Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[Little Eggy]

I'm glad I have three other boxes as the air button/bar on my 12 month old Nero has suddenly started sticking.
I see from a search of the forum that these boxes are not of the best quality so maybe I shouldn't be too shocked.
Just wondered if anyone else had experienced anything similar and if there's an easy answer.

[Steve_freereeder]

I'm glad I have three other boxes as the air button/bar on my 12 month old Nero has suddenly started sticking.
I see from a search of the forum that these boxes are not of the best quality so maybe I shouldn't be too shocked.
Just wondered if anyone else had experienced anything similar and if there's an easy answer.

Scarlatti instruments are not the best quality, but I've seen worse. You should be able to find out fairly easily why your air button is sticking:

1. Remove the bass-end hand strap, by removing the screws, or unscrewing the rotella adjusting wheel if it has one (I don't think so on a Nero).

2. Remove the bass end grille plate - the sheet of ply where your hand palm rests against and usually with cut outs for the grille cloth and also the air button. The plate is usually attached by a screw at each corner, often through the axis of the 'feet'. It may be that the air button is rubbing on the bass end plate slot for some reason - perhaps it has got bent or otherwise slipped out of alignment.

3. With the bass end plate removed, you should be able to see the air button mechanism. It is usually pretty straightforward: a sprung lever or wooden wedge which opens and closes a square or rectangular palette which has a felt/leather facing to seal over the hole leading to the internal chamber of the instrument.

4. Sometimes the palette slips out of position on the metal lever arm and binds somewhere. It is usually obvious when this happens. Just reposition the palette and secure with a blob of hot-melt glue or some PVA.

5. Another fault might be the spring breaking or slipping off its anchor points. Again this should be fairly obvious. In the case of a broken spring, you should be able to get a replacement from Charlie Marshall. If it's just slipped off, then reposition it with the help of a small screwdriver blade/pliers/tweezers.

Let us know how you get on and/or describe the fault which you find. A couple of close-up photos might be helpful too.

[Little Eggy]

Thanks very much for such a speedy and detailed reply. I will let you know how I get on. I have never attempted to open a box before and - as my wife would attest - I am not the world's most practical person.

[Theo]

You don’t say how the buttonbis sticking.  Is it stiff to operate? Is it staying open after being released? Is it not possibly blue to open?

[Little Eggy]

I have fixed it - does that make me a bona fide fettler?   Certainly not.

I took the back off and could see immediately that the bar had slid down the side of the springed arm which pivots thereby lifting the palette. I re-screwed the metal base plate which anchors the pivot and it seems to be correctly aligned now, and is working OK.

Photos attached - the misalignment is clear.

[Little Eggy]

Thanks again to Steve and Theo for your responses.  This is a splendid forum.

[Steve_freereeder]

I have fixed it - does that make me a bona fide fettler?   Certainly not.

I took the back off and could see immediately that the bar had slid down the side of the springed arm which pivots thereby lifting the palette. I re-screwed the metal base plate which anchors the pivot and it seems to be correctly aligned now, and is working OK.

Photos attached - the misalignment is clear.

Well done! 
Note cheap and nasty Chinese construction method: the mechanism base plate is only secured with one screw. Although you have re-aligned and tightened up the screw on the mechanism base plate, I think you can see how easy it will be for it to come loose again, especially with repeated use of the air button.

The remedy is easy of course: add a couple more screws through the base plate holes which are already there. It's just bad practice and poor quality control to only use one screw! There should be three minimum, ideally four. Use some screws of the same length as the one which is there and Robert is your father's brother, as they say.

[Theo]

Agreed that one screw is insufficient, but two is plenty. Hohner air valves have been working reliably with two screws each since 1930! Of course more screws are likely to be fine too.

[Gena Crisman]

Interesting to see inside your nero - is it a newer one with the 3rds stop, or, an older one? Interesting to see your bass pallets are plastic (a reasonable thing to be the case). I have a photo from some months ago where I took apart my nero's bass side to see about lightening the spring for the air button as I tried someone else's box and instantly realised how much strain my thumb was experiencing. I did a quick hack with lolly sticks rather than actually messing with the spring since I didn't feel comfortable doing that, especially in case it hadn't have worked (it worked great though!). I bought my nero 2nd hand from Hobgoblin in Sept 2016, it is a model without a 3rds stop.

I don't have a photo of the 'before' state it seems, but, perhaps this photo of what my arm looked like will be of some use to you:


(Also pictured: the nero's rotella. 2nd picture is of detatched mechanism and of the bellows/internal side. You can see the type of air button they have in the background also, along with some very dry lubricating grease)

The metal of the arm up to the air button was quite easy to manipulate in direction to adjust it versus my air button, so my first thought would have been, is it possible that it has bent (further?) out of shape with time and ran off to the side? Your arm doesn't look particularly straight to me but it's hard to tell from the pictures (it's hard enough to judge from mine). Either way, some other photos I have of the inside of my box show that the screws for this plate do not penetrate into the air tight portion on my box, so you should not have to worry about having left empty screw holes or anything like that (if I've understood what you've said you've done correctly), but, that is something I would urge you to consider if the apparent solution is to adjust some screws like this in the future.

I'm unsure if your plate is secured with 1 screw (I feel I can see a 2nd screw) - the plate on mine is secured with 3, the 3rd is very cheekily placed under the metal part of the air button arm that is used as the pivot, making it hard to manipulate.

Glad to hear you have got it fixed! Messing with my air button is the first thing I did on the road to get me feeling more confident about peeking inside my instruments, and the confidence to do that has come in handy a few times.

[Steve_freereeder]

I'm unsure if your plate is secured with 1 screw (I feel I can see a 2nd screw)...

Yes Gena, you're right. There are two screws. The other one is partially visible in photo 2. So - ignore what I said in my previous post about the base plate twisting. It looks to be OK. 

[Little Eggy]

There are two screws in the metal base plate. I was able to tighten them both to anchor the mechanism.

It had been suggested that I remove the hand strap to take the back off. There seemed no way of doing this but it didn't matter as the back came off via the four feet and I was able to get inside.

I bought it in Nov 2016 from Hobgoblin, Bristol.  It has one chrome plated stop for removing the thirds.

Thanks everyone.

[Steve_freereeder]

There are two screws in the metal base plate. I was able to tighten them both to anchor the mechanism.

Excellent! That should help to stop the air button wedge slipping off the rod in the future.

It had been suggested that I remove the hand strap to take the back off. There seemed no way of doing this but it didn't matter as the back came off via the four feet and I was able to get inside.

It's not always essential, but often it is more convenient to remove the hand strap. Leaving the strap in place can make it awkward to remove the bass end plate (depends on the make/model of instrument), but clearly you managed OK. Removing the strap also gives you more room to work inside, especially if you are working with the bass/chord pallets and mechanism.   

If adjusted by a rotella wheel, simply loosen the strap using the wheel until the threaded bolt on the end of the strap pops out of the wheel axis. You can then just fold the strap out of the way. Reverse the process to re-secure the strap.  If there is no rotella wheel, the hand strap will be secured by screws at each end, possibly with a chrome cover plate to neaten the ends. Just remove the screws at one or both ends.

[Little Eggy]

"If adjusted by a rotella wheel, simply loosen the strap using the wheel until the threaded bolt on the end of the strap pops out of the wheel axis. You can then just fold the strap out of the way."

Ah...I see what you mean.  I am somewhat nervous about 'popping it out' as, in my experience, things 'pop out' and this is followed by collapse or explosion of all relevant parts.    I will see how my repair goes I think.... Thanks for the advice though.

[playandteach]

Should be safe. The Rotella is a captive nut. The threaded bolt simply screws back in.

[Little Eggy]

Oh dear - the button bar on my Nero started sticking again. 

I took the back off again - and also the hand strap (that helped a lot) - and the fixing plate was still firm.   It was the thin arm which had bent over so that it wasn't being pressed by the button bar.

I've tweaked it again but I fear the arm is simply not strong enough.  If it goes again I will return here and seek advice on - maybe - a replacement wire.  I guess the other option would be to try and fix a wider piece of metal behind the button bar itself, to stop the thin arm from sliding out to the side.