Category: Vibraphones

Bergerault Vibraphone (part 4) (Job No: 1214)

This post continues on from 1214: Bergerault vibe (part 3) and started with 1214: Bergerault vibe (part 1)

The inner two note rails are only supported at the high end of the vibraphone by a metal bracket.  Onto this bracket is also mounted the motor.
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Because I have increased the depth of the two outer rails this bracket no longer fits.
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So I just modified the design a little, and welded new outer supports in.  Now it will also be stronger, and certainly welding is a lot stronger than brazing which is how Bergerault make their instruments.  Welding is fusing two like metals together, so essentially it becomes one piece, whereas brazing uses a different metal to join the two elements, like glueing them together.
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Now this bracket is on, the top frame is rigid, all it needs is the motor unit.  Then I can put the legs on the vibe, and put the notes back on.
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It’s both satisfying and dissatisfying to see it all finished.  On the one hand it is good to see a finished instrument, especially when the job has been so involved.  On the other hand it looks just the same as it did when it came in, which is the point, but still I can’t really see any evidence of all the work I have done.

Bergerault Vibraphone (part 3) (Job No: 1214)

This post continues on from 1214 Bergerault vibe (part 2) and starts with
1214: Bergerault vibe (part 1)

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The above image shows my progress with the Bergerault vibraphone over the last three days, from the left; prime, undercoat, top coat.

This is the moment, before I put the new note rails into the instrument, to sort out any problems with the inner two note rails.

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Unsurprisingly, these rails were also loose.  Like the original outer rails, these also have a single tenon towards upper side of the rail.  This is supplement with a tiny bracket at the bottom.

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As Paul the Porter pushes the instrument at the top, there is greater friction at the wheels making the instrument rock from side to side.  The leverage exerted by the very long rails on four octave instruments is enough to break open a single tenon joint, especially if it is located at either end (top or bottom).  Again this is a design flaw; a demonstration of a lack of knowledge, forethought, and expertise.
I go to museums and see objects made literally hundreds of years ago that demonstrate the type of joint needed to resist a particular force.

Once the glue is dry on the inner note rails, I can then glue in the outer rails.

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If you look very closely at this end of the outer note rails, there are two holes.  This is an idea that I ripped off those museum pieces.  It’s called a pegged tenon joint.  Back in the day, they would have used a wooden peg, today I use a big screw.  This screw ensures that the tenon cannot be pulled out, and massively increases the strength of the joint – why wouldn’t I do it, it took less than five minutes.

At the end of the day, I will remove the clamps and do one final coat of paint so that it will be finished for the final assembly.

This post continues in 1214: Bergerault vibe (part 4)

Bergerault Vibraphone (part 2) (Job No: 1214)

This post continues on from 1214: bergerault vibraphone (part 1)

The timber I bought is European Oak.  I could have also used Ash, but that was not available.  Both are known for their structural rigidity as opposed to the original timber, which is hidden behind a plastic veneer, but looks to be African Mahogany which is a cheap easy to use timber, which is not known for its strength.

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After planing the timbers to size, I marked off the length and angles, to duplicate the existing note rails.

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Because I am doubling the depth of the note rail, I put a double tennon at the ends to go into the end boards.  This will massively increase the overall strength of the instrument.  These outer rails are the only joints that hold the whole instrument together, so they must be good (unlike how they were).

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Pictured above are the note rails with double tennons roughed out ready for the mortices to be dug.

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Once All the new mortices were dug, I ended the day with a dry assembly to expose any problems.

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Yamaha Vibraphone (Job No: 1200)

If vibraphones are moved around whilst set up, common sense would dictate that the pedal is raised up off the floor, so that it doesn’t drag along the floor and bend the adjustment rod.  Well that’s what this instrument was in for; a demonstration of how rare common sense is.

Furthermore Yamaha vibes have a detachable motor and control unit.  On instruments that live set up, like this one, this is an annoying feature.  The way the motor is attached is fine, that can be tightened in place, but the control unit just hooks over the note rail.  So whilst it was in my hands, I was asked to permanently fix it to the instrument.

However, as I was moving the instrument it became apparent that something else was wrong.

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The drawing above shows Paul the Porter pushing an instrument along, about to enter a room.  The force is being applied to the top of the instrument, however the wheels running along the floor have resistance in the opposite direction.  As Paul wheels the instrument through the door and consequently over the door tread, the resistive force increases further in a shock loading.  This is why instruments in general, including this vibraphone end up wobbling.

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As can be seen from the drawing above the movement on the instrument is greater at the top than the bottom.  The top frame, which is the note bed, is therefore being pulled apart.

The only way to resolve this situation, is to continue the destruction, in a controlled manner, until the weak link is exposed.

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On Yamaha vibraphones, as can be seem above, everything is pegged and glued together.  Which is fine, if it is designed and assembled correctly.  However if it is not, this self destruction is exactly what happens as the badly designed frame starts wobbling and all the screws work loose.

There is not much I can do within the remit of the job.  Ultimately, I would have to extensively modify the instrument making complete new sections.  However I can’t return an instrument that I can see is falling apart, so everything was glued and clamped back together.

Straightening the connecting rod between pedal and damper bar was easy.  For the speed controller I just made a little plate that went on the underside of the unit and hooked under the note rail.  Both of which I forgot to photograph.

Bergerault Vibraphone (part 1) (Job No: 1214)

These Bergerault four octave vibraphones are massive!  Even though vibe notes are made from aluminium, that doesn’t make them light, in fact the opposite is the case.  Percussion instruments are heavy, but vibraphones are particularly so.

The reason for this vibraphone coming into my workshop was because the butterflies in the resonators were hitting the underside of the note bars.  When I went to collect it, I spotted the probably cause, and verified it with my straight edge once back at base.

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Because the vibraphone is so big, it is hard to get it all in the photo and still see the issue when the notes are on, but after I have removed the notes it can be clearly seen that the instrument sags in the middle.

The first job is to remove the base frame, which are attached to the end boards.  It was at this stage that I noticed another potential problem:

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The little blocks that Bergerault have put in to hold the resonators, are wonky.  I will have to investigate this, because I also noticed that the resonators didn’t hang straight, they were pulled in at the bottom.  I suspect that this is a Bergerault design error, but it just seemed wrong to me.

Once the legs are off, I can now remove the High End board using the motor support bracket to hold the note rails.
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Next the motor and control unit are removed.  I will take the opportunity to improve this whole area which at the moment looks like a dogs dinner.

Finally the offending rails can now be removed from the Low End Board.  Classic understatement, I had to sit down and take a breather after I finally got them out!
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Now I am ready to make some replacement rails – time to go shopping for timber.

The story continues in 1214: Bergerault vibraphone (part 2)

Premier 751 Vibraphone (Job No: 1179)

A Premier 751 vibraphone in to have a service.  Particular issues are inconsistent damping and note sustain.

A quick look at the frame revealed no major issues, however the fan shafts were very noisy, so I started here.
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The Premier 751 Vibe is no longer made, so all spare parts are now obsolete.  When Premier stopped making this vibraphone, I was invited over to buy all the remaining spares.  Therefore if I don’t have it, then its unlikely that anyone else will – unless of course that they don’t do many of these very common vibes!

One of the problems with the fan shafts being noisy is the central bearing (pictured above).  In order to get this on the fan shaft (because it can’t go past the butterflies), the top of the bearing is sliced through, therefore it loses structural rigidity.  This becomes a real problem when it is forced into the resonators; forced because they were made a little bit too long, so they have to be bent to get them in.  The same thing happens at the low end, but there the bearing doesn’t have to be cut.  This bend creates a pinch point on the rotating shaft, and an ambiguity in positioning, this is where the noise comes from.  Thankfully because these spare have run out, I now have no option but to make a replacement, which means that I may as well solve the problem permanently.

First on the list of improvements is better material, I use a low friction nylon.  I would have used PTFE, but in
this instance it needs to hold a thread.  The originals are moulded plastic, so they start with a structure and add bits to the design for strength, because mine are cut from a sheet of material, I start with a block and remove bits where needed, but there is still a big increase in mass.  Therefore mine are way stronger than they need to be (which means that they should never need changing).

There is of course another benefit.  These bearings are now made when needed, and modified so that the holes are all aligned correctly so that the fan shaft runs true.  They are essentially matched sets.

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The central bearing is made in two halves and held together with machine screws, but all of the bearings have a little hole for oiling.  This is the complete opposite to progress – I have copied a concept used on vibes made in the 1930’s in the UK (where we invented engineering and are still unsurpassed), all I have done is used modern materials.

The only problem is that they don’t fit!  I went through several designs a few years ago, trying to make them so that would go in the space available, but they all failed.  Since then, I decided simply to increase the available space.  This means cutting the resonator tubes, and unlike every other time I have seen a tube modified, I remove the tubes from the set to work on them and not damage all the others.  It’s a no brainer!

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As can be seen above, I have increased the chord length of the cut out, and its depth.

Premier 751 Vibraphone refurbish (part 2) (Job No: 1205)

The first part of this blog is 1205: Premier 751 (part 1)

Looking at the pedal bar, shows one reason for the wobbly frame:
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This bar joins the bottom of the vibe together, and is the fulcrum around which the damper pedal rotates.  The two plastic ends have a locating peg inside a profiled end to suit the leg frames, the hole (pictured) at either end accepts a “J” bolt which is tightened to secure the whole frame.  As can be seen, the holes in the very thin walled tube get badly worn (on the left it is broken out, relying on only the plastic insert).  If the legs aren’t held in place securely at the bottom, there is obviously no chance that vibraphone will be stable.

The good news is this has inspired me to write a blog about my top ten bad designs. In which the Premier 751 vibraphone appear twice, because the second bad design concept is using the resonator tubes as a structural element.
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The front row of tubes form a diagonal line from the low notes to the upper notes, this diagonal can be utilised to make a triangle which are very strong.  Triangles are very strong, which is why they are seen on all of my frames, and why I give a lifetime guarantee (my lifetime).  The problem with the Premier 751 vibraphone is that the resonators are fixed at the high end (if you disregard the rubber band!), in other words the peak of the triangle is open, so its not really a triangle at all, and therefore not strong at all.

So, the non triangle combined with a badly attached bottom bar results in a frame that wants to wobble, and succeeds really well.  It’s a good job they came to me with it then, isn’t it?  What I have done is make a bar to fix the legs, thus creating a parallelogram – the notes rails, and the pedal bar being the two parallel sides.  A second bar hinged at the top of the leg frame, and fixed on the first bar creates my (integral) triangle for strength, and prevents the legs from going rhomboid.  Simple (but its how you apply it that makes the difference!)
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What I find annoying, is having to re-do other peoples repairs. This vibe had loads of issues, lots of little things that someone had made a dogs dinner of. For instance:
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Welding and soldering the butterflies on. Between the butterflies is where the fan shaft runs through the central bearing. Now it has welding marks, and filing marks, and guess what, now it has an annoying “tick, tick, tick, tick” sound as it rotates. I have spent the time to clean it all up, and it is nearly gone, but essentially the fan shaft is ruined.

Anyway, rant over. After repositioning the damper springs, that were put in wrong (in fairness, these were not of consistent quality as a spare part when they were available), and re felting the bar, and the notes cleaned, the vibes are done.

For the remaining time the vibes are sitting in my workshop, I bed the notes into the new felt. I leave the connecting rods off the pedal, set the damper bar high, and pull the notes down with a clamped beam.
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Premier 751 Vibraphone refurbish (part 1) (Job No: 1205)

This set of vibes needed a bit of tlc, or in other words a complete overhaul.

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There are a couple of issues that the customer specified that need to be looked into:  it’s really rickety and unstable, and the motor keeps snapping belts.

Whilst I was stripping the instrument down to service the parts, I drew up a long list of other problems.  Some faults I repair immediately, whilst other issues I put to one side to be looked at in isolation.

For instance:
The speed controller has been taken apart by someone and re-assembled incorrectly, so there was a bolt floating loosely around the main terminal block  which should be securing it.  Idiots!
The mains power lead going into the transformer housing has a slice through the insulation (on both the live and neutral (brown and blue) wires).

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Along with a couple of other issues on the motor wiring, means that the whole lot was removed to be looked at later, because whoever did it was trying to kill someone!

What I tend to do is overhaul the frame first.  This is both because it is big and takes up most of the bench, but also so that everything else gradually gets put onto it until I have a complete instrument ready to be checked.

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The photo above is looking down the length of the instrument at the low end.  You will have to zoom in.  I put a straight edge on top of it to show that it is bent all over the place.  This not only looks bad, but the deformation is primarily where the legs attach (probably one reason why the instrument wobbles badly).  Straightening this is a good job to do on a cold morning – I have a forming bar, a hammer, an anvil and a pair of strong arms…

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This never comes out perfectly, but it certainly gets close to straight, and once it is put back on the instrument, it will no longer be that noticeable.

The story continues in: 1205: Premier 751 (part 2)

Premier Vibe Motor Conversion (Job No: 1101)

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This is a replacement motor unit made for a Premier 751 vibraphone.  The on/off switch, and potentiometer are on fly leads so that they can be fit either side of the leg hinge, on the underside of the high end transom.  The grey box contains the speed control PCB, capacitor, and various connectors, with an IEC socket fitted so that the power cable can be removed.

The motor carriage is made to fit 750 & 751 vibes, but will probably fit older models.  Like everything I make, it has been designed to overcome problems that I have had to repair many times.  This carriage is not only strong enough to actually hold the motor, but will actually stiffen the note rails and their joining piece.

Locating the pot and on/off switch to the end frame avoids the normal difficulties experienced when bowing the notes, and the leg hinge will offer protection to the components during transportation.

The grey box is the brains.  The IEC socket was a moment of realisation during conversation with the customer.  By using a standardised socket as opposed to permanently wired, prevents straining or damaging the cable which occurs when winding it around the instrument, and makes replacement simple.  In fact finding a replacement cable on a gig is now simplicity; just borrow the cable one powering the kettle, or pc, or guitar amp, etc, etc.  Additionally, there is now no need for anyone other than myself to open that grey box!  Finally, there are two small holes on the side, the small one is the power led on the PCB, the larger one is access for the trimming pot which can be used to increase the maximum speed, so can be ignored.

To fit it, six holes need to be drilled, four for the motor carriage and one each for the pot and power switch. Then its just a matter of routing the cable.

Vibraphone Motor (Job No: 892)

Annoyingly the motor and speed control unit I had in stock just didn’t work. I had to design a removable motor unit for a vibe, and the motor assembly was at its core. To make matters worse the speed controller has been dropped by the manufacturer, so I now have an entirely new system to fit into an existing design. The final added layer of complexity is that I have to modify the new controller in order to achieve the same usability.

Having been shopping, I now have everything I need:
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