Hohner treble key force

[colinm]

My Hohner Cassotto 1 uses compression springs for treble key pressure, has anyone tried to adjust these, i wish to reduce pressure from 135 gm to about 80 gm.

 

[Dingo40]

My Hohner Cassotto 1 uses compression springs for treble key pressure, has anyone tried to adjust these, i wish to reduce pressure from 135 gm to about 80 gm.

Would not doing this risk having pallets leaking air? :huh:

 

[colinm]

My Hohner Cassotto 1 uses compression springs for treble key pressure, has anyone tried to adjust these, i wish to reduce pressure from 135 gm to about 80 gm.

Would not doing this risk having pallets leaking air? :huh:

 

[boxplayer4000]

Colinm:
When Hohner set the spring force they chose a strength which was a compromise between a comfortable playing force and a force sufficient to keep the pallets closed and air-tight when not being played. Careful thought is required before altering the balance. Have you considered the key travel?  Quite often the key travel can be reduced with no effect on how the accordion plays but the 'feel' of the keys to the player is much better.

 

[colinm]

KBoxplayer 
Are you referring to all hohner models or just the cassotto 1. Treble key movement is 5mm which ie easy to change on the white keys, more difficult on the black.
I still think 125 g is excessive for key force, just wondered if anybody had ever had a cossotto 1 or probably 2

 

[debra]

I never had a Hohner Cassotto 1 but have worked on a Hohner with the same spring mechanism. I would rather not try to change it but if you must, use a Dremel with carbon disk to take a bit off a spring. If you try it with the lowest note and you get no air leak then that force should also be enough for higher notes.
But as others have said: Hohner chose the compromise between easy playing and still having no air leaks and now you are betting that they were too conservative... I just hope you are right.

 

[colinm]

Good point, starting on low note, its quite a struggle getting the couplers back in position, so i  will just hang on in case ther are more suggestions before starting.
Any snags with aiming for 3 mm key travel ?

 

[boxplayer4000]

Key Force.
Colinm:
My comment covers all accordions cassotto or standard.
Measuring the key force about 20mm from the end of the white keys on my Morino (cassotto) 1VM the key force in the middle of the keyboard is about 81g and on the lesser used keys at top and bottom is about 88 to 95g.
The key travel is about 4/4.5mm, which is quite shallow but it does not appear to impede air flow and the reeds are very responsive.
I suppose care is required in measuring key force so that comparisons are valid. I used coins placed on the keys then weighed a fairly large quantity of coins to get an accurate weight of individual coins.
How are you measuring key-force?
I recommend caution before making changes.

 

[colinm]

Boxplayer
I bought an old gauge on eBay which works well, if i cut a biy off thr springs i can always pack them up to return to standard

 

[debra]

Good point, starting on low note, its quite a struggle getting the couplers back in position, so i  will just hang on in case ther are more suggestions before starting.
Any snags with aiming for 3 mm key travel ?

When you lower key travel you also reduce how far the pallets open. You can reduce key travel more on a non-cassotto instrument than on the cassotto instrument because the pallets in cassotto always already open less far. So for the Hohner Cassotto 1 I would advise against lowering the key travel to 3mm.
Check how far the pallets open inside the cassotto first!
When the pallets open less (especially in the cassotto) the frequency of the notes goes down (they are "choked" a bit) and thus the whole instrument will need retuning.

 

[colinm]

I,ve. Reduced the force ro about 100 g and the travel to 3mm on a low black note and white note, seems ok, the travel will probably increase as the felt beds in
I will get some more felt and play it without couplers for a while.

 

[JIM D.]

Your solution is a no no . Relieving the spring tension will only create pad leaks.
Lowering you keyboard is what is necessary . Ive been doing this for 40 years now for Pros ( some you may know) that wanted a quicker action.
Please read --
http://accordionrevival.com/ACCORDION_REPAIR_2.php#Setting_up_a_key

Lowering your keyboard properly will not effect your Cassotto.

 

[colinm]

Hohner have contacted me and say thar 110 g is the minimum pressure to prevent leakage