Stagi Hayden Duet Concertina

[David Barnert]

9 hours ago, DaveRo said:

Here are some pictures.

 

Thank you. From these pictures, I draw the following conclusions:

 

The studs are more like what I remember, but appear to be different (shallower) hardware from what’s seen in the photo I posted from the fabbricaconcertine.com web site.

 

The buttons are slanted at different angles on the left and right sides. I measure it as approximately 7 degrees on the right and 16 degrees on the left. Brian Hayden’s specs call for 10.5 degrees on both sides:

 

Quote

16mm between the centres of buttons along the rows 9mm between one row and the next above - to give an equal spacing of 12mm between the nearest buttons along the diagonal. The rows to slope down at an angle of 10.5 degrees towards the thumbs. Large flat top buttons are preferable.

 

Button size and spacing cannot be measured in the photographs because of scaling uncertainties, but it is clear that the diagonal rows are often neither straight nor evenly spaced (particularly on the left), which couldn’t happen if the specs were followed (as they were in the Bastari version).

 

[DaveRo]

The row are straight in all directions and at both ends, despite their appearance in the photos.

 

The button spacing on each row is the same on both ends, but the rows are closer together on the left, making the diagonal button spacing less.

 

Button diameter 8 (all distances in mm, nearest mm)

 

Distance between button-centres of the triangle C - D - G (or any other triangle on the same side):
Right:  C  17  D  14  G  17  C
Left:    C  17  D  13  G  16  C

 

On both ends the upper button of the nearest row (C or G#) is opposite the top of the handrest (i.e. the leather strap).

 

Distance C to G# (same both ends) 68

Perpendicular distance from edge of handrest to centre of C and G# buttons:
                              Right       Left
Handrest to C        45           58
Handrest to G#      53           42

 

So I calculate the slope as - right: 6.7 deg, left: 13.6 deg.

 

It was only when I was considering the conundrum - why have closer rows on the left when there are fewer rows to fit in? - that I noticed that the handrests about 5mm nearer to you on the right.

 

It's as if the two ends were designed independently by different people!