Maybe someone might reply if I'm less specific in my subject line :-)

I'm rebuilding a Myford ML4 (3.75" centre height) lathe at present. When I
bought the lathe I found, too late, that the headstock spindle and bearings
were badly scored. I bit the bullet and had the damaged spindle hard
chromed and reground. I've fitted a set of good bearings, from a spare
headstock but when I went to fit the spindle, it was very tight, and when
fully home, was almost impossible to turn. I dismantled everything and
measured to OD of the bearings; the original bearings were found to be .003
smaller (measured in the 'sprung open' form) than the ones I used as
replacements; measuring the bore in the headstocks showed the same
difference with the spare headstock having the larger bore.
My question is, what would be the best way to adjust the bearings to size,
do they need to be line-bored after fitting to the headstock?
If you're not familiar with this lathe, the bearings are plain bronze split
bearings mounted in a split headstock bearing housing (not removable bearing
caps).
Martin.


--
martindot herewhybrowat herentlworlddot herecom

This might be a good application for an adjustable reamer. - GWE

Martin Whybrow wrote:
Maybe someone might reply if I'm less specific in my subject line :-)

I'm rebuilding a Myford ML4 (3.75" centre height) lathe at present. When I
bought the lathe I found, too late, that the headstock spindle and bearings
were badly scored. I bit the bullet and had the damaged spindle hard
chromed and reground. I've fitted a set of good bearings, from a spare
headstock but when I went to fit the spindle, it was very tight, and when
fully home, was almost impossible to turn. I dismantled everything and
measured to OD of the bearings; the original bearings were found to be .003
smaller (measured in the 'sprung open' form) than the ones I used as
replacements; measuring the bore in the headstocks showed the same
difference with the spare headstock having the larger bore.
My question is, what would be the best way to adjust the bearings to size,
do they need to be line-bored after fitting to the headstock?
If you're not familiar with this lathe, the bearings are plain bronze split
bearings mounted in a split headstock bearing housing (not removable bearing
caps).
Martin.

"Martin Whybrow"

wrt solid/split HS bearings
when I went to fit the spindle, it was very tight, and when
fully home, was almost impossible to turn.

Keep hand turning, unless so tight that tht doesn't seem to make sense.

And
My question is, what would be the best way to adjust the bearings to size,
do they need to be line-bored after fitting to the headstock?

Hand scrape? A triangular (three-sided) scraper will work.

If you blue the bearings, and gently scrape off just the blue?
Frank Morrison

In article ,
Grant Erwin wrote:
Martin Whybrow wrote:
Maybe someone might reply if I'm less specific in my subject line :-)

I'm rebuilding a Myford ML4 (3.75" centre height) lathe at present. When I
bought the lathe I found, too late, that the headstock spindle and bearings

[ ... ]

If you're not familiar with this lathe, the bearings are plain bronze split
bearings mounted in a split headstock bearing housing (not removable bearing
caps).
Martin.

This might be a good application for an adjustable reamer. - GWE

Except that the flutes tend to catch on the split -- unless you
can find an adjustable reamer with a steep spiral on the flutes.

I think that it would need to be fitted with a pilot which uses
the other bearing as an alignment aid, too. Two pilots -- one turned to
fit the un-reamed other bearing, and then one turned to use the just
reamed one as a reference while reaming the other bearing. Something
like the reamer setups for camshaft bearings in automotive engines.

An alternative way to do would be with a bearing scraper and
spotting blue.

Good Luck,
DoN.
--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

(DoN. Nichols) wrote in
:

In article ,
Grant Erwin wrote:
Martin Whybrow wrote:
Maybe someone might reply if I'm less specific in my subject line
:-)

I'm rebuilding a Myford ML4 (3.75" centre height) lathe at present.
When I bought the lathe I found, too late, that the headstock
spindle and bearings

[ ... ]

If you're not familiar with this lathe, the bearings are plain
bronze split bearings mounted in a split headstock bearing housing
(not removable bearing caps).
Martin.

This might be a good application for an adjustable reamer. - GWE

Except that the flutes tend to catch on the split -- unless you
can find an adjustable reamer with a steep spiral on the flutes.

I think that it would need to be fitted with a pilot which uses
the other bearing as an alignment aid, too. Two pilots -- one turned
to fit the un-reamed other bearing, and then one turned to use the
just reamed one as a reference while reaming the other bearing.
Something like the reamer setups for camshaft bearings in automotive
engines.

An alternative way to do would be with a bearing scraper and
spotting blue.

Good Luck,
DoN.



Why not just take the .003 off the spindle OD ? Seems it would be easier
than trying to line bore the headstock.

--
Anthony

You can't 'idiot proof' anything....every time you try, they just make
better idiots.

Remove sp to reply via email

In article ,
Anthony wrote:
(DoN. Nichols) wrote in
:

In article ,
Grant Erwin wrote:
Martin Whybrow wrote:
Maybe someone might reply if I'm less specific in my subject line
:-)

I'm rebuilding a Myford ML4 (3.75" centre height) lathe at present.
When I bought the lathe I found, too late, that the headstock
spindle and bearings

[ ... ]

I think that it would need to be fitted with a pilot which uses
the other bearing as an alignment aid, too. Two pilots -- one turned
to fit the un-reamed other bearing, and then one turned to use the
just reamed one as a reference while reaming the other bearing.
Something like the reamer setups for camshaft bearings in automotive
engines.

An alternative way to do would be with a bearing scraper and
spotting blue.

[ ... ]

Why not just take the .003 off the spindle OD ? Seems it would be easier
than trying to line bore the headstock.

Because of some of the text which I snipped. He had the scored
bearing surface built up with chrome and ground true and concentric.
Taking off that last 0.003" may take you back to the original metal,
except for chrome in the scores, which would be more likely to split off
and *really* mess up the bearings. :-)

Enjoy,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

"Fdmorrison"
Hand scrape? A triangular (three-sided) scraper will work.

If you blue the bearings, and gently scrape off just the blue?
Frank Morrison

I recently fitted new bronze bearings to an ML7 lathe. They were too tight
( which is how Myford deliberately make ém ) and I hand scraped them using a
3 cornered scraper and bearing blue. It was a Saturday afternoon. My
favourite coffee and the football on the radio made the hours pass sweetly.
Totally worth the effort for the most impotant fit on your lathe and helps
keep the old skills alive that got us were we are today.

Dean.

"Dean" wrote in message
...

"Fdmorrison"
Hand scrape? A triangular (three-sided) scraper will work.

If you blue the bearings, and gently scrape off just the blue?
Frank Morrison

I recently fitted new bronze bearings to an ML7 lathe. They were too tight
( which is how Myford deliberately make ém ) and I hand scraped them using
a
3 cornered scraper and bearing blue. It was a Saturday afternoon. My
favourite coffee and the football on the radio made the hours pass
sweetly.
Totally worth the effort for the most impotant fit on your lathe and helps
keep the old skills alive that got us were we are today.

Dean.


Dean and Frank
Nice to see the same suggestion twice, it kind of instils confidence.
I've not scraped bearings before, looks like I'll get my chance now.
Thanks to all for the suggestions.

Martin.

--
martindot herewhybrowat herentlworlddot herecom