would help to assess the problem.
Kryn

Thanks. Bit of a choir getting a pic up, took me longer to work that out than it did to pull the spindle out!!

That's chore by the way, but I would reckon the reamer is the best bet for accuracy all round. Clean the crud off the reamer after, rather than the bore, before.

Originally Posted by Michael G

Brett, my thoughts would be that the spindle should be hard, so it is possible that the rough surface is pick up from other spindles that have been mounted in there. Perhaps check the spindle with a file and if it is hard, try gently filing, reaming or using abrasive to remove the extra material.

Michael

You could be right, it was made in 1980 so someone could have mounted the wrong taper at some stage. I could be wrong, it might not even be a morse taper and that's what's caused the problem. I haven't used it, this is how it came to me. It's just an#assumption#that all drill/mill type machines use a morse taper or R8. More than likely the cause is a simple case of dirty, rusty, dinged up, old tapers being put in there.

The plan of attack so far is to mount MT3 reamer in lathe, secure spindle to cross slide, rotate chuck by hand to ream taper. See any problems?

I also note there are lots of MT around with a bit missing in the middle, just has the start and end of the taper and a lower bit in the middle. Is there any reason for this?#

Originally Posted by burraboy

That's chore by the way, but I would reckon the reamer is the best bet for accuracy all round. Clean the crud off the reamer after, rather than the bore, before.

Smarty... I was singing#

I'll remember that though, thanks, I've learnt today, lol.

That is what you would call a " galling " experience AKA

PITA galling and metal to metal galling

I know, Ive got too much time on my hands

Originally Posted by slhouetteV8

You could be right, it was made in 1980 so someone could have mounted the wrong taper at some stage. I could be wrong, it might not even be a morse taper and that's what's caused the problem. I haven't used it, this is how it came to me. It's just an#assumption#that all drill/mill type machines use a morse taper or R8. More than likely the cause is a simple case of dirty, rusty, dinged up, old tapers being put in there.

The plan of attack so far is to mount MT3 reamer in lathe, secure spindle to cross slide, rotate chuck by hand to ream taper. See any problems?

I also note there are lots of MT around with a bit missing in the middle, just has the start and end of the taper and a lower bit in the middle. Is there any reason for this?#

Wouldn't you just mount the MT 3 reamer in the tailstock and turn the chuck by hand ?

I don't see how the cross slide comes into the equation ?

Rob

Originally Posted by nearnexus

Wouldn't you just mount the MT 3 reamer in the tailstock and turn the chuck by hand ?

I don't see how the cross slide comes into the equation ?

Rob

I didn't think it would fit at first. There's plenty of room, so yes I will just mount the reamer in the tailstock.

First thing, check with a file if that spindle is case hardened. Because if it is, the reamer will just rub and blunt itsef in the first couple of seconds. Then you can toss the reamer goodbye. A hardened spindle can only be ground. Good quality spindles are always and invariably hardened.

If the spindle is soft the reamer trick will work, but use lots of oil and very high pressure from the tailstock and rotate the chuck by hand only. To avoid ending up with excessive runout, you should first verify that your lathe's headstock and tailstock line up. Then mount the mill spindle in the lathe chuck. The backside of your reamer should have a center, they almost all do. Put a dead center in the tailstock and use it to push the reamer into the workpiece. Use a lathe dog or similar to prevent the reamer from rotating, or a spanner if the reamer has square section end. This method is almost as good as using a floating chuck. Under no circumstances, ever, turn the chuck backwards, even if it appears to bind, because that would instantly take the sharp edge off the reamer lips and may even break a lip out. And use a good quality reamer with finely ground lips. Some cheap MT reamers have rough grinding marks that will leave ring marks in the male taper - these are excellent to put morse tapers in wood to make a storage rack for MT tools, but should really not be used on machine tool spindles.

Once you have restored the taper, keep it absolutely hospital clean when swapping tools. Because the more often you have to clean it up with a reamer, the more runout will it develop.

Edit: the reason some morse tapers have a relieved center section, is to make them less sensitive to wobbling because of dirt. If you keep it clean, you do not need the relief. You can buy taper cleaners made from wood, with strips of chamois.