|
Posted by on February 16, 2008, 6:12 am
Please log in for more thread options
> Still trying to refurbish the Boxford AUD.
>
> The Cross slide has several thou of movement, mainly in the middle of
> the travel.
>
> The entire slide including the leadscrew can be pulled backwards and
> forwards and it seems to be play between the leadscrew thrust bearing
> and the saddle itself.
>
> Is there any way to tighten this up?
>
> Someone suggested that I adjusted the cross slide dial, but it seems
> immovable longitudinally on its shaft, though it can rotate to reset a
> zero.
>
> On a second issue, the Cross slide dial has 250 divisions,
> corresponding I thought to 125 thou of movement per revolution, 250 thou
> change in diameter.
>
> Putting a DTI seems to indicate only 100 thou, plus or minus the
> movement mentioned above.
>
> Is it likely that the leadscrew had been changed or am I
> misunderstanding the nature of the beast?
>
> Lastly, it has been fitted with a one HP single phase motor. The revs
> drop perceptibly under any load. Indeed I can all but stall it by
> applying =A0'squeeze' finger pressure to the main lead screw where it
> leaves the gear box and did stall it parting off a 20 mm delrin bar
> using a 1/16th parting tool. Using it on steel only removes dust rather
> than swarf or chips with any tool.
>
> Is this normal?
> Everything seems to turn freely and with the belts removed light
> pressure turns the chuck. After 30 mins at the highest speed the
> intermediate pulley shaft is warm, but the headstock is still cool to
> the touch.
>
> Any help gratefully accepted
> Robin
>
> --
> rsss
> ------------------------------------------------------------------------
> rsss's Profile:http://www.rcgroups.com/forums/member.php?u=3D70106
> View this thread:http://www.rcgroups.com/forums/showthread.php?t=3D818948
Robin
As always these days I am pushed for time but a couple of comments on
your questions. The cross slide leadscrew on an AUD normally has a
couple of ball thrust races that provide location. If you have found
the Yahoo Boxford users group:
http://groups.yahoo.com/group/BoxfordLathe-UserGroup
Try a search within messages on "thrust washers for cross slide" and
it will point to a number of possible causes and fixes. Depending on
the age of your machine it may have a design that is closer to the
Southbend original and there is a good information on repair here:
http://www.wswells.com/crossfeed_screw/crossfeed_repair_index.html
Can't help with the dial graduation except to say that there were a
number of dials available including a "direct reading" version.
On your motor issue you don't say what motor you have; my own AUD was
single phase from new and has a Crompton Parkinson 0.75hp 1425 rpm
motor fitted and I can assure you that it provides plenty of grunt and
you will certainly not stall it as you describe whilst keeping your
fingers. Mine parts off 2" steel with ease and would do so all day. My
only experience here is with a cheap (MM) motor that I bought for my
old 918 lathe, while small and marked at 1hp it wouldn't pull the skin
off a rice pudding. In my opinion, the only 1hp thing about it was the
marking, I replaced it with a very old .5hp Hoover motor and had no
further problems with that machine. Have you another single phase
motor you can try? Unless you are doing something unusual a good
quality .75hp motor will be fine although a 3 phase and VFD would be
my choice if I were to remotor mine. Sorry but I'm no electrician so
can't give any clues as to what might be wrong with your motor. The
warm intermediate shaft is fairly usual. If it is the older plain
bearing type it needs lubricating daily down the centre of the shaft,
if the newer ball bearing type it is "lubricated for life".
Regards
Keith
| 
Yahoo! 
Google 
Windows Live 
del.icio.us 
digg 
Netscape 
XML Sitemap
>
> The Cross slide has several thou of movement, mainly in the middle of
> the travel.
>
> The entire slide including the leadscrew can be pulled backwards and
> forwards and it seems to be play between the leadscrew thrust bearing
> and the saddle itself.
>
> Is there any way to tighten this up?
>
> Someone suggested that I adjusted the cross slide dial, but it seems
> immovable longitudinally on its shaft, though it can rotate to reset a
> zero.
>
> On a second issue, the Cross slide dial has 250 divisions,
> corresponding I thought to 125 thou of movement per revolution, 250 thou
> change in diameter.
>
> Putting a DTI seems to indicate only 100 thou, plus or minus the
> movement mentioned above.
>
> Is it likely that the leadscrew had been changed or am I
> misunderstanding the nature of the beast?
>
> Lastly, it has been fitted with a one HP single phase motor. The revs
> drop perceptibly under any load. Indeed I can all but stall it by
> applying =A0'squeeze' finger pressure to the main lead screw where it
> leaves the gear box and did stall it parting off a 20 mm delrin bar
> using a 1/16th parting tool. Using it on steel only removes dust rather
> than swarf or chips with any tool.
>
> Is this normal?
> Everything seems to turn freely and with the belts removed light
> pressure turns the chuck. After 30 mins at the highest speed the
> intermediate pulley shaft is warm, but the headstock is still cool to
> the touch.
>
> Any help gratefully accepted
> Robin
>
> --
> rsss
> ------------------------------------------------------------------------
> rsss's Profile:http://www.rcgroups.com/forums/member.php?u=3D70106
> View this thread:http://www.rcgroups.com/forums/showthread.php?t=3D818948