Tag: problem

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.

Calfskin Bass Drum (Job No: 1267)

The very first thing that needs to happen is to un-rope the drum and see what lies beneath.  The heads have obviously been causing a problem because on has been screwed to the shell.

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The job is now straight forward, but time consuming.  Whilst I am soaking a head until it is really wet and pliable, the drum shell can have the star marks removed – it looks like these were stickers, because it is the glue that has been left behind.

I also treat the bearing edge a process I have detailed in 1233: Vintage Bass Drum (pt 2).

With everything ready I stretched the head onto the shell using my drum press.  Because neither head had a collar I did one side first then the other.

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With the splicing and whipping on the rope redone, I rope the drum whilst it is still in the press to maintain tension.  It also saves a lot of hard work pulling rope as hard as possible and the subsequent suffering with blisters!

Slingerland timp (part 2) (Job No: 1247)

The first part of this post can be read in 1247: Slingerland timp (part 1), in which the base casting was overhauled.

Now the casting is back from being welded and has been painted and re-assembled.  The leg wobble has been corrected with larger bolts and spacers to ensure a tight fit.  I replaced the link bar between the two legs with a solid strip of steel so they cannot become untied whilst the drum is being moved.

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With everything reassembled it is just a matter of putting on a new drum head…

However, the drum head didn’t fit the counter hoop!  The cause of the problem (and two and half hours of my life being wasted) is because Slingerland made the hoop on the small side, and Ludwig mad the head on the big side.

I learnt at school that if you multiply the diametre of a circle by pi you get the circumference.  Now I work with circles all the time, and I know that pi equals 3.14159 off the top of my head (it is actually a lot, lot longer, but to 5 decimal places is good enough for me!), but many calculators have a button marked π.  So why is it seemingly impossible for major manufacturers to make a circle of the correct diametre?

So first I have to make as much room inside the counter hoop as possible by planishing the rivets that hold the lugs on as flat as I can.

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Then I have to squeeze the head in mechanically, and use a hammer and block to seat it against the surface of the hoop so it sits flat on the drum.  Just look how tight it is:

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For me this is just another example of how so many instruments are made by people who don’t understand how important these supossedly minor details are to the overall quality of the sound.  If a drum head is too tight in the counterhoop it chokes the sound.  As it happens I got the drum to sound great, which took a few tricks, but was an unexpected surprise (and a releif!)

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Adams Universal Timpani Problem (part 3) (Job No: 1243)

This post started with Adam’s problems (pt 1).

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So yesterday ended in frustration, meaning that today (yet again) I had to finish off that section of work before doing today’s work.

So the pedal had to be removed several times to be modified and get enough clearance for that nut.  The problem being that I didn’t want to remove that section of the pedal casting completely.

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This drum was the most difficult, which is why I tackled it first.  The other two were more straight forward, but still needed to be checked and tweaks made.
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So the new mechanisms are all in.  They are simple and effective.  The ball joint between both rods is the key, it compensates for any alignment issues between the base casting and the bowl.

Now the new mechanisms are in, the rest of the overhaul can be done which is straight forward on these drums.  After I have finished inverting the drums, the tuning guages can be looked at.  I did have to change the length of the linkage rod between the guages and the fixing point on the central rod because I had moved the fixing point higher up the drum (Obviously I had to shorten them).  What I noticed was excessive wear on the socket joints, so new sockets were fitted.

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Finally all the other rods joined to the spider and the heads can be put on.

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Epilogue.

It is unusual for me to put on clear heads, but interesting because you can see what is going on inside the drum when everything is up and running.  When the customer was collecting the timps, we were setting the heights, and we noticed that the legs foul the rods inside.

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In the photo above in the foreground is the guage with its link rod receding towards the central pull rod which is behind the leg.  Notice how the leg is touching the link rod.

My first thoughts were I had made a mistake, but after looking at each drum individually and thinking about it, I realised that I had inadvertently nearly (but not quite) resolved the issue by moving the central pull rod back and the guage linkage higher.  The mistake I made was the assumption that Adams had made things correctly.  If there is one cardinal sin in my work, it is to assume that things are made correctly.  This of course explains the excessive wear on the guage linkages, obviously whenever the legs are pushed into the bowl, they are bending things out of their way.

All in all, we were not impressed – another schoolboy error by one of the major manufacturers that I have to resolve.  This is why it takes time for me to overhaul timpani, the list of model specific problems that I rectify continually grows!

Adams Universal Timp Problem (part 2) (Job No: 1243)

This post follows on from Adam’s problems (pt 1).

So day one was mainly spent setting up the drums, and making the bottom blocks.  Today starts with finishing the installation of the other two blocks, before making more components.

The original central tuning rod has been removed from the pedal, and is now actually central held by a guide block.  So now I need make a secondary linkage to join that rod to the pedal.  I still have an attachment on the pedal, but nothing on the central rod, so this is where I start.

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Going through the photos, I take a length of brass stock and the rod end which will go on the end of the linkage rod from the pedal mark everything up and drill lots of holes in it.  (There are an awful lot of Rod’s around!)  After the smaller perpendicular holes are drilled, the pieces go in the lathe to have the longitudinal hole drilled.  The fixings holes are tapped, then the longitudinal hole is reamed to make sure it is round and will fit nicely on the central pull rod (There is only a 0.02mm gap all around so it will be tight).  Lastly the components are preassembled.

Next I make the linkage rod which is simple, I just have to run a thread on the end.

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Finally I can assemble the parts on the first drum and check that I have all the clearances, which I didn’t.

The problem is that manufacturers make product and forget that they are making musical instruments.  A lot of effort is put into making new ranges of more, essentially shit instruments, in an attempt to generate the desire to buy in a limited number of consumers.  Very little effort and value is put on the making and assembly of those instruments.  Cheap materials are used wherever possible, and because people are expensive, the cheapest possible labour is used.  So your pride and joy was probably assembled by monkeys, the dregs of society who get pissed at lunchtime and are still high the morning after.  They work for a wage packet, they don’t give a toss about whether the holes are right, it’s the near enough attitude, and near enough is not good enough to make something that makes musical noises.

So when the bowls are put on the cradles, they can be out of alignment by over an inch.  I can compensate, or remount the bowls with new holes.  I choose to compensate.  So in this instance I had remount the connection on the pedal, then make another rod, then further modify the pedal, then reassemble to check, disassemble, modify the pedal………………………..

The final part of this job is Adam’s Problems (pt 3)

Adams’ Universal Problem (part 1) (Job No: 1243)

The Adam’s universal timpani are good little drums, the best thing Adam’s make, but they do have one major problem.  The owner of these drums has decided to get me to rectify the problem.  So what is it?
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In a nutshell, when you change pitch with the foot pedal, it doesn’t pull in the centre.

The bowl sits in a cradle that has three legs and a pedal incorporated.  The pedal is a big lever that is attached at the back of the cradle.  The central pull rod is attached to this lever, which becomes a fixed point along the length of that lever.  As the lever moves, that fixed point travels through an arc, not just up and down, so in relation to the centre line of the drum, is moves forwards and backwards.  Furthermore, this fixed point is actually slightly to the front.  Neither of these things is going to give consistent tuning, and is a massive schoolboy error – but just see how many other makes of timps have the same issue, at least this make can be resolved.

In the picture above I am actually recording set up measurements so that the drums get put back together correctly, but it demonstrates the problem perfectly.   I have dropped a rod down the centre line of the drum, and I’m recording how far the spider is pulled by the pedal.  Looking closely, it is clearly visible how far from centre the original fixing point is by the size of the angle between the two rods.

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So what I do is to separate the central pull rod from the pedal by making a secondary linkage, but as you can imagine, it is a little bit more involved than that.  These posts are essentially one days work.

I need to take lots of measurements, which use lots of tools that have been made specifically for the purpose – so many tools that I need to do a job simply are not available.  For instance, below I am measuring how much vertical movement down the centre line I will get on the new mechanism.

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Once all measurements are taken and everything is removed from inside the drum, I can locate the centre of the bowl.

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My design fixes the central pull rod in the centre at the base, and guides it vertically with a guide block.
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The bowl is removed from the cradle and the base casting can be prepared and modified if needed to accommodate the new design.
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Now I can fit the guide block and reinstall the bowl ready to start work on the next stage tomorrow.
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The story continues in Adam’s Problems (pt 2)

…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:

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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:

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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 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)