agent.5 ...thanks, and for others please read.
agent.5: For payment sent. No, nobody else.
All, please read:
I did have a very good email exchange with Arjen , suggesting a couple of things. He voiced a few concerns, on a number of issues. Having not asked him if I could poet his email, I will not until I get word from him that he will allow it.
I however post my response to him in it's entirety (the points he brings up are pretty obvious based on my response to him:
thanks for your thoughtful and sincere (I believe) email. Your observations regarding the GB are accurate, and I appreciate your candor.
Now some specific points in reply to your's and some background history:
* "rather high" cost---YES, but no when you consider the options
* The conclusion of one day is something closer to two weeks. Any that have contacted me directly, that have shown what I consider to be a genuine interest will be looked after, regardless of the cost to me
* I'm not an "expert" but I've been involved in audio long enough and I do have a good understanding of all the principles involved. My education is in physics.
* Initially I got involved in making improvements to an existing commercial turntable for Grant Fidelity (please see my signature on diyAudio)
* That product has what I might consider the "appearance " of a good piece, although when viewed in comparison to other high end tables, is let down by the "finishing" (or what the manufacturer believes is finishing. I believe it should bee in the "beginning"...), the bearing and the tonearm specifically, and a visual design that mimics suspended tables, when it is not. The fit and finish of what is there is very good, and after modifying one of the turntables with a bearing from an old Sony DD turntable, and changing the arm from the stock one to a Linn Akito ll, it was/is apparent that the bearing is the weak link. The "modded" turntable is easily in the same league as my much more expensive Oracle Alex Mkll/SME 309 mag combination. Not the same, but definitely in the same league.
* Currently I have 2 of these tables in pieces in my office. I wouldn't begin to suggest what these tables are "worth" (not much), but can tell you they are not $3000 tables at any level, but I have seen the exact same table with a factory arm ranging in price from USD $1800-$3300 (although I am Canadian it seems the "international" currency of trade is the much over valued American dollar...Our "loonie", a CAD$ 1 coin trades at USD $.98 )
* After all the effort trying to make an existing turntable better, I realized that the diy enthusiast has essentially no options for a kit or pieces, and often would run into the exact same problems as I was having. Scheu is virtually non-existent here. I don't even know if they still offer kits. The "BIX" kit from Hong Kong had received some decent reviews, then some terrible ones, and has stopped selling turntables. Teres stopped with platter and bearing kits, but recently started back up at USD $1400+ for the bearing and platter. I then thought of offering the fruits of my labour to many that would need these pieces , at a very reasonable cost (at least 20% off of what I might consider a reasonable amount). it result in a couple of things: provide many diyAudio folks--particularly those that purchased the Maxxon motor GB , with an excellent platter and bearing ; allow me to contact some manufactures/makers to get the pieces made for a reasonable cost based on some minimum quantity.
* The original manufacturer had no interest in providing me with parts for a GB. A second (and third) manufacturer were contacted. The second maker , already a manufacturer of high-end, well reviewed and reasonably priced turntables, provided a quote. They had asked not to be identified as a possible source. It is their bearing that is so "secretive" in description. The second maker was provided with my original design, but suggested that it was so close in concept and specification to their own design (which has been around for a number of years) that it made no sense to do something custom. I agree.The original platter and bearing design (my original) have definite specifications, but due to my involvement with the commercial design I could not provide that information , other than basic dimensions. Here's the crux---- they required a commitment (read that as a prepaid order) for 100 pairs of platters and bearings, without me ever seeing one in the flesh--but based on review of their existing tables would be excellent. Or keep looking. Had I received serious interest in the GB , and prepayment for the platters and bearings, I would have advanced that route. Due to the lack of commitment, I simply cannot afford to swing $50,000 in platters and bearings on my own. The proposed cost to the GB purchasers would have been as high as $500-$525
* That leaves the original maker , who finally has made a quote, and I am expecting to see a prototype soon. The proposed cost of this option is something like CAD $400-$450 (no final pricing but based on the cost and "guestimate" on freight to me)
* and I do know I have "vented" a little on the thread. I do have some others that may be a little less emotional regrading this project to rely on. If my patience wears any thinner I will be asking for help.
Again Arjen, thanks for the thoughtful email. I hope I have answered some of your concerns. I am endvouring to alleviate all ears and concerns shortly.
So folks, I haven't really given up. I am just slightly frustrated. I will ask Ian Grant of Grant Fidelity to comment if I feel I am ill equipped to provide you with a solid answer. But please do not create a deluge of emails to him regarding this. He does monitor this thread, and if questions are posted here he will try to answer any as far as his end of this project goes.
My intention has never been to offend any, or avoid "proper" answers but I have been limited in my ability to provide much of the information based on Ian's manufacturing partners and his need for a better product.
stew
agent.5: For payment sent. No, nobody else.
All, please read:
I did have a very good email exchange with Arjen , suggesting a couple of things. He voiced a few concerns, on a number of issues. Having not asked him if I could poet his email, I will not until I get word from him that he will allow it.
I however post my response to him in it's entirety (the points he brings up are pretty obvious based on my response to him:
thanks for your thoughtful and sincere (I believe) email. Your observations regarding the GB are accurate, and I appreciate your candor.
Now some specific points in reply to your's and some background history:
* "rather high" cost---YES, but no when you consider the options
* The conclusion of one day is something closer to two weeks. Any that have contacted me directly, that have shown what I consider to be a genuine interest will be looked after, regardless of the cost to me
* I'm not an "expert" but I've been involved in audio long enough and I do have a good understanding of all the principles involved. My education is in physics.
* Initially I got involved in making improvements to an existing commercial turntable for Grant Fidelity (please see my signature on diyAudio)
* That product has what I might consider the "appearance " of a good piece, although when viewed in comparison to other high end tables, is let down by the "finishing" (or what the manufacturer believes is finishing. I believe it should bee in the "beginning"...), the bearing and the tonearm specifically, and a visual design that mimics suspended tables, when it is not. The fit and finish of what is there is very good, and after modifying one of the turntables with a bearing from an old Sony DD turntable, and changing the arm from the stock one to a Linn Akito ll, it was/is apparent that the bearing is the weak link. The "modded" turntable is easily in the same league as my much more expensive Oracle Alex Mkll/SME 309 mag combination. Not the same, but definitely in the same league.
* Currently I have 2 of these tables in pieces in my office. I wouldn't begin to suggest what these tables are "worth" (not much), but can tell you they are not $3000 tables at any level, but I have seen the exact same table with a factory arm ranging in price from USD $1800-$3300 (although I am Canadian it seems the "international" currency of trade is the much over valued American dollar...Our "loonie", a CAD$ 1 coin trades at USD $.98 )
* After all the effort trying to make an existing turntable better, I realized that the diy enthusiast has essentially no options for a kit or pieces, and often would run into the exact same problems as I was having. Scheu is virtually non-existent here. I don't even know if they still offer kits. The "BIX" kit from Hong Kong had received some decent reviews, then some terrible ones, and has stopped selling turntables. Teres stopped with platter and bearing kits, but recently started back up at USD $1400+ for the bearing and platter. I then thought of offering the fruits of my labour to many that would need these pieces , at a very reasonable cost (at least 20% off of what I might consider a reasonable amount). it result in a couple of things: provide many diyAudio folks--particularly those that purchased the Maxxon motor GB , with an excellent platter and bearing ; allow me to contact some manufactures/makers to get the pieces made for a reasonable cost based on some minimum quantity.
* The original manufacturer had no interest in providing me with parts for a GB. A second (and third) manufacturer were contacted. The second maker , already a manufacturer of high-end, well reviewed and reasonably priced turntables, provided a quote. They had asked not to be identified as a possible source. It is their bearing that is so "secretive" in description. The second maker was provided with my original design, but suggested that it was so close in concept and specification to their own design (which has been around for a number of years) that it made no sense to do something custom. I agree.The original platter and bearing design (my original) have definite specifications, but due to my involvement with the commercial design I could not provide that information , other than basic dimensions. Here's the crux---- they required a commitment (read that as a prepaid order) for 100 pairs of platters and bearings, without me ever seeing one in the flesh--but based on review of their existing tables would be excellent. Or keep looking. Had I received serious interest in the GB , and prepayment for the platters and bearings, I would have advanced that route. Due to the lack of commitment, I simply cannot afford to swing $50,000 in platters and bearings on my own. The proposed cost to the GB purchasers would have been as high as $500-$525
* That leaves the original maker , who finally has made a quote, and I am expecting to see a prototype soon. The proposed cost of this option is something like CAD $400-$450 (no final pricing but based on the cost and "guestimate" on freight to me)
* and I do know I have "vented" a little on the thread. I do have some others that may be a little less emotional regrading this project to rely on. If my patience wears any thinner I will be asking for help.
Again Arjen, thanks for the thoughtful email. I hope I have answered some of your concerns. I am endvouring to alleviate all ears and concerns shortly.
So folks, I haven't really given up. I am just slightly frustrated. I will ask Ian Grant of Grant Fidelity to comment if I feel I am ill equipped to provide you with a solid answer. But please do not create a deluge of emails to him regarding this. He does monitor this thread, and if questions are posted here he will try to answer any as far as his end of this project goes.
My intention has never been to offend any, or avoid "proper" answers but I have been limited in my ability to provide much of the information based on Ian's manufacturing partners and his need for a better product.
stew
Stew,
I feel bad because I had indicated that I would be interested in the platter/bearing and have decided to back out, but I think that your email shows precisely the problem: lack of details from the 'secret' supplier, and sketchy (at best) details from the other manufacturers you had talked to. The unknown supplier could, for all we know, be offering up their rejects? What recourse would we have? What guarantees are there in this kind of venture? none that i know of...
None of the information you have supplied regarding any of the proposed suppliers has inspired any confidence, for me at least. I realize that this is not your fault but (for me) it remains as the main problem.
There was some (rather excited/defensive/objectionable) discussion over the bix offerings on ebay earlier in the thread, but with that offering, at least we know the cost, and exactly where we will end up, given that it was a well known offering.
So in the end, I think that it may have been better if you could have sourced what was needed from a local machine shop or something. At least then all the details, costs, etc, would be known up front, and more importantly the manufacturer would be known as well...
just my thoughts.
b
I feel bad because I had indicated that I would be interested in the platter/bearing and have decided to back out, but I think that your email shows precisely the problem: lack of details from the 'secret' supplier, and sketchy (at best) details from the other manufacturers you had talked to. The unknown supplier could, for all we know, be offering up their rejects? What recourse would we have? What guarantees are there in this kind of venture? none that i know of...
None of the information you have supplied regarding any of the proposed suppliers has inspired any confidence, for me at least. I realize that this is not your fault but (for me) it remains as the main problem.
There was some (rather excited/defensive/objectionable) discussion over the bix offerings on ebay earlier in the thread, but with that offering, at least we know the cost, and exactly where we will end up, given that it was a well known offering.
So in the end, I think that it may have been better if you could have sourced what was needed from a local machine shop or something. At least then all the details, costs, etc, would be known up front, and more importantly the manufacturer would be known as well...
just my thoughts.
b
mantisory, feeling bad....
was not the end result for any that I had hoped for. You need not apologize. All I can say, as I posted in my last post(a rsponse to Arjen who had emailed me directly) is that a lot of all this is out of my direct control. A local machine shop could have provided me with a quote, that they would be willing to honour, and a time-line for delivery. This has gone from a 2-3 week time-line to something near 2 months. I had already sourced another manufacturer when Ian's folks agreed to do the platters and bearings..and I thought we should give them a chance.
Knowing what I know now, the use of a local shop is the path that would have provided the least resistance, a result that would be easy to do QC on, and seek guidance from the machine shop. This would have been taken care of weeks ago had this been the path. For that I am sorry to all.
Ian Grant (Grant Fidelity) is the channel that has been used to access the manufacturers, I have asked him to chime in any time. He is at least as frustrated about the suppliers as I am.
Regarding the Bix table, I made no negative results per say, but rather noted that diy HiFi is no longer providing the Bix kits, and was getting out of stock of them, and any and all pieces they had left (at least that is the appearance).
When I finally end up with a platter and a bearing, I will post here. Also if any provide money to my Paypal account, if no platters an bearings are forthcoming, an alternative will be provided (assuming approval from the parties involved) or a complete refund, as determined by those that had paid into Paypal on an individual basis.
stew
was not the end result for any that I had hoped for. You need not apologize. All I can say, as I posted in my last post(a rsponse to Arjen who had emailed me directly) is that a lot of all this is out of my direct control. A local machine shop could have provided me with a quote, that they would be willing to honour, and a time-line for delivery. This has gone from a 2-3 week time-line to something near 2 months. I had already sourced another manufacturer when Ian's folks agreed to do the platters and bearings..and I thought we should give them a chance.
Knowing what I know now, the use of a local shop is the path that would have provided the least resistance, a result that would be easy to do QC on, and seek guidance from the machine shop. This would have been taken care of weeks ago had this been the path. For that I am sorry to all.
Ian Grant (Grant Fidelity) is the channel that has been used to access the manufacturers, I have asked him to chime in any time. He is at least as frustrated about the suppliers as I am.
Regarding the Bix table, I made no negative results per say, but rather noted that diy HiFi is no longer providing the Bix kits, and was getting out of stock of them, and any and all pieces they had left (at least that is the appearance).
When I finally end up with a platter and a bearing, I will post here. Also if any provide money to my Paypal account, if no platters an bearings are forthcoming, an alternative will be provided (assuming approval from the parties involved) or a complete refund, as determined by those that had paid into Paypal on an individual basis.
stew
Hi Stew, I'm still hangin' on, 4-600 bucks is a lot of cash, no doubt, but in retrospect I just can't see how a platter + bearing of high quality can be any less than. I certinly to not have the know how to order it on my own. So, I'm hangin and seeing what you can come up with.
What a test for you though, it is appreciated!
Stan
What a test for you though, it is appreciated!
Stan
Hi all DIYers thinking about Stew's (Nanook) offering.
It was with my ok that Stew started this offering based on a turntable design Grant Fidelity has been working on for about a year now to make into something I'd put our name on. It's a good looker with great sound potential and is fondly known as the 'damn GT-455' internally at GF.
Our factory in China on the GT-455 has all the ability and factory gear to make a high quality, high-end turntable with proper guidance. The platter and plinths are fine, the bearing design was not right from day one, the tonearm was always a work in progress and the motor had issues due to the bearing. The factory has now managed to sell this with our improvements to others who are selling what GF believes to be 'not ready for market' for many thousands of dollars, our target price for the turntable was under 1.5k loaded.
I've gotten to know Stew since he signed up to be a GF demostrator and we have similar interests in 'frugalphile' (Dave Dlugos term) and we chatted a lot about Stew's $2.19 tonearm
which sounds great.
Thats when we decided to let Stew loose on making the GT-455 into a contender, which evolved into the concept of Stew starting up the GF DIY division. We have lots of access to lots of DIY gear.
About halfway into this we approached a major Turntable manufacturer and they are excited about working with GF to rebrand their products for North America and are more than willing to provide us with their platter and bearing (motor and tonearms as well), but only in 100 quantity batches. So we need a lot of 'paid' interest to go in this direction. Minimum 20, 30 prefered.
Our original factory has sent out 2 new prototypes of the bearing (and platter, but as stated they are fine) and we then get to see Stew's new design in action. We can go with these in smaller quantities if they test out as expected.
I hope this clears up a few things. Stew, GF and our factories have put a lot of time into this and we appreciate your patience with us as we sort out our end. Stew will be heading up our DIY division.
Happy to answer any DIY questions here.
Ian
It was with my ok that Stew started this offering based on a turntable design Grant Fidelity has been working on for about a year now to make into something I'd put our name on. It's a good looker with great sound potential and is fondly known as the 'damn GT-455' internally at GF.
Our factory in China on the GT-455 has all the ability and factory gear to make a high quality, high-end turntable with proper guidance. The platter and plinths are fine, the bearing design was not right from day one, the tonearm was always a work in progress and the motor had issues due to the bearing. The factory has now managed to sell this with our improvements to others who are selling what GF believes to be 'not ready for market' for many thousands of dollars, our target price for the turntable was under 1.5k loaded.
I've gotten to know Stew since he signed up to be a GF demostrator and we have similar interests in 'frugalphile' (Dave Dlugos term) and we chatted a lot about Stew's $2.19 tonearm
which sounds great.Thats when we decided to let Stew loose on making the GT-455 into a contender, which evolved into the concept of Stew starting up the GF DIY division. We have lots of access to lots of DIY gear.
About halfway into this we approached a major Turntable manufacturer and they are excited about working with GF to rebrand their products for North America and are more than willing to provide us with their platter and bearing (motor and tonearms as well), but only in 100 quantity batches. So we need a lot of 'paid' interest to go in this direction. Minimum 20, 30 prefered.
Our original factory has sent out 2 new prototypes of the bearing (and platter, but as stated they are fine) and we then get to see Stew's new design in action. We can go with these in smaller quantities if they test out as expected.
I hope this clears up a few things. Stew, GF and our factories have put a lot of time into this and we appreciate your patience with us as we sort out our end. Stew will be heading up our DIY division.
Happy to answer any DIY questions here.
Ian
Ian, sklimek, lead belly, Arjen and others....
First, to Arjen: sorry for not waiting for you to get back to me before posting my reference to you in the last couple of posts.
Many have provided moral support. I completely appreciate that. And if it has seemed that I have picked on anyone specifically, my intention has never been to cause any to feel the need to be defensive. If I have offended any, please accept my apologies..
I've taken a couple of days off working on the turntable in any way shape or form, I needed the break. But I have been working on a pair of loudspeakers for a diy article in Affordable$$Audio, a less expensive take on Linkwitz's "Orion" build. Open baffle mid-bass + , and an aperiodic down-firing sub-woofer with 250 watts each (a stereo pair). Total cash outlay, sub CAD$1000, for parts, wood, amps drivers, etc. A truly fullrange speaker system. Thankfully, everything can be turned down. I think we'll try my old (but new ) Altec 409-8D speakers in there for the OB type. (I'll post some pix if anyone is interested)
To all, it really is just my frustration that is getting in the way, caused from 2 different directions, the downstream (end user-purchaser's), and upstream (the manufacturer's end). It seems to me this should just be a straight forward purchase/exercise. I take responsibility for some of the shortcomings in this GB and lack of communication, as my ignorance to the realities of manufacturer's willingness to work with their clients may have pushed me to make un-realistic timelines.
Ian's confidence in me is partially based in what he has seen what I can do with very little money, a pair of pliers and a tube cutter. And my $2.19 tonearm is only an example. Good sounding re-plinths and some turntable mods done on the fly on his kitchen counter may be another (kind of like P10's on the fly, "hand me my knife I'll fix those drivers for ya" escapades at various audio get togethers). I thoroughly do understand the design requirements for analog systems, and have been into vinyl for 20 years +, selling, modifying and making mechanical analog bits (as crude as some may seem , as I have no machining capability myself). I am in no way what I might consider an electronics guy, but can do it in a pinch.
And what he has stated is true regarding "the turntable", I've seen 3-4 "other "turntables selling in the $2000-$3300 range of essentially the same turntable (from the same maker) that we have, with our improvements made to them and "in the market" already. And in many folk's estimation it was/is not ready for prime time (at least from our perspective). So if I have a little trepidation about releasing too much information, it is because of this, and one of the manufacturer's wishing not to be identified (the second supplier of high-end tables). that's it. No "ultra paranoia", but the reality of what has happened.
I'm also willing to forfeit that perhaps I have been a little to enthusiastic because to me the changes required and the ease of a better bearing seems, well, {I]simple[/I]. As soon as I get anything further to post regarding the bearings themselves, I'm going to stay a little scarce here. As always I will answer any emails sent directly to me.
stew
First, to Arjen: sorry for not waiting for you to get back to me before posting my reference to you in the last couple of posts.
Many have provided moral support. I completely appreciate that. And if it has seemed that I have picked on anyone specifically, my intention has never been to cause any to feel the need to be defensive. If I have offended any, please accept my apologies..
I've taken a couple of days off working on the turntable in any way shape or form, I needed the break. But I have been working on a pair of loudspeakers for a diy article in Affordable$$Audio, a less expensive take on Linkwitz's "Orion" build. Open baffle mid-bass + , and an aperiodic down-firing sub-woofer with 250 watts each (a stereo pair). Total cash outlay, sub CAD$1000, for parts, wood, amps drivers, etc. A truly fullrange speaker system. Thankfully, everything can be turned down. I think we'll try my old (but new ) Altec 409-8D speakers in there for the OB type. (I'll post some pix if anyone is interested)
To all, it really is just my frustration that is getting in the way, caused from 2 different directions, the downstream (end user-purchaser's), and upstream (the manufacturer's end). It seems to me this should just be a straight forward purchase/exercise. I take responsibility for some of the shortcomings in this GB and lack of communication, as my ignorance to the realities of manufacturer's willingness to work with their clients may have pushed me to make un-realistic timelines.
Ian's confidence in me is partially based in what he has seen what I can do with very little money, a pair of pliers and a tube cutter. And my $2.19 tonearm is only an example. Good sounding re-plinths and some turntable mods done on the fly on his kitchen counter may be another (kind of like P10's on the fly, "hand me my knife I'll fix those drivers for ya" escapades at various audio get togethers). I thoroughly do understand the design requirements for analog systems, and have been into vinyl for 20 years +, selling, modifying and making mechanical analog bits (as crude as some may seem , as I have no machining capability myself). I am in no way what I might consider an electronics guy, but can do it in a pinch.
And what he has stated is true regarding "the turntable", I've seen 3-4 "other "turntables selling in the $2000-$3300 range of essentially the same turntable (from the same maker) that we have, with our improvements made to them and "in the market" already. And in many folk's estimation it was/is not ready for prime time (at least from our perspective). So if I have a little trepidation about releasing too much information, it is because of this, and one of the manufacturer's wishing not to be identified (the second supplier of high-end tables). that's it. No "ultra paranoia", but the reality of what has happened.
I'm also willing to forfeit that perhaps I have been a little to enthusiastic because to me the changes required and the ease of a better bearing seems, well, {I]simple[/I]. As soon as I get anything further to post regarding the bearings themselves, I'm going to stay a little scarce here. As always I will answer any emails sent directly to me.
stew
Hello Stew, others,
Stew, thanks for proceeding the way you did in the posts above. I do not have time to follow this thread daily. Our private conversation is of no further importance here; your answers speak for themselves.
For others: I was and will stay interested in this GB and have confidence in the approach of Stew and his companion regarding the quality of platter and bearing. My latent concern – and apparently I was not the only one - was that prospects for the GB really had a hard time to imagine what exact concrete product they could hope for and when it would be delivered. Diy’ers only buy hope untill they open the package, don’t they. My PM to Stew only shared the experience that this is a common pittfall in (starting) entrepreneurship and can be easily prevented.
Please keep this going, Arjen.
Stew, thanks for proceeding the way you did in the posts above. I do not have time to follow this thread daily. Our private conversation is of no further importance here; your answers speak for themselves.
For others: I was and will stay interested in this GB and have confidence in the approach of Stew and his companion regarding the quality of platter and bearing. My latent concern – and apparently I was not the only one - was that prospects for the GB really had a hard time to imagine what exact concrete product they could hope for and when it would be delivered. Diy’ers only buy hope untill they open the package, don’t they. My PM to Stew only shared the experience that this is a common pittfall in (starting) entrepreneurship and can be easily prevented.
Please keep this going, Arjen.
hello all...
I am told with some certainty by Ian that there are actually a couple of samples en route as I type this. Ian will get back to Calgary and send them along. I have some photos from the manufacturer, but will wait to post any until I actually receive the samples , and take my own photos and physical measurements. Then I need to put a table together and listen. Once I believe that the quality is there, I will post my results and an "ad hoc" review (but how can I be unbiased?).
Once this is verified, I will post the results. Ian can provide potential delivery dates, and all is back on.
I understand that the cost of $400-600 is a scary thing, sight unseen, and as pointed out, is quite a bit more than typical group buys. My hope is that those that are interested (still, if any) will find the results worth the wait.
The new avatar is a stealth modded Walther PPK, a la James Bond...
I am told with some certainty by Ian that there are actually a couple of samples en route as I type this. Ian will get back to Calgary and send them along. I have some photos from the manufacturer, but will wait to post any until I actually receive the samples , and take my own photos and physical measurements. Then I need to put a table together and listen. Once I believe that the quality is there, I will post my results and an "ad hoc" review (but how can I be unbiased?).
Once this is verified, I will post the results. Ian can provide potential delivery dates, and all is back on.
I understand that the cost of $400-600 is a scary thing, sight unseen, and as pointed out, is quite a bit more than typical group buys. My hope is that those that are interested (still, if any) will find the results worth the wait.
The new avatar is a stealth modded Walther PPK, a la James Bond...
here's an update.
I've decided to go it alone and not rely on anyone else for anything else. We got a couple more samples via Ian Grant, and the factory could not follow my explicit instructions, (including using the proper materials with ASTM , DIN and SAE material numbers.
They completely pooched one of platter/bearing assemblies to the point that it may not be able to be salvaged at all.
I had a great discussion with one of the folks at Immedia (Spiral Groove) who assured me that finding competent manufacturers is one of the biggest hastles in high-end audio (and I've learned pretty quick.)
The quality control can occur at a local level.
To go with he "high end" maker required an investment of $15k-$20k, which is something I personally can't swing.
I am still working on this, but doing it all on my own. I know Ian and Rachel have been frustrated regarding the factory's inability to follow the instruction.
I thought I would calm completely down on this until I had a complete solution for the platters and bearings in hand. As soon as I have something in hand I will post, both here and perhaps a new thread as well.
I've decided to go it alone and not rely on anyone else for anything else. We got a couple more samples via Ian Grant, and the factory could not follow my explicit instructions, (including using the proper materials with ASTM , DIN and SAE material numbers.
They completely pooched one of platter/bearing assemblies to the point that it may not be able to be salvaged at all.
I had a great discussion with one of the folks at Immedia (Spiral Groove) who assured me that finding competent manufacturers is one of the biggest hastles in high-end audio (and I've learned pretty quick.)
The quality control can occur at a local level.
To go with he "high end" maker required an investment of $15k-$20k, which is something I personally can't swing.
I am still working on this, but doing it all on my own. I know Ian and Rachel have been frustrated regarding the factory's inability to follow the instruction.
I thought I would calm completely down on this until I had a complete solution for the platters and bearings in hand. As soon as I have something in hand I will post, both here and perhaps a new thread as well.
Re: some answers..
I have.
The usual failure mode is cracking of the thrust pad just below the contact surface of the ball (or above if the bearing is inverted) as this is where the maximal shear stress arises. This maximal shear stress can be taken as approximately half the mean contact pressure (the load divided by the contact area).
Because ceramics are stiff the contact area is small so the mean contact pressure is high. This is after all why they are used - the small contact area reduces the friction.
The trouble is that ceramics usually don't have very good shear strength. In ductile materials (metals) the maximal shear stress allowable is roughly half the stress required to stretch* the material by 0.2%. Ceramics won't do this for the simple reason that they break long before they reach 0.2% stretch.
The rule of thumb seems to be that for ceramics the shear strength and the tensile strength will be roughly equal but ceramics have woeful tensile strength, often about 0.1% of their elastic modulus.
The net result is that a ductile material like steel can support a contact pressure which is about ten times as large as a ceramic material of equivalent stiffness. This is why you'll often see a ceramic ball and a steel thrust plate - the contact area will be slightly larger and the steel is much tougher so the maximal supported load will be very much greater.
*Technically 0.2% plastic yield. This used to confuse me because for steel the 0.2% yield point happens to be very close to 2% of the elastic modulus.
Nanook said:
I have.
The usual failure mode is cracking of the thrust pad just below the contact surface of the ball (or above if the bearing is inverted) as this is where the maximal shear stress arises. This maximal shear stress can be taken as approximately half the mean contact pressure (the load divided by the contact area).
Because ceramics are stiff the contact area is small so the mean contact pressure is high. This is after all why they are used - the small contact area reduces the friction.
The trouble is that ceramics usually don't have very good shear strength. In ductile materials (metals) the maximal shear stress allowable is roughly half the stress required to stretch* the material by 0.2%. Ceramics won't do this for the simple reason that they break long before they reach 0.2% stretch.
The rule of thumb seems to be that for ceramics the shear strength and the tensile strength will be roughly equal but ceramics have woeful tensile strength, often about 0.1% of their elastic modulus.
The net result is that a ductile material like steel can support a contact pressure which is about ten times as large as a ceramic material of equivalent stiffness. This is why you'll often see a ceramic ball and a steel thrust plate - the contact area will be slightly larger and the steel is much tougher so the maximal supported load will be very much greater.
*Technically 0.2% plastic yield. This used to confuse me because for steel the 0.2% yield point happens to be very close to 2% of the elastic modulus.
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