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Author Topic: 3D Printed Reedblocks  (Read 2930 times)

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ChrisLDD

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Re: 3D Printed Reedblocks
« Reply #20 on: December 31, 2018, 04:54:17 PM »

A more practical question that comes to mind is whether this will adhere to wax as well as a wood reed block, or if you would use something else to affix the reed plates to the block.

Waxing reeds onto plastic was actually one of my concerns. It appears to work very well:)
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bellowpin

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Re: 3D Printed Reedblocks
« Reply #21 on: December 31, 2018, 05:15:17 PM »


Attached is a pic. of the bass reed-block.
It weighs 67g with an additional 14g used for the raft upon which it was printed.
 
the weight saving is impressive , if the structure is stiff enough for the purpose of reedblocks. with a" honey comb" type shape it seems that the strength is in the central spine ( which as to be thin to allow reed tongues to swing ), and the base ,joined at 90 degrees.  I wonder how much the aluminium reed plates add to the strength and stiffness.
     making the reed plate fit tightly into the block may help rigidity.  could you "print" a plastic block with a slot or trench in the base,that the edge of the reedplate  may sit in??  vintage concertina reeds fit snugly into a slot, though tapered.   can the plastic option have some sort of added value??   wood is cheap and strong,but not that stable in changing humidity.
  brian..
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IanD

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Re: 3D Printed Reedblocks
« Reply #22 on: December 31, 2018, 06:30:01 PM »


PLA is light, but it's certainly not strong or stiff in comparison with wood (neither is ABS) -- go and look up the material properties if you don't believe me, or try twisting one of the blocks and see how much stiffer a wood one is. Almost all non-composite (non-fibre-filled) plastic materials have the same problem -- wood has suprisingly good properties, or maybe not so surprising if you consider the millions of years of evolution that went into it...

I would certainly agree that the PLA would not come off as well in a 'twist-test', but I don't expect the reed-blocks in an accordion to be subjected to that sort of stress … and I don't believe that that's the whole story as to what would make something sound good.

I have a number of empty reed-blocks lying around my desk that I keep for reference, some wood, some aluminium, and now some plastic. They each have their own unique characteristics and associated sound.

My experience so far, is that the reeds I've fitted into the PLA reed-block sound surprisingly good.
And, oh yes ... prototyping is now a doddle!

It's not that they'd be subjected to that kind of stress, it's just the easiest way to see how stiff (Young's modulus) the material is. Received wisdom is that reed blocks (and fondo, and case) should be as stiff and non-resonant as possible (incuding cross-bracing) to prevent energy being sapped from the reed -- maybe PLA is OK not because it's stiff (it isn't) but it has internal damping (loss) to suppress any resonances?

3D-printed blocks would seem to make it easy to try out different shapes, especially ones that can't easily be made with conventional materials -- or at least, they would if only they didn't take almost a full day to print... :-(

Having concertina-like slots for reeds might work or might not, the combination of PLA being not very rigid and having a tendency to run away from stresses (creep) would probably mean that the grip on the reed would relax over time.
« Last Edit: December 31, 2018, 06:32:11 PM by IanD »
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IanD

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Re: 3D Printed Reedblocks
« Reply #23 on: December 31, 2018, 06:33:40 PM »

A more practical question that comes to mind is whether this will adhere to wax as well as a wood reed block, or if you would use something else to affix the reed plates to the block.

Waxing reeds onto plastic was actually one of my concerns. It appears to work very well:)

Probably because of the rough surface in 3D-printed PLA/ABS. Good news though :-)
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malcolmbebb

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Re: 3D Printed Reedblocks
« Reply #24 on: December 31, 2018, 07:14:58 PM »

The Chinese "Chansons" have plastic reed blocks - although quite possibly a different plastic. However, they take wax perfectly well.
They also have narrow ribs to locate the reeds, this might be more difficult on a printed block.
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Squeaky Pete

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Re: 3D Printed Reedblocks
« Reply #25 on: December 31, 2018, 08:21:50 PM »

The Chinese "Chansons" have plastic reed blocks - although quite possibly a different plastic. However, they take wax perfectly well.
They also have narrow ribs to locate the reeds, this might be more difficult on a printed block.

I would presume these are injection moulded in some kind of thermoplastic. Ideal for huge quantities and much more solid than printed blocks.
But for wood, if this is still considered, Accoya is phenomenally dimensionally stable.
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