Stiff octave key

[ArtyLady]

Can anyone advise me is it easy to adjust my octave key as it is quite stiff? is it just a case of tweaking a screw and if so which one, or does it need a lighter spring (in which case I'll wait until I can hold of my tech)

thanks in advance

 

[ArtyLady]

I've just looked again and it's seems to only be a problem when it switches over to the top mechanism - so presumably not the spring?

 

[Stephen Howard]

With the crook removed from the body, finger an octave A and grip the little pin that stick up above the crook socket. Try to move it up and down. Does it move freely, with no sense of stiffness or sluggishness?
Now finger an octave G and repeat. Does this make any difference?
If all is well then it's likely your octave mech is fine - and either the spring on the crook key has failed...or the pads are sticking.

If there's some sluggishness it might simply be down to a lack of lubrication. Some oil will help, but if the existing oil has dried it might be fouling the mechanism. A strip down would be the fix, but a good 'get by' is a couple of drops of cigarette lighter fluid place on the junctions where the key barrels meet, and where they butt up against the pillars.

One other test you can do is to get a small screwdriver and give the octave key mech screw a turn back and forth. Watch the mech as you do so to see if the whole thing rises and falls. If so this would indicate a bent rod screw.
If it doesn't do this, but a single key on the group moves as you turn the screw then it may mean one of the keys is bent.

 

[ArtyLady]

With the crook removed from the body, finger an octave A and grip the little pin that stick up above the crook socket. Try to move it up and down. Does it move freely, with no sense of stiffness or sluggishness?
Now finger an octave G and repeat. Does this make any difference?
If all is well then it's likely your octave mech is fine - and either the spring on the crook key has failed...or the pads are sticking.

If there's some sluggishness it might simply be down to a lack of lubrication. Some oil will help, but if the existing oil has dried it might be fouling the mechanism. A strip down would be the fix, but a good 'get by' is a couple of drops of cigarette lighter fluid place on the junctions where the key barrels meet, and where they butt up against the pillars.

One other test you can do is to get a small screwdriver and give the octave key mech screw a turn back and forth. Watch the mech as you do so to see if the whole thing rises and falls. If so this would indicate a bent rod screw.
If it doesn't do this, but a single key on the group moves as you turn the screw then it may mean one of the keys is bent.

Hi Stephen thanks for that - did the first test and it did move up and down freely (albeit only a tiny little bit of movement is this correct?) Is it okay to use WD40 to lubricate? I'm still wondering if I can get a lighter spring for it.

 

[Stephen Howard]

Yes, it will only move a little.
If all is well there is no immediate need to oil it - but if you wish to I would use something a little heavier than WD40.

http://www.shwoodwind.co.uk/HandyHints/oilaction.htm

It may help to oil the ends and the central pin of the swivel arm. The second shot down on this page shows you what it looks like:

http://www.shwoodwind.co.uk/Reviews/Saxes/Tenor/mauriat_66r_tenor.htm



You won't need to change the springs...they can be tweaked to lighten them - though some care has to be taken to maintain the internal balance of the whole mech. One spring too weak or too strong can cause it to fail - and there are three to take into account on a modern horn; the thumb key spring, the crook key spring and the G key spring.

 

[jbtsax]

Allow me a second opinion here if I may. When A with the octave key is fingered with the neck (crook) removed, moving the "pin" should open and close the body octave key against the resistance of the G key spring. Any tiny movement before the body octave key is engaged just indicates slop or lost motion in the octave key floating mechanism.

The true test is when G is fingered with the octave key pressed. In this setting the "pin" should move effortlessly up and down a distance of 4mm or more. If this is the case, it rules out friction in the octave key floating mechanism. Next unhook the spring attached to the thumb octave touch and move it up and down to check for friction in its hinge. If you don't have a spring hook, this can be done with a #8 crochet hook. If this moves freely you have eliminated problems with the body part of the mechanism.

The next thing to check would be to make sure the the neck octave key is moving freely. Sometimes it can get bent and rub against one of the "u" shaped guides. The spring should be just stiff enough to keep the pad on the vent when it is turned upside down and you blow into it with the end stopped to create pressure.

If both areas pass the test and it is still moving sluggishly, it indicates friction where the tube covering the "pin" to eliminate noise meets the ring from the neck. I like to use teflon tubing for this application. If your sax has a different material, try putting a dab of cork grease on it to make it more slippery. After all of this, the neck octave opens slowly or sluggishly when you finger from G to A, the thumb octave touch spring needs to be made a bit stiffer to "dominate" the spring on the neck key.

 

[Stephen Howard]

After all of this, the neck octave opens slowly or sluggishly when you finger from G to A, the thumb octave touch spring needs to be made a bit stiffer to "dominate" the spring on the neck key.

Going from octave G to A, the thumb key (and thus the spring) does nothing at all. The power that drives the mech at this point comes from either the crook key (A down to G) or the G key (G up to A). All that increasing the touchpiece spring will do is make that particular key heavier in action.

 

[jbtsax]

Of course you are correct that the spring of the G key drives the body to neck octave key exchange. It must close the body octave key with a greater force than the flat spring keeping the neck octave open. My mistake. I should have said "the G key spring needs to be made a bit stiffer in order to dominate the spring on the neck key". However, the thumb key spring does play an important role as well, and that is to quickly and firmly close the body octave when playing G octaves and to quickly return the octave post to its rest position when the thumb key is released.

Now that things have become quite complicated, going back to the octave key being "stiff". If that actually means that the thumb key is hard to push and has nothing to do with the octave mechanism then the fix is quite easy. Take the crochet hook and pull the spring back away from it's "cradle" a bit and then let it return. Keep doing this till the spring has the lighter feel you prefer.

 

[ArtyLady]

Oh my head!!!:shocked::shrug::shrug::shrug::shrug::shrug::shrug:🙂))
Think I'll just wait til I can get hold of my tech...........

 

[Sue]

Oh my head!!!:shocked::shrug::shrug::shrug::shrug::shrug::shrug:🙂))
Think I'll just wait til I can get hold of my tech...........

Haha - good decision 🙂

 

[Stephen Howard]

Oh my head!!!:shocked::shrug::shrug::shrug::shrug::shrug::shrug:🙂))
Think I'll just wait til I can get hold of my tech...........

Very wise.

Octave mechs are finicky buggers at the best of times, let alone ones that are worn/damaged/badly built - and, generally speaking, if you can't resolve the problem with a drop of oil it's probably best to let an expert cast an eye over it.
And that's just the modern ones. When it comes to some of the more esoteric vintage mechs even I've been known to scratch my head while I try to work out how they function.

 

[gladsaxisme]

I just love all this tech stuff I ought to copy it out so I've got it for later rather than try to find this thread again ....John

 

[Ivan]

I just love all this tech stuff I ought to copy it out so I've got it for later rather than try to find this thread again ....John

You might find it quicker and easier to translate the dead sea scrolls