Pro-ject 1.2 turntable has ground to a halt

[Roy]

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!

[Audio Empire]

On Sat, 1 Jan 2011 12:04:08 -0800, Roy wrote
(in article >):

> 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!

Sounds to me like you need to take some measurements and see where the
clearance issues actually lie. I don't know the Pro*ject table in question,
and my suggestions are general for turntables that have the platter assembly
suspended on springs. If the turntable platter/sub-chassis has a suspension
then I suspect that the suspension has sagged. In some tables, it's possible
to adjust screws inside the springs that the platter/sub-chassis sits on to
raise of lower the assembly. So it might yield to adjustment. If you can
raise (or lower depending on the design) the sub-chassis as it sits on its
springs, be careful to use a level on the PLATTER to make sure that you
adjust all the suspension springs exactly the same amount. Turntables need to
remain level.

Other than that, I suggest that you contact Sumiko, the importer/distributor
(if you're in the USA) in Berkeley Ca. and talk to one of their technicians.

[Bill Noble[_2_]]

On 1/1/2011 12:04 PM, Roy wrote:
> 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!

without looking at the specific TT, I would be willing to guarantee you
that the TT has a suspension that has sagged, it probably has some
rubber or plastic components (grommets, maybe) that have compressed or
expanded, replace them, or shim them, not the platter to sub platter
mating surface. It should cost almost nothing to repair unless the
suspension components need to be replaced, and then cost would depend on
how you elected to fix them. I've had similar issues when I used a
Craftsman TT (no, not Sears, the UK company), and it used short lengths
of elastic rubber for the suspension.

[Roy]

Thanks for the advice. I'll pursue!

On Jan 2, 12:06=A0pm, Bill Noble > wrote:
> On 1/1/2011 12:04 PM, Roy wrote:
>
> > 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!
>
> without looking at the specific TT, I would be willing to guarantee you
> that the TT has a suspension that has sagged, it probably has some
> rubber or plastic components (grommets, maybe) that have compressed or
> expanded, replace them, or shim them, not the platter to sub platter
> mating surface. =A0It should cost almost nothing to repair unless the
> suspension components need to be replaced, and then cost would depend on
> how you elected to fix them. =A0I've had similar issues when I used a
> Craftsman TT (no, not Sears, the UK company), and it used short lengths
> of elastic rubber for the suspension.

[David[_22_]]

"Roy" > 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!

Strange, I thought the Project 1.2 was not a suspended subchassis turntable,
I though it was very basic much like the Rega Planar 3?
Is this not the case?
If it is then the only answer is that the bearing housing on the underside
has come unscrewed.

If is is a suspended subchassis design then it sound like one of the springs
has either broken or come unfixed.

D

[Trevor Wilson[_3_]]

"Roy" > 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. The only effective solution is to replace the platter. Your local
distributor may still have stocks. Otherwise, you're screwed. It is not
acceptable to use the platter in that condition.


--
Trevor Wilson
www.rageaudio.com.au

[Bill Noble[_2_]]

On 1/5/2011 3:54 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. The only effective solution is to replace the platter. Your local
> distributor may still have stocks. Otherwise, you're screwed. It is not
> acceptable to use the platter in that condition.

if it is a diecast platter, just replace with aluminum or other metal of
your choice - any machine shop could make it for you

[Audio Empire]

On Sat, 8 Jan 2011 07:20:41 -0800, Bill Noble wrote
(in article >):

> On 1/5/2011 3:54 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. The only effective solution is to replace the platter. Your local
>> distributor may still have stocks. Otherwise, you're screwed. It is not
>> acceptable to use the platter in that condition.
>
> if it is a diecast platter, just replace with aluminum or other metal of
> your choice - any machine shop could make it for you

It's probably not worth it. After all, one can buy a pretty good Rega, Music
Hall or even a new Pro*Ject 'table for less than $300.

[Arny Krueger]

"Audio Empire" > wrote in message

> On Sat, 8 Jan 2011 07:20:41 -0800, Bill Noble wrote
> (in article >):
>
>> On 1/5/2011 3:54 PM, Trevor Wilson wrote:
>>> > wrote in message
>>> ...

>>> **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. The only effective solution is to
>>> replace the platter. Your local distributor may still
>>> have stocks. Otherwise, you're screwed. It is not
>>> acceptable to use the platter in that condition.
>>
>> if it is a diecast platter, just replace with aluminum
>> or other metal of your choice - any machine shop could
>> make it for you
>
> It's probably not worth it. After all, one can buy a
> pretty good Rega, Music Hall or even a new Pro*Ject
> 'table for less than $300.

If a manufacturer sold me a turntable with a sagging platter and did not
stand behind it, it would be the last turntable of that brand that I ever
bought.

[Audio Empire]

On Sat, 8 Jan 2011 18:18:11 -0800, Arny Krueger wrote
(in article >):

> "Audio Empire" > wrote in message
>
>> On Sat, 8 Jan 2011 07:20:41 -0800, Bill Noble wrote
>> (in article >):
>>
>>> On 1/5/2011 3:54 PM, Trevor Wilson wrote:
>>>> > wrote in message
>>>> ...
>
>>>> **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. The only effective solution is to
>>>> replace the platter. Your local distributor may still
>>>> have stocks. Otherwise, you're screwed. It is not
>>>> acceptable to use the platter in that condition.
>>>
>>> if it is a diecast platter, just replace with aluminum
>>> or other metal of your choice - any machine shop could
>>> make it for you
>>
>> It's probably not worth it. After all, one can buy a
>> pretty good Rega, Music Hall or even a new Pro*Ject
>> 'table for less than $300.
>
> If a manufacturer sold me a turntable with a sagging platter and did not
> stand behind it, it would be the last turntable of that brand that I ever
> bought.
>

Well, I think it would depend upon the circumstances. The Pro*ject 1.2 was a
cheap table IIRC, and it IS 10 years old. Even Rolls-Royce won't stand behind
a 10 year old Rolls other than to supply replacement parts.

[Trevor Wilson[_3_]]

Audio Empire wrote:
> On Sat, 8 Jan 2011 18:18:11 -0800, Arny Krueger wrote
> (in article >):
>
>> "Audio Empire" > wrote in message
>>
>>> On Sat, 8 Jan 2011 07:20:41 -0800, Bill Noble wrote
>>> (in article >):
>>>
>>>> On 1/5/2011 3:54 PM, Trevor Wilson wrote:
>>>>> > wrote in message
>>>>> ...
>>
>>>>> **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. The only effective solution is to
>>>>> replace the platter. Your local distributor may still
>>>>> have stocks. Otherwise, you're screwed. It is not
>>>>> acceptable to use the platter in that condition.
>>>>
>>>> if it is a diecast platter, just replace with aluminum
>>>> or other metal of your choice - any machine shop could
>>>> make it for you
>>>
>>> It's probably not worth it. After all, one can buy a
>>> pretty good Rega, Music Hall or even a new Pro*Ject
>>> 'table for less than $300.
>>
>> If a manufacturer sold me a turntable with a sagging platter and did
>> not stand behind it, it would be the last turntable of that brand
>> that I ever bought.
>>
>
> Well, I think it would depend upon the circumstances. The Pro*ject
> 1.2 was a cheap table IIRC, and it IS 10 years old. Even Rolls-Royce
> won't stand behind a 10 year old Rolls other than to supply
> replacement parts.

**Regardless of legal and moral obligations, when manufacturers make really
stupid mistakes, they should ensure that those mistakes are rectified. A
sagging platter is just ridiculous. Turntable platter technology is hardly
rocket science.

An example: Recently, I've had occaision to service a Counterpoint product.
The original parts are NLA. Although the unit is 20 years old, the
manufacturer has provided exemplary backup service, guiding me to suitable
replacement parts, even though he has no chance of making a profit from that
assistance.


--
Trevor Wilson
www.rageaudio.com.au

[Harry Lavo]

"Trevor Wilson" > wrote in message
...
> Audio Empire wrote:
>> On Sat, 8 Jan 2011 18:18:11 -0800, Arny Krueger wrote
>> (in article >):
>>
>>> "Audio Empire" > wrote in message
>>>
>>>> On Sat, 8 Jan 2011 07:20:41 -0800, Bill Noble wrote
>>>> (in article >):
>>>>
>>>>> On 1/5/2011 3:54 PM, Trevor Wilson wrote:
>>>>>> > wrote in message
>>>>>> ...
>>>
>>>>>> **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. The only effective solution is to
>>>>>> replace the platter. Your local distributor may still
>>>>>> have stocks. Otherwise, you're screwed. It is not
>>>>>> acceptable to use the platter in that condition.
>>>>>
>>>>> if it is a diecast platter, just replace with aluminum
>>>>> or other metal of your choice - any machine shop could
>>>>> make it for you
>>>>
>>>> It's probably not worth it. After all, one can buy a
>>>> pretty good Rega, Music Hall or even a new Pro*Ject
>>>> 'table for less than $300.
>>>
>>> If a manufacturer sold me a turntable with a sagging platter and did
>>> not stand behind it, it would be the last turntable of that brand
>>> that I ever bought.
>>>
>>
>> Well, I think it would depend upon the circumstances. The Pro*ject
>> 1.2 was a cheap table IIRC, and it IS 10 years old. Even Rolls-Royce
>> won't stand behind a 10 year old Rolls other than to supply
>> replacement parts.
>
> **Regardless of legal and moral obligations, when manufacturers make
> really
> stupid mistakes, they should ensure that those mistakes are rectified. A
> sagging platter is just ridiculous. Turntable platter technology is hardly
> rocket science.
>
> An example: Recently, I've had occaision to service a Counterpoint
> product.
> The original parts are NLA. Although the unit is 20 years old, the
> manufacturer has provided exemplary backup service, guiding me to suitable
> replacement parts, even though he has no chance of making a profit from
> that
> assistance.

Counterpoint has always provided good personal service. The SA-2 Preamp I
owned was one of the most satisfactory long-term purchases I ever made.
Included personal advice as to optimal loading for my Accuphase AC2
cartridge.

[Bill Noble[_2_]]

On 1/8/2011 12:12 PM, Audio Empire wrote:
> On Sat, 8 Jan 2011 07:20:41 -0800, Bill Noble wrote
> (in >):
>
>> On 1/5/2011 3:54 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. The only effective solution is to replace the platter. Your local
>>> distributor may still have stocks. Otherwise, you're screwed. It is not
>>> acceptable to use the platter in that condition.
>>
>> if it is a diecast platter, just replace with aluminum or other metal of
>> your choice - any machine shop could make it for you
>
> It's probably not worth it. After all, one can buy a pretty good Rega, Music
> Hall or even a new Pro*Ject 'table for less than $300.
>

well, i would be surprised if machining a platter cost more than $50 to
$80, I'd probably just make a new platter and be done with it, but it
isn't my TT, after all

[Audio Empire]

On Mon, 10 Jan 2011 07:15:43 -0800, Bill Noble wrote
(in article >):

> On 1/8/2011 12:12 PM, Audio Empire wrote:
>> On Sat, 8 Jan 2011 07:20:41 -0800, Bill Noble wrote
>> (in >):
>>
>>> On 1/5/2011 3:54 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. The only effective solution is to replace the platter. Your local
>>>> distributor may still have stocks. Otherwise, you're screwed. It is not
>>>> acceptable to use the platter in that condition.
>>>
>>> if it is a diecast platter, just replace with aluminum or other metal of
>>> your choice - any machine shop could make it for you
>>
>> It's probably not worth it. After all, one can buy a pretty good Rega, Music
>> Hall or even a new Pro*Ject 'table for less than $300.
>>
>
> well, i would be surprised if machining a platter cost more than $50 to
> $80, I'd probably just make a new platter and be done with it, but it
> isn't my TT, after all
>

I do a lot of classic auto restoration. Sometimes, on pre-war cars, one has
to have parts made, so I have a lot of experience at this. Even small parts
are very expensive to have machined. What it ends up being is something like
$300 for, say, one piece of a hydraulic fluid reservoir or $400 for FIVE of
them. It's the machine set-up costs that cost the money, not the actual
machining of the parts themselves. I suspect that a new turntable platter
would be a similar deal.

[Arny Krueger]

"Audio Empire" > wrote in message


> I do a lot of classic auto restoration. Sometimes, on
> pre-war cars, one has to have parts made, so I have a lot
> of experience at this. Even small parts are very
> expensive to have machined. What it ends up being is
> something like $300 for, say, one piece of a hydraulic
> fluid reservoir or $400 for FIVE of them. It's the
> machine set-up costs that cost the money, not the actual
> machining of the parts themselves. I suspect that a new
> turntable platter would be a similar deal.

Glad you said it first!

A turntable platter would be the sort of thing you might want to have made
from a solid piece of aluminum. I'm not going to do the math to calculate
what sort of a solid piece of aluminum like that would weigh, but I can see
parting ways with $50 or so, only to have just a piece of raw aluminum, and
no machine work even planned...

$500 for a nicely turned and balanced platter? Easy!

[Dick Pierce[_2_]]

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!

If the platter was made of butter, yeah, I could believe
is. But even the crappiest imaginable diecast part if
not going to sag except under some pretty extreme loads,
like a stack of a couple of thousand LPs all at once,
maybe. And cheap diecast Al isn't going to sag, it's
going to crack. Aluminum is simply not going to cold-
flow at those loadings. And the loading required to
cause more than micron-type deflections is many orders
of magnitude beyond what you would encounter.

A more likely explanation is something like the platter
bearing mount has slipped, the suspension has sagged or
similar.

But the claim that even the crappiest of diecast platters
has sagged, essentially under it's own weight is, well,
extraordinary.

[Trevor Wilson[_3_]]

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've seen the problem several times with cheap Pro-Ject turntables. When I
saw the first one, I reacted the same way you just did - I refused to
believe it. Explaining to a client was even more difficult. When I saw the
second one, I was slightly less surprised. By the time the third one rolled
along, I realised that there was a major problem. I also noted that more
expensive Pro-Ject turntables did not exhibit the problem.

>
> If the platter was made of butter, yeah, I could believe
> is. But even the crappiest imaginable diecast part if
> not going to sag except under some pretty extreme loads,
> like a stack of a couple of thousand LPs all at once,
> maybe. And cheap diecast Al isn't going to sag, it's
> going to crack. Aluminum is simply not going to cold-
> flow at those loadings. And the loading required to
> cause more than micron-type deflections is many orders
> of magnitude beyond what you would encounter.

**Regardless of what you, me and everyone else thinks, I've seen the effect
several times. I don't know enough about metallurgy to understand what is
occuring, but occuring it is. Or was. I've not seen the problem for several
years. And to reiterate: The platter is some kind of cast alloy. It is not
(pure) aluminium. I have never seen the problem with any other brand.

>
> A more likely explanation is something like the platter
> bearing mount has slipped, the suspension has sagged or
> similar.

**More likely? Certainly. The reality is something else. Examining the
platter form the side will reveal that the outside edge has sagged relative
to the centre. Weird? Certainly.

>
> But the claim that even the crappiest of diecast platters
> has sagged, essentially under it's own weight is, well,
> extraordinary.

**I agree. It is, however, the fact.


--
Trevor Wilson
www.rageaudio.com.au

[Trevor Wilson[_3_]]

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.


--
Trevor Wilson
www.rageaudio.com.au

[Arny Krueger]

"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.

[Dick Pierce[_2_]]

On 1/11/2011 9:56 AM, Trevor Wilson wrote:
> Dick Pierce wrote:
>> 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.

Merely another claim, and no less an extraordinary one at that.

[Audio Empire]

On Tue, 11 Jan 2011 10:42:24 -0800, Arny Krueger wrote
(in article >):

> "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.
>
>

The AR tables were great products and were (mostly) very well made. In fact,
I've a buddy who modified the sub-chassis on his late-sixties vintage AR
'table so that it could take another arm (the original AR arm was the
'table's Achilles heel - it was lousy) and his modified AR was every bit as
good a Linn Sondeck LP-12. In fact, except in a few details, they were almost
identical in the way they were designed. He installed an AudioQuest PT-6 arm
(made by Jelco in Japan) on it, and as far as I know, he's still using it.
When Teledyne bought AR, they changed the table somewhat. Instead of a having
a straight-sided 12-inch platter, the Teledyne unit had a flared platter that
was larger in diameter at the bottom of the rim than it was at the top. They
also canned that awful Edgar Villchur arm in favor of a jeweled gimbal-mount
arm from a Japanese source.

The tables were so well made, that there are literally thousands of them
still in use. The original units used two tiny "clock motors" and they are
impossible to get belts for anymore (so I've been told) but the later,
single-motor units (XA, XB etc.) still have belts available from places like
"Needle Doctor" for about $20.

I doubt if any AR platter has ever "sagged".

[Scott[_6_]]

On Jan 11, 12:03=A0pm, Dick Pierce > wrote:
> On 1/11/2011 9:56 AM, Trevor Wilson wrote:
>
> > Dick Pierce wrote:
> >> 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 i=
n
> > good quality castings, is certainly not unheard of. Apparently, die cas=
ting
> > causes all kinds of stresses in the material, which if not controlled, =
can
> > lead to cracking and/or the deformation I described.
>
> Merely another claim, and no less an extraordinary one at that.

Dick, there are claims and there are claims. Your claims are just
claims too. The thing is, Trevor's claims are based on observation.
And you can't start beating the bias effects or psychoacoustics drum
here. It's simple geometry. It would be pretty hard to mistakenly
diagnose a sagging platter three times if one is even remotely careful
in their observations. You have offered nothing to disprove Trevor's
observations other than icredulity. You will have to do better than
that if you want your claims to be accepted over Trevor's.

Here is a link to another person making the same claim.
http://www.diyaudio.com/forums/analogue-source/118674-project-one-turntable=
-platter-problem.html

[Arny Krueger]

"Dick Pierce" > wrote in message


> On 1/11/2011 9:56 AM, Trevor Wilson wrote:
>> Dick Pierce wrote:

>>> Are you SERIOUS? The platter has sagged? Please!

Pretty weird.

>> **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.

> Merely another claim, and no less an extraordinary one at
> that.

Detroit, being an automobile-making town, has a lot of die casting activity
going on. I've heard from plant engineers of unfortunate things happening,
particularly related to casting the cases of automatic transmissions, which
are large and relatively thin. Massive cracking under stress and leaks due
to porosity while unusual, do happen. However, having a casting slump under
its own weight is AFAIK totally unheard of.

Pro-ject truntables are said to be made in the once-communist Czech Republic
in a factory that was actively making turntables during the decades of
ruinous Soviet control. Iron curtain countries have a sad but lengthy
history of cut corners and poor quality products. They may have figured out
ways to cut corners that are even unheard of in Detroit! ;-)

[Scott[_6_]]

On Jan 5, 3:54=A0pm, "Trevor Wilson" > wrote:
> "Roy" > 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 th=
e
> outer rim has saged, relative to the spindle. Cheap, crappy die casting I
> guess. The only effective solution is to replace the platter. Your local
> distributor may still have stocks. Otherwise, you're screwed. It is not
> acceptable to use the platter in that condition.
>
> --
> Trevor Wilsonwww.rageaudio.com.au

You are guesing that it is a die cast platter? Pro Ject does use MDF
for it's platters on a few of their cheapest models. Could the Pro
Ject 1.2 be using MDF?
http://www.project-audio.com/main.php?prod=3Drpm13&cat=3Dturntables&lang=3D=
en
"=95 The resonance-optimised platter is made of medium density fibre."
http://www.project-audio.com/main.php?prod=3Dessential&cat=3Dturntables&lan=
g=3Den
"=95 MDF platter with felt mat "

[Arny Krueger]

"Scott" > wrote in message


> You are guesing that it is a die cast platter? Pro Ject
> does use MDF for it's platters on a few of their cheapest
> models. Could the Pro Ject 1.2 be using MDF?
> http://www.project-audio.com/main.php?prod=3Drpm13&cat=3Dturntables&lang=3D=
> en
> "=95 The resonance-optimised platter is made of medium
> density fibre."
> http://www.project-audio.com/main.php?prod=3Dessential&cat=3Dturntables&lan=
> g=3Den "=95 MDF platter with felt mat "

MDF is well known to slump in high humidity. It is heavy enough that it
could be an effective turntable platter if used in the right quantities.