I've got an 'Acupath mill' ( Taiwanese import mill vintage 80's) with a
trashed X axis ball screw. The move crew took it apart to get it in the
room, the results was the little balls all over the inside of the knee.
I think I have a way to fix it.

I need to find a stray ball somewhere in the nooks and crannies of the
machine so I can order some new balls. McMaster has a huge selection of
inch and metric balls, usually run about $.10 each, need perhaps 150 of
them so $15 or $20 would cover it. This site shows how a ball screw nut
is threaded on a ball screw:
http://www.nookindustries.com/ball/B....cfm#BallArbor
If the arbor was a chunk of aluminum in the proper size, had a suitable
groove cut in one end, one should be able to populate the ball screw nut
by holding the grooved end up and dropping them in one by one. Once it's
full, transfer to a tube with a sharp edge, screw it on to the screw.

Wadda ya think?

RoyJ wrote:

I've got an 'Acupath mill' ( Taiwanese import mill vintage 80's) with a
trashed X axis ball screw. The move crew took it apart to get it in the
room, the results was the little balls all over the inside of the knee.
I think I have a way to fix it.

I need to find a stray ball somewhere in the nooks and crannies of the
machine so I can order some new balls. McMaster has a huge selection of
inch and metric balls, usually run about $.10 each, need perhaps 150 of
them so $15 or $20 would cover it. This site shows how a ball screw nut
is threaded on a ball screw:
http://www.nookindustries.com/ball/B....cfm#BallArbor
If the arbor was a chunk of aluminum in the proper size, had a suitable
groove cut in one end, one should be able to populate the ball screw nut
by holding the grooved end up and dropping them in one by one. Once it's
full, transfer to a tube with a sharp edge, screw it on to the screw.

Wadda ya think?

Probably do-able, but not a lot of fun. Check carefully as there are
most likely two sizes of balls that alternate.

Heh. Any one want to buy an Acupath mill? (minor problems with X axis)

Pete C. wrote:
RoyJ wrote:
I've got an 'Acupath mill' ( Taiwanese import mill vintage 80's) with a
trashed X axis ball screw. The move crew took it apart to get it in the
room, the results was the little balls all over the inside of the knee.
I think I have a way to fix it.

I need to find a stray ball somewhere in the nooks and crannies of the
machine so I can order some new balls. McMaster has a huge selection of
inch and metric balls, usually run about $.10 each, need perhaps 150 of
them so $15 or $20 would cover it. This site shows how a ball screw nut
is threaded on a ball screw:
http://www.nookindustries.com/ball/B....cfm#BallArbor
If the arbor was a chunk of aluminum in the proper size, had a suitable
groove cut in one end, one should be able to populate the ball screw nut
by holding the grooved end up and dropping them in one by one. Once it's
full, transfer to a tube with a sharp edge, screw it on to the screw.

Wadda ya think?

Probably do-able, but not a lot of fun. Check carefully as there are
most likely two sizes of balls that alternate.

RoyJ wrote:

Heh. Any one want to buy an Acupath mill? (minor problems with X axis)

Depends on how far away and how much...

Take a look / post on cnczone.com, plenty of home builders there and the
occasional unintentional ballscrew disassembly. Should be some good
references to ballscrew repacking to be found.



Pete C. wrote:
RoyJ wrote:
I've got an 'Acupath mill' ( Taiwanese import mill vintage 80's) with a
trashed X axis ball screw. The move crew took it apart to get it in the
room, the results was the little balls all over the inside of the knee.
I think I have a way to fix it.

I need to find a stray ball somewhere in the nooks and crannies of the
machine so I can order some new balls. McMaster has a huge selection of
inch and metric balls, usually run about $.10 each, need perhaps 150 of
them so $15 or $20 would cover it. This site shows how a ball screw nut
is threaded on a ball screw:
http://www.nookindustries.com/ball/B....cfm#BallArbor
If the arbor was a chunk of aluminum in the proper size, had a suitable
groove cut in one end, one should be able to populate the ball screw nut
by holding the grooved end up and dropping them in one by one. Once it's
full, transfer to a tube with a sharp edge, screw it on to the screw.

Wadda ya think?

Probably do-able, but not a lot of fun. Check carefully as there are
most likely two sizes of balls that alternate.

On Sat, 05 Jul 2008 21:48:39 -0500, RoyJ
wrote:

I've got an 'Acupath mill' ( Taiwanese import mill vintage 80's) with a
trashed X axis ball screw. The move crew took it apart to get it in the
room, the results was the little balls all over the inside of the knee.
I think I have a way to fix it.

I need to find a stray ball somewhere in the nooks and crannies of the
machine so I can order some new balls. McMaster has a huge selection of
inch and metric balls, usually run about $.10 each, need perhaps 150 of
them so $15 or $20 would cover it. This site shows how a ball screw nut
is threaded on a ball screw:
http://www.nookindustries.com/ball/B....cfm#BallArbor
If the arbor was a chunk of aluminum in the proper size, had a suitable
groove cut in one end, one should be able to populate the ball screw nut
by holding the grooved end up and dropping them in one by one. Once it's
full, transfer to a tube with a sharp edge, screw it on to the screw.

Wadda ya think?


Roy, I think you ought to send it off to a ball screw rebuilder and
let them refill the ballscrew. They will check it and used the proper
sized balls, putting it as good as new..or damned close.

And its not all that expensive

Gunner

Political Correctness is a doctrine fostered by a delusional,
illogical liberal minority, and rabidly promoted by an
unscrupulous mainstream media, which holds forth the
proposition that it is entirely possible to pick up a turd by the clean end.

Not as many references as I would have expected but some good info none
the less. Thanks.

The different sized balls worries me a bit. I doubt if I will be able to
find many of the balls that came out, they were considered "trash".
Suspect I'll just go with what seems to work, concede the last little
bit of backlash will stay due to a quick fix.

Pete C. wrote:
RoyJ wrote:
Heh. Any one want to buy an Acupath mill? (minor problems with X axis)

Depends on how far away and how much...

Take a look / post on cnczone.com, plenty of home builders there and the
occasional unintentional ballscrew disassembly. Should be some good
references to ballscrew repacking to be found.


Pete C. wrote:
RoyJ wrote:
I've got an 'Acupath mill' ( Taiwanese import mill vintage 80's) with a
trashed X axis ball screw. The move crew took it apart to get it in the
room, the results was the little balls all over the inside of the knee.
I think I have a way to fix it.

I need to find a stray ball somewhere in the nooks and crannies of the
machine so I can order some new balls. McMaster has a huge selection of
inch and metric balls, usually run about $.10 each, need perhaps 150 of
them so $15 or $20 would cover it. This site shows how a ball screw nut
is threaded on a ball screw:
http://www.nookindustries.com/ball/B....cfm#BallArbor
If the arbor was a chunk of aluminum in the proper size, had a suitable
groove cut in one end, one should be able to populate the ball screw nut
by holding the grooved end up and dropping them in one by one. Once it's
full, transfer to a tube with a sharp edge, screw it on to the screw.

Wadda ya think?
Probably do-able, but not a lot of fun. Check carefully as there are
most likely two sizes of balls that alternate.

RoyJ wrote:

Not as many references as I would have expected but some good info none
the less. Thanks.

The different sized balls worries me a bit. I doubt if I will be able to
find many of the balls that came out, they were considered "trash".
Suspect I'll just go with what seems to work, concede the last little
bit of backlash will stay due to a quick fix.

Having the wrong sized balls overall will give you backlash, having them
all the same size will give you rapid wear. Think of how a ballscrew
works - the balls are rolling along between the two surfaces, the
ballscrew and the ball nut. All rolling in the same direction, i.e. the
front of one ball and the back of the one in front of it are going in
opposing directions, so if they contact they rub and wear. The
intermediate undersized balls placed between them contact to two balls
and act as an idler, and since they are undersized they do not contact
both the ballscrew and nut.

"Gunner Asch" wrote in message
...
On Sat, 05 Jul 2008 21:48:39 -0500, RoyJ
wrote:

I've got an 'Acupath mill' ( Taiwanese import mill vintage 80's) with a
trashed X axis ball screw. The move crew took it apart to get it in the
room, the results was the little balls all over the inside of the knee.
I think I have a way to fix it.

I need to find a stray ball somewhere in the nooks and crannies of the
machine so I can order some new balls. McMaster has a huge selection of
inch and metric balls, usually run about $.10 each, need perhaps 150 of
them so $15 or $20 would cover it. This site shows how a ball screw nut
is threaded on a ball screw:
http://www.nookindustries.com/ball/B....cfm#BallArbor
If the arbor was a chunk of aluminum in the proper size, had a suitable
groove cut in one end, one should be able to populate the ball screw nut
by holding the grooved end up and dropping them in one by one. Once it's
full, transfer to a tube with a sharp edge, screw it on to the screw.

Wadda ya think?


Roy, I think you ought to send it off to a ball screw rebuilder and
let them refill the ballscrew. They will check it and used the proper
sized balls, putting it as good as new..or damned close.

And its not all that expensive

Gunner

Political Correctness is a doctrine fostered by a delusional,
illogical liberal minority, and rabidly promoted by an
unscrupulous mainstream media, which holds forth the
proposition that it is entirely possible to pick up a turd by the clean
end.

www.rockfordballscrew.com

This place has VERY fast turn-around or very good prices on repair. Even the
standard turn-around is pretty fast.

I have used them several times...first one was a 1 1/2" dia. 72" long...I
dropped it off after work sorta on my way home...next day, they call to tell
me it was done...at 11:00am. AND they had their driver going out anyway,
he'd drop it off...machine was back online by close of the first
shift...total lost time 36 hrs...cost...$500.us

Cheap at twice the price.

Mike

RoyJ wrote:

I've got an 'Acupath mill' ( Taiwanese import mill vintage 80's) with a
trashed X axis ball screw. The move crew took it apart to get it in the
room, the results was the little balls all over the inside of the knee.
I think I have a way to fix it.

I sure hope you find a few balls. Mic them all, as others mentioned, every other ball is
smaller to be a spacer of sorts that doesn't bind.

Wes