Tech/maintenance G# mechanism on vintage Hawkes & Son alto from 1920s/30s

[saxmad]

I'm repadding this old high pitch alto but have run into a problem with the G# mechanism, in particular with the needle springs. Am I correct in saying the key lever's spring returns the lever and the key's spring should return the padded key?

 

[PigSquealer]

When you depress the pinky G# The key cup should open. It is sprung to open. The linkage arm you press is sprung to close / return. There is a gentle balance relationship between the two. The arm being slightly stronger and the key cup being just light Enough to open. But not so much you get a sluggish response.

when a spring is detached;

a closed key the spring will be on the opposing side of the rod Or angled “away”

a open key the spring will be on the same side of the rod as the key Or angled “towards” the key.

 

[PigSquealer]

Here’s an example from a upper stack area. All the keys are open. The springs are all facing the tone holes (keys).

 

[stitch]

I'm repadding this old high pitch alto

Why?

 

[PigSquealer]

Why?

I never question why somebody wants to fix something. I also repair instruments that most would consider scrap. The “It’s not worth it” kind.…..because I can. Tons of old instruments are still enjoyed around the home.

 

[stitch]

. Tons of old instruments are still enjoyed around the home.

It's not that it's old, it's that it's high pitch.

Fair enough if it's cheap and you want something to practise repair without worrying if you screw it up, but once it's done you're left with an instrument that is of little practical use.

 

[PigSquealer]

it's high pitch.

once it's done you're left with an instrument that is of little practical use.

Ok so what ? Who am I to tell the owner what kind of enjoyment he’ll get out of it. Maybe he’s got a vintage band all HP playing outside in the park. Obviously he knows what he has.

 

[stitch]

Ok so what ?

Agreed ... to an extent.

I wasn't intending to start an argument; it was a genuine question. As you say, there are many reasons to restore an instrument, the fact that it's fun amongst them, and I wondered what those reasons were in this case.

 

[PigSquealer]

Agreed ... to an extent.

I wasn't intending to start an argument; it was a genuine question. As you say, there are many reasons to restore an instrument, the fact that it's fun amongst them, and I wondered what those reasons were in this case.

I apologize for my edgy response. It just gets to me when somebody says it’s not worth it, these have no use or why waste your time. In these regards I’m a little more open minded than most. Yeah it would be interesting to know why @saxmad took an interest in this particular instrument. H. P. Instruments pretty much went out the window with the treaty of Versailles.

Concert pitch - Wikipedia

en.wikipedia.org

I’m just thankful there’s still one around that someone has taken an interest in. Personally I’ve never played a H.P. Instrument. Have you? If so what was it like?

 

[saxmad]

I'm rebuilding it for the sheer enjoyment of being able to play it.

 

[PigSquealer]

I'm rebuilding it for the sheer enjoyment of being able to play it.

Excellent! Would love to see the finished project 🙂

 

[thomsax]

Off topic. I'm sorry.

 

[saxmad]

@PigSquealer - I've attached an image. The linkage lever shows, as you previously stated, the needle spring can only be secured one way, to return the arm.

The "retaining" part of the key cup needle spring looks, to me anyway, that it would not be possible to exert sufficient pressure on the key cup to close it. The needle spring goes through the post and is a straight.. direction to the retaining part of the key cup.

You will notice the stack's rod is loose because I am still working on the horn.

 

[Stephen Howard]

Can't see a problem with that - it all looks like it's supposed to.
Both springs will point forward - away from the rear of the horn to the front. The spring on the cup key will cause the cup to raise - and the spring on the touchpiece or lever arm will cause the touchpiece key to raise. The magic happens at that point where the two keys connect to each other. The rising action of the touchpiece acts on the rear of the cup key and forces it closed. (against the pressure of its own spring).

The only thing that closes the G# cup key is the touchpiece key (and the link from the Auxiliary F that sits over the top of the G# key cup)

 

[jbtsax]

The issue I have found with this "back" G# key design is that the mechanical connection often requires the G# touch spring to be set quite heavy to get a positive closing of the G# key. A bit of friction at the point of contact can exaggerate the problem. I have had some success using thin teflon sheet on one piece and thin synthetic felt on the other with teflon powder rubbed into the surface.

 

[PigSquealer]

@saxmad
The part the spring hooks is generally called a cradle. Sometimes a Cleat. Look at the red arrow. It’s hard to see in the picture but that should be clearing the key foot. The spring that opens the key I’ve circled in blue. In this picture it would go into the slot. Looks to me like the spring could be tired from bending. It’s not straight. for whatever reason if you’ve moved it it may be indexed in a different location. These are fussy little buggers.
There is a delicate balancing act between the two. Friction as @jbtsax mentioned can wack the setting. Also trying to set things on a dirty unit can add complication.

Have A similar unit on the bench today. The key foot is covered with Teflon.

Detached

 

[saxmad]

Brilliant - many thanks indeed.

 

[peterpick]

friction really is a problem with these mechanisms. i find that old cork on one or both surfaces can impede the action. sometimes nothing at all is better...... i certainly see that teflon sheet and felt might work as jbt sax suggests but there's often not much room for clearance.

 

[jbtsax]

The synthetic felt from JL Smith is .020" and the ptfe sheet from the same source is .005" so combined they have a thickness of .025". Plus the synthetic felt can be hammered thinner when required.

 

[PigSquealer]

The cork I use is 1/64 .0154 or 1/32 .0312
The Teflon film is .003 it’s also available in greater thicknesses.