Tag: damper

Premier 751 Vibraphone (part 2) (Job No: 1279)

This Premier 751 Vibraphone is one of those instruments that seemed to have everything wrong with it; the frame was out of shape, major elements like the damper system were broken, and the motor was hanging off.  In 1279: Premier 751 vibe (pt 1) I discussed the structural work that I have done, starting from the ground up, and ending with the commencement of a new damper system.

wpid-wp-1444977859672.jpg

Most of the work in making a new damper system is in the set up, by which I mean how this intrinsically simple system is fitted to the instrument. This is discussed in greater detail in 1260: Premier 701 vibe (pt 2) and it can be seen that I take great care in ensuring that everything is set parallel so that when the damper is used, it rotates freely around its fulcrum points. In reality, because I do not compromise on the quality of materials, the felt I use is of exceptional quality and soft enough to compress around any localised discrepancies. Therefore ironically I have more leeway in the set up of the damper bar, but I cannot guarantee that the same felt will be used from now on, and if a job is worth doing, do it properly. Of primary importance is how the bar makes contact with the underside of the note bars, this is it’s function after all; it needs to be simultaneous across the entire range (left to right or up and down the vibe) as well as between the naturals and accidentals (front to back). So as well as getting everything mechanically efficient, it is this element that I want to get right. I have only ever seen an adjustable system on an Adams vibraphone, and it struck me as a very good idea, especially considering their history of inaccuracy when mass producing components; needless to say despite their system being adjustable, no one had set it up properly before I finally got hold of it, but that is a question of mass produced instruments being assembled by minimum wage factory workers.

The final part of the damper system is joining it to the pedal. In the photograph above I have dropped plumb lines down so that I can mark where, along the damper bar, I want the connections placed. This is an example as to why, when I built the workshop, I put a raised floor in. Besides the added comfort of standing all day on a wooden floor, as opposed to the great discomfort (and harm) from standing on concrete, installing a floor meant that I could get the whole area perfectly flat using a laser level. With a horizontal surface to work off, I know that every time I drop a plumb line down off an instrument, it will be perpendicular to the floor. In practice this means that the two rods that pull the damper are now both pulling at the same rate in the same direction – this is so difficult to achieve that most manufacturers opted to have one pull rod and a central pedal.

I suppose the big question is why do I bother? There are several perspectives to the answer. A vibraphone player generally has an indirect contact with the instrument, they use mallets or bows to generate the sound. To control the sustain and decay on (and in) the whole they rely on a mechanical system. It is my task to give them the very best tools to do their job, so I want the damper system to be expressive as possible and I want consistency across every note. When I say this is my job, it seems blindingly obvious why I go to great lengths to get things perfect. The counter is also true: if a vibraphone does not have this done by a maker or repairer, then they are not doing their job. Furthermore, it is in my nature to be extremely particular and exacting, which why I became an instrument maker, but despite the lack of financial reward the main rewards are in job satisfaction. Over time, to achieve the same level of job satisfaction and therefore reward, I have to aim higher and higher and only my very best work gives that satisfaction. Consequently I always do my best, still living to the Scout promise after all these years!

wpid-wp-1444982558012.jpg

Whilst I was working on this vibe, I use the opportunity to try out my moulding system for replacing the note pegs. There are more details on this kit in 1264: Premier Vibe Note Pegs. There was also a new motor system fitted (1101: Premier vibe motor conversion) and some new alternative spare parts that I have made. In the photograph below the motor speed control can be seen tucked away inside the top transom, and two new note cord hoop mouldings. The Two cord hoop mouldings I have made in bronze as opposed to plastic, so I will be very surprised if they ever break again. They are a little bit more expensive than the originals were, but the originals are obsolete and I have run out, but my replacements are far superior, but it is the unit cost which has prevented me from replacing all of them.

wpid-wp-1444982950273.jpg

wpid-wp-1444983593240.jpg

Premier 751 Vibraphone (part 1) (Job No: 1279)

wpid-wp-1439540643965.jpg

Here is a Premier 751 Vibraphone in a bit of a state, sent in to me to be made usable.  Whenever I get an instrument like any of the Premier 7 series vibes, I always ask how the instrument used.  This is because I have invariably seen the same model instrument many times before and have a good knowledge how they break.  For example, the resonators on the 751 (or 701) vibraphone are fixed in two points at the low end, but at the high end there is no mechanical fixing, they simply rest on a transom.  Using gravity is fine on most instruments for holding resonators in place because of their mass, but to then expect gravity to be a structural component of an instrument’s design and resist the much larger forces of motion and mechanics is simply ridiculous.  And yet I see it used all the time, by every manufacturer and even overlooked in most renovations, which is how I have come to the conclusion that either nobody knows what they are doing, or that they are making things to fail to generate future income.

So to get back to this vibraphone, what has resulted is that when viewed from above, the frame has become rhomboid and when viewed from the front it has become trapezoid.  If this frame distortion is ignored, the instrument will eventually just die, but with a simple sub frame the problems can be rectified.  The frames I make have a life time guarantee, that’s my lifetime, not the life time of a product (which is up to the moment it breaks), so essentially they are extremely strong, strong enough to be used to pull a frame back into alignment as opposed to just retaining it in a distorted shape.  Alignment of an instrument is very important for longevity, especially when there are moving components like on a vibraphone.

wpid-wp-1439540573975.jpg

Everyone has a method of working, I start at both ends; from the ground up and the top down.  What I am doing is working from the known points and verifying that those datum lines are correct.  By the ground up I mean the contact with the floor, and the top down is the players interaction.  In order to get fit a subframe to Premier vibes it is necessary to remove the two lower transoms, this makes it easier to also fit new casters.

Another constantly recurring problem with most percussion instruments is the material used to make the frame out of.  Aluminium is used because it is “light weight”, but it only saves weight if the component is designed properly to overcome its low strength, mostly manufacturers just use more of it to add strength which is expensive and heavier than steel.  Premier have deviated from the norm and actually used an extrusion; all the little grooves massively increasing the components bending resistance.  Where the casters are bolted on, Premier have even used the plastic end cap as an internal support to the tube to resist the tube crushing and wear on bolt holes.  In fact on most of the Premier vibraphones I see, it is the steel note rails and not the aluminium that is visibly bent.

However, the problem I encounter when modifying an aluminium frame is holding the fixings in place.  To simply drill a hole and put a steel bolt through is never going to last; the aluminium extrusion will compress introducing a gap, therefore movement, and therefore wear on the holes thus rendering the whole exercise a complete waste of time, effort and the customers money.  This means that I have to make a whole range of subsidiary components to support the bolts which will affix the proposed frame modification, which takes careful thought, time and always some compromises to keep the ultimate cost down.

wpid-wp-1439966437451.jpg

The final subframe looks very simple, but it is doing many jobs:  It holds the four casters parallel to the ground, fixes the width of the instrument, pushes the back two casters outwards to remove the frame twist, pulls the frame back square so that the note bed is horizontal, and holds it there during use of the damper pedal, and finally it increases the structural strength of the whole vibraphone so that it can withstand being wheeled around the buildings where it lives and is played.  Like all my solutions, I use the minimum number of wing nuts to reduce the players time when setting up or packing down; three nuts and the legs can be folded away.  The only downside is that one has another component to carry, but only because I retained the original pedal bar to save money.

wpid-wp-1439967306938.jpg

With the frame problems now rectified I turn my attention to the next area, and look at the damper bar.  It is immediately apparent that there is a problem – one of the leaf springs has broken.  They always break, the constant bending work hardens the steel making it increasingly brittle until it snaps.  The thread in the plastic ball is stripped, and the ball is cracked.  The felt is more like carpet than felt, and the bar itself is bent.  Each of these problems can be repaired, but then you would still be left with an ineffectual damper system which has components that are prone to failure, and that is not what my customers want back as a completely refurbished instrument.  Additionally my aim is always to return instruments that will give years if not decades of use.

Having made a new damper system recently on another vibraphone (1260: 701 vibe damper (pt 2)), it was a good opportunity to repeat the process.  I am constantly reviewing how I do things and looking for improvements, or developing methods to make the process quicker and cheaper without compromising quality.  This was no exception, I tweaked a few aspects of the design and the construction but essentially it is the same as before.  By increasing the width of the bar I have increased the surface area of the note in contact with the felt which results in much better damping.  On an operational level, because the bar is hinged, and because I have designed it, there is minimal horizontal travel as the bar travels through its arc.  The original design, because of the leaf springs, shifts left to right as the bar is pulled down and up; this lateral movement not only drags the notes around, but from a musical perspective it creates woolliness in the damping.

The original Premier damper system, is an ugly, inelligent and inefficient design solution that I would never have been happy with, but that is essentially my gripe with most instruments and all of the brand manufactures; they put into production badly designed products which are then made cheaply and badly, and endorsed by high profile musicians.  Even worse, a high profile musician “designs” and markets a new instrument.  Whilst musicians know when they are playing on a nice instrument, they generally have very little idea as to what makes the instrument good besides the obvious.  I have spent decades learning about materials, mechanical engineering, acoustics, etc, and I have more questions than ever.  It’s like the drummer that wants to be a front man – the musician that wants to make instruments.  Why don’t they start with something easier to understand and simpler to make like a violin or a guitar for their private enjoyment?

This repair continues in 1279: Premier 751 (pt 2)

Premier Tubular bells (Job No: 1277)

Moving parts by their very nature will always cause problems, especially so if they are not regularly serviced or designed and made badly.  This is the case with these Premier tubular bells.  In defence of the customer, there isn’t actually anything they could have done in particular to have prevented the noise produced from the damping system.



As seen clearly the noise problem in this tubular bell damping system arose mainly from the choice of materials; the wooden dowel. In defence of Premier they have economic constraints; everyone wants to spend as little as possible on musical instruments, so for Premier, and indeed any manufacturer, they have to shave off costs at every opportunity.  Wooden dowels are cheaper than ptfe rod, so wooden dowels are used; spending time to minutely check every component takes time which in turn increases production costs.  There is a solution however; the customer has to pay more – simple.  Whether initially they pay more to have a proper instrument made, or they pay more to have a cheaper instrument re-engineered, either way the only answer I see is the musician paying more money.  Ultimately you get what you pay for.

It could be worse however, and I have seen worse systems, at least I could work with what I had to silence the problems.  Other than the damping system, there were creaks that originated from the frame in general, these were removed by re-assembling the frame with a care and the usual attention to details.

Premier 701 Vibe damper (part 2) (Job No: 1260)

In 1260 (pt1), I looked at all the work I had to do before I could even start looking at the reason why this Premier 701 vibraphone had come in to be repaired.

wpid-img_20150428_155950.jpg

Having fixed all the issues with the frame and therefore I have an instrument that doesn’t continually change shape, I can put the notes on and define a centre line for the damper bar.

There are several different approaches used to control the movement of a damper bar; this system that I am making is my favourite.  It has the fewest number of parts to make, which means that it is quicker and cheaper to fabricate.  This also means that the tolerances (manufacturing discrepancies) don’t add up and become too great.  But above all that, it is the system that seems to go wrong the least number of times.

What I should say, is that I have no intention of replicating the system made by Premier and used on their 701 and 751 vibes.  The Premier design is actually quite neat, but it doesn’t really work very well, has an Achilles heel, and all the spares are now obsolete. 

wpid-img_20150428_163436.jpg

Back to the vibraphone.  Now that I know where the damper bar needs to be, I can make the levers around which it will rotate.  All of the manufacturers who use this system, fix the levers to the damper bar with screws.  I have used very thin wall steel instead of aluminium, so I have chosen to weld them on in position and have fewer parts to go wrong and end up with a more resilient design.  This is one major reason for choosing steel over aluminium, the other is that it is stronger.  Yes it is very slightly heavier than the aluminium the manufacturers use, but when that is substituted for aluminium stock that doesn’t bend in use, the thicker walled aluminium actually weighs more than the steel.  This is a common misconception about aluminium.



The connection rods between the damper bar and the pedal are always a bit tricky, both in design, where there is always a compromise, and in application.  The design problems are mainly concerned with ease of use when the vibraphone is being transported.  The issues in application are that they want to fall down towards the pedal exactly where the motor sits.  Therefore the positioning is also a compromise.  The actual method I use are simply tubes that have a telescopic rod that connects to the pedal.  This will be seen in 1260 (pt 3) when all the bits are back from the powder coaters and chrome platers.

Premier 701 Vibraphone (part 1) (Job No: 1260)

This whole job is a bit embarrassing, not for me, but for all the other people who have been associated with this instrument before it ended up in my workshop.  Most of all it is embarrassing for the man who bought as a birthday present to his son, discovered a problem with lack of damping, and ten months later the son is nearly another year older!

wpid-img_20150423_154938.jpg

I do have the notes and resonators, but as can be seen the damper bar is missing – taken to be repaired.  So the job is to sort out the lack of damping.

The damper bar on these Premier vibes is rubbish and now all the parts are obsolete.  Why anyone would go to the trouble of remaking parts to get a badly designed assembly to work is a mystery to me.  The main problem with the design is the leaf springs which work harden over time and snap like the top of a tin can when you wiggle it to get it off.  I could make new springs in an hour, but why make something that is destined to break?  Furthermore, because I don’t have the original damper bar I don’t know what condition the ball joints are in, or if the bar is straight which are the other major issues.

Immediately when the instrument was delivered I noticed a problem.

wpid-img_20150427_160010.jpg

The bottom bar which carries the pedal, and around which the pedal rotates, has been welded to the frame.  How could I resolve any damping problems if I were to ignore the point of operation?  First big question therefore is why the damper bar was removed for repair when the whole instrument should have been taken.

I know why the damper bar was welded into place.  As can be seen from the photo, several attempts have been made to sort the problem.  It’s unbelievably bad and so obvious only someone stupid would have failed to realise that the pedal acts against springs which therefore will try and rotate the tube.  So the two screws in the ends didn’t work because they have created a nice axle.

wpid-photogrid_1430294141180.jpg

The first thing to do is to make a new bar, because the only way to that one off is with an angle grinder.  Because the damper bar and springs slide onto the tube and are riveted in place the ends need to be both the same diameter of the tube and removable.

wpid-img_20150428_110324.jpg

I put flats on the under side of these caps which sit on a little square bar welded to the leg frames to stop the rotation.

wpid-img_20150423_172802.jpg

Whilst I was welding, I put mounting plates on for the casters – in the picture above it can be seen what the previous person did.

wpid-img_20150428_133620.jpg

The damping system will not work if the legs aren’t attached to the top frame or the frame to the note rails.

wpid-photogrid_1430297641776.jpg

The whole thing needed to be removed straightened and refitted, so that the top and bottom are now both solid, all I then had to do was join the two halves, except the holes don’t even line up.

wpid-photogrid_1430297818980.jpg

I think that the owner said that he bought the instrument from a school – I certainly hope that this is not the work of the metal work teacher, but I suspect it is.  As a digression, I applied to do teacher training in the early 2000’s, become a craft and design teacher; I was told that I was under qualified.  You don’t need a bloody degree to make something square!

wpid-screenshot_2015-04-29-10-03-532.jpg.jpg

That was hot, hard work!  Fire and brawn to pull the thing straight.  The frame that has been built (which actually needs to be binned) is massively heavy 6mm steel!  I would make a shelter out of this stuff and still guarantee it for life.

Finally I can assemble the instrument and begin to look at the actual damper bar which will be in 1260 (pt 2).

wpid-img_20150428_153742.jpg