Winter tip

[Steve]

If your workshop is like mine, cold and damp until next spring, bring
indoors those chinese digital scales&readouts...they don't like it uppem you
know!

[David Billington]

I wasn't greatly pleased when ones of the reader heads failed on my
Newall lathe DRO. It seemed to be temperature related or a least related
to temperature cycling, I suspect a solder joint failure but the items
is completely potted as it can work under water. Warming it up could
bring it back to life but wasn't practical so it had to be replaced. The
scales are cheap, being bearings in a tube (a bit simplistic) but the
reader head is not. That was the 2nd failure as the display also failed,
a Newall tech mentioned they are prone to that if subjected to vibration
as it can cause the power supply chip leads to fail, a bit poor for the
class of kit I think. It did fail when I was doing an operation with a
slitting saw that caused some vibration but the unit was mounted in a
common location off the back of the headstock and I would consider that
the normal operation of my lathe shouldn't be the cause of such a failure.

[Mark Rand]

On Thu, 26 Nov 2009 20:12:10 +0000, David Billington
<d...@djbillington.freeserve.co.uk> wrote:

>I wasn't greatly pleased when ones of the reader heads failed on my
>Newall lathe DRO. It seemed to be temperature related or a least related
>to temperature cycling, I suspect a solder joint failure but the items
>is completely potted as it can work under water.

If it was potted, there's no way it should have failed due to moderate
vibration. I'd be looking to demand a replacement!

Mark Rand
RTFM

[David Billington]

Mark,

Maybe I should have given more detail. The reader head, which is potted,
failed in a way that may have indicated thermal cycling as an issue but
the display head failed at a separate time and isn't potted. Still I
understand that the normal location for the lathe DRO display is on the
headstock and should be capable of with standing normal levels of
vibration. The occasion it failed was unusual in that the slitting saw
operation was causing some chattering but the overall operation was
short, maybe an hour. In addition to these failures the Newall DRO has
suffered occasional glitches trashing the linear compensation even with
the latest firmware, luckily noticeable as the effected display value is
on another planet, not even in the ball park. The first fault occurrence
of the display power supply happened at about 5 year occasion use, not
day in day out, the reader head at about 6 year so both outside
warranty. I compare this to the Sony Millman unit on my BP which is now
about 14-15 years old and I've had it for 13-14 years and it has never
given any problems and some operations have made the arm on which it
sits vibrate like the Newall did without failure.

[Andrew Mawson]

"David Billington" <d...@djbillington.freeserve.co.uk> wrote in message
news:4b0ef44c$0$2539$da0f...@news.zen.co.uk...

IIRC the Newall scales are guaranteed for life

AWEM

[Tony Jeffree]

On Fri, 27 Nov 2009 08:42:26 -0000, "Andrew Mawson"
<andrew@no_spam_please_mawson.org.uk> wrote:

>> warranty. I compare this to the Sony Millman unit on my BP which is
>now
>> about 14-15 years old and I've had it for 13-14 years and it has
>never
>> given any problems and some operations have made the arm on which it
>> sits vibrate like the Newall did without failure.
>
>IIRC the Newall scales are guaranteed for life

Presumably "for life" means until they stop working...?

Regards,
Tony

[David Billington]

The scales maybe, they're the tube with the balls in, the reader heads
are 1 year or 3 years depending on type. The analogue ones which can
only be used with Newall displays are 3 years, the digital RS422
differential quadrature ones I have are 1 year as they can be used with
other makers equipment, but in my case aren't.