A Woman’s Nightmare….

[Deleted Member 2]

Dat het vaker voorkomt betekent niet dat het beter werkt.  Zoiets als een poppetje in je auto voor geluk...

[Deleted Member 2]

Theo,

Het onderstaande artikel is gepubliceerd in het VinylEngine forum als deel van een reeks. Er wordt vaak gesproken over "turntable" omdat het tenslotte de core business van dat forum is. Het besprokene is echter generiek van toepassing en geeft een goed inzicht in koppelen (spikes) vs dempen (trillingsenergie omzetten). Het complete artikel is hier te vinden:http://www.vinylengine.com/turntable_forum/viewtopic.php?f=18&t=58779&start=14

Energy Transfer or Conversion - Coupling vs Damping

Since this is about turntables, it is very relevant to discuss the more general aspects of how energy can be transferred or converted. For our purposes here we will refer to each as coupling and damping. The terms are used often in different ways, depending on the application. I am not using these terms in any specific traditional or technical way. I using them as terms for this discussion to describe more broader aspects in physics. For clarity I will define the basic meaning in relation to our usage herein.

Definitions:

Coupling: The efficient transfer of energy from one point to another.
Damping: The conversion of energy into heat isolating one point from another.

First, let's talk about coupling. When two objects are in direct contact with one another any vibrations from one will transfer to the other, to greater or lesser degrees. This is dependent on the efficiency of the the surfaces involved to transfer energy between them. Many factors contribute to this efficiency; the properties of the materials involved, how similar the properties of each material are to each other, and any intervening material between the two objects. Coupling has many positive applications. For instance sending energy away from a place where it may do harm, or sending it somewhere else to be absorbed. However, coupling can be a bad thing. It may introduce energy from an external source to a place where you do not want it. With coupling this transfer of energy is usually bi-directional. Meaning when coupling is working well energy goes both ways, whether you want it to or not.

Damping is sort of the opposite, but not quite. You are still transferring energy. However the transfer occurs into an intervening material or device that takes that energy and absorbs it. This absorption occurs most often by taking this energy and converting it into heat inside the material or device. This conversion to heat occurs at a molecular level. Generally the material involved creates a "resistance" to mechanical energy. It doesn't transfer the energy between its own molecules easily. Various material have high resistance and some have a low resistance. Lead is a good example of high resistance material. Glass or steel are very low resistance materials. One material that has an exceptionally high resistance for vibration is Sorbothane.

The basic concepts for Coupling and Damping are depicted below.



Looking at this image you can see some very fundamental problems created by many popular held beliefs in the audiophile world. They are essentially backwards. The idea of putting gear on spikes does not do what is commonly believed. It will not for instance remove all the energy away from a CD player and transfer it to the shelf. Nor will it reduce it in the circuits or mechanics in a significant way. Any vibration in the CD has already shook the components before it gets to the spike. In addition, since energy transfer is bi-directional any vibration on the shelf is transferred into the CD player. People claim they hear a difference, and they very well may be. However, now they have their gear vibrating even more. So the sound may indeed change. I doubt it is really a good change.

I will diverge from turntables here and give some historical perspective. I will also show more of how people draw the wrong conclusions from something and then incorrectly apply those conclusions. And how these erroneous conclusions seem to always become "The Audiophile Laws of Physics & Faith".

The first use of spikes in audiophile applications came about from its use on loudspeakers. This was not done to decouple or couple the speaker as is commonly given as the reason for the improvement in sound. It was done to prevent movement of the speaker from the the inertia of cone movement, especially on carpets. See the diagram below.



Looking at the diagram you can see that what we are dealing here is not transfer of energy between to objects. We are dealing instead with Isaac Newton and his Third Law of Motion.

Newton's Third Law of Motion:

When one body exerts a force on a second body, the second body simultaneously exerts a force equal in magnitude and opposite in direction to that of the first body.

So if we look at the diagram we can see the loudspeaker on the left is sitting on a carpet without spikes. Of course as we all know, the speaker will wobble quite freely. When the drivers move the cabinet wants to move in the opposite direction, according to Newton's law. The loudspeaker cabinet movement is greater at the top of the cabinet and less at the bottom; its like an upside down pendulum. This movement changes the distance to the listener in a very tiny but significant way. The time alignment between the drivers varies and so does the phase relationships. This causes a smearing of the imaging. In addition slight Doppler shifts occur, ever so slightly shifting pitch up and down. And the degree of change is not consistent between the various drivers. Also energy is lost in pushing the cabinet.

By adding spikes the idea was to pierce through the carpet and have the cabinet being held firmly in place, significantly reducing this movement. Also using three spike meant the cabinet self leveled and distributed the fores equally. Again this improves rigidity and stability of the cabinet. The cabinet moves very little regardless of the forces involved. The audible result? The imaging tightens up as well as the bass response.

Somehow, along the way people began speculating as to the reasons why spikes improve imaging and bass response when used on loudspeakers. Not realizing the basic actual physics involved and why the spikes were incorporated, many came to the erroneous conclusion that the loudspeakers are now "better coupled to the floor". They thought they were reducing the affect of issues like cabinet resonances, changing 1/2 space coupling and a host of other incorrect theories. So these erroneous conclusions led to more bad theories (and exploitation by manufacturers). The idea became if it works for speakers using spikes or hard things on everything in audiophile land should reap the same benefits. However this idea was based on incorrect conclusions based on speculative and subjective reasoning. When in actuality the physics says what was needed in these other applications was instead isolation ... damping.

So when you are tempted to go out and drop $50 bucks on some Myrtlewood blocks or $250 dollars on gold plated spikes to "isolate" your preamplifier, apply the actual physics and think again about these theories. Do you really want to transfer all the vibrations in your house, coming from your other equipments power supplies, that truck going by in the street and your loudspeakers and couple then directly into your preamp? Simply because someone claims it will improve your imaging because of coupling (or even claiming decoupling). Hmm ...

The Control of Energy In Turntables

Understanding the movement of energy and applying that knowledge correctly in a turntable design is extremely important. There are times when we want energy to "flow". Other times we want it to go away as much as possible. So the selection of materials and especially the combinations of the same is tantamount to a well performing turntable.

In modern turntable design there seems to be a trend in building tables that use a great amount of coupling. The idea is to transfer vibration away from the stylus/groove interface point. This is good thinking, but how that is accomplished is varied and so do the actual results. A very common idea is to couple one thing to another and hope the energy will be absorbed.

Take the case of a turntable like a Rega RP1 or other similar designs. Here you have a tonearm coupled directly to a slab. Also attached to this slab is the platter bearing. The idea is all the vibration, all the forces in the tonearm and the noise from the platter bearing are to be coupled to the slab. Also the slab is coupled directly to the shelf or stand by spikes. So the energy is then supposed to go out of the turntable from the slab into the shelf or stand. Does this work? You'd think it would by the common audiophile belief system. However, (and here's the catch) the mass of the slab is too low and the materials used in it do not present the correct resistance to vibration. Instead what happens is the bearing noise is transferred to the tonearm. The energy from the tonearm goes down into the bearing. In addition any vibration from the shelf transfers up into the slab. As a consequence of this "Coupling Gone Wild" you get a crazy hedonistic party of vibration from every which way.

This is why you hear about so many after market isolation products for Rega tables. However these tables are popular. Why? Because of the widely held belief amongst many, who heard about the wonders of coupling. If spikes work on speakers "because of coupling" it must work on turntables (and everything else). Sadly using coupling in this manner is actually counterproductive for sound and music. And the ideas are drawn from the incorrect conclusions made from the aforementioned loudspeaker application.

In reality a balanced approach would be to use coupling and damping in concert to achieve true control of vibration, noise, resonances and other forms of mechanical energy.

Some Specifics on Resonance and Vibration

Vibration can be induced into an object. Resonance is where an object wants to vibrate at a specific frequency as result of its mass and shape.

My new girlfriend heard me talking about resonance and vibrations. And she made reference to some rap song from some rap guy I never heard of. How it makes her vibrate and her resonance is when she's dancing! She has a twearking video on YouTube demonstrating her good use of physics. Newton would be proud. A body in motion and all that. God .... I love that video. I watch it sometimes when she's at work and I'm lonely. She's so hot. Hmm ... she's in the living room reading right now. Be right back ...

[walks into living room] Heeeey babydoll! What's up! I was just online writing about vibrations and I thought .........

Ok ... I'm back now. I feel more ... umm ... relaxed! And no ... I'm not giving anyone the link to YouTube, darn it!

Anyway ... Controlling resonances and vibrations in tonearms is a complex issue. One poster in the thread asked about a number of issues with tonearms (eight to be precise). Some are very relevant to our discussion in this particular post.

First let me clarify something I said about fluid dampening in a particular tonearm in my first post. This was relevant to the fundamental tonearm resonance (which I will refer to from this point on as "Fr"). I said that using fluid damping does not change the Fr. This is not totally accurate, it does lower it very very slightly (about 1 or 2 Hz). However, fluid damping does not make it possible to use any compliance cartridge on this one tone arm. The Fr phenomenon still exists and one needs to know the arms effective mass to calculate it properly. The fluid damping does one important thing, it does increase the damping factor in the cantilever/armature mechanism of the cartridge. However this is really most important in a high compliance cart with low mass arm type setup when you are using low tracking forces. In this tonearm however the idea, badly implemented, is supposed to stop Fr from occurring. This it cannot do without first changing the laws of physics. What it does do is mask some tracking problems by damping vertical movement in the arm. The arm is a badly designed and fiddly uni-pivot. To keep it somewhat stable the damping was added (instead of designing a proper uni-pivot or a normal bearing). But they can't say that so they came up with this bogus explanation for it being there.

So what is fluid damping anyway? It is using a viscous fluid to absorb energy. It can be performed at a specific rate by using a fluid of a specific viscosity. It can be done simply with a cup and a spoon. Put some viscous fluid in a cup and move the spoon around. The more thickness the fluid has the more resistance is presented to the spoon in the direction it is moving. This is a form of damping. Take this example in miniature. Imagine a tiny "spoon" attached to a tonearm, with a tiny "cup" with thick fluid in it. It is easy to visualize how this could dampen resonances or vibrations in tonearm. It is used in some designs for a variety of damping applications.

It is also used in turntable suspensions as well. The Oracle Delphi MKVI, for instance, uses little cups and spoons to dampen lateral (side-to-side) movement of its sprung suspension. Other designs use fluid damping in other ways. However, the shape, size and orientation of the "spoon" and the precise amount of viscosity of the fluid are critical for the specific application. It makes using this damping scheme difficult to calculate (yes ... there are ways to calculate this and the formulas are complex). It is even more difficult to use the trial and error methodology. While it works in variety of application, it is very difficult to design. It can also be very messy for the end user. "Honey, I got turntable goo all over your new carpet!"

So are there easier ways to achieve damping and coupling in tonearms. Of course there is. Let's talk about tonearms resonances and vibrations and some ways to control them. First I should point out there are certain resonances that are not avoidable, like Fr. However, we need to control it. In this case putting Fr in a range where it has the least amount of negative effect on the sound or function of the arm/cart system and the phono stage. This is why it is important to match the right compliance cartridge to a tonearms effective mass. The combination of the cantilevers stiffness combined with the mass of the cartridge (and hardware) and the effective mass of the tonearm, combine together to produce a single frequency or note of resonance. By doing the math, you can put the system into resonance in a range of frequencies where it doesn't cause problems. This happens to be between 7hz to 10Hz for the most common tonearm cart combos. These things will always resonate when brought together, but by careful math and understanding you can control these resonances where they end up doing little harm.

As I mentioned earlier, coupling can be varied by materials. By combining various materials you can contour the amount or type of energy transfer, like down the length of a tonearm. Tonearms are funny things. You don't want them to vibrate yet you want to be able to transfer the energy created by the stylus away from the cartridge. So you need the best of both worlds. Damping and coupling. It's a delicate balance. One way it can be achieved is to use different materials along the length of the tonearm. For instance, a rigid aluminum cartridge mount connected to carbon fiber wand, attached to another pieces of aluminum at the pivot. This can in effect control vibrations and at the same time transfer energy down the arm and out through the bearing. This is accomplished by controlled transfer. Meaning there is a transition between different materials which changes the speed at which energy travels over time. In physics this described as a materials mechanical impedance. These abrupt changes prevent specific resonances from being setup, while at the same time still moving energy away from the cart. In a way, this is using less than perfect coupling to produce a certain amount of damping. Creative, eh? The Graham Phantom II and the Origin Live tonearms use this principle to good effect.

The shape of the arm wand can have an impact as well. As I mentioned early in this section, the mass and shape of an object helps determine its fundamental resonance, the note it naturally vibrates at. Think of a vibraphone key. A straight rectangular hard bar that when struck excites into resonance at a particular note. Because of its non-varying shape and consistent mass over its length it produces a very pure tone or frequency with few harmonics or overtones. Objects can also resonate at a numbers of notes at the same time, simply by changing its shape. Take a bell. For the most part it is a straight cylinder, but then flares out at the bottom. It has a primary note or frequency produced by the straight cylinder, but the flare is added to give it overtones; extra notes in addition to the main one. However if you make it perfectly conical it doesn't seem to want to make much of a sound at all. That is because over the length of a cone the mass and size continuously change therefore no specific resonance can occur easily (except over its length).

A tapered arm wand, like you see on some straight wands from SME, work to vary the speed of energy transfer and the reduction of resonances by changing mass along the route. The narrow end of the taper has lower mass, the wider end has more mass. And this change in mass increases linearly, it is different at every point as you go down the length of the wand. They tend to not resonate at any given frequency. Yet they manage to move energy well.

Curved arms are supposed to do the same thing, however in actuality the effect of curvature has only a small impact in controlling vibrations and resonances. It was utilized years ago when there where much fewer choices in materials compared with today. So back then it was an improvement. Today it is unnecessary. Curving an arm is not as important anymore in this regard because we have a wider range of materials that do a much better job on their own, without the need for curves.

One other note. Detachable headshells impede coupling and therefore have a tendency to reflect energy back to the stylus. This is why they fell out of favor. They have very pronounced negative affects on numerous aspects of music.

Tonearm Bearings and Coupling

A very important aspect in coupling is giving the energy somewhere to go, and an easy way to transfer it. We all know how things in nature tend to take the path of least resistance. Rivers do this. We all know about this in electricity and electronics in general. The same it true for mechanical energy. In tonearms we want the energy from the cartridge to go somewhere else or simply go away. An important way to accomplish this is by making sure the pivot or bearings be able to transfer the energy down into the mounts. The simplest most direct way to do this is by having rigid bearings (and enough of them) to transfer energy efficiently. However it must do this while offering the least amount of friction in the pivot. This can be difficult. The standard four point gimble bearings is the best type for transfer of energy, however they offer the highest amount of friction. Conversely, Uni-pivots offer the least amount of friction, but are very poor in transferring energy since all that energy must pass through a tiny single point.

So now this begs to ask a question that nobody seems to ask. Which is more important, friction or energy transfer? The answer is clearly energy transfer. Why? Let's look at some basic physics. Uni-pivot bearings are essentially a single point that is held in place by the force of gravity. The actual bearing point of contact is extremely low in mass, relatively speaking. This presents a difficult path for energy to travel through. So, what happens when energy is presented with a high mismatch such as this. Well ... a small portion does get transferred through the bearing. What is left over gets reflected back; to its source which in this case is the stylus. Oddly, this same energy after wiggling the stylus a little bit, now reduced slightly more, gets reflected by the stylus back down the arm again. Back and forth, again and again, until the energy finally does get dissipated by the mass of the arm. In physics this is known as a standing wave.

Now when we look at this mathematically we discover that the difference in friction between the best uni-pivots and the better standard four point gimble designs works out to be about 1% in frictional drag differential. The friction is so low in both designs as to have no negative affect in the working of the arm. However, the energy transfer differences can be as much as 40%, depending on how much damping is used in the uni-pivot design to kill the standing wave. And it is this standing wave of unused energy that creates unnecessary resonances and vibrations in the stylus that do have an significant affect on music.

This is not to say that uni-pivots cannot be designed in such a way to minimize these affects. Bob Graham worked on mitigating these problems for decades and seems to have tackled most of inherent problems in damping these standing waves and making a great sounding uni-pivot. However IMO, all these features that have made his arm famous are designed to correct inherent flaws in the uni-pivot concept. His designs works, but they are much ado about nothing. The problems he solved are problems that simply do not exist in other types of arms, only uni-pivot. The work would have been unnecessary had a more standard bearing design (nearly as frictionless with modern machining techniques) been employed.

There are also designs that employ both systems. These are commonly known as dual pivot designs. Basically you have a uni-pivot for your horizontal plane and a standard gimbled bearing for the vertical. Some designs have this reversed. It should give the best of both worlds, lower friction and reasonably good energy transfer. Origin Live uses this system. It seems to work well, IMO.

It should be pointed out that uni-pivot bearings are very easy to make. They also have very low production costs when made in the numbers for commercial distribution. I suspect this is why they are becoming so popular. However, Uni-pivot needs corrective solutions (which include more varied issues than what I so far have mentioned). If these corrective solutions, like those used in the Graham Phantom II, are not utilized then these uncorrected arms do not perform well. The truth is a standard gimbled bearing arm, made well, will outperform a uni-pivot that lacks sophisticated corrective technologies.

Mass, Materials & Physics - A Small Treatise on Absorption

The use of high mass to absorb energy is a well understood fact in physics. The choice of materials that have the right amount of mass and vibrational resistance for a particular type and magnitude of energy is an engineering science, to say the least. In current table designs the physics of this are just apparently being ignored in a vast amount of the designs being offered. However we hear phrases like "massive platter" or "high mass sub-chassis" or "massive bearing" bantered around quite a bit. All the while implying some amount of control over vibration and resonances. When one actually analyzes the materials and amounts of mass being employed, this control is simply either ineffective or inadequate. Some designs do it right.

We have looked at both coupling and damping and explored ways where one can create the other. The two are intrinsically connected in fact. When dealing with energy in turntables the two must always be given equal importance. One cannot control vibration simply with coupling, nor can damping be used exclusively. Mass can do both, it can transfer energy and it can dampen it. But not always at the same time. The choice of material and its inherent properties must be chosen for its combined coupling vs. damping properties. And this based on the function as well the interpretation with a given design aspect. For instance, if you want a plinth that absorbs energy, you simply could use a great deal of mass. However, in this case mass alone involves a surprising large mass to do the job. Large blocks of granite weighing in the high tens of pounds for example. Incidentally, in plinth designs in non-suspension turntables using MDF, the amount of mass required to absorb the same amount of mechanical energy as a block of granite weighing 40lbs works out to be about 240lbs of MDF. Imagine your Rega or VPI weighing in at 250lbs! So you get the idea.

So high mass cannot be seen as some panacea for energy absorption. From a practical perspective very few of us can live in our homes with turntables massive enough to be vibration and resonance free due to mass alone.



I think this is enough at this point. I did say I was going to touch upon suspensions a bit in this installment. However, upon reflection that is a topic more suited to other more specific topics. Where this post was meant as a primer for the physics behind these two very important aspects of turntables. Coupling and damping. We will see in more detail in the next post how these relate directly to all aspects of turntable designs and other important physics not yet discussed.

Stay Tuned,

John LeVasseur

[Hifi Addict]

Een duit in het zakje 
http://www.audiopoints.com/OLDSITE/proving.html
http://www.audiopoints.com/OLDSITE/coulomb.html

Maaruh Theo, hoe staat het eigenlijk met je dddac 

[twani]

Still need to start the project   Gaat echt gebeuren natuurlijk (anders gaat Monique de aanschaf van een zak met weerstandjes twv €450 nóg raarder vinden ) maar........... Het is mooi weer, collega's op het werk zijn op vakantie dus weinig vrije tijd, de tuinschutting moest ook nog worden vernieuwd.....  Enz enz enz.

Dat met dat koppelen/ontkoppelen is me nog al een verhaal op zich zeg   ik ga me beraden....

Dank allen maar weer....

[Hifi Addict]

Je wilt natuurlijk de omgevingstemperatuur niet nog verder opvoeren met die warme soldeerbout  Aan de andere kant, het soldeert wel makkelijker!!!! 

[Deleted Member 2]

Still need to start the project   Gaat echt gebeuren natuurlijk (anders gaat Monique de aanschaf van een zak met weerstandjes twv €450 nóg raarder vinden ) maar........... Het is mooi weer, collega's op het werk zijn op vakantie dus weinig vrije tijd, de tuinschutting moest ook nog worden vernieuwd.....  Enz enz enz.

Dat met dat koppelen/ontkoppelen is me nog al een verhaal op zich zeg   ik ga me beraden....

Dank allen maar weer....

Relax!

[AbZ]

Dat met dat koppelen/ontkoppelen is me nog al een verhaal op zich zeg   ik ga me beraden....

Henk heeft wel errug lang verhaal geplaatst    Verder niets mis mee imho,
maar de hoofdzaak is gewoon dat spikes niet doen wat men meestal denkt.

[twani]

En voor diegenen die denken dat het tóch niet gaat gebeuren..

[Kingpin]

@Onder013: mooi verhaal. Eigenlijk is het ook beter om je speakers te ontkoppelen dmv schuim. Auralex heeft daar mooie systemen voor.
Zelf gebruik ik deze voor m'n Velo sub, maar je zou het ook zelf kunnen maken.
Ook voor gewone speakers zowel monitoren als vloerstaandres is het beter om het op deze manier te doen ipv spikes te gebruiken.



Maar zo zijn er ook andere producten.

[Hifi Addict]

Ik gebruik(te) deze voor luidsprekers, aanzienlijk verschil: http://www.equarack.com/products.htm

[Deleted Member 2]

Eigenlijk is het ook beter om je speakers te ontkoppelen dmv schuim. Auralex heeft daar mooie systemen voor.
Zelf gebruik ik deze voor m'n Velo sub, maar je zou het ook zelf kunnen maken.
Ook voor gewone speakers zowel monitoren als vloerstaandres is het beter om het op deze manier te doen ipv spikes te gebruiken.

Met het schuim er tussen maak je geen koppeling met Auralex. Geen idee wat Auralex doet, maar als het om massa gaat waarin trillingen omgezet worden warmte (wrijving van de in beweging gebrachte moleculen) is het schuim een ongewenst obstakel.

Gr
Henk

[Deleted Member 2]

En voor diegenen die denken dat het tóch niet gaat gebeuren..

Dit is niet meer dan een verzameling electronica me*k. Zou een mooie aanvulling zijn voor mijn collectie onafgemaakte projecten....

Met opgewekte groet,

Henk

[Kingpin]

Met het schuim er tussen maak je geen koppeling met Auralex. Geen idee wat Auralex doet, maar als het om massa gaat waarin trillingen omgezet worden warmte (wrijving van de in beweging gebrachte moleculen) is het schuim een ongewenst obstakel.

Gr
Henk

Het schuim/systeem van auralex (bv ProPad) zorgt voor een ontkoppeling van je speaker met de ondergrond (ipv spikes die koppelen), het doet niets anders dan isoleren van de omgeving.
Hierdoor verkrijg je een betere soundstage en betere resolutie in het midden en laag.
Het is trouwens niet louter een stuk schuim maar bestaat uit delen waaronder een mdf plaat omhulst in melamine, daaromheen wordt het absorberende schuim aangebracht.
Auralex was maar een voorbeeld, gaat om het principe.

[Deleted Member 2]

Het schuim/systeem van auralex (bv ProPad) zorgt voor een ontkoppeling van je speaker met de ondergrond (ipv spikes die koppelen), het doet niets anders dan isoleren van de omgeving.
Hierdoor verkrijg je een betere soundstage en betere resolutie in het midden en laag.
Het is trouwens niet louter een stuk schuim maar bestaat uit delen waaronder een mdf plaat omhulst in melamine, daaromheen wordt het absorberende schuim aangebracht.
Auralex was maar een voorbeeld, gaat om het principe.

OK

[Kingpin]

Je kan nog een stap verder gaan door een echt 'zwevende' ophanging te gebruiken totaal los van de grond





Hierdoor heb je een totale verticale ontkoppeling.

[AbZ]

Hierdoor heb je een totale verticale ontkoppeling.

Ziet er geweldig uit 
  maar de ontkoppeling zal toch ook afhangen van het gewicht dat erop rust.
Dit is het probleem van alle kant&klare oplossingen (oa Auralex).

[Kingpin]

Ziet er geweldig uit 
  maar de ontkoppeling zal toch ook afhangen van het gewicht dat erop rust.

Meen dat het werkte tot 50kg.

Dit is het probleem van alle kant&klare oplossingen (oa Auralex).

Precies.
Vuistregel is volgens mij dat het materiaal niet meer dan 10% mag inzakken van de totale hoogte van het gebruikte schuim onder belasting om het beste resultaat te bereiken.

[AbZ]

Meen dat het werkte tot 50kg.
Precies.
Vuistregel is volgens mij dat het materiaal niet meer dan 10% mag inzakken van de totale hoogte van het gebruikte schuim onder belasting om het beste resultaat te bereiken.

Je zou dan de kracht van die magneten moeten kunnen instellen.
Anders is het toch 'gewoon' een veer die maar op 1 'gewichtsklasse' naar wens werkt...

[Kingpin]

Je zou dan de kracht van die magneten moeten kunnen instellen.
Anders is het toch 'gewoon' een veer die maar op 1 'gewichtsklasse' naar wens werkt...

Wbt de magneten is de werking altijd goed zolang ze maar geen contact maken, gaat om het principe dat er geen trillingen kunnen doorvloeien, zolang daar lucht tussen de magneten zitten kan dat niet.

[AbZ]

Wbt de magneten is de werking altijd goed zolang ze maar geen contact maken, gaat om het principe dat er geen trillingen kunnen doorvloeien, zolang daar lucht tussen de magneten zitten kan dat niet.

Die redenering klopt niet hoor.  Je raakt in de war door die lucht ertussen.  Als de ondergrond trilt/beweegt verandert de positie vd magneten en kunnen ze de zaak gewoon naar boven drukken.  Kan niet anders tenzij je echte gewichtloosheid hebt.

Je zult wel een soort luchtvering (weerstand) hebben en traagheid van het zwevende deel.

[Kingpin]

Die redenering klopt niet hoor.  Je raakt in de war door die lucht ertussen.  Als de ondergrond trilt/beweegt verandert de positie vd magneten en kunnen ze de zaak gewoon naar boven drukken.  Kan niet anders tenzij je echte gewichtloosheid hebt.

Je hebt gelijk, zal wel door de warmte komen
Vandaar de max 50kg.

[twani]

Nou, ik kan dus solderen   (ff voor mezelf klappen ). Ik ben al een aardig eind gevorderd met voeding nummer één, die van het XMOS board zullen we voor het gemak maar zeggen.

Zal nog een fotootje maken zo direct.

[twani]

Vast geen "vakwerk" vergeleken met de "tinnen soldaten" die hier op het forum ook aanwezig zijn maar volgens mij moet het er in ieder geval wel mee spelen

[Kingpin]

Goed werk zo te zien

[twani]

Het ziet er in het echt nog wel iets fraaier uit. De verbindingen glansen mooi.....