Cheep Bellows For Reed Testing Table.

[Discord]

Hello everyone.

I am new to Concertina.net and this is my first post.

 

 

I would like to set up a cheep reed tuning table with bellows beneath.

It is not for professional use. Just good enough to work and give me some practice on a cheep,battered, derelict concertina that I have seen in a junk shop.

At the moment I would not take a file anywhere near my good concertina.

 

The tuning rigs that I have seen so far have decent, working concertina bellows beneath. I have been looking for an alternative bellows substitute.

 

The best alternative that I have seen is a water container meant for camping. They can be bought on an internet auction site for around £7 (English Pounds).

They are cylindrical and collapse like a concertina bellows. Available in sizes up to 10 litres.

 

Has anyone else used one of these, and if so was it up to the job?

 

Cheers.

 

 

 

 

[Geoff Wooff]

I have been using a cheap 'chinese lantern' 20 button anglo that someone gave me in the '70's. I took one end off and screwed on a piece of plywood, made a porthole in this at the centreline of the bellows and screwed another piece of plywood over this 'air hole', cut a narrow air slot in it , fixed a couple of metal strips to this central cover and made two tapered slips of metal so as to be able to emulate the holding slots of a reedpan.

 

This has worked for me ever since... clamped to a table or work bench, the lower end of the Lantern is still intact and its air button can be used to close the bellows and its hand strap used to pull the bellows down (open) when the weight of the still intact end is not sufficient to sound a reed.

 

Cost ? Virtually nothing more than a short afternoon's work.

Edited May 8, 2016 by Geoff Wooff

[Greg Jowaisas]

If inclined you could consider using a small air pump. I did some experiments with a camping air mattress pump. You'll need a small, box made airtight except for deliberate openings. It acts as a resonating chamber and air reservoir, The top of the box can have a fixture to hold the reed above an appropriate sized vent. The bottom of the box holds the plastic tubing leading to the mattress pump. The idea is to use the air intake of the pump, reversing its intended function to create draw pressure in the box and excite the reed.

 

Preliminary tests experimented with different sized diameters of tubing and the results were promising. Advantages are a consistent pressure and continuous sound. Disadvantages were those little pumps can be noisy and need to be isolated or noise insulated to not interfere with tuning.. Most of the camping type pumps work on batteries so can be used "in the field". Some come with a converter for plug in. In the USA you can buy one in the $8-$15 range.

 

Greg

[Discord]

I like the idea of an electric pump but wonder if a hand operated bellows that allowed different pressures to be applied would be better for identifying various faults ?

 

The other thing that I am thinking is , as the different sized reeds in the instrument have different sized air slots, do I have to make a set of seatings for the various sized reeds.

Using different, appropriate sized air slots in them?

 

Definitely a one step forward two steps back thing that I am getting into.

 

Cheers again.

[Greg Jowaisas]

I like the idea of an electric pump but wonder if a hand operated bellows that allowed different pressures to be applied would be better for identifying various faults ?

 

The other thing that I am thinking is , as the different sized reeds in the instrument have different sized air slots, do I have to make a set of seatings for the various sized reeds.

Using different, appropriate sized air slots in them?

 

Definitely a one step forward two steps back thing that I am getting into.

 

Cheers again.

Taking the lead from Wally Carroll I've used a laboratory grade Gast pump for tuning the past 12 years. That just seemed the best reliable and quiet pump available at the time. I'm sure there are less expensive and more than adequate alternatives.

 

Once you establish a pressure equivalent to an average bellows draw it is possible to do some trouble shooting on the tuning jig, for example recognizing a need for set adjustment.. There is probably a way to change (via valve?) the pump pressure and to simulate light and hard bellows work but i have not found that necessary. I don't think there is any substitute for "hearing" the reed inside the concertina in a playing context to make necessary adjustments.

 

One vent size seems to work reasonably well for all regular anglo and treble english size reeds. Adjustable grippers which approximate the slot sides hold the reed in place and can accommodate different size reeds.

 

Greg

[nicx66]

http://www.ebay.com/itm/Concertina-Squeezebox-Accordion-Fruntali-Brand-AS-IS-/272244619061?hash=item3f630b3735:g:vOsAAOSwIzNXOYv4

[Discord]

Nice suggestions.

I have my eye on an even cheaper, low grade instrument on ebay UK.

The last wreck that I looked at sold for an incredible price .

I now have a moral dilemma , what I look on as junk only fit for spare parts, other people see the hidden value or an economic entrance level machine.

Cheers all.

[Theo]

If you consider an accordion bellows then you have a huge choice of very cheap bellows, you might even find one for nothing.

[Dana Johnson]

One thing to consider is having chambers below your reed port. I use three different sizes to approximate the chamber sizes used for those reeds that use that port size. If your tuning rig is substantially different from what the reeds will face, the reeds can be drawn off from what they would normally be. I just glued little boxes under my reed ports, with appropriate sized pad holes on them. I know others have used them, but oddly, I found that reeds that were happy to sound with concertina bellows would not sound with the much larger volume of the accordion bellows ( even a relatively small one. No idea why really, Rich Morse used a portable tuner that had a few folds of an accordion bellows, and it worked fine. Pumps and the like are fine for doing a lot of tuning. You can set them for any pressure level in their range usually, but are overkill for home tuning. You can even use the bellows from your fixer upper to tune it's own reeds. Just make your plates to fit it. ( replace the ends with your tuning rigging.). You can even use a sheet of plexi with a pad hole cut in it and place it over the reed pan still in the bellows. Pull or push the whole mess up or down to sound the reeds you want. With an even pull or push you can get within a cent or two pretty easily. Before you do any tuning though, you need to understand how to raise or lower your reed's pitch properly. The basics are: to raise pitch, you need to remove metal in the top 1/4 of the reed near the tip. Reducing the mass where it swings the most raises pitch. Lowering pitch, you can either add a film of lead free solder in that same area, ( non destructive and removable, or remove metal in the lower 1/4 of the reed near the clamp. Reducing thickness at the point of greatest bending lowers the pitch. ( faster than removing the same amount of metal at the tip raises it.). The center half of the reed is the least effective place to thin, because the lowering effects tend to balance the raising effects enough so you can weaken the reed without getting much results. Most tuning requires sub-microscopic amounts of metal removal. The higher the reed's pitch, the more difference any metal removal will make. A low reed with a light swipe of a file may only move a few cents, but a high reed with the same amount of metal removed might change a semi tone! High reeds are much more difficult to tune. It is easy to overshoot your mark and then overshoot again trying to correct it. Pretty soon the already thin tip is wrecked.

Dana

Edited May 23, 2016 by Dana Johnson