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Re: Swat the Bearings

Some older lathes held the spindle axially by the pulley abutting the bearings and or their seat and some even older lathes used a thrust outboard bearing (I have one that the pointed outboard spindle rides in a cup). Some newer lathes use the inboard bearing itself as the spindle register. I can see that a strong axial force _could damage these. I can see too, that spherical and tapered bearings _could be damaged by a big ole axial swat.

As I've said before, IMHO that the force needed to firmly seat a MT or to tighten a screwed on accessory will harm the ball bearings in a modern lathe is largely an urban myth.

For a more scientific point: If Leo L. (or the other Leo) says something will work ....it will!

Turn to Safety, Arch Fortiter

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Reply to
Arch
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Here's one for the argument folks: I have been reading nailshooter's

> problems with the Jacob's chuck lostening in the headstock and some gave > advice for a drawbar (exellent) and others said to swat it with a mallet > which will also work. Now the problem: some suggested that swatting it > with a mallet will hurt the bearings. Why? Not only have I swatted a chunk > of wood onto a spur center in the headstock, I have also tightened the > tailstock into a lot of pressure on those bearings and then turned on the > lathe. The bearings did not even protest. Often I have mounted an > unbalanced piece of wood on the lathe and turned it on. There was shock to > those bearings in all sorts of directions and no problem, except maybe to > my nerves. So why would a little swat or two with a mallet hurt them? We > are talking a little wooden mallet, not a 9 pound hammer. > Have fun with it guys and gals.

What kind of bearing? Tapered roller? Ball? Formerly sealed but now vulnerable to grit and gunk infiltration because of seal shift ball?

Reply to
George

In message , Darrell Feltmate writes

Depending on the type of bearing, ball, roller, tapered roller you will see a different effect. Ball and tapered rollers will be worse impacted by a sideways impact.

But it needs to be put into perspective.

When impacted you can cause small indentations in a bearing casing this will increase the wear rate of the bearing, and as it progressively gets worse it will start to rumble till it gets so bad it finally fails catastrophically

If you look at a lathe bearing it is a little similar to an Auto wheel bearing, maybe smaller, less balls./ needles in the races, but similar shaft size.

Now for the perspective 4 auto bearing will easily allow a 1 Ton car to travel >100,000 miles at 60mph which is about 1000rpm under quite trying conditions

So back to the lathe, although you may cause damage to the bearing the chances are you will burn out a motor first.

Now as the bearing surfaces are hardened, if you use the tail stock to push the item in the head stock home , I really cant see any damage, which is almost always caused by the impact

Just my 1 pence worth :)

Reply to
John

"Arch" wrote: (clip) For a more scientific point: If Leo L. (or the other Leo) says

^^^^^^^^^^^^^^^^^^^ Sorry to disappoint you, Arch, but I did make a mistake once. I thought I was wrong when I wasn't.

Reply to
Leo Lichtman

Reply to
robo hippy

hitting a bearing can (and often does) cause Brinelling - the point contact of the balls gets driven into the races leaving little dents

Reply to
William Noble

It wasn't me Darrell! The only loosening of the headstock I have is between my ears. Not sure a drawbar would help that. ;^)

Robert

Reply to
nailshooter41

Anyone who has worked with toolroom equipment like a lathe that is cutting intermittent steel knows that the impacts are severe, but the bearings do never fail for this. You get what you paid for, quality hurts only once, cheap hurts every time you have to use it. Have fun and take care Leo Van Der Loo

FWIW, I recently disassembled a Jacobs #18 ball bearing chuck that was nut running accurately - the thrust bearing had a whole row of little dents in it from somone hitting the bearing (who knows why) - so brinelling is a real phenomena. I'd avoid hitting the bearing in a longitudinal direction if I could avoid it

Reply to
William Noble

LMAO!! You bet.

Hey... at least there is some constructive activity here, right?

Robert

Reply to
nailshooter41

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