Rega Planar 6 sagging issues

[DimitryZ]

Rega sell 2mm tonearm spacers. Having thus determined that a 2mm adjustment of arm height is considered significant by the manufacturer, I would think the acceptable threshold for deviation from flat for the plinth should be less than 2mm.

Aligns with 1.6 mm reported by PD. What was the bent in the table in question from OP?

 

[Craig B]

Rega sell 2mm tonearm spacers. Having thus determined that a 2mm adjustment of arm height is considered significant by the manufacturer, I would think the acceptable threshold for deviation from flat for the plinth should be less than 2mm.

The one flaw in your logic is that Rega consider the 2mm spacer as significant only when it keeps the tail end of the tallest cartridge bodies from coming into contact with the record.

 

[DimitryZ]

The one flaw in your logic is that Rega consider the 2mm spacer as significant only when it keeps the tail end of the tallest cartridge bodies from coming into contact with the record.

Nonetheless, PD shared with us their internal QC value of 1.6mm. That's their limit, and seems like a very fair one.

 

[Craig B]

Two different things, @dimitry; 1) a reasonable allowance of a 1.6mm variance across the front edge of the plinth, vs. 2) the unlikely possibility of any variance between main bearing and tonearm mount, especially so, considering an enhanced double brace system is employed between these two shorter distance points, one of which is well outside of the support triangle.

"DOUBLE BRACE TECHNOLOGY
Rega’s double brace technology, with integral custom matched aluminium tonearm and hub pillars to ensure maximum rigidity and accuracy." [emphasis mine]​

If we turn things round a bit, and take into consideration where Rega's plinth development has ventured, some are agitating over a superfluous bit of material that doesn't perfectly align with their dust cover, when they should be relieved that said cover won't be leaving rub marks across the front edge of the lovely Polaris HPL matte finish.

 

[Yank]

Aligns with 1.6 mm reported by PD. What was the bent in the table in question from OP?

I was replying to your post stating 3mm to be benign...

 

[paul darwin]

Yank, we sell 2mm spacers for those customers who might be obsessed with the minutiae of VTA adjustment, to suggest that it is in any way relevant to the design and / or of our turntables and plinths shows a misunderstanding of the design philosophies employed and the ultimate benefits of our brace technology.

 

[Craig B]

Some decades ago, Rega offered different thickness spacers for RB250/RB300/RB600 tonearms. ISTR that the thickest of these (10mm!) was mainly intended for use when mounting RB tonearms on other than Rega decks. Regardless, on classic Planar plinths, the 4mm and thicker spacers require the use of the Rega sleeved mounting nut.

I've a vague memory of these having been available in 2mm, 4mm, and 10mm thicknesses. If one wanted 6mm or 8mm one could resort to stacking. I never did encounter a 10mm one; nor the need to stack any combination of 2mm and/or 4mm on Rega tables.

Here is a pic that appears to confirm the sizes that were available back then.

Whilst on the subject, with Rega 3-point mount tonearms, use of the 'All in one' 2mm, 4mm, 6mm, 8mm spacer (now discontinued?) requires the use of the included longer length mounting screws if setting to 6mm or 8mm, otherwise, the holes within the plinth are likely to strip. Conversely, under no circumstances should the longer screws be used with the 2mm or 4mm height settings as (on the thinner plinths in particular) the screws are likely to penetrate the bottom of the plinth and/or make using the standard length screws a problem in future. I mention this because I've seen a few of these spacers go on the used market sans longer screws, sometimes with the shorter ones left in the bag instead.