Author Topic: Designing new air button system- thoughts?  (Read 210 times)

Euanbrown

  • Member
  • *
  • Posts: 20
  • longtime BCC# owner Jonelli (Mengascini)
  • Location: Edinburgh
Designing new air button system- thoughts?
« on: January 07, 2018, 11:25:27 AM »
My three row Mengascini  has a black piano key style air valve lever placed on the top right of the base of the box. This has been fine for air control and for reaching associated bases when playing in C, G, D and A.  However  inspired by this forum I've started to venture into Bflat land and further 'south'.    The sad fact is that while the RHS  is fine I can't reach the relevant base buttons and control the air!  Im thinking of modifying the air bar control lever and would be interested to hear  any forum members views/experience on how this could be done.  An obvious solution would be to build a valve control lever that extends at least x2 the distance of the current lever  (this would  require some serious re-engineering  though as the current lever 'hinges' at the top  and a press lever equal along its entire length would be better I suppose).  A related problem, but one I imagine I can solve  by 'relearning', is that as  I came from 2 row melodeon background,  I used my thumb to control the air button and  still use it to  control the lever  on the BCC#. If I put a full length bar in,  I guess I'll  have to use my palm to control the lever- is that what most people on here do? (Another question is why Mengascini fit what is effectively a piano accordion control on a button box?)

Any suggestions /comments gratefully received!


John Macrae

  • Member
  • *
  • Posts: 87
  • Location: Inverness
Re: Designing new air button system- thoughts?
« Reply #1 on: January 07, 2018, 04:21:54 PM »
Hello Euan,

If you look back at previous posts in the Instrument Construction and Repair section, you will come across one headed "Full-length air bars".
This should contain much of the information you need. Most, if not all, modern British Chromatics, bizarrely, have a completely inadequate and cheaply improvised air valve control lever which is just a black piano accordion key which is usually attached at the top by a reed which acts as a spring "hinge". There are photographs, in one of my posts, of the conversion from that arrangement which was carried out by John Crawford on my Shand Excelsior. It consisted of a metal lever attached and hinged at both ends to the inner surface of the bass plate. The connection to the valve was made by a metal tube which fitted over the pin attached to the valve. Have a look at the Full length air bars posts. My Shand Morino and Excelsior air valve levers were extended by John to Fdim to allow ease of playing in the flats.

John Macrae

Euanbrown

  • Member
  • *
  • Posts: 20
  • longtime BCC# owner Jonelli (Mengascini)
  • Location: Edinburgh
Re: Designing new air button system- thoughts?
« Reply #2 on: January 07, 2018, 05:54:09 PM »
Thanks John,

I see that there are some good solutions there already! Thanks for the  redirect!

Euan

Bill

  • Administrator
  • *****
  • Posts: 580
  • Location: Ayrshire
Re: Designing new air button system- thoughts?
« Reply #3 on: January 07, 2018, 07:20:19 PM »
The topic that John refers to is at http://buttonbox.org.uk/index.php/topic,252.0.html. It contains much useful information and photos.

I have modified air valves and air bars on a number of accordions (5 so far). Each one was different. Two main design considerations are: the location where the air bar contacts the air valve mechanism (usually the end of a lever); and the space between the inside of the bass board and the bass machine. If space is tight (and it usually is) it might be easier to accommodate an air bar design based on the Hohner Gaelic's, rather than the U–shaped Shand Morino one. Attached is the photo from KLR's original post.

Euanbrown

  • Member
  • *
  • Posts: 20
  • longtime BCC# owner Jonelli (Mengascini)
  • Location: Edinburgh
Re: Designing new air button system- thoughts?
« Reply #4 on: January 07, 2018, 09:44:08 PM »
Thanks Bill,

looks like the Hohner Gaelic might be a good solution- there is not a lot of space in there!

Poldubh

  • Member
  • *
  • Posts: 72
  • Location: Scotland
Re: Designing new air button system- thoughts?
« Reply #5 on: January 08, 2018, 10:35:04 AM »
Euan,
I have a Hohner Gaelic if you want a look at it.

Paul