Tag: pedal

-1. Rock, roll and twist again?

This post is part of My top ten bad designs series of posts.

Percussion instruments are three dimensional objects, so in order to effectively describe what I am looking at when I see design problems, below is a diagram of the three axis on which measurements are made.

wpid-img_20150313_1705252.jpg.jpeg

The X direction of movement is forwards and backwards.  The Y direction is left and right.  The Z direction is up and down.

However musical instruments don’t just exist on paper, they are used in the real world, and thus are subjected to forces that are also three dimensional.

wpid-img_20150313_1718042.jpg.jpeg

These forces are called Roll, Pitch and Yaw.  They are measured in degrees around their respective axis, and I have colour coded them for clarity.  For example, Roll (in green) occurs when an instrument wobbles front to back, it is measured in around the Z axis.  Pitch is one that wobbles side to side.  Yaw is an instrument that has a note bed that rotates when viewed from directly above.  In this post I am looking at roll.

Paul the Porter, and Preschool Paul are going down to the park.  As they approach the see saw, they notice that it is balanced horizontally on its base.

wpid-img_20150313_1556292.jpg.jpeg

Preschool Paul loves the see saw, he knows all about how, when on side goes up, the other side goes down because it is only fixed in the middle.  Now imagine that the see saw is the low end of an instrument; as the naturals go down, the accidentals go up.  This is roll. 

wpid-wp-1426262913041.jpeg

Oops!  And here it is, our first example of bad design – a Bergerault Pedal Glock with a central leg at either end.  Just like the see saw above!  Now glockenspiels may not be very wide at the low end, but they are wide enough, and certainly heavy enough for this central leg to be a weak link in the design.  Consider also that it is a “pedal” glock, so there is the additional problem of moving parts within the damping mechanism that need to operate efficiently.  In my professional opinion I give this instrument no chance of surviving for the long term.

Even Preschool Paul knows that standing on one leg is a recipe for disaster.  Instead he stands with his legs spread wide whilst holding his heavy school bag above his head.

wpid-img_20150313_1847592.jpg.jpeg

Now this as we all know is solid and stable, and on paper looks like the perfect solution to roll.  However, if Preschool Paul removes his shoes and stands on a polished floor…

wpid-img_20150313_1848102.jpg.jpeg

With socks sliding along a polished floor, his feet slide apart.  Substitute the feet for wheels, and make the centre of the X the weakest part…

wpid-screenshot_2015-03-13-18-57-322.jpg.jpeg

Oh look, we have an Adams marimba using a design that is featured on just about every one of their instruments.  A design that is fundamentally floored in concept and the end result is hundreds of instruments all over the place that suffer from dreadful roll issues.  What is more, because the same components are used on all of their instruments, the bigger the instrument, the bigger the problem.

Bergerault use a capital I as the basis of their design – I for inadequate.  Adams use an X for exceptionally bad.  Any instrument design that transfers the weight of an instrument directly through its centre line is always going to be exceptionally bad and the resultant instrument is going to be inadequate to withstand the forces applied.

So what is the solution to preventing roll?  For me, simple is best, and the simplest solution is a square.  The only decision is either solid or hollow.

wpid-wp-1426580097829.jpeg

The problem with a solid end, like the Deagan Arora (above) is weight, so I mainly go with a hollow square, ie, two legs, the bottom transom with the casters attached, and the top defined by the note bed.  In order to maximise stability, I make the legs as wide as possible, even splaying the legs out at the narrow end to make a trapezium.

wpid-img_20150313_1920042.jpg.jpeg

In the next part of this series I will look at pitch, which is when the instrument rocks from side to side.

Bergerault Pedal Glock (part 2) (Job No: 1239)

All the metal work needed to stop this Bergerault pedal glock collapsing at every inopportune moment was made in 1239 Bergerault pedal glock (pt 1).

I have a few golden rules when it comes to making and repairing percussion instruments, for instance it has to sound good, work, last, etc. In application I also have considerations to make and using experience I identify and remove potential problems before they happen.

This glockenspiel has two examples, first on the list are rattles.  Has it not dawned on the manufacturers that percussion instruments are played by hitting them, and that due to their very nature of being musical instruments they vibrate.  So anything that can work loose and vibrate will do.  Why on earth then would you choose to use a buckle on a percussion instrument?

wpid-wp-1425372723482.jpeg

Needless to say, they go in the bin!

The next problem is the damper pedal which just hangs off the end of the connecting rod.  Of course this is fine if the instrument never moves and of course the world has a perfectly flat uniform surface.  The damper bar is sprung, so any movement on the instrument will cause movement in the springs – they bounce.  Low and behold the pedal becomes detached, bits snap off, get bent….

wpid-wp-1425372887127.jpeg

It is only because I am also a quantum physicist as well as an instrument maker, who does a bit of neuro surgery on the side, that I am capable of coming up with solutions to these problems.  Webbing loops instead of buckles, and I remake the pedal connector with bigger sides so the pull rod cannot come off (which is fine if the instrument always stays set up). 

wpid-screenshot_2014-11-07-09-33-153.jpg.jpeg

With those bits of idiocy resolved, the instrument can be assembled and finished.

wpid-wp-1425548675461.jpeg

Bergerault Pedal Glock (part 1) (Job No: 1239)

There is a big problem with the Bergerault pedal glock; it falls apart if you move it. Besides from being highly irritating, this self destructive characteristic also causes things to break, fall off and get lost. This is a shame, because the instrument sounds nice.  So what happens is that they get sent to me to be sorted out!

wpid-wp-1423929325548.jpeg

In explanation of what the problem is I’ll use an analogy with our old friend Paul the Porter:

Paul the Porter is playing on the see saw, in the park with Preschool Paul.  When the two Paul’s are sat at either end, Preschool Paul gets flung high into the air which he loves.

wpid-wp-1425280477376.jpeg

After a little while Paul the Porter’s nerves have been sufficiently jangled so he moves towards the centre.  Preschool Paul is amazed that they now balance and he begins to understand the mechanical principles of leverage.

wpid-wp-1425280688735.jpeg

So returning to our glockenspiel and looking at the base of the instrument, it is immediately apparent (to me) that there are serious design flaws which mean that there will always be problems with this instrument falling over.  Thus the Bergerault Pedal Glockenspiel appears in my top ten bad designs, which includes a detailed explanation of what is happening.

wpid-wp-1425281340543.jpeg

In brief, the picture above shows the main offender – the bottom bar has an adjustment on it to alter its length.  This facilitates removing it from the glockenspiel when it is being folded down, but also now means that the legs are not fixed at the bottom.  So when the glock is being wheeled along, this bottom bar offers no structural support.  Returning to our analogy of the see saw,  looking from directly above, the two wheels move about this point like a see saw, compressing the adjustment shorter so it actually falls off immediately prior to the instrument collapsing!

My solution, which applies to just about every instrument I look at, is to sort out the very bottom of the instrument.  It is only when the four wheels are fixed firmly in place that there is any hope for the rest of the instrument to be stable. 

wpid-wp-1425283005648.jpeg

A large part of the job is getting the attachment of the new frame to the existing working well.  All of my designs keep the number of wing nuts for the player to remove to the absolute minimum; I spend time making it properly to save my customers time every time they set the instrument up.

In the first picture the screw is soldered in place so that it cannot rattle loose and fall off.  The second photo shows the screw and a bolt holding the metal in place.  In this instance I have used two points of contact (usually I have three) so that the see saw effect cannot occur.  The third picture shows the cutout around the peg onto which the pedal arm will rotate; the cut out enables the subframe to be lifted off the glockenspiel.

Once both ends are complete they can be joined together with a bar of fixed length.  The two legs cannot now move apart, but the entire strength is still reliant on the welded joint in the centre, and the screws holding the frame onto the glock.  One of the reasons why I extend the connection to the transom as wide as possible is so that I can triangulate between the two points, and therefore massively increase the strength of the frame.

wpid-wp-1425283863116.jpeg

Bergerault have already got diagonals from the note bed to the legs, but because the instrument is height adjustable they come down from the top to ensure that the uprights (theoretically) remain parallel.  However they have built a castle on sand, like all the manufacturers (and me) instruments are designed from the top down, but I build instruments from the ground up making sure that the foundations are solid.  Therefore I make sure that the uprights are triangulated to the (now) solid base frame.

wpid-wp-1425284981439.jpeg

With all the metal work complete, I can send the frame to the powder coaters and resolve the other problems which irritate the customer in 1239: Bergerault pedal glock (pt2)

…How to release a jammed pedal on a Premier Timp

(Every Percussionist Should Know…)
…How to release a jammed pedal on Premier timpani.

This post follows on from an article I wrote explaining in detail about what components make up the Premier clutch mechanism and how they work as a unit.  This theoretical knowledge will help in resolving most problems a timpanist will encounter with setting up the mechanism.

However this post is involved with directly resolving the problem of the pedal being stuck in the down position.  What I don’t mention in the video is that before you launch into the job, just have a look to see if there are missing or loose parts.

Furthermore, there are only two reasons why the pedal will have become stuck.  The first is worn, loose or missing parts.  If nothing is missing then the internal workings of the clutch might have become worn, in which case it needs to be looked at.  The second reason is that it has been set up by someone who doesn’t know what they are doing.  There are plenty of self proclaimed “experts” out there!



…How to adjust Ludwig Timp pedal.

(Every Percussionist Should Know…)
…How to correctly adjust the balancing action on a Ludwig timp so the pedal doesn’t creep.  The video below explains how to do it properly.



Below is a cross sectional drawing of the ludwig mechanism:

wpid-img_20150115_0902542.jpg.jpeg

So as the pedal (1) pushes down it pulls the central tuning rod down (5), which stretches the head to get a higher pitch.  The spring adjustment screw (2) winds the spring towards itself making it tighter, so the spring is pulling in the same direction as the pedal movement, ie. pulling in the opposite direction (in the mechanism) as the drum head.

The problem in the design is that the elastic properties of the drum head change with the diametre of the drum, but the same spring is used throughout.   The further a spring is stretched, the harder and harder it becomes to stretch it; these properties of a spring were used to good effect in exercise products:

wpid-screenshot_2015-01-15-09-23-102.jpg.jpeg

What this means in the real world is that on the larger drums the spring is too powerful, and on smaller drums not powerful enough.  It is however way more complicated than that, but you just don’t need to worry about it, let’s face it, the manufacturers don’t even understand it, otherwise they would use the correct springs!

Obviously this problem quickly became apparent as Ludwig increased the range of drums they made, so the solution was to put a bicycle brake caliper in the only place they could put it, between the pedal and the balancing mechanism.  And there it has stayed ever since, through many “completely new designs” that the company have launched over the years.

Bergerault Pedal Glock (Job No: 1202)

Bergerault have secured a place in my top ten bad designs with this pedal glockenspiel.  In order to minimise the number of removable parts and create a glock that is really quick and easy to assemble, they have this “great” idea of being able to adjust the length of the pedal.
wpid-wp-1415265743497.jpeg

In itself this is a stupid thing to do, but they were forced to do so in order to make the rest of the design work.

The problem is that the legs fold out, and are secured in place first (albeit with diagonal braces that are also badly designed), and then the bottom bar is put in afterwards.  The bottom bar sits on little pins at either ends to enable it to rotate and thus becomes the pedal.  These pins are the problem, the bar has to be reduced in length to get it over,  then lengthened to “secure” it in place.

As a finishing touch, the method of holding the bottom/pedal bar at its full length is a throw back to the 1970’s, a wing screw and a nut.  I remember when certain makes of cymbal stand first started using nylon inserts, now they all do and with good reason as any percussionist will agree, finally something that consistently works.

The end result of all these stupefyingly bad design errors is an instrument that collapses as it is being wheeled about.

The next problem on the list are the connecting rods to the damper mechanism.  At the bottom they hook over little nylon wheels on the pedal.

wpid-wp-1415350401474.jpeg

These just become detached while you wheel it about making an irritating noise and becoming hooked on things and being bent, except when they don’t become detached and then get bent when the instrument collapses.

The real problem with these rods is at the other end, where a leather belt is used to connect them to the damper bar.

wpid-wp-1415350696206.jpeg

Yes that is a leather belt.  The photo is actually off another instrument.  This glock had a variety of materials including string, gaffa tape and cable ties.  Leather needs to be cared for, otherwise it dries out and degrades.  The buckles just rattle.

There are a lot more design issues with this glockenspiel, but those three were the problems on this instrument.  However it is not all bad, the notes do sound really good, and after all that is the most important part of an instrument.  It is just a shame that the rest of it is, well, basically shit.

So what did I do?  In reverse order: 
I took the damper mechanism out and sewed two webbing loops to replace the missing leather straps, and eliminate the rattling buckles.  There is no need for the length of these loops to be adjustable, and the webbing won’t degrade as quickly (3 years to 30+ years).

wpid-screenshot_2014-11-07-09-33-154.jpg.jpeg

One of the nylon wheels on the damper pedal was missing, so I made two new ones that prevent the connecting rods from coming off.  This instrument is never folded down.

wpid-screenshot_2014-11-07-09-33-153.jpg.jpeg

I made an additional bottom bar that fits behind the pedal bar.  This secures the legs in one position; they can neither be pushed in or pulled outwards.

Finally I put on better castors.
 

wpid-img_20140827_131444.jpg