Melodeon.net Forums

Discussions => Instrument Design, Construction and Repair => Topic started by: John MacKenzie (Cugiok) on December 30, 2017, 09:03:30 PM

Title: Igor bellows
Post by: John MacKenzie (Cugiok) on December 30, 2017, 09:03:30 PM
FInished phase one. Fairly airtight. Now for the tuning

SJ
Title: Re: Igor bellows
Post by: mr hohner on December 31, 2017, 04:12:11 AM
Fantastic work sir!!!  :||: :||: :||:
Title: Re: Igor bellows
Post by: Steve_freereeder on December 31, 2017, 08:16:31 AM
...Fairly airtight...

Only fairly airtight? Do you know the sources of your leaks? If you have new bellows, any leaks are either (a) going to be around the gaskets - try gently tightening the screws a little more; or (b) from the pallets - check each one for seating and seal.

A leaky gasket can often be found by holding the bellows close to a damp cheek and pushing the bellows gently. You should be able to feel a cool stream of air from any leaking point.

Similarly you might be able to detect a leaky pallet using the same method. Also, check visually for any obvious leak caused by the pallets not being aligned and overlapping the tone holes. A bright LED torch shone inside the bellows in a darkened room might show a sliver of light from a misaligned pallet. Reposition as necessary.

If that all seems OK then check the seating of each pallet using a thin tapered strip cut from a Rizla cigarette paper.

Insert the fag paper strip under each pallet in turn, using it a sort of feeler gauge. Allow the lever arm spring to trap the fag paper and try pulling it out. Test both sides and both ends of each pallet in turn. The spring pressure should 'grab' the fag paper at each test position. If it slides out easily, you know there will be a leak at that side/end. Do each pallet in turn, treble and bass sides.

If you find a leak, (and assuming the pallet facing material is in good condition) you will need to reset the pallet, either by re-glueing the pallet on the lever arm, or if the pallets are screwed onto the lever arm, by using finger and thumb pressure to very gently bend the pallet towards the leak.
Title: Re: Igor bellows
Post by: Lester on December 31, 2017, 08:45:06 AM
Only fairly airtight? Do you know the sources of your leaks? If you have new bellows, any leaks are either (a) going to be around the gaskets - try gently tightening the screws a little more; or (b) from the pallets - check each one for seating and seal. <snip>

Or (c), one I find commonly on old Hohners, the fondos being no longer airtight where they meet the casework. A bead of PVA around the joint usually fixes this.
Title: Re: Igor bellows
Post by: Steve_freereeder on December 31, 2017, 01:06:38 PM
Only fairly airtight? Do you know the sources of your leaks? If you have new bellows, any leaks are either (a) going to be around the gaskets - try gently tightening the screws a little more; or (b) from the pallets - check each one for seating and seal. <snip>

Or (c), one I find commonly on old Hohners, the fondos being no longer airtight where they meet the casework. A bead of PVA around the joint usually fixes this.
Good point, Lester!
Title: Re: Igor bellows
Post by: Grape Ape on December 31, 2017, 06:04:29 PM
Cugiok, what did phase 1 entail? Did you retape the bellows?
Title: Re: Igor bellows
Post by: Grape Ape on December 31, 2017, 06:05:38 PM
Also why "Igor?"
Title: Re: Igor bellows
Post by: John MacKenzie (Cugiok) on December 31, 2017, 06:09:42 PM
No, I sent the old bellows to Igor, (in Slovenija) and he made me new ones. I had to strip off the old corners etc., and refit, and regasket, when he returned them. Apart from that I refaced all the pallets, and tidied the rest up. I couldn't figure out how to limit the button travel though, as the levers and keys together only just fit the aperture in the keyboard, leaving no room for padding, until they were fully inside, and the buttons located in their holes.

Sir John
Title: Re: Igor bellows
Post by: Malcolm Clapp on December 31, 2017, 10:40:24 PM

 I couldn't figure out how to limit the button travel though, as the levers and keys together only just fit the aperture in the keyboard, leaving no room for padding, until they were fully inside, and the buttons located in their holes.


Best done with the keyframe detached from the body. and using a stiffened grade of felt, around 4 mm thick (uncompressed). Fixing the felt to the floor of the keyboard needs only a little adhesive if cut accurately, as the stiffness of the felt will not allow bunching or lateral movement sometimes found with the usual woven baize (sp?) material.

While you're at it, it might also be worth replacing the tiny brass screws which hold the keyframe with a slightly larger/longer size (or even with small nuts and bolts) to avoid the seemingly common problem of the spring pressure pulling the screws from the wood. (May need a slight enlargement of the holes in the keyframe.)

Hope this might assist, though ideally should perhaps have been done prior to the work on the pallets and key alignment....
Title: Re: Igor bellows
Post by: John MacKenzie (Cugiok) on December 31, 2017, 10:47:42 PM
Thanks for that. I have been toying with the idea of cutting the bottom edge of the keyboard cover off, then doing a mod, that will allow it to be replaced with just a couple of screws

SJ
Title: Re: Igor bellows
Post by: Malcolm Clapp on December 31, 2017, 11:10:11 PM
Thanks for that. I have been toying with the idea of cutting the bottom edge of the keyboard cover off, then doing a mod, that will allow it to be replaced with just a couple of screws

SJ

Thinking outside the box (duh!), if you were considering that sort of surgery, why not cut the front edge off instead. Felt can then be slipped in under the keys, then replace the edge with a concave moulding to give you a (desirable?) thumb groove like on the Preciosa model. I've never tried this myself, but the initial cut would appear more likely to succeed than removing the bottom edge, which I have tried in the past, but with disastrous consequences....
Title: Re: Igor bellows
Post by: John MacKenzie (Cugiok) on December 31, 2017, 11:16:47 PM
I Like that a lot

SJ
Title: Re: Igor bellows
Post by: malcolmbebb on December 31, 2017, 11:32:12 PM
Personally I would prefer a button limiting method just under the buttons, as you suggest.

However, Theo's widely used method is inboard of the finger board assembly, immediately in front of the hinges. This does not require surgery of the fingerboard.

Although I am much in favour of the Liliput/club type finger groove.  :||: :|||:
Title: Re: Igor bellows
Post by: Theo on January 01, 2018, 12:59:43 AM
Another option is to get an Acorn keyboard from Pete Ward. If you ask him for one without pair you can stain and varnish it to match the box.
Title: Re: Igor bellows
Post by: Malcolm Clapp on January 01, 2018, 01:35:23 AM
Another option is to get an Acorn keyboard from Pete Ward. If you ask him for one without pair you can stain and varnish it to match the box.

Or you could do that after you stuff up the removal of the bottom of the existing keyboard.... like wot I did.  :-[ :-[ :-[
Title: Re: Igor bellows
Post by: John MacKenzie (Cugiok) on January 01, 2018, 10:02:27 AM
Did you try cutting a panel in the bottom, or taking a complete slice off with a band saw, Malcolm?

SJ
Title: Re: Igor bellows
Post by: Grape Ape on January 01, 2018, 02:01:53 PM
Noooo- don't cut it up!  I used Theo's method on my Presswood and it worked wonders.  Easy to do as well.  Just cut a small strip of wood, top with felt, and glue under the mechanism in the box not the keyboard.  Took all of ten minutes and been playing it ever since. 
Title: Re: Igor bellows
Post by: Theo on January 01, 2018, 02:35:25 PM
Yes, but I recommend fixing with screws rather than glue.  You might want to make adjustments later. And it’s quicker, you can assemble immediately without having to wait for glue to dry.
Title: Re: Igor bellows
Post by: Grape Ape on January 01, 2018, 03:57:33 PM
I used a non permanent glue.  Didn’t really need it even as the piece of wood I used was the perfect size and had a snug fit on it’s own.  Would be very easy to remove if for some reason I were to decide I actually preferred when my fingers used to sink into the holes....
Title: Re: Igor bellows
Post by: Malcolm Clapp on January 01, 2018, 09:35:40 PM
Did you try cutting a panel in the bottom, or taking a complete slice off with a band saw, Malcolm?

Short answer is the band saw slice. A woodworking friend has a very very well-equipped workshop, but still managed to get the keyboard to more or less disintegrate. If only we had an infinite supply of keyboards to practice on, I think it might have worked....

Cutting a panel would probably have been a better solution, but a new replacement keyboard better still.....

Title: Re: Igor bellows
Post by: John MacKenzie (Cugiok) on January 01, 2018, 09:37:49 PM
It's a decorated keyboard, sadly.


SJ
Title: Re: Igor bellows
Post by: Malcolm Clapp on January 04, 2018, 12:58:55 PM
Looks just like yours, John. (Not the one we "sliced")

https://www.youtube.com/watch?v=cB-JyBo98ws (https://www.youtube.com/watch?v=cB-JyBo98ws)

Good luck with the restoration.



Title: Re: Igor bellows
Post by: invadm on January 04, 2018, 05:13:55 PM
I couldn't figure out how to limit the button travel though, as the levers and keys together only just fit the aperture in the keyboard, leaving no room for padding, until they were fully inside, and the buttons located in their holes.
Sir John
have you not seen the photos of button limiting- the easier way- sir John? please don't cut the original fingerboard :(  I can send you a few if you wish just to save that keyboard :D
and are you going to tune it your self or send it to your trusted tuner ? if you are planing to send it for tuning ,any of the tuners will be able to limit the buttons for you, won't cost much.     
Title: Re: Igor bellows
Post by: John MacKenzie (Cugiok) on January 04, 2018, 05:57:09 PM
Thanks for all the helpful advice. I had seen the illustration of the Theo method, but had misunderstood the instructions. Now I know where to place the piece of wood, I shall sort it, tout suite.
As to tuning, it has C/F reeds in it at the moment, and I have ordered a set of ready tuned (sic) G/C to put in their place. I have a C/F Liliput, and am restoring a C/F Club I as well. So have no need of another C/F box. I'm sure the reeds will find a home eventually. I also have another C/F, the style with the wreaths top and bottom on the front, and the metal faced keyboard, that is my next project. Not intending to keep it, but it will do for practicing on. (Going to tackle retaping the bellows on that one)
No chance of my getting bored this winter ;)

Sir John
Title: Re: Igor bellows
Post by: triskel on January 04, 2018, 06:21:38 PM
I also have another C/F, the style with the wreaths top and bottom on the front, and the metal faced keyboard, that is my next project. Not intending to keep it, but it will do for practicing on. (Going to tackle retaping the bellows on that one)
No chance of my getting bored this winter ;)

You might not be intending to keep it but, if it's fettled well, you may find you do. Those 3515s are the best (and were the most expensive) small 2-voice (and 3-voice!) boxes that Hohner ever made - and I'm not alone in thinking that...

The only 2-row Hohner I have as a "keeper" is one of them that Nils Nielsen converted (from C/C#) to C#/D for me years ago, and it's a mighty little box!!!  (:)
Title: Re: Igor bellows
Post by: John MacKenzie (Cugiok) on January 04, 2018, 06:34:18 PM
That's the fella, mine is white.


SJ
Title: Re: Igor bellows
Post by: boxcall on January 04, 2018, 07:29:09 PM
You could do what Triskel's box has ( a removable panel) to limit the travel if you don't do the strip of wood. Or do similar on the back ( what I would suggest) versus taking a cut off of the back in which you would have to add back the amount you remove, I think.
I did a similar to my 1040 finger bd. which looks like yours except I had to make a panel on the front because it was missing wood between the buttons. I'm pretty sure you could do this on the back leaving the edges and the top of finger bd as is.

Picture of what I did here, I did this with a router. I made a template of the exact size I wanted and use a flush cutting bit to remove unwanted area, then cut a piece to fit on a table saw and rounded the radius needed by hand.
http://forum.melodeon.net/index.php/topic,16508.60.html#lastPost
I also posted an attachment, if it shows up.
Title: Re: Igor bellows
Post by: invadm on January 05, 2018, 09:16:04 AM
So have no need of another C/F box. I'm sure the reeds will find a home eventually.
Sir John
My main key is C/F sir John  (:) if your CF Koch blocks are looking for a new home PM me.
Title: Re: Igor bellows
Post by: Henry Piper on January 07, 2018, 11:35:38 AM
I also have another C/F, the style with the wreaths top and bottom on the front, and the metal faced keyboard, that is my next project. Not intending to keep it, but it will do for practicing on. (Going to tackle retaping the bellows on that one)
No chance of my getting bored this winter ;)

You might not be intending to keep it but, if it's fettled well, you may find you do. Those 3515s are the best (and were the most expensive) small 2-voice (and 3-voice!) boxes that Hohner ever made - and I'm not alone in thinking that...

The only 2-row Hohner I have as a "keeper" is one of them that Nils Nielsen converted (from C/C#) to C#/D for me years ago, and it's a mighty little box!!!  (:)
I recently acquired a similar box in A/D from Portugal and have just had the reeds fettled by Theo who has done a wonderful job on them, its now quite the LOUDEST box I've ever owned particularly the bass end !! with a glorious rich sound, and so easy to play.  its definitely one of the best old boxes Ive ever owned, and one I shall not part with.
Title: Re: Igor bellows
Post by: John MacKenzie (Cugiok) on January 07, 2018, 12:29:34 PM
Yes it seems to be characteristic of these early A/D models. I have an early pressed wood in those keys too. The model with the wooden grille, and the decorated bass cover, sometimes known as the Marca Registrada model, on German Ebay. It too is very loud indeed.

SJ
Title: Re: Igor bellows
Post by: John MacKenzie (Cugiok) on January 08, 2018, 10:51:38 AM
Well, I'm sad to report, that now the festive season has finished, and I have had time to get back to this project, that I have discovered the source of the leaks. They are both on the corners of my new bellows, where they are glued to the frame.
I have emailed Igor, and await his response, but in the meantime, I am not very pleased.

Sir John
Title: Re: Igor bellows
Post by: Winston Smith on January 08, 2018, 10:57:59 AM
What a bummer, Sir John. But I expect that Igor will be as disappointed as you are.
Title: Re: Igor bellows
Post by: Steve_freereeder on January 08, 2018, 11:52:58 AM
Well, I'm sad to report, that now the festive season has finished, and I have had time to get back to this project, that I have discovered the source of the leaks. They are both on the corners of my new bellows, where they are glued to the frame.
You should be able to work some dilute PVA glue into the leaky areas, using a thin blunt blade or a small artists' paint brush. Try a 50/50 solution of PVA woodworking glue and cold water. The diluted glue will travel into any gaps by capillary action better than undiluted, more viscous, glue. Remove the bellows from the instrument first.

After adding the glue, clamp the bellows to the frame in the area you've worked on, just moderate force; not too hard. Wipe up any excess glue which oozes out with a damp cloth before it has had a chance to set fully.

Once it's dry, reassemble and test for leaks. Any leakage should be much reduced, if not completely cured, but if there are any remaining gaps/leaks, just repeat the process.
Title: Re: Igor bellows
Post by: John MacKenzie (Cugiok) on January 08, 2018, 12:00:34 PM
Thanks Steve. I had discovered a previous post where it was recommended to use a syringe for this, and that is what I plan to do..

SJ
Title: Re: Igor bellows
Post by: John MacKenzie (Cugiok) on January 09, 2018, 06:52:41 PM
Right folks, thanks for the input. I injected via syringe, a 50/50 mix of PVA and water, mopped off the excess, and put a board and a weight on the bellows. Today all seems to be tacketty boots. Fingers crossed. I also piped a bit of the mix into the inside of the corners too, where they join the frame.

SJ
Title: Re: Igor bellows
Post by: Steve_freereeder on January 10, 2018, 12:58:19 AM
Right folks, thanks for the input. I injected via syringe, a 50/50 mix of PVA and water, mopped off the excess, and put a board and a weight on the bellows. Today all seems to be tacketty boots. Fingers crossed. I also piped a bit of the mix into the inside of the corners too, where they join the frame.

Excellent news!  (:)

Quote
tacketty boots
tickety boo?