Hi- I'm working on a restoration of a TD125 and looking for a thrust bearing. I was planning to use Delrin, but I'm open to other suggestions if you know of something better.
The bearing is a disk - 10mm diameter x 1-2mm thick.
More than happy to pay if someone has the ability to machine something.
Thanks much, Mike
The bearing is a disk - 10mm diameter x 1-2mm thick.
More than happy to pay if someone has the ability to machine something.
Thanks much, Mike
You get Delrin rods in that size, Teflon too.
Machining is a cut off, chop saw or lathe.
A local workshop may do it.
Machining is a cut off, chop saw or lathe.
A local workshop may do it.
Thanks @NareshBrd , I was able to find someone that could machine one before.
Bit of a bump on this!
Bit of a bump on this!
Does anyone know the SIZE bearing on the spindle?
I have, literally, spent hours looking through forums, notes, tech articles in several languages and have only found ONE unofficial comment saying it’s 6mm.
Measure twice, cut once. I don’t want to tear apart my spindle to measure the part if I can’t get a replacement.
Does anyone have a verifiable SOURCE for this dimension?
Thanks in advance.
I have, literally, spent hours looking through forums, notes, tech articles in several languages and have only found ONE unofficial comment saying it’s 6mm.
Measure twice, cut once. I don’t want to tear apart my spindle to measure the part if I can’t get a replacement.
Does anyone have a verifiable SOURCE for this dimension?
Thanks in advance.
The early versions used a 10mm shaft, with a captive ball, that was, I think 6mm.
Later models had the conical shape machined onto the shaft itself.
Have a look here for more useful info:-
https://www.theanalogdept.com/td_platter_bearings.htm
Later models had the conical shape machined onto the shaft itself.
Have a look here for more useful info:-
https://www.theanalogdept.com/td_platter_bearings.htm
@ralphfcooke - thanks. been there. scoured their pages, not one mention of bearing diameter.
Short of finding a later model conical spindle, I’m planning on just yanking the ball, replacing it with a sapphire sphere and dropping in a sapphire thrust plate. Not that expensive a proposition, and it just might work.
Short of finding a later model conical spindle, I’m planning on just yanking the ball, replacing it with a sapphire sphere and dropping in a sapphire thrust plate. Not that expensive a proposition, and it just might work.
In my TD-124 I use a 6mm SiNi ball running on a sapphire thrust plate without any problems. The only thing is despite having a fancy brass endcap on the bearing the oil leaks out over time and I worry about it running dry. The sapphire disc just sits on the old thrust plate and can be removed and reversed/replaced if needed. Been running this way for two years.
I am considering two different changes as experiments.
1) Torlon is easily available as a "strip" 1 and 2 mm thick. I may just hole punch a disc and replace the sapphire disc with the Torlon. No machining as the soft Torlon will conform slightly to the ball. No need for machining I hope. This would be similar to the original design.
2) Leave the sapphire disc thrust surface and use a Torlon ball which are easily sourced from McMaster-Carr as is the strips of Torlon.
I'm really just wondering if having a slightly cushiony surface at the thrust point might give me some improvement but I really am happy with things the way they are.
I am considering two different changes as experiments.
1) Torlon is easily available as a "strip" 1 and 2 mm thick. I may just hole punch a disc and replace the sapphire disc with the Torlon. No machining as the soft Torlon will conform slightly to the ball. No need for machining I hope. This would be similar to the original design.
2) Leave the sapphire disc thrust surface and use a Torlon ball which are easily sourced from McMaster-Carr as is the strips of Torlon.
I'm really just wondering if having a slightly cushiony surface at the thrust point might give me some improvement but I really am happy with things the way they are.
I bought a Thorlon disc from VinylNirvana, there’s still some rumble I can HEAR at mid-volumes (some of which is vinyl-quality too) in between tracks I suspect is coming from the ball bearing/spindle.
Shaft measurements are a little worn, like 9.955mm-10.00mm on the bearing surface (I have a new set of bushings coming).
My next step is replacing the ball.
As popular as the TD125’s were I’m surprised there isn’t a mfr for a replacement bearing hub/spindle as there is for the TD124.
I found a source for 6mm Si3N4 (to be pedantic about it) balls, just looking for confirmation that Thorens used THAT size in the TD125 I & 2 as well.
https://www.bcprecision.com/
Shaft measurements are a little worn, like 9.955mm-10.00mm on the bearing surface (I have a new set of bushings coming).
My next step is replacing the ball.
As popular as the TD125’s were I’m surprised there isn’t a mfr for a replacement bearing hub/spindle as there is for the TD124.
I found a source for 6mm Si3N4 (to be pedantic about it) balls, just looking for confirmation that Thorens used THAT size in the TD125 I & 2 as well.
https://www.bcprecision.com/
If any of you followed the rebuilding of our Russco idler drives than you know of the drastic improvement in noise reduction achieved by switching from steel bearing on steel bearing or pad. This was replaced by using Delrin on one surface and keeping steel for the other surface. As vibration enters into the boundry of the dis-simialar materials it is killed off, much like what happens in a constrained layer plinth. Steel on steel or other hard material offers no boundry for the vibration and it just passes through.
BillWojo
BillWojo
Thanks, @BillWojo.
I’d gotten to thinking about this, dissimilar materials reducing resonance, then @WntrMute2 mentioned SiN balls.
This is actually the least expensive option (source I linked runs about $12 for 5 of them) and I’ve already got a Thorlon pad.
Now, whether Sapphire (thrust plate) and Thorlon or SiN ball would be best might be worth experimenting with.
I’m obviously not a materials scientist so this is experimental, but standing on the shoulders of internet audio electronics forum giants should get
me farther faster and more economically than doing it from the ground up.
I’d gotten to thinking about this, dissimilar materials reducing resonance, then @WntrMute2 mentioned SiN balls.
This is actually the least expensive option (source I linked runs about $12 for 5 of them) and I’ve already got a Thorlon pad.
Now, whether Sapphire (thrust plate) and Thorlon or SiN ball would be best might be worth experimenting with.
I’m obviously not a materials scientist so this is experimental, but standing on the shoulders of internet audio electronics forum giants should get
me farther faster and more economically than doing it from the ground up.
The above is what I was thinking in wanting to experiment with replacing the two hard surfaces with one that is slightly compliant. That said, I cannot hear ANYTHING I would attribute to bearing noise in mine. @NormB - why not just buy both a 5 and a 6 mm ball? They are not expensive and it certainty will be one of them.
@WntrMute2 (Wm Gibson fan?).
Well, as I mentioned earlier, I’d seen ONE comment SOMEwhere about a 7mm ball. It’s unlike Swiss/Germans to change things as a matter of course, sticking with what works instead, but it’s not unheard of, either.
Maybe I’ll call/contact VinylNirvana later - I’ve spent enough there in the past 3 years to presume upon them for the information.
Thanks.
Well, as I mentioned earlier, I’d seen ONE comment SOMEwhere about a 7mm ball. It’s unlike Swiss/Germans to change things as a matter of course, sticking with what works instead, but it’s not unheard of, either.
Maybe I’ll call/contact VinylNirvana later - I’ve spent enough there in the past 3 years to presume upon them for the information.
Thanks.
Well, Dave at VinylNirvana didn't know. Suggested I contact Steve Clarke over at TheAnalogDept.com...
Nope. No idea.
He (Steve) thought the Silicon Nitride ball might be MORE abrasive than the steel ball - but the steel ball in mine has already worn a pocket into the hardened steel disc at the bottom of the spindle shaft bearing retainer.
I put a Thorlon (Torlon?) disc in and will get around the grinding out the brass retainer, measure the ball - which I THINK is 6mm or 6.5mm - and buy a sapphire or Si3N4 Grade 3 ball to replace. Best surface grade on steel is something like Grade 25, IIRC.
Thanks.
Nope. No idea.
He (Steve) thought the Silicon Nitride ball might be MORE abrasive than the steel ball - but the steel ball in mine has already worn a pocket into the hardened steel disc at the bottom of the spindle shaft bearing retainer.
I put a Thorlon (Torlon?) disc in and will get around the grinding out the brass retainer, measure the ball - which I THINK is 6mm or 6.5mm - and buy a sapphire or Si3N4 Grade 3 ball to replace. Best surface grade on steel is something like Grade 25, IIRC.
Thanks.
The Torlon disc measured 9.55-9.57mm across and shifted back and forth in the bottom about 2mm visually, so I figure a 10mm Sapphire disc should work.
Thing is, the price, $15 is nothing compared to the single S&H charge of $20 from the only place I could find them online. And they don’t have the grade 3 balls I’m looking for (Delrin, which I’ll experiment with).
Been playing more since putting in the Torlon and have to admit, much of what I’m hearing as “rumble” is bad vinyl. The more discs I play the more I find with high levels of background noise.
Oddly, it’s newer vinyl. 40-70 year old discs are MUCH quieter.
Thing is, the price, $15 is nothing compared to the single S&H charge of $20 from the only place I could find them online. And they don’t have the grade 3 balls I’m looking for (Delrin, which I’ll experiment with).
Been playing more since putting in the Torlon and have to admit, much of what I’m hearing as “rumble” is bad vinyl. The more discs I play the more I find with high levels of background noise.
Oddly, it’s newer vinyl. 40-70 year old discs are MUCH quieter.
I bought mine from Edmund Optics. I bought two each for the Thorens and 4 for my VPI which has a flywheel so maybe the shipping cost didn't bother me too much. Good luck and keep us informed as to how you make out.
5mm. NOT 6. NOT 7. But 5mm.
Got a couple of SiN balls on order (5 to a pack from BCPrecision). Will see how this works and talk to a machinist friend to see if he thinks he can smooth out the pocket for the ball - a lot - maybe order a 5.5mm ball after.
Hum, that's a surprise!
Did you have to destroy the retaining clip to remove it?
I recall from other TT bearings is that you only really want the ball to spin with the shaft and not move in the spindle pocket so that's why it is often left rough. VPI and others glue the ball in place with super glue. The ball should spin on the thrust plate not spin in the shaft sometimes and other times be spinning on the thrust plate. I smoothed that pocket on a well type bearing and occasionally you could hear it clunk. Solved with a dap of glue. Won't make that mistake again.
Did you have to destroy the retaining clip to remove it?
I recall from other TT bearings is that you only really want the ball to spin with the shaft and not move in the spindle pocket so that's why it is often left rough. VPI and others glue the ball in place with super glue. The ball should spin on the thrust plate not spin in the shaft sometimes and other times be spinning on the thrust plate. I smoothed that pocket on a well type bearing and occasionally you could hear it clunk. Solved with a dap of glue. Won't make that mistake again.