Qwin
08-11-2020, 18:11
A friend needed an Alignment Protractor for his Grace G-707 and couldn't locate the original Grace Protractor, so I did the CAD work for him.
Other Grace owners might find this useful.
The Grace G-707 and G-707 mkII Arms use Alignment Geometry similar to Stevenson's.
Like Rega and Technics, they are all similar, but not exactly the same as Stephenson's, or each other.
I used the numbers from the Vinyl Engine data base and John Ellinson's spread sheet and this is what the Grace comes out as:
https://www.jkwynn.co.uk/Pics/Z_038_G-707_Alignment.gif
Using this I made the drawing and PDF file linked below.
Grace, like Rega use an Effective Length of 237mm and a Spindle to Pivot of 222mm.
The offset Angle however is 21deg, compared to Rega's 22deg.
Using the Grace Alignment Geometry, with their own Null Points, as I have done, mounts the cartridge well into the headshell and square to the fixing slots, no twist.
https://www.jkwynn.co.uk/Pics/Z_038_G707_Protractor.pdf
Other Grace owners might find this useful.
The Grace G-707 and G-707 mkII Arms use Alignment Geometry similar to Stevenson's.
Like Rega and Technics, they are all similar, but not exactly the same as Stephenson's, or each other.
I used the numbers from the Vinyl Engine data base and John Ellinson's spread sheet and this is what the Grace comes out as:
https://www.jkwynn.co.uk/Pics/Z_038_G-707_Alignment.gif
Using this I made the drawing and PDF file linked below.
Grace, like Rega use an Effective Length of 237mm and a Spindle to Pivot of 222mm.
The offset Angle however is 21deg, compared to Rega's 22deg.
Using the Grace Alignment Geometry, with their own Null Points, as I have done, mounts the cartridge well into the headshell and square to the fixing slots, no twist.
https://www.jkwynn.co.uk/Pics/Z_038_G707_Protractor.pdf