AR-TA XA Platter Height Issue

[njm]

Hi All,

So I've been doing some minimal refurbishing of a pretty nice TA/XA turntable. One thing that I haven't been able to figure out is why my platter sits higher than it should from the plinth. My understanding is that the spring compression isn't really the issue here, as I've taken measurements with the nuts near the top and bottom of the studs and it's way off either way. Leveled, it's about twice as far from the plinth as it should be (1/4" instead of 1/8") The only thing I can think is that my table is the one that has the platter bearing kind of "floating" in the well, and I'm wondering if there's a divot it's supposed to sit in down there (I can't get a good look in there). If there is, maybe it's possible the divot is filled with old grease, and the bearing isn't seating into it all the way? Anyhow, any advice would be much appreciated.

 

[GChief]

Did you put new “heavier” springs on it during your refurb?

 

[njm]

Did you put new “heavier” springs on it during your refurb?

I didn't. It's got the stock suspension still. On that front, I'm wondering if a small amount of wobble is expected, because I got it pretty darn close to perfectly leveled, and there's still a very slight wobble in the platter. The tone arm seems to be able to handle it pretty well, and I only notice a slight amount of flutter on frequencies probably in the 5-10 khz range when there's no accompaniment, but I do have a new belt coming. Maybe that will clean up the slight wobble?

 

[GChief]

It was just a thought. I won’t be much help, when I redid mine I didn’t have any issues and everything went back together without a problem. Hopefully one of the AR TT gurus will see this.

GL

 

[Nashou66]

It shouldn't wobble at all. I have 5 here and none wobble.

Is the shaft tight in the well, that is, is there any play if you move it back and forth?

Did you try to polish the shaft and maybe remove too much material from it?

Check to see if the platter is warped as well.

We have to understand what you mean by wobble, as if there is play in the shaft/bearing assembly or if the platter is not true and flat.

Nashou

 

[njm]

It shouldn't wobble at all. I have 5 here and none wobble.

Is the shaft tight in the well, that is, is there any play if you move it back and forth?

Did you try to polish the shaft and maybe remove too much material from it?

Check to see if the platter is warped as well.

We have to understand what you mean by wobble, as if there is play in the shaft/bearing assembly or if the platter is not true and flat.

Nashou

Hi, thanks for the reply. It seems tight. I didn't polish the shaft, just lubricated it with liquid bearing oil. In terms of the wobble: if I lay on the ground with the platter parallel to my line of sight, as I watch it spin I can see a slight amount of up/down play in the movement of the platter. I haven't measured it (haven't thought about how to do that), but my guess would be about a mm. It's slight, but I can see it when I'm in the above position in relation to it. As far as the platter height issue, any insight there? Thanks again for taking the time. Much appreciated.

 

[njm]

It was just a thought. I won’t be much help, when I redid mine I didn’t have any issues and everything went back together without a problem. Hopefully one of the AR TT gurus will see this.

GL

Thanks for responding either way. Much appreciated.

 

[likebike23]

In my AR-TX the platter bearing well was fairly corroded and was a very tight fit with the platter shaft. I sanded the well to a level I thought was good, but evidently it wasn't.

I had difficulty getting the platter to seat all the way down in the well when I added oil. It was like the trapped air under the shaft couldn't escape due to it being tight. The platter in yours might have such a tight fit that there is trapped air under it that won't allow it to seat fully.

In my case I needed to polish the well more, removing the corrosion better and enlarging the bore enough for the platter to seat and rotate properly.

 

[njm]

In my AR-TX the platter bearing well was fairly corroded and was a very tight fit with the platter shaft. I sanded the well to a level I thought was good, but evidently it wasn't.

I had difficulty getting the platter to seat all the way down in the well when I added oil. It was like the trapped air under the shaft couldn't escape due to it being tight. The platter in yours might have such a tight fit that there is trapped air under it that won't allow it to seat fully.

Ah. That could very well be it. Maybe clean all the lubrication out of there and see if it seats completely? Did you end up finding a solution?

 

[njm]

It shouldn't wobble at all. I have 5 here and none wobble.

Is the shaft tight in the well, that is, is there any play if you move it back and forth?

Did you try to polish the shaft and maybe remove too much material from it?

Check to see if the platter is warped as well.

We have to understand what you mean by wobble, as if there is play in the shaft/bearing assembly or if the platter is not true and flat.

Nashou

 

[njm]

So I just checked, and sure enough, there is a slight amount of play between the shaft and the well. I didn't polish the shaft, so I'm guessing the bearing well has deteriorated slightly? What is the best fix for this?

 

[likebike23]

Ah. That could very well be it. Maybe clean all the lubrication out of there and see if it seats completely? Did you end up finding a solution?

The solution for me was to polish the well more. It needed more material (corrosion) removed to make the fit looser. A little bit of sanding, test fitting, a little more sanding, test fitting until it was good.