Yes it's true - Well actually Raymore, MO. Next stop, cow pastures. So there are at least two TD-124s in Missouri!
One of the nagging questions on my TD-124/II has been whether the mild wobble seen in the stepped pulley was simply bushing wear or a bent shaft. I decided no harm in seeing if I could rock it, and yep, it rocks, so I've got a new pair of bushings on order from Spain.
Meanwhile, I've confirmed that the mystery bushing in the kit I bought awhile back is for the idler wheel, so that's in a hot oil bath today. Now I just need to get dowels and such so I can safely press old out, new in. Progress comes slowly, but it's progress nonetheless.
Meanwhile, I've confirmed that the mystery bushing in the kit I bought awhile back is for the idler wheel, so that's in a hot oil bath today. Now I just need to get dowels and such so I can safely press old out, new in. Progress comes slowly, but it's progress nonetheless.
Thorens TD 124/II bushing hot oil bath - YouTube
For anyone who finds it fascinating to watch air bubble out of a bushing immersed in hot oil . . .
For anyone who finds it fascinating to watch air bubble out of a bushing immersed in hot oil . . .
I drilled a hole in a wood block slightly larger than the bushing diameter, so it would catch the center of the idler wheel. I then used a wooden screw clamp (I've had a set of these for wood working for 30years) to apply pressure, forcing the old one out with the new one. Unfortunately, the new one is so tight it requires more force than the spring currently provides to turn when engaging the stepped pulley. It fit the shaft fine before being pressed in, so not quite sure what to do. ADDED: I understand some change in fit will result from compression as it's pressed into place, but this seems excessive. Just in case, I've added another "From Spain" bushing to my order, along with a set of main spindle bushings. Might as well have them all. Still would like to figure a way to lightly lap the platter spindle, as I can feel the scoring with a fingernail. Top only, of course. Bottom seems about like new.
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That shouldn't happen. Check to see if there is a burr on the inner diameter of the bushing. Unfortunatly you can't just drill the thing out if there's a larger discrepancy. You would have to reem it or hone it. Other wise you'd create a source for rumble.
Sent from my Garminfone using Tapatalk
Sent from my Garminfone using Tapatalk
It felt tight as I slipped it over the shaft, meaning same amount of resistance top to bottom. No burrs. The origin of the replacement bushing is a little suspect, which is why I've gotten a full set (sans motor) on the way. I had some concern that using the replacement to press out the old bushing might put more pressure on the new one that was good for it, but it really didn't seem to take much pressure at all to do the job, so I'm not convinced it was my doing - but ya never know. Oh, and I've got a Max Headroom 12" single somewhere!
Couple of comments here, scoring on the upper shaft surface is extremely common on TD-124 with a lot of run time particularly if it was a unit that had nylon bushings originally. (When they start to seize they score the shaft, which accelerates the process of seizing) A lot of tables were retrofitted with new bearing housings when this happened during the products production life time. The other common cause was dry or damaged bearings. A light lapping of any raised metal is acceptable, do no more IMO. The only table I have seen that did not have this issue out of the ones I have overhauled was mine, and that was simply because it was barely used and then forgotten for 40yrs. (I've lost track but I can think of six I have overhauled off the top of my head, and have another on the way.)
Do not drill the oilite bushing as this may do further damage and can result in closed pores. (Generally honing or reaming will close the pores according to the makers of oilite bushings in the UK so replacement is the best option.) If you can identify the fragment causing the scoring you may be able to remove it with an x-acto knife. Better might be to replace the pair of bushings. Note that one crooked insertion of the spindle may cause this to occur again. Frankly I would fill the well about 1/3 full of 20wt oil, make sure that the upper bushing is wet and allow it to settle. Spin the spindle and listen carefully for scraping noises - if there are none you are good to go.
Check periodically for further damage, if there is none I would not obsess about it.
I understand why honing is not recommended. But a reem is a cutter and is how a bronze bushing is made. A good stint in an ultrasonic cleaner would remove the cuttings.
But hey, if its not I recommended practices fir the tt stuff then I'd shy away from doing it.
Nick
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Test run after idler wheel bushing replacement - YouTube
OK, perhaps false alarm on the new idler wheel bushing. I've got it moving well enough to turn on its own, although it clearly needs some breaking in, which is going on now. The video above shows the strobe as I shift speed 33 1/3, 45, 78 and back down. Some of the sloppiness is likely the idler wheel, but the belt's not been replaced yet.
Kevinkr - no worries, if a bushing isn't right, I've learned enough to know only someone well versed in tooling sintered bronze, someone with the right tools, should attempt it. I'd be much more inclined to get another bushing. As for the platter spindle wear at the top, I agree. Nothing I'd do would be intended to do any more than smooth out the scoring - not to try and get back to a mirror finish. I don't want to reduce the diameter even 1/1000 of a mm if I don't have to.
Now - here's a question. Anyone successfully set up a rig for truing up the metal disk that the rubber portion of the idler wheel is affixed to? Mine's walking up and down the stepped pulley a hair and I'm thinking it shouldn't be an impossible task to fix it.
OK, perhaps false alarm on the new idler wheel bushing. I've got it moving well enough to turn on its own, although it clearly needs some breaking in, which is going on now. The video above shows the strobe as I shift speed 33 1/3, 45, 78 and back down. Some of the sloppiness is likely the idler wheel, but the belt's not been replaced yet.
Kevinkr - no worries, if a bushing isn't right, I've learned enough to know only someone well versed in tooling sintered bronze, someone with the right tools, should attempt it. I'd be much more inclined to get another bushing. As for the platter spindle wear at the top, I agree. Nothing I'd do would be intended to do any more than smooth out the scoring - not to try and get back to a mirror finish. I don't want to reduce the diameter even 1/1000 of a mm if I don't have to.
Now - here's a question. Anyone successfully set up a rig for truing up the metal disk that the rubber portion of the idler wheel is affixed to? Mine's walking up and down the stepped pulley a hair and I'm thinking it shouldn't be an impossible task to fix it.
Kevinkr - I did a thread search and saw at one point you had ordered the Thakker belt and got the impression you planned on comparing it to the OEM belt you said he also sold. Yesterday I messaged him, asking for some clarification on the two ads he has up currently, one for $24.50, the other $38.50. For the life of me, I couldn't determine from the ads (which had the same belt photo) if they were really for different belts, or if he'd simply raised his price and not killed the old ad. What he sent back only added to my confusion. I imagine something may have gotten lost in translation.
"This kind of genuine “Thakker” precision drive belt is manufactured by the same producer with the original specifications (identical material and identical measures) as the “Thorens” drive belt, only two differences exist between a “Thakker” and a “Thorens” belt: drive the price and the print."
So, before I buy a replacement belt, what was your experience with the two he was offering? One any different than the other and if so, how so?
Thanks
"This kind of genuine “Thakker” precision drive belt is manufactured by the same producer with the original specifications (identical material and identical measures) as the “Thorens” drive belt, only two differences exist between a “Thakker” and a “Thorens” belt: drive the price and the print."
So, before I buy a replacement belt, what was your experience with the two he was offering? One any different than the other and if so, how so?
Thanks
I never tried the cheaper Thakker belt, and cannot recommend the more expensive one at all. Lots more detail on the belts.. The best ones come from Schopper, now at a considerable price increase. There is a fellow on eBay in FLA that I reference further along in the thread - his belts have worked very well on 60Hz tables, and the belts are very inexpensive.
Speed change is never accomplished instantaneously particularly in the downward direction due to platter inertia, to reduce wear and tear on the driveline I generally wait a few seconds and manually slow the platter down before reengaging the mechanism - this reduces wear on the idler.
I would not attempt to true the idler as long as it does not hit the next lower step on the idler I would expect the effect on performance to be minimal. Replacement idlers and rare NOS ones show up on eBay from time to time.
Speed change is never accomplished instantaneously particularly in the downward direction due to platter inertia, to reduce wear and tear on the driveline I generally wait a few seconds and manually slow the platter down before reengaging the mechanism - this reduces wear on the idler.
I would not attempt to true the idler as long as it does not hit the next lower step on the idler I would expect the effect on performance to be minimal. Replacement idlers and rare NOS ones show up on eBay from time to time.
Kevinkr - Thanks for the belt info., will check out the FLA seller. Good point about platter inertia, something I'd not thought of at all. Can't be good on the belt either. AND - about your comment that replacing the idler wheel bushing should help reduce rumble - the graphs I pulled this morning suggest I achieved a 9-12dB drop from 0-20Hz, more than that 20-100Hz. This from comparing charts pulled from the run-out on the record I've been using as a benchmark. Waveform looks a lot nicer too. Guess I'm going in the right direction.
Excellent improvement!
Agreed - but - I'm still suspicious of the new idler bushing. It may be the cause of the run-out I'm seeing on the wheel. Oil coming to the top, between bushing and shaft is capturing a little air and a close ear can hear a bubbling in sync with the wheel traveling up and down. Since I've got another coming from Spain I might as well change it out. I'll probably let it sit until then to protect the shaft. FLA belt seller's running a 2 for 1 sale, so I've got belts coming as well.
Question on rebuilding the motor. I know you've done it (more than once?) But saw some comment suggesting you had second thoughts about doing it, at least in one case. Also read something about "tinned bronze" bushings on some early models. True for some of the MK IIs? Gripping top washer on all motor mounts tells me there is certainly some vibration there, so if it's a "can't hurt to rebuild" situation, I'll order the parts kit from eBay. Apparently I'm finally getting into this project.
Idler bushing replacement - Before/After charts
In the first pic, the top waveform and spectrograph were taken a few weeks ago, prior to yesterday's replacement of the idler wheel bushing. The bottom was taken this morning. Both represent a small segment of the runout, side 1, John Coltrane Quartet - Ballads. Rumble filter on the pre-amp was engaged (hopefully one day that won't be necessary, but it's how I've been grabbing charts so need to stay consistent for now).
For reference, the second pic shows a sample of track 2, also taken this morning.
I'm not happy with the new idler bushing, though it clearly is making an improvement on the low end. It will be getting replaced soon as the new one arrives. I'm also aware that the stepped pulley bushings are sloppy, so those will get swapped out at the same time. Once I've made those changes, I'll pull another set of charts.
In the first pic, the top waveform and spectrograph were taken a few weeks ago, prior to yesterday's replacement of the idler wheel bushing. The bottom was taken this morning. Both represent a small segment of the runout, side 1, John Coltrane Quartet - Ballads. Rumble filter on the pre-amp was engaged (hopefully one day that won't be necessary, but it's how I've been grabbing charts so need to stay consistent for now).
For reference, the second pic shows a sample of track 2, also taken this morning.
I'm not happy with the new idler bushing, though it clearly is making an improvement on the low end. It will be getting replaced soon as the new one arrives. I'm also aware that the stepped pulley bushings are sloppy, so those will get swapped out at the same time. Once I've made those changes, I'll pull another set of charts.
Attachments
When I first started posting here about my Thorens TD-124/II, I mentioned that it came to me by way of a friend in Arizona. What I likely did not say was where that friend lived. Well the town name's known to a lot more people these days - Yarnell. My friend John lives in a trailer on the east side of town and far as he knows the trailer is still there after the fire. As far as he knows because he, his girlfriend, and their cats have been living with relatives in Phoenix for the past week and as of this morning authorities hadn't cleared residents to go back to Yarnell. Power and water were still out last I heard. Anyway, some things are more important than audio gear, so I hope everyone will send good thoughts in the direction of Yarnell, AZ. 18 firefighters died there and a lot of people will return to nothing but a pile of ashes. John and his girlfriend are likely among the more lucky ones
Hello missouricatman
This is one of those times when I wish I wasn't right, but the number of firefighters that died is 19.
I live 30 miles from Yarnell which seems like a safe distance. It isn't though, when you consider that one of the recent wildfires has moved at the rate of 4 miles in 20 minutes. Scary!
I wish your friend good luck.
Sincerely,
Ralf
This is one of those times when I wish I wasn't right, but the number of firefighters that died is 19.
I live 30 miles from Yarnell which seems like a safe distance. It isn't though, when you consider that one of the recent wildfires has moved at the rate of 4 miles in 20 minutes. Scary!
I wish your friend good luck.
Sincerely,
Ralf
Hi Raif,
Yes, you're right. 19. Thanks for correcting that. Considering where you live, you probably know the storage lockers on the west end of town run by an EMT named Phil and his wife. My friend John and his girlfriend Dennie live out back on that property. They often sell by the roadside out front. John sent me a hurried message as they were loading up the cats and heading to PHX. It wasn't until later he told me the flames were only a few hundred yards away.
Jim
Yes, you're right. 19. Thanks for correcting that. Considering where you live, you probably know the storage lockers on the west end of town run by an EMT named Phil and his wife. My friend John and his girlfriend Dennie live out back on that property. They often sell by the roadside out front. John sent me a hurried message as they were loading up the cats and heading to PHX. It wasn't until later he told me the flames were only a few hundred yards away.
Jim
Spindle upgrade - thoughts?
Lots of things on order, but haven't pulled the trigger on a spindle upgrade. Specifically I've been looking at one that provides a more substantial end cap, replacement wear pad and silicone nitride ball bearing. I'd appreciate hearing from anyone who has installed the kit. Do you feel it's beneficial. If so, how so? Thanks in advance
Lots of things on order, but haven't pulled the trigger on a spindle upgrade. Specifically I've been looking at one that provides a more substantial end cap, replacement wear pad and silicone nitride ball bearing. I'd appreciate hearing from anyone who has installed the kit. Do you feel it's beneficial. If so, how so? Thanks in advance