Tag: universal

Adams Universal Timpani (Job No: 1263)

When I overhaul a set of timps, there is a lot of work involved over a period of days or even weeks. My approach is to fix everything properly; I am after all a professional and that is what I am being paid to do. However not everyone is as conscientious, and in the end, you get what you pay for. So when I work on timpani, I am fixing problems associated with wear and tear, and the dogs dinner that the previous person made of the job. The posts on timpani pick out examples of problems I encounter, rather than me writing, and you reading the same thing every time I do a set of timpani (which is why I have coloured this bit blue).

When these Adams copper universal timpani were brought in to be overhauled, the customer was complaining, amongst other minor issues, about the drums buzzing.  As soon as I heard the drums I knew what the problem was:

Adams universal timpani are built using the same method as Ludwig timps; the bearing edge is formed from a steel extrusion which is then fitted into the bowl.  In this case the bowl is made of copper, but the same process is used with their fibreglass timpani.  Fibreglass bowls are stuck to the metal ring with the same polyurethane resin (probably) used to make the bowl, however both Ludwig and consequently Adams have not used an adhesive but a mechanical fixing (pop rivets) to make the joint between a copper bowl and a steel hoop.  The big problem is that copper bowls are spun into shape, and there is always a discrepancy between the size of the bowl and the steel bearing edge hoop.  Spinning metal is a bit of a black art, so regardless of mechanical automation the size of the bowl will (and do) always vary.  Rolling hoops is also one of those things that is difficult to do exactly.  Therefore, this gap is almost bound to happen, so paper tape is used to fill the gap prior to riveting the bowl in position.

The principle of this method is a nice solution, but the application of the technique employed, by which I mean the use of packing tape, is not something that I would do.  Being brutally honest, I cannot give conclusive, evidence based, acoustic arguments as to why is it a bad idea, but my gut feeling (and experience?) makes me think it is.  There is a further problem of electrolytic corrosion – the copper of the bowl and the zinc plating on top of a steel hoop, are all joined with an aluminium rivet.  Now this isn’t a major problem, but why would you even introduce it into the equation?



The really bad creak on the 26″ timpani turned out to be in one of the tuning nut boxes.  This was difficult to find, and awkward to solve.  It is one of those problems that I will have to look out for when I do this type of timp in the future.

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)