It is a very clever design. If I were you, I might try all 2024 aluminum carriage with a total mass of about 40-50 g. I can hear more dynamics with aluminum headshell and carriage. Carbon fiber is somewhat muted. I also would increase the thickness of the headshell to 3 or 4 mm.
It's actually @niffy design I just copied it mostly.
In my setup the CF is not muted, I have incredible detail with silent background. On some pressings I can hear cutter head resonance/noise, changes in EQ mid song and over dubs. This carriage passes the sweep test, this is where I play a sweep with volume turned down and listen to the needle talk for peaks.
I will give your aluminium carriage idea a try. I have heaps of 6061 T6 off cuts to experiment with. I'm going to build a new LTA that pivots up for changing LP's to reduce the realestate the arm takes up, and this sliding LTA will be passed onto a friend who owns a Goldmund Reference with a faulty T3F so I'll need another carriage.
In my setup the CF is not muted, I have incredible detail with silent background. On some pressings I can hear cutter head resonance/noise, changes in EQ mid song and over dubs. This carriage passes the sweep test, this is where I play a sweep with volume turned down and listen to the needle talk for peaks.
I will give your aluminium carriage idea a try. I have heaps of 6061 T6 off cuts to experiment with. I'm going to build a new LTA that pivots up for changing LP's to reduce the realestate the arm takes up, and this sliding LTA will be passed onto a friend who owns a Goldmund Reference with a faulty T3F so I'll need another carriage.
Mike,
I don't have any ideas. However, the direct contact part of the headshell does make a difference. Here is a photo to show what I have experienced.
From left to right, 1, one mm brass with two mm magnesium. 2, two mm magnesium. 3, two mm carbon fiber with two mm African black wood. 4, four mm brass. 5, four mm African black wood. My personal preference is brass. However, brass is heavy. 2024 aluminum is nice, too. I also really like Audio-technica Technihard headshell. African black wood and carbon fiber do sound differently. Some may prefer them. In any case, I believe the best strategy is to mix different materials. For a carriage like warrjon's, I would use magnesium around the areas of the wheels. Magnesium is sound-deading material even more than carbon fiber. It may reduce the possible noise caused by the movements of the wheels. For counterweight areas, carbon fiber may be ideal.
It's not simple, we are talking material science and how sound energy travels through materials. This is the energy BELOW the resonant frequency Rf of the arm wand/carriage as below Rf the carriage/wand acts as a rigid beam, and at Rf and the harmonics of Rf it bends like a wet noodle, albeit microscopically.
For example if you bolt an aluminium body cartridge to an acrylic HS there will be about 46% of the energy reflected back to the cartridge and the reflected wave will be in phase. If you bolt the same cartridge to a carbon fiber HS there will be about 8% reflected energy and the reflected wave will be inverted.
So it matters a lot what the whole arm wand/carriage and cartridge body are made from as to how the system deals with this energy.
With a conventional one piece arm wand on a PTA i can visualise that description and the wet noodle analogy is vivid. however even in that set up, what would be happening in the separate head shell, separate analysis and noodle? Then, with our LTA's we have many separate parts each capable of resonating separately, is this potentially a resonance everywhere problem, or much less because they are each small and light?
I have read what folk have written about this and prefer the latter idea of course, but if there is opportunity for improvement its worth some thinking.
Back up at coating, Titanium Nitride, how is this done, can i easily get a hard smooth coating on the carriage rails as opposed to aluminium?
I have read what folk have written about this and prefer the latter idea of course, but if there is opportunity for improvement its worth some thinking.
Back up at coating, Titanium Nitride, how is this done, can i easily get a hard smooth coating on the carriage rails as opposed to aluminium?
As to TIN coating, there are several technologies to perform it. The best of them give extremely precise and smooth coating exactly following the surface of processed part. We may definitely call that space technology.
As for me, the question is, if to cover with TIN the average alluminum or steel arm tube, will it increase rigidity enough, and if yes -how thick the layer shoud be?
https://www.tincoat.net/coatings-offered/tin-titanium-nitride/
https://www.wallworkht.co.uk/content/tin/
As for me, the question is, if to cover with TIN the average alluminum or steel arm tube, will it increase rigidity enough, and if yes -how thick the layer shoud be?
https://www.tincoat.net/coatings-offered/tin-titanium-nitride/
https://www.wallworkht.co.uk/content/tin/
Every component has its own resonance, but of course it's a little more complex than that. When you fix 2 or more parts together like a removable HS on a pivoting arm the system has resonant frequency which will be different from each component separately. If the connection is sufficiently rigid the individual parts will resonate as a single unit. If the connection is not rigid then the 2 parts will resonate together as well as separately.
TIN coatings are used on machine tools to increase wear resistance they do nothing to increase rigidity.
The Technics EPA-100 for example with its titanium arm wand is NOT TIN coated. The arm wand is nitride hardened.
https://en.wikipedia.org/wiki/Nitriding
TIN coatings are used on machine tools to increase wear resistance they do nothing to increase rigidity.
The Technics EPA-100 for example with its titanium arm wand is NOT TIN coated. The arm wand is nitride hardened.
https://en.wikipedia.org/wiki/Nitriding
Warren. with machine tools there is no need to make them light. There is already enough rigidity without counting several micrometers of TIN. Tonearm tube is another case. The miniscule amounts of energy and stresses acting on the TA tube allow to hope and expect different outcome. IMHO it is worth trying.
As Henry Royce (of Rolls-Royce) said, "at the limit, all materials are rubber". Or wet noodle! "Rigid" is an inexact, and often unhelpful, term.
Hi Warren,
Nice looking carriage 😁.
Do you know what the total mass including cartridge and counterweight is?
Niffy
Nice looking carriage 😁.
Do you know what the total mass including cartridge and counterweight is?
Niffy
Hi Warren,
I couldn't agree more. This is why I designed my carriage as a single piece in a way that would mean that it would resonate at a single higher frequency.
TIN coating will have little effect on the bending stiffness of components such as an armtube, the layer is too thin. It may have limited effect in improving rolling resistance if used to coat softer materials for the wheels and rail. As the TIN layer is still very thin the modulus of the underlying material that supports it will still be the predominant factor in determining rolling resistance. TIN is for abrasion resistance rather than rigidity.
Niffy
I would both agree and disagree as to stiffness and rigidity of TIN. It depends only on the layer thikness, and who can stop us from ordering a thicker layer, let's say, of 20 micrometers, or even more? If pretty alike technology works for speakers (tweethers), why not to try? Finally a matter of coast and availability...
I haven't seen these materials before Mikey, but the cost, that's roughly the budget for a complete arm for me..............however, concerning other feedback, i cannot hear that carbon is making anything dull in my current construction, one of the difficulties is that its impossible (in my experience) to isolate a trial to say just carbon versus aluminium, because stiffness and weight and construction techniques go unavoidably with such a change and then one doesn't know the cause.
Are there any formulae giving at least guidance about resonant frequencies that you can steer me towards please? i could then at least try to estimate what might be better or worse, even if i cannot calculate absolute values..........for example i could consider the section of some parts if i knew what direction would be beneficial......
Carriage mass with CW is 54g without the 8g cartridge so 62g both.
The current Vee cups are M3 setscrews radiused and polished and I have ordered some Sapphire Vee cups. The pins are carbide this time not HSS.
Here are some Physics modules from Iowa State Uni that will give you a good understanding of sound propagation through materials.
https://www.nde-ed.org/Physics/Sound/index.xhtml
What price are you seeing? These discs are about USD25 each. I'm envious if that's your cost for tonearm materials!
Hi Mikey, the link showed a total of $101, so yes, I would certainly expect to build a complete arm for that. I do like the idea that good doesn't need to be expensive. I also don't have a lathe or a bench drill, so its all done with hand tools apart from an electric drill to take the hard work out of bit of grinding and polishing. I am sure some accuracy could be improved with some better tools, but the only thing i know would be useful that's expensive might be some bearing surfaces and finishes. the rest is mostly small and inexpensive, so experiments can be done without much cost
M
M