So you have just small piece of magnesium alloy interface between headshell and air bush? Interesting.
I am trying to go back to find some good picture of your assy,...
I will use powder coating on all alu alloy parts. It will add some additional damping.
Will use brass interface to connect headshell to carbon arm tube. What you think of brass interface parts in setup?
Zz
I am trying to go back to find some good picture of your assy,...
I will use powder coating on all alu alloy parts. It will add some additional damping.
Will use brass interface to connect headshell to carbon arm tube. What you think of brass interface parts in setup?
Zz
Nice setup Super,...
Though this interface would be so tiny and small ring i get your point about weight,...
but i still don't get how did you attach all this to air bushing
As you saw from my sketch i will make alu clamp in which will press and secure air bush with a grub screw, then will press fit arm tube in clamp (and all other parts)
Zz
Though this interface would be so tiny and small ring i get your point about weight,...
but i still don't get how did you attach all this to air bushing
As you saw from my sketch i will make alu clamp in which will press and secure air bush with a grub screw, then will press fit arm tube in clamp (and all other parts)
Zz
I must admit that it is not elegant solution at all
So what is the final weight of your assy?
Zz
The most elegant solution to a problem is normally the simplest. Gluing the headshell directly to the bearing case is super simple. Not only does glue minimize mass and allow lower pivot point it also allowed Jim to minimize arm length. The bearing already has an aluminium case, I don't think it needs another.
Niffy
Niffy,...
I highly respect your excessive knowledge behind tonearm and moving stylus science. I am still reading your posts in awesome Colin thread about DIY linear tonearm and enjoying your meticulously written posts on subject and learning from you guys, and saying that i must admit that a lot of this stuff is still beyond me so to speak,...but,...
being engineer and machinist for 25 years in motor vessel sector (small boats and trans ocean one) i saw on numerous occasions glue of any kind (being epoxy,polyester,vinilester,methacrylate,cyanoacrylate) fail under certain load condition or fail with no load condition just because bad surface prep and with aging in time.
More of that i am avid rc model builder whole my life (RC gliders,planes, helicopters, boats, sailboats, cars,..name it, so i know when even best epoxy out there fail from any of reasons possible,...
Furthermore i thought initially that interface between cartridge and mass of the carriage (and air bush) must be firm and stiff to ground any resonances which may occur in grove tracking. Now i can see from Jim pics that it would be hard to press these two complex shape parts to achieve good bonding in between
Or maybe i am wrong completely and let stick glue everything. it is easier
Cheers
Zz
I highly respect your excessive knowledge behind tonearm and moving stylus science. I am still reading your posts in awesome Colin thread about DIY linear tonearm and enjoying your meticulously written posts on subject and learning from you guys, and saying that i must admit that a lot of this stuff is still beyond me so to speak,...but,...
being engineer and machinist for 25 years in motor vessel sector (small boats and trans ocean one) i saw on numerous occasions glue of any kind (being epoxy,polyester,vinilester,methacrylate,cyanoacrylate) fail under certain load condition or fail with no load condition just because bad surface prep and with aging in time.
More of that i am avid rc model builder whole my life (RC gliders,planes, helicopters, boats, sailboats, cars,..name it, so i know when even best epoxy out there fail from any of reasons possible,...
Furthermore i thought initially that interface between cartridge and mass of the carriage (and air bush) must be firm and stiff to ground any resonances which may occur in grove tracking. Now i can see from Jim pics that it would be hard to press these two complex shape parts to achieve good bonding in between
Or maybe i am wrong completely and let stick glue everything. it is easier
Cheers
Zz
Super10018, Niffy, Oberon and a lot other members of this DIY forum
I am full of admiration by the craftsmanship, devotion and level of skills that you guys are showing, and I am very envious, as my own mechanical skills are sadly lacking.
Nevertheless I am puzzled by the fact, that no one have overcome (or perhaps even thought about) an obvious problem in these designs, namely the looong and , to a certain degree, uncontrolled air tubing and tonearm wire.
I am in the process of making a proof of concept version of a solution to this , consisting basically of parts from a couple of salvaged DVD drives.
What I am doing is , I have made a sledge that runs over the main bearing on two rails and have two Photo diode/photo transistor gaps (from a salvaged PC mouse ) that detects the position of the main bearing relative to the sledge. This in turn controls the moving of the sledge (DVD drive sledge motor) so the sledge is always very close to the main bearing. The sledge carries the air tubing and tonearm wiring with some advantages here such as no drag on the main bearing, no loong unshielded tonearm wires and no problems with uncontrollable forces on the long tubes wires (wind pressure from opening doors etc.)
On top of that, the sledge doubles as detector of where the needle is relative to the record (grooves) and has tells the lift mechanism to raise or lower the lift accordingly. The sledge grabs the tonearm when the lift is engaged , so the arm will be completely automatic, of course with manually overide.
Sorry if there are obvious pitfalls to this , I have been overlooking, in that instance, please bear with me.
I am full of admiration by the craftsmanship, devotion and level of skills that you guys are showing, and I am very envious, as my own mechanical skills are sadly lacking.
Nevertheless I am puzzled by the fact, that no one have overcome (or perhaps even thought about) an obvious problem in these designs, namely the looong and , to a certain degree, uncontrolled air tubing and tonearm wire.
I am in the process of making a proof of concept version of a solution to this , consisting basically of parts from a couple of salvaged DVD drives.
What I am doing is , I have made a sledge that runs over the main bearing on two rails and have two Photo diode/photo transistor gaps (from a salvaged PC mouse ) that detects the position of the main bearing relative to the sledge. This in turn controls the moving of the sledge (DVD drive sledge motor) so the sledge is always very close to the main bearing. The sledge carries the air tubing and tonearm wiring with some advantages here such as no drag on the main bearing, no loong unshielded tonearm wires and no problems with uncontrollable forces on the long tubes wires (wind pressure from opening doors etc.)
On top of that, the sledge doubles as detector of where the needle is relative to the record (grooves) and has tells the lift mechanism to raise or lower the lift accordingly. The sledge grabs the tonearm when the lift is engaged , so the arm will be completely automatic, of course with manually overide.
Sorry if there are obvious pitfalls to this , I have been overlooking, in that instance, please bear with me.
Koldby,...
There are some places on the net i saw such proposal to servodrive tube and wires, but as it sounds great and it would be probably, if you manage to make it, it is, at least for me, complicated to achieve and we all want to keep it KISS as long as it is possible and doable (well sometimes i overly complicate my projects but it is in my nature by default)
I saw Kuzma airline on action, and other Kuzma products as well I am Croatian guy and my gf lives in Slovenia just half hour from Kuzma. I was there last week but i doubt that there are some great sonic disadvantages to drag this tube and wires some 4cm left and right from center of recorded material on record.
Anyway i would like to see your device for sure
Cheers
Zz
There are some places on the net i saw such proposal to servodrive tube and wires, but as it sounds great and it would be probably, if you manage to make it, it is, at least for me, complicated to achieve and we all want to keep it KISS as long as it is possible and doable (well sometimes i overly complicate my projects
but it is in my nature by default)I saw Kuzma airline on action, and other Kuzma products as well
I am Croatian guy and my gf lives in Slovenia just half hour from Kuzma. I was there last week but i doubt that there are some great sonic disadvantages to drag this tube and wires some 4cm left and right from center of recorded material on record.Anyway i would like to see your device for sure
Cheers
Zz
Koldby,...
There are some places on the net i saw such proposal to servodrive tube and wires, but as it sounds great and it would be probably, if you manage to make it, it is, at least for me, complicated to achieve and we all want to keep it KISS as long as it is possible and doable (well sometimes i overly complicate my projects
I saw Kuzma airline on action, and other Kuzma products as well
Anyway i would like to see your device for sure
Cheers
Zz
I have some experience in air bearing and wire drag and problems with long runs of very thin unshielded tonearmwire, where the thinness of the wire was first priority and not sonics. I was importer of the original Maplenoll Air bearing record player (platter airborne too) in Denmark for many years. It is not so much the +/-4cm movement, but look at the length of the wires and tubes in order to minimize the drag from the +/-4 cm movement required. I can tell you that the mechanical work on the tonearm itself is much more complicated and requires much more precision than the sledge. Maybe it is the electronics that scares people away, but I am an electronic engineer so that is easy for me.
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Hi Zz,
Of course it is all down to the quality of the glue join. For the best adhesion both parts have to be clean and of a suitable material. The two components have to fit snugly so you have as thin an adhesive layer as possible, don't use the glue as a filler. Firmly clamping the components whilst the adhesive cures is essential. I often make a custom jig just for this reason. A little known fact about epoxy is that in really needs to be heat cured to get the best results. I tend to bake my components, whilst still in the clamping jig, for an hour or so at 85-100°C. Properly cured epoxy is like glass, brittle and hard. The degree to which you can heat cure will be dependent upon the temperature that the components can withstand. Gluing when done correctly,as I'm sure Jim has, is a strong and valid method.
Niffy
Of course it is all down to the quality of the glue join. For the best adhesion both parts have to be clean and of a suitable material. The two components have to fit snugly so you have as thin an adhesive layer as possible, don't use the glue as a filler. Firmly clamping the components whilst the adhesive cures is essential. I often make a custom jig just for this reason. A little known fact about epoxy is that in really needs to be heat cured to get the best results. I tend to bake my components, whilst still in the clamping jig, for an hour or so at 85-100°C. Properly cured epoxy is like glass, brittle and hard. The degree to which you can heat cure will be dependent upon the temperature that the components can withstand. Gluing when done correctly,as I'm sure Jim has, is a strong and valid method.
Niffy
By the way , when it comes to air borne tonearms, I would, if I had the skills (or had a mechanical workshop with skilled people in ) do it like this.
The air bearing should be inverse , that is hollow axle with small holes and a solid bearing. The movement of the bearing should only be ,say , 10 mm so it is in fact a closed high pressure bearing. You then move this bearing across the record surface, if you want a short tone arm or alongside the platter if you want the center of the bearing horizontal with the stylus. All the mechanical items for making that movement (stepper motors linear bushings aso. ) and the electronics to manage it is easily obtainable these days with all the CNC , plotter and 3D printers made everywhere. This was not the case when the first air bearing and roller bearing emerged many moons ago.
The air bearing should be inverse , that is hollow axle with small holes and a solid bearing. The movement of the bearing should only be ,say , 10 mm so it is in fact a closed high pressure bearing. You then move this bearing across the record surface, if you want a short tone arm or alongside the platter if you want the center of the bearing horizontal with the stylus. All the mechanical items for making that movement (stepper motors linear bushings aso. ) and the electronics to manage it is easily obtainable these days with all the CNC , plotter and 3D printers made everywhere. This was not the case when the first air bearing and roller bearing emerged many moons ago.
Niffy,...
I am aware that it is doable and fine working solution but engineer in my head is always yelling at me 
like " Do complex shape, make it CNCed from light alloy, make it look like spider net, it must look and feel like a million dollars " and this screaming is sometimes unbearable, believe me
joke aside i am planing to properly design my bearing clamp to be extremely light. I usually do all CAM planning and management so that my friends at CNC routers have really easy work in following this process from start to finish.
Koldby,...
I got you where you are going, but, dont you think that will introduce additional parasitic resonance from this servo contraption? And whatabout stiffness of whole system? As i understood the first level of this would be reversed airbearing with 10mm of linear shift, laying on another bigger contraption also on normal air bearings controlled with stepper motor and sophisticated electronics
Believe me even this usual approach to airborne linear tonearm would yield
at least total 1500-2000 euro of material, parts and CNC services
if we do live in perfect world i would build space ship but we do not
Cheers
Zz
I am aware that it is doable and fine working solution
but engineer in my head is always yelling at me like " Do complex shape, make it CNCed from light alloy, make it look like spider net, it must look and feel like a million dollars " and this screaming is sometimes unbearable, believe me joke aside i am planing to properly design my bearing clamp to be extremely light. I usually do all CAM planning and management so that my friends at CNC routers have really easy work in following this process from start to finish.
Koldby,...
I got you where you are going, but, dont you think that will introduce additional parasitic resonance from this servo contraption? And whatabout stiffness of whole system? As i understood the first level of this would be reversed airbearing with 10mm of linear shift, laying on another bigger contraption also on normal air bearings controlled with stepper motor and sophisticated electronics
Believe me even this usual approach to airborne linear tonearm would yield
at least total 1500-2000 euro of material, parts and CNC services
if we do live in perfect world i would build space ship but we do not
Cheers
Zz
Niffy, Jim,...
All airborne linear tonearm i ever saw on net and in person have wire/airhose going up than hanging down or exiting straight than hanging down.
Does any of you try to put some sort of hang hook just above airbush when is in the middle of record and give it a little bit of slack to minimize tension?
Zz
All airborne linear tonearm i ever saw on net and in person have wire/airhose going up than hanging down or exiting straight than hanging down.
Does any of you try to put some sort of hang hook just above airbush when is in the middle of record and give it a little bit of slack to minimize tension?
Zz
I can see you dont like the idea at all.. That is ok., but why would the contraption be bigger than it is in, say smilys tonearm? And no reason to use air bearings for the servo contraption, bu roller bearings. If you want to CNC everything, price will be high whatever you do, I would , as I said , use the parts already there even though they are made for other purposes.Koldby,...
I got you where you are going, but, dont you think that will introduce additional parasitic resonance from this servo contraption? And whatabout stiffness of whole system? As i understood the first level of this would be reversed airbearing with 10mm of linear shift, laying on another bigger contraption also on normal air bearings controlled with stepper motor and sophisticated electronics
Believe me even this usual approach to airborne linear tonearm would yield
at least total 1500-2000 euro of material, parts and CNC services
if we do live in perfect world i would build space ship but we do not
Cheers
Zz
I fail to see that there should be problems with stiffness in this idea more so than in others. And why should there be parasitic resonances in this technology. I would rather think there could be introduced resonances in long air tubes and long flimsy wires than in something as rigid as linear roller bearings?
But then again I can see you do not like the idea, so I will just leave it here. Good luck to all.
Exactly, my goal was to make the arm as short as possible, too. Any extra structure will extend the length of the arm.
Actually, I was inspired by Versa Dynamics arm. They must use some of glue to attach the head shell on air bearing.
Attachments
Koldby,..
Where i say i don't like idea? I just said that it would be more complicated and expensive for diyers to achieve and furthermore if you please i would like to see any sort of drawing to understand better.
If your airbearing is connected to a carriage which slide on rollerbearing activated by stepper motor than it defeat its purpose and will introduce feedback resonances from stepper motor drive belt or screw no matter what u use.
So again i would like to see drawing to understand better
My tapered carbon wand will be less than 5inch long and with high taper ratio so it will be better than any tangent tone arm and as i said previously i dont like idea of whole package above my records.
Again my perception of do it yourself does not involve all to be done at home when i have resources to be built relatively inexpensive on CNC machines
So don't jump with conclusions my friend
Cheers
Zz
Where i say i don't like idea? I just said that it would be more complicated and expensive for diyers to achieve and furthermore if you please i would like to see any sort of drawing to understand better.
If your airbearing is connected to a carriage which slide on rollerbearing activated by stepper motor than it defeat its purpose and will introduce feedback resonances from stepper motor drive belt or screw no matter what u use.
So again i would like to see drawing to understand better
My tapered carbon wand will be less than 5inch long and with high taper ratio so it will be better than any tangent tone arm and as i said previously i dont like idea of whole package above my records.
Again my perception of do it yourself does not involve all to be done at home when i have resources to be built relatively inexpensive on CNC machines
So don't jump with conclusions my friend
Cheers
Zz