Tag: overhaul

Slingerland Timpani (part 1) (Job No: 1247)

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Looking at the picture above I have a song running through my head, “Oh, what shall we do with the drunken sailor?”  Those stupid little bars to join the legs together, they will go in the bin!

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).

So before I get to the legs, I have to decide whether I need to raise the toe.

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In this case it is evident that the toe does need to come up a lot.  That is level, and the adjustable casters are at their lowest position.  With that decision made I can look at the legs.



What I did notice is how badly the castings were cleaned up (or not).

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Working on the mechanism is difficult because everything is riveted together, so these have to come out in order for the parts to be cleaned, inspected, etc.
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This post continues in 1247: Slingerland timp (pt 2)

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)

Premier Concert Timps (Job No: 1246)

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).

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So I did the usual process on this pair of drums: strip everything off the drum, so that whilst the castings are being welded I can work on the mechanisms.

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Then after the base castings are back and painted I can get straight into the rebuild and setup.  At the end of the rebuild, the bowls go in, and the heads are put on.  I usually do the counter hoops with the mechanism, so the bowls are the last thing I look at.

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Which is why it is so annoying when the PTFE tape is removed from the rim to reveal big bloody holes!

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As you can see above, these holes are deep, also notice how dry the glass fibres are (I’m lifting them up with the Stanley knife).  If you zoom in on the photo, you can see that there is a gap between the outer layers, and inner layers.  In fact, large areas were cracked and had to be removed, so the bowl ended up looking like this:

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So is this Premier not making the bowls properly, or customer damage?  Well it is a bit of both.  Yes it took a bit of abuse to actually break the outer layers into the void, but there should be no void in the first place!  If I had made these drums, even if, like these they were made in the mid to late 1980’s, I would repair them free of charge under “my lifetime guarantee” because they clearly were badly made.
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And finally, above is a very dusty, but repaired bowl.  Now I can finish the job and put the heads on, grrrr!

LP Xylophone Notes (Job No: 1242)

Out of the whole family of keyboard percussion instruments, xylophones suffer the most with going out of tune.  There are two reasons, first the note bars seasoning, second from being played.

Due to atmospheric changes wooden note bars absorb and release moisture, as the moisture leaves the wood, it takes a bit of matter with it, so the note will always go out of tune even if the instrument is not played.  However this is more evident in marimba bars which are wider, thinner and more extensively arched, whereas xylophone bars are more chunky and tuned to fifths, or should be, but more of that later.

When xylos are played, hard beaters are used, and these damage the surface of the note bar leaving indentations.  Therefore nothing harder than the note bar should be used to play it, so no hard plastic beaters if the piece has lots of fortississimo.  Furthermore the edges of the bars take a battering, and they become frayed.  When the bars are tuned, I have to remove this loose material, which further affects the tuning.  Eventually I run out of wood to tune the bars, or the internal structure of the wood has been softened or split thus killing the sound, so new bars need to be bought or made.

One last bit to finish off, there is a trend now in new instruments towards thinner bars which have been octave tuned as well as using cheaper woods like padouk.  Wrong, wrong, wrong!  Thinner bars don’t give the stacato sound of a xylophone, octave tuning just sounds wrong – a xylophone has a jarring sound, that is what it is for musically, and padouk is even more prone to damage and splitting.  So not only are they not xylophones, but more like piccolo marimbas, they will not last very long – years instead of decades!  Finally, because the bars are so thin, my job of retuning them is severely limited.

So lets get into the job.  First I get a plank of Honduras Rosewood that will do the job.

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This is then ripped to give me the width.  I got two lengths out of this plank which is enough to do all the notes.

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These batons are then cut down into the lengths required for the note bars, resulting in lots of sticks of wood.   I then plane to faces to get them flat and square.

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I can then thickness them to the correct width and depth.  I now have a pile of equally sized sticks of wood.

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The next job is to drill the holes for the note cord.  It takes ages to set the drill up so the notes are held in the correct place, and flat on the bed of the vice.  Getting the angle right is the easy bit (if you have the right equipment).  However once everything is set it is quick to drill all the sticks.

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I can now put the radius on the edges of the bars.

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Now I finally have note bar blanks which can be varnished and tuned.

Bell Frame (part two) (Job No: 1241)

The beginning of this post is 1241: Bell Frame (pt 1) which covers most of the work that was done.  Whilst the metal work was away being powder coated, the board was finished and varnished.  What I end up with, is a whole pile of bits to be reassembled on various instruments.

I was asked about the strength of the hinge and the boards flexing under body weight in a comment on (part one).  The main bar around which the whole step rotates supports the front edge of the forward board, and there is a steel brace to support the outer edge of that forward step.

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The new extension board has braces running across the width of the board both fore and aft.  These braces also provide the pivot points around which the legs rotate.

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Below is a short video showing how it all works.



Premier Concert Fibreglass Timps (Job No: 1237)

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).

This set is a bit of a mixed bag of types of timpani, but the fibreglass bowls need repairing which gave me the opportunity to try and explain what is going on a bit better.

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The knife is pointing at a little bubble in the rim of the timp bowl.





The other bowl in the pair also has problems on the bearing edge.

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After everything is clean and dry, they can be filled.





It can now be seen that the previous repair on the second bowl was also not right, it was a low spot on the bearing edge.  The filler I used is still visible sat on top of the old grey filler, which means that the grey filler was below the line of the rim.

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Bell Frame (part one) (Job No: 1241)

This is a height adjustable bell frame with an integral step that I made a couple of years ago. The concept was brought to me by a musician for me to design and realise. It has come back to have a modification made.

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The problem is the depth of the step; the playing position is too close to the bells. The only practical solution is for me to replace the solid board with two halves that open out like a book.

Now that I am satisfied that it will work, and more importantly, will solve the problem, I need to make some legs. Unfortunately I will need four legs so that it is a free standing unit; I don’t like the idea of standing on something with two legs and relying on the hinges to hold the other end.

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Above shows the four legs made, and work has begun on the diagonal braces.

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The new step made and tested – I jump on it as hard as I can.

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Like all of my frames, I make them as simple to use as possible. One wing screw needs to be undone to fold the legs in.

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The same wing screw now goes back, and holds the whole assembly in place for transportation.

The story continues in 1241: Bell Frame (pt 2)

Bell tree refurbish (Job No: 1240)

It is not uncommon for me to be given a box of bits with a request to make a usable instrument.

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As can be seen, this bell tree is on its last legs, or rather stumbling around drunk, spewing its bells and generally falling apart.  This is a nice job to ease myself back into work after the new year.

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Having removed all the bells I can repair the frame.  It’s the same old story; percussion instruments are designed and made by people who do not understand basic principles of applied forces, like leverage or motion.  As the top has bent in, the reinforcing corner blocks have acted as fulcrums to help pull the instrument apart.  This is compounded by the manufacturing technique which has used glue and nails.  As can be seen the back is being pulled off the nails (driven up through the base), which means that nails were the wrong choice, because they just don’t work in that direction.

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So I pull everything apart, remove all the nails, ready to rebuild it using glue and screws, because screws pull things together providing a mechanical connection as opposed to pinning in place, which is what nails are for.  The second reason for screws is that they provide a clamping force which means that the glue will work better (I also probably use better quality glue).

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Whilst the glue is drying on the frame, the next jobs can be completed.  First on the list is to straighten the rod.

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Next I polished the bells so that they look the part. 

There is only one sleeve in the box of bits, so I had to make another which will hold the bells in place at the top.

Finally I can reassemble, and finish the job.

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