Did someone say reduced speed 60 hertz pulley?
I read at least some of every post in this thread as I listened to records on my Mk I SN: 2045. This is the first time she's spun a disc since 1984 or so. At that time she was running slow and had been ever since I bought her for 50 USD in the used equipment rack at a local audio shop around 1977. I tried to fix her several times with no success so I just lived with slightly slow music until someone, (I can't remember who under what circumstances,) gave me flawless Mk II SN: 85982. Flawless that is, except for a big splash of bright red nail polish on the mat with a bit spilled over the upper platter. I swapped decks, armboards and platters and Bob's your uncle I had a properly functioning Frankenthorens. Life happened, digital happened, so by the mid nineties she was used for little more than ripping discs. Even then I got tired of manually entering track information so I usually just bought used CD's of my favorites. Fast forward and I remember that I've got a bunch of cool old records and discover that my decks are worth something but I don't need two.
I dug out the old one. First I spent 8 hours or so peering through a microscope picking bits of red out of the mat grooves with a dull X-acto knife. Pleased with the ruselt I totally disassembled the deck detailing each part as I went along. The belt and idler seem perfect and even the gummimuffins aren't too bad but I intend preform Mk II upgrade anyway. The thing that amazed me was how little wear the parts showed. The record spindle was a bit tarnished so I polished it with jeweler's tripoli and rouge on buffing wheels. Figuring I couldn't hurt I put the spindle bearing surfaces to the wheel using only the finer rouge. The light wear marks disappeared almost instantly. So that wasn't the cause of the slow running. I ordered bronze bearings, 1mm Durlin and gasket material from McMaster Carr and rebuilt the spindle housing. Disassembling the motor I found the motor shaft bearing surfaces perfect and the bearings moved freely in their keepers so I just oiled the motor and reassembled it.
With every thing ready for reassembly, and having found nothing amiss I feared that I'd put her together and she'd still be running slow. I was thinking perhaps bad motor windings. I had the idea that if worse came to worse I could make an oversize motor pulley. At this point I needed to drive to Detroit so while I was there I figured I'd pick up a reamer for the pulley bore. I don't have a microcrometer so with digital calpers I measured the motor shaft and came up with somthing like 4.74mm. Thinking, "What kind of crazy size is that?" I switched the caliper to merican and it read .1875. Hey, I can deal with 3/16". I got the reamer, returned home, put her togther, fired her up and after a short warm-up the speed was correct in the middle of the break range. Of course had I found this thread first I'd have known the problem was the plastic bearings.
I really enjoyed reading this and I learned a lot from you guys. Thank you all. So now I didn't need an oversize pulley, but gee, I got the reamer, so for grins I took up the undersize pulley challenge. It was fun and I'm pleased with the result. It seems to run smooth with no apparent vibration. Since I have no way to balance the thing I tried to keep the mass as low as possible.. It measures 1.151" and runs slower but within the break range. Still I'm going with the stock pulley and don't intend to do the impressive experimentation that some of you are. However, I will continue to follow this fascinating thread. So Kevin, The pulley's yours for the price of postage. I'd love to see what you do with it.
Doug
I read at least some of every post in this thread as I listened to records on my Mk I SN: 2045. This is the first time she's spun a disc since 1984 or so. At that time she was running slow and had been ever since I bought her for 50 USD in the used equipment rack at a local audio shop around 1977. I tried to fix her several times with no success so I just lived with slightly slow music until someone, (I can't remember who under what circumstances,) gave me flawless Mk II SN: 85982. Flawless that is, except for a big splash of bright red nail polish on the mat with a bit spilled over the upper platter. I swapped decks, armboards and platters and Bob's your uncle I had a properly functioning Frankenthorens. Life happened, digital happened, so by the mid nineties she was used for little more than ripping discs. Even then I got tired of manually entering track information so I usually just bought used CD's of my favorites. Fast forward and I remember that I've got a bunch of cool old records and discover that my decks are worth something but I don't need two.
I dug out the old one. First I spent 8 hours or so peering through a microscope picking bits of red out of the mat grooves with a dull X-acto knife. Pleased with the ruselt I totally disassembled the deck detailing each part as I went along. The belt and idler seem perfect and even the gummimuffins aren't too bad but I intend preform Mk II upgrade anyway. The thing that amazed me was how little wear the parts showed. The record spindle was a bit tarnished so I polished it with jeweler's tripoli and rouge on buffing wheels. Figuring I couldn't hurt I put the spindle bearing surfaces to the wheel using only the finer rouge. The light wear marks disappeared almost instantly. So that wasn't the cause of the slow running. I ordered bronze bearings, 1mm Durlin and gasket material from McMaster Carr and rebuilt the spindle housing. Disassembling the motor I found the motor shaft bearing surfaces perfect and the bearings moved freely in their keepers so I just oiled the motor and reassembled it.
With every thing ready for reassembly, and having found nothing amiss I feared that I'd put her together and she'd still be running slow. I was thinking perhaps bad motor windings. I had the idea that if worse came to worse I could make an oversize motor pulley. At this point I needed to drive to Detroit so while I was there I figured I'd pick up a reamer for the pulley bore. I don't have a microcrometer so with digital calpers I measured the motor shaft and came up with somthing like 4.74mm. Thinking, "What kind of crazy size is that?" I switched the caliper to merican and it read .1875. Hey, I can deal with 3/16". I got the reamer, returned home, put her togther, fired her up and after a short warm-up the speed was correct in the middle of the break range. Of course had I found this thread first I'd have known the problem was the plastic bearings.
I really enjoyed reading this and I learned a lot from you guys. Thank you all. So now I didn't need an oversize pulley, but gee, I got the reamer, so for grins I took up the undersize pulley challenge. It was fun and I'm pleased with the result. It seems to run smooth with no apparent vibration. Since I have no way to balance the thing I tried to keep the mass as low as possible.. It measures 1.151" and runs slower but within the break range. Still I'm going with the stock pulley and don't intend to do the impressive experimentation that some of you are. However, I will continue to follow this fascinating thread. So Kevin, The pulley's yours for the price of postage. I'd love to see what you do with it.
Doug
I'm sure I'm late to the party but I just saw one of those. We idler wheel that's metal with an o ring on the edge. Anyone try these? Worth trying? There 160 bucks on ebay. I never saw them before.
Also who sells the motor mount spring kit for the td124 that replaces the rubber bushing? I'm still running the gel bushing which if I recall where deemed inferior to the stock bushings.
Thanks,
Nick
Also who sells the motor mount spring kit for the td124 that replaces the rubber bushing? I'm still running the gel bushing which if I recall where deemed inferior to the stock bushings.
Thanks,
Nick
15569 is up and running again, or at least the motor, step pulley and idler wheel!
[/IMG]
The observant diyaudio member will notice that the idler is running too high, I will adjust that!
The step pulley:
It did some thorough cleaning. Obviously so good that I managed to rip out the internal felt oil retainer.
I flushed the bushing with hot oil
I polished the shaft which had some markings. There was even a mark after the bearing ball on top of the shaft. I managed to polish that away.
I tested the step pulley after the treatment and there was still some ticking sound comming from it, so I did a second round of cleaning and polishing. After that only the whirl from the step pulley
Idler wheel:
I also mounted a new idler wheel, made by Simone L, after I cleaned and polished the shaft. In first try the idler made some ticking noises; I polished and cleaned the shaft and idler once again and flushed with new oil (Castrol Classic Z 20W). Now completly quiet. I probably had some small particles stuck in shaft/bushing.
Really quiet! Holding my ear 10 cm/4 inches from the step pulley and idler. I hear the whirl from the step pulley. The idler is quiet. Standing 1 metre /3 feet away it I can not hear the step pulley
Today I runned it (without platter) for six hours and afterwards cleaned and flushed the step pulley and idler bushings with new oil. Still silent standing 1 metre away!
Tomorrow I will mount the platter and play some Music. There is a SME 3009R and an Ortofon SPU waiting to offer their services!
//
Nils
The observant diyaudio member will notice that the idler is running too high, I will adjust that!
The step pulley:
It did some thorough cleaning. Obviously so good that I managed to rip out the internal felt oil retainer.
I flushed the bushing with hot oil
I polished the shaft which had some markings. There was even a mark after the bearing ball on top of the shaft. I managed to polish that away.
I tested the step pulley after the treatment and there was still some ticking sound comming from it, so I did a second round of cleaning and polishing. After that only the whirl from the step pulley
Idler wheel:
I also mounted a new idler wheel, made by Simone L, after I cleaned and polished the shaft. In first try the idler made some ticking noises; I polished and cleaned the shaft and idler once again and flushed with new oil (Castrol Classic Z 20W). Now completly quiet. I probably had some small particles stuck in shaft/bushing.
Really quiet!
Holding my ear 10 cm/4 inches from the step pulley and idler. I hear the whirl from the step pulley. The idler is quiet. Standing 1 metre /3 feet away it I can not hear the step pulleyToday I runned it (without platter) for six hours and afterwards cleaned and flushed the step pulley and idler bushings with new oil. Still silent standing 1 metre away!
Tomorrow I will mount the platter and play some Music. There is a SME 3009R and an Ortofon SPU waiting to offer their services!
//
Nils
Thanks Nils.
I see your running the idler pull I was asking about. What do you think of it? Is it worth the cost? It makes some interesting possibilities for try different durometer o rings, and different o ring material. I imagine a low durometer is quiter then a high durometer. Possibilities for trying different materials could be quite the improvement. There are many different types. There's fluropolymers, epdm, nitrial, buna, and silicone. There's also different formulations of each material too. To give specific improved properties other then hardness. For instance the resistance to extrude. Also expansion rates. Resistance to gas lancing too, and explosive decompression.
I see your running the idler pull I was asking about. What do you think of it? Is it worth the cost? It makes some interesting possibilities for try different durometer o rings, and different o ring material. I imagine a low durometer is quiter then a high durometer. Possibilities for trying different materials could be quite the improvement. There are many different types. There's fluropolymers, epdm, nitrial, buna, and silicone. There's also different formulations of each material too. To give specific improved properties other then hardness. For instance the resistance to extrude. Also expansion rates. Resistance to gas lancing too, and explosive decompression.
Hi nhuwar,
I mounted the idler wheel last night, and have only tried without the platter mounted sofar It is not fair to compare with my original idler which needs a new bushing and also with another idler wheel from Technical and General in the UK ( I am not sure they are around anylonger)
The only thing I can say that it is completly quiet, perfectly round and of high quality. It is thinner and lighter than the original. As you mentioned it comes with a variety of o-rings. At this stage however I do not know if it works with the platter! I will know more tomorrow!
// Nils
Last time I checked the geltec bushings were about 10dB quieter than the stock style bushings, and there are a number of posts in this thread with graphs that illustrate that fact pretty clearly. I've used both and the geltec clearly do a better job.
The springs are available from Hanze HiFi in Holland, they work fine, but I can see roughly 1mm of deflection off center with a Schopper belt installed.
There are a variety of noise mechanisms associated with the idler, some are generated by the idler itself and others are transmitted through the idler from other drive train components. Mirko makes both an excellent OEM style replacement with IMLE runs very quietly, and a light weight metallic disk version that allows the use of various elastomer O rings - I have not tried this as I feel perhaps incorrectly that several mm of supple rubber tire in the OEM configuration does a better job isolating the platter from noise generated by the drive train. Note that is opinion only, and I acknowledge I could be wrong - likely it is significantly better than a hardened, dimpled OEM idler..
I have four idlers, and really only two of the four I have are fully acceptable in use on my tables. The other two have issues with hardened rubber spots that make an audible thump when that portion of the idler come in contact with the stepped pulley - there are no visible defects. One idler makes a variable swishing noise as it rotates and one can see the tire is off center even though the running surface of the tire is true about its entire circumference. I may attempt to replace the bushings on these two as well since they seem a bit sloppier than the others. The tables otherwise run fine with any of these idlers and there is not obvious problem in playback, just in the mechanical symphony coming from under the hood which is considerable on my older MKI table and almost completely absent now on my MKII after much effort. (All detailed here)
The springs are available from Hanze HiFi in Holland, they work fine, but I can see roughly 1mm of deflection off center with a Schopper belt installed.
There are a variety of noise mechanisms associated with the idler, some are generated by the idler itself and others are transmitted through the idler from other drive train components. Mirko makes both an excellent OEM style replacement with IMLE runs very quietly, and a light weight metallic disk version that allows the use of various elastomer O rings - I have not tried this as I feel perhaps incorrectly that several mm of supple rubber tire in the OEM configuration does a better job isolating the platter from noise generated by the drive train. Note that is opinion only, and I acknowledge I could be wrong - likely it is significantly better than a hardened, dimpled OEM idler..
I have four idlers, and really only two of the four I have are fully acceptable in use on my tables. The other two have issues with hardened rubber spots that make an audible thump when that portion of the idler come in contact with the stepped pulley - there are no visible defects. One idler makes a variable swishing noise as it rotates and one can see the tire is off center even though the running surface of the tire is true about its entire circumference. I may attempt to replace the bushings on these two as well since they seem a bit sloppier than the others. The tables otherwise run fine with any of these idlers and there is not obvious problem in playback, just in the mechanical symphony coming from under the hood which is considerable on my older MKI table and almost completely absent now on my MKII after much effort. (All detailed here)
Just for reference. I've never had a problem with the TD124 running too fast and not being able to control it. It is a simple matter of adjusting the eddy magnet into the correct proximity with the stepped pulley for correct operating speed. Is it possible we are agonizing far too much over step pulley noise?
-Steve
then something else.
Is motor wired correctly to the voltage terminal?
Probably it should be mentioned that the voltage terminal should be selected correctly for the mains you have. you know, put the screw in the 100/120 hole if your mains is 110/120 vac. Just covering that base.
What is mains voltage at input. 110 to 120 should work fine.
Using correct drive pulley? 50hz / 60hz
Is eddy magnet very strong? It should be. It should be strong enough to pull itself toward the step pulley when the set screw is loose.
-Steve
I should think the 100-120 hole is preferable.
My exp is with earlier models, all mk1 and some early mk1 (2729, 2128 and 2078). I have a 13943 now using windings that I took from 7888 that does not exhibit any such problems. (13943's windings were shorted.)
Fwiw, I've got some new mkII revision windings coming from Simone. I'll reserve my comments on this until I see what kind of operating speed I have with those.
-Steve
You're not the first. when I purchased 2729 (my first td124) the previous owner couldn't get the thing to run at correct speed. He complained that it ran too fast. Well, it ties in with your exp since that seller had the drive pulley upside down as well. Ok for me, though. I got a good price on that unit sold to me as a fixer-upper with an unresolved issue.
It was hiding in plain sight.
-Steve