Pro-ject 1.2 turntable has ground to a halt
"Trevor Wilson" wrote in message
Dick Pierce wrote:
On 1/5/2011 6:54 PM, Trevor Wilson wrote:
wrote in message
...
I have an approximately 10 year old Pro-Ject 1.2
turntable. Over the last year, the big heavy platter
has begun scraping as it spins, and has finally ground
to a halt. If I elevate the platter, by putting a shim
(two old CDs) between it and the sub-platter, that
elevates it enough that it spins again, but with lots
of wobble. Obviously not an ideal fix.
I don't know what's happening, but I'm guessing the
sub-platter (which is what actually spins, driven by
the motor/belts) has descended/sunk a bit.
Has anyone experienced anything similar with this
turntable? Is there any way to fix this problem?
Thanks in advance!
**Common problem with some of the Pro-Ject TTs. The
platter sags! Remove the mat and look at the platter
from the side. You will probably note that the outer
rim has saged, relative to the spindle. Cheap, crappy
die casting I guess.
Are you SERIOUS? The platter has sagged? Please!
**I just spoke with a mate who is very experienced in all
kinds of metal-working technology. He said that such a
problem, whilst unusual in good quality castings, is
certainly not unheard of. Apparently, die casting causes
all kinds of stresses in the material, which if not
controlled, can lead to cracking and/or the deformation I
described.
In order for that sort of thing to happen, the casting has to be very thin.
Usually turntable platters have far more thickness than is needed for
mechanical strength, in order for there to be enough weight. I remember the
3.3 pound "lightweight" die cast platter for my AR turntable. It was pretty
uniformly 1/4 - 3/8 inch thick. It would never sag under its own weight.
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