Valve Springs

[Newell Post]

Does anyone know if Bach sells slightly stiffer than normal valve springs? I can find standard and "light" replacement valve springs. But I would like springs that are just a little bit stiffer, faster, and less "mushy." I know I can try to stretch the standard ones slightly, but I would like springs that come from the factory just a little more "aggressive." Thanks.

[GeorgeB]

@Newell-Post
Check out Austin Custom Brass. I bought a Selmer trumpet from Trent that needed new valve springs and he provided a high speed set made by Brass Sound Creation. Talk about stiff... He has sizes that fit Bach horns, too.

[grune]

You are not the first person I encountered to ask this question. The answer, I believe, is no.

The maths and metallurgy for springs is complicated, and springs for instruments are a very specialised item, so I rather doubt you will find anybody to help you. Thus you will be left to DIY experimentation to try to fabricate a spring for the spring rate/force you desire. I shall be very curious to read your method and results.

[barliman2001]

Until a very few years back, Bach did sell up to five different spring tensions (depending on model).

[Newell Post]

@GeorgeB You know, I had a set of those "Sound Creation High Speed" springs lying around in my spare parts box that I bought a few years ago and never used. I put them in and couldn't tell much difference between them and a new set of Bach OEM springs. I have a "Pro Constellation" C trumpet I bought from a guy that has VERY stiff springs. I don't what those things are, but you really need to mash those valves. They are very fast and very reliable, but you gotta really muscle them.

[ROWUK]

"Stiffer" and "faster" are two completely different things.

My experience is that the speed of the valve is based on mass, proper break in, correct oiling and freedom from aerosols/deposits - not spring tension. If any of these factors are not tightly controlled, we can have a stiffer spring, but no increase in performance. Stretching a spring offers no performance increase at all and the possibility that the spring is no longer true which would actually hurt performance.

That being said, I have never had a trumpet after cleaning and adjustment that was too slow with the standard springs. I did have a period where I wanted a stiffer feel - that actually made me more consciously bang the valves down.

Let us remember that there are two parts to valve action - first down, then back up. Stiffer springs can very well slow down the down stroke by increasing resistance to compression. Our fingers do not behave in a linear fashion.

[barliman2001]

Rowuk Hath Spoken.

[Trumpetb]

There is a balance

The stiffer the spring the slower the downstroke and the faster the upstroke.

There is a wide margin for acceptable stiffness that will give satisfactory speed in both upstroke and downstroke.

Standard springs meet the requirements very well as long as the valve is clean and well oiled.

New springs on older instruments may be too light if original manufacturers springs are unavailable and aftermarket springs have to be used.

If this is the case then the spring can behave sluggishly and hang and this is unfixable until the weak spring is replaced with a stronger spring or otherwise made to be stronger.

Fixing the spring by making it stronger almost without exception means stretching it.

Making a spring stronger by stretching it is proven by anecdotal evidence, empirical evidence, and is also explained by the correct application of Hooke's Law.

A stretched spring is no stronger in its overall travel but because it is longer it becomes effectively stronger at the small changes of length at the extreme compression end of its travel which is where we typically use it.

In a recent example I had an issue with an old cornet that had clean valves and was well oiled and had new springs fitted but continually hung the valves.

Stretching the springs solved the problem and they never hung or misbehaved in any way again.

It would be correct to say that stretching a spring offers no performance increase at all when examined in its behaviour over its entire length of its compression.

However there is a performance increase if only a small portion of its compressive length is examined at the extreme end of its travel in compression.

This is where we use the springs compression in a valve, at its extreme end of travel. So we can see an increase in performance there as I did in my example.

This characteristic benefit only shows up in a very few cases where the spring is too weak to lift the valve and in most cases stretching a spring will bring no benefit.

[ROWUK]

@trumpetb I will insist that "stretching" the spring will not improve performance. We may be able to squeeze a bit more life out of it, but if our stretch is NOT ABSOLUTELY STRAIGHT, the spring is damaged and will actually have worse performance.
Stretching a spring for more tension also assumes that the stretched wire will hold the stretch, that would have to be proven on a case by case basis.

I would insist that Hookes law does not apply here.

F = kx

“F” being the amount of push or pull is on the spring

“k” being a constant, indicating the stiffness of the spring

“x” being the distance the spring was pushed or pulled

Our distance that we stretched is a deformation of the wire and the "new" base for testing. Stretching the spring means that we exceed its elasticity, thus destroying all of the original parameters. What K is left after deformation depends on the spring material and tension. Now, if we retemper after stretch, we have a new animal. I have never read about retempering valve springs.

[Dale Proctor]

Many years ago, my experience with stretching valve springs was that a large percentage of the time, they compressed a bit crooked afterward and made noise scraping the inside of the valve casing. Lesson learned, and I’ve not stretched any more springs. A short spring is inherently stiffer than a longer spring, as long as all the spring’s other basic characteristics are the same, so stretching one and then preloading it by compressing it to fit it back onto the valve does pretty much nothing to make it stiffer.

[Trumpetb]

Ok

First point,

springs are made of spring metal that upon deformation will return to its original position or length.

In the case of a coil spring, the spring will return to its original length if the spring when deflected has remained within its elastic limit.

If however the spring is extended beyond its elastic limit it enters its plastic phase and will no longer return to its original length.

The spring having deformed to a new length will then have a new and greater elastic range.

The result is the spring behaves as it did when it was its original length and can be expected to give a normal life but with different characteristics.

Of course stretching a spring manually is a somewhat hit and miss process and is subject as you say to variance on a case by case basis.

The principle of deformation in the plastic range producing a permanent change in the length however holds true.

Regarding the second point, in my opinion Hookes law always applies. The only question is how it applies.

The behavior of a spring specifically in its coefficient of restitution is largely unchanged however I take your point that we cannot claim that the coefficient of restitution of the spring is identical after the stretching action is completed to what it was before stretching.

Empirical research and real world examples however have repeatedly demonstrated that the valve coil spring shows a greater strength after stretching, this increase in strength is I think not open to debate as it is easily demonstrated.

In so far as the increase in strength leading to stronger spring strength in a brass instrument valve is concerned, that is much harder to establish using Hookes law.

First of all a coil spring strength increases as its deflection increases. This is a given, if it were not true a car spring would not balance the weight of the car mid way in its travel, the car would collapse on the spring down to the floor or remain at the top of its travel.

The reality is the weight of the car reaches equilibrium with the recoil strength of the spring. As the spring deflects it becomes stronger until the weight of the car is in equilibrium with it.

If we take a brass instrument coil spring of a length of 2 inches and compress it to 1 inch as it is fitted to the valve, then in depressing the valve we overcome spring tension at its 50% position.

Let us assume that at this 50% position the spring tension is not quite enough to return the valve against gravity and oil stiction.

If we extend the spring to 3 inches so that it is now 3 inches long and not 2, then to refit the now longer spring into the same valve, it is not compressed to 50% of its length but is instead compressed to 33.33% of its length.

That equates to a significant increase in spring strength by that simple mechanism of stretching it.

As a spring is compressed more it exhibits greater resistance to change in length which is another way of saying the spring becomes stronger.

The overall elasticity of the spring remains unchanged throughout and therefore hooks law applies but we are compressing the spring more when placed in the valve and valve block the result is a stronger spring.

This might be declared speculative were it not for the empirical evidence that stretching a spring and then replacing it in the valve does indeed increase spring tension.

This is easily demonstrated. I have stretched springs many times and in each and every case the spring was made stronger and in no case did it remain the same or rendered weaker.

If the theory fits the observed facts and the observed facts can be shown to repeatedly and reliably fit the theory then the theory is likely to be correct, and in my opinion this is the case here.

The caveat here is where spring tension is already adequate, increasing it by stretching will not show any advantage.

[Dr GO]

@trumpetb said in Valve Springs:

Ok

First point,

springs are made of spring metal that upon deformation will return to its original position or length.

In the case of a coil spring, the spring will return to its original length if the spring when deflected has remained within its elastic limit.

If however the spring is extended beyond its elastic limit it enters its plastic phase and will no longer return to its original length.

The spring having deformed to a new length will then have a new and greater elastic range.

The result is the spring behaves as it did when it was its original length and can be expected to give a normal life but with different characteristics.

Of course stretching a spring manually is a somewhat hit and miss process and is subject as you say to variance on a case by case basis.

The principle of deformation in the plastic range producing a permanent change in the length however holds true.

But also the change in K holds true. In this situation, K wins. Rowuk is spot on with his assessment.

However, there is a solution. Buy a new spring and do keep it intact this time. This will make things O"K" again.

[Dr GO]

Personally, I am no spring chicken, and after over 60 years of playing, I have never had an issue with springs or valve actions in any of my 10 trumpets. They can all keep up with my be bop lines, and that is all that matters.

[Newell Post]

So, I started this string because I have an old Mercedes with valves that would hang up and balk. The answer was some light hand lapping of the pistons (even though they appear to have been lapped before) plus replacing the Bach springs with Jupiter springs. The Jupiter springs have the same "barrel" shape as Bach, but are longer and a little bit stiffer.

[Trumpetb]

@Dr-GO

K never was an issue it stays the same but that does not help matters.

This becomes a situation that requires solving outside the ability of a new spring to solve when there is no new spring available for the instrument that works correctly.

In my own case a 65 year old instrument that went out of production 60 years ago and in which the only available replacement spring is a third party spring that does not work satisfactorily.

It is always the right choice to use the correct spring, unless there is no correct spring available, I already said that.

Having tried several alternate new springs none of them worked satisfactorily and it became clear that no useable new spring was available

My choices were then to have a bespoke spring specially designed and wound for the instrument at great cost or to wind a spring myself. Neither of these were palatable to me.

Stretching the new springs that were not strong enough was a quick and easy solution that I knew would work and it worked.

If it is a choice between quick cheap and easy, and slow expensive and difficult, I will choose quick cheap and easy every time. In 2 minutes it was done.

The springs are now strong enough and work perfectly and the valves are performing faultlessly and have been ever since.

A theory that says a stretched valve spring is not stronger than it was before stretching is clearly wrong because experimental results reveal that it is stronger after stretching and many times this has been proven over the years.

Trying to prove to me that stretching a spring cannot make it stronger, will not really benefit anyone, because the reality is it does make it stronger, so I hope nobody tries to do that.

I am very pleased that you have never seen a problem with your instruments but nonetheless these problems can and do exist and if members do suffer them then knowing that stretching the springs can sometimes help and can be a strong reliable and robust fix, may assist them.

We are after all trying to be helpful to members.

[barliman2001]

@dr-go Well said!

[stumac]

I have only stretched one set of springs, I think it was a Conn 22b that belongs to a friend, the problem was the valves were not returning to the top, stretching fixed this. I have a Courtois French Besson trumpet that came from the factory when they moved out of France, I believe it was a prototype that never went into production. The valve springs were so strong it was painful for my arthritic fingers to press. Searching the stock of 2 repairers did not find suitable. The springs the original were 12mm internal diameter, I thought I might be able to expand a smaller dia one. A set of Yamaha Flugel horn springs were about 10mm id and had a lot of turns, forcing the springs over a 12mm rod and tapping all round with a small hammer until the spring released its hold on the rod gave me a spring of the right length and strength, a 100 gm weight will depress the valve 1/2 way which seems to be common on several of my horns. ( Could someone please tell me how to paragraph a post) Regards, Stuart.

[Trumpetb]

@Newell-Post this is an excellent thread thanks for starting it.

I also have replaced springs with similar springs intended for a different instrument with good results, there appears to be a broad range of different specifications of spring that will work just fine and will replace the originals as long as the valve is well cared for and lubricated.

I think many players believe that only the correct spring made by the manufacturer will do, whereas as long as the length and diameter are close enough almost anything will work fine.

My most surprising success was ordering a set of euphonium springs to replace a trumpets tired springs when I could not find the correct ones.

They had the same diameter and length as the trumpet spring they had to replace so I thought they might be a good alternative. They fitted perfectly, work excellently and have worked perfectly ever since.

@stumac

One of the joys of buying as I do ancient instruments is the tired old springs they come with.

And it is difficult to source original manufacturers springs when they stopped making them 60 or 80 or 100 years ago. Make do and mend is what we have to resort to.

That was a fabulous result with your courtois springs and very enterprising your innovation and abilities in fabrication are beyond mine and your success confirms my beliefs.

A spring is just a spring and near replacements if we mess up are readily available from other manufacturers new stock so we can knock them about and mess with them to achieve what we need from them and should have no fear of doing this.

But it is wise to have replacements in our hands before bending and shaping experiments begin so we can easily and quickly recover if we make a mess of it.

A set of new springs costs less than a bottle of valve oil so ordering two or three sets to play with wont break the bank and if they work well or can be made to work well then we have saved a good instrument from disaster.

Your excellent work on those courtois springs is an inspirational to us all.

As for the paragraph question I use a laptop computer and have no issues so I cannot comment on how to paragraph if you use a smartphone.

[ROWUK]

I guess that we will get no agreement, so let us agree to disagree. Every stretched spring experiment that I know about (with my 55+ years of playing there were a few), have not improved anything. Sticky valves remained sticky, the valves were never faster and more often than not, the scraping noise from bent springs. Pages of irrelevant math do not change the basic premise, so why argue? I have all of the stuff to measure and document the changes (I train our employees and customers to operate and service thermal cutting machines where we use springs in various functions), but have no interest as I have never had a positive experience related to the trumpet or our machines.
I would further advance that springs do not increase playing speed as our fine motor activity is what it is and the quality of the valve lubrication is the deciding factor and very much subject to environmental factors (temperature, aerosols, stroke angle when depressing the valve).
In my world, stiffer springs are for calming the brain of certain players, not increasing performance.
I am always amazed at how smooth and light the action of my valves are after a „maintenance“ by technicians that I trust. I am anally retentive about cleanliness next to godliness when applied to trumpet valves, but still, they apply magic, not springs. They also are very adament about not stretching.

[Trumpetb]

Hi Rowuk,

Your response is thoughtful and enlightened.

All I can offer is that I do not immediately stretch springs as some might do when valves misbehave I spend weeks cleaning and reassembling the valve parts with great care attempting to discover the true reason for the problem so it can be resolved.

I then check my finger articulation and oil carefully and copiously, and only then when all other possibilities are exhausted do I then replace the springs.

If that also fails to fix sluggish and slow valves, only then do I stretch the springs as a last resort.

In every single case the final stretching has worked and it has never failed to resolve the issue and it is this that has forced me to reach my conclusions.

My instruments are as yours are, clean throughout and the valve action is when tested by techs and other players found to be of remarkably high quality as yours are.

Stretching springs when the problem lies with poor oiling, dirty valves, or badly assembled valves will fix nothing.

However upon occasion the valve springs are just too tired and simply not strong enough to do their job, and in that case alone, stretching the spring will have a good chance of resolving the issue.

I do believe that we are in agreement in all but this one area, and I agree we must agree to disagree.

I respect your position and your opinion and I respect the way you express it.

We each have a different truth and my truth is based upon my experience honestly stated and your truth is based upon your experience honestly stated and I respect that.

Each of our truths is valid because each is based upon our different experiences.

Your techs who insist on not stretching does cause me concern, however I am forced to fall back upon my experience and I am left with the many cases where stretching has worked.

I respect techs immensely and would normally accept their opinion without question but I have to go with my experience in this which opposes that view.

I will say that some years ago a very capable tech wound me a bespoke set of new springs and these performed perfectly. Perhaps the techs prefer to have the chance of selecting and fitting the best springs for the job themselves rather than have a player gamble on the results of a home DIY fix.

Such a home fix may not resolve anything and could cause other issues like for example the bending of the springs and making them noisy as you have already suggested.

That is a very professional attitude and I fully approve of it.

Please be assured I am not trying to prevent players placing instruments in the hands of techs, I am trying to give players another option that can work and might serve to get them through a gig or make a horn playable when a tech is unavailable.

Thank you for your comments.