So noted. I'm curious about the fiber washer, is this something you had on hand, or was it procured specifically for this purpose; and if so, where from? Any idea what its original purpose may have been so I can go looking for a similar part?
To be honest, I'd considered removing the whole mechanism and fitting a powered cueing setup of my own design, as the full auto operation wasn't all that important to me. I'd do prefer to have a curing mechanism However, rather than simply "dropping the needle" by hand. That said, siince you have apparently developed a working solution for the original design, I'll try to run with that first and hope it works for me.
One final side thought, you mentioned Fedron. Hadn't thought about that stuff in 20 something years. Back in 1996 I spent a miserable but quite instructive year doing refurbs on large duplicating systems and we used a lot of that to clean and recondition feed tires and belts on those machines. Always hated working with it, very nasty stuff. But I guess a jug of it will need to be added to my bench supplies now.
To be honest, I'd considered removing the whole mechanism and fitting a powered cueing setup of my own design, as the full auto operation wasn't all that important to me. I'd do prefer to have a curing mechanism However, rather than simply "dropping the needle" by hand. That said, siince you have apparently developed a working solution for the original design, I'll try to run with that first and hope it works for me.
One final side thought, you mentioned Fedron. Hadn't thought about that stuff in 20 something years. Back in 1996 I spent a miserable but quite instructive year doing refurbs on large duplicating systems and we used a lot of that to clean and recondition feed tires and belts on those machines. Always hated working with it, very nasty stuff. But I guess a jug of it will need to be added to my bench supplies now.
This is incredible news for sure. Its been fun watching your progress on the TT. Your attention to detail is evident here from your detailed descriptions to your high res pictures. Were lucky to have helpful tech's like you here on AK. I feel especially fortunate because the Turntable in question is mine. This unit is in stunting condition and deserves to be enjoyed. When I first powered it up I was very sad to see it had issues. As I'm quickly learning Watthour you like a good challenge and meet them head on. I can't wait to pick up this TT. Thanks for all your hard work on this XR-Q9. Fever
Part III
After some extended use, it appears that one more item required attention. The cueing clutch had been functioning flawlessly. The tone arm clutch had begun slipping, preventing the arm from positioning reliably. It would stutter at times, and not make proper position. Refer to the factory exploded view diagram:
The tone arm slip clutch driver "friction pulley" (Item 25) had lost traction. I previously mentioned that applying silicone grease to the clutch disc (Item 10) was indicated in the factory directions, but commented that this was a BAD idea. I now better understand why. The "pulley" is actually two rubber discs, like flat washers or tires, sandwiched into the cutout space in the drive shaft/gear (Item 23) with a thrust washer (Item 24) between the shaft and the upper tire. The lower tire had taken a set/distorted from 40 years of being sandwiched in there:
www.wwdsltd.com/files/XR-Q9-30ASpring.jpg
It could have been reversed, but I felt that another thrust washer (not in the factory parts diagram) needed to be added to the lower end of the stack, just like the one on the upper end. This helps apply even pressure to the discs and allows better engagement of the "friction pulley" rubber discs.
www.wwdsltd.com/files/Q9-25BFrictionClutchShim.jpg
The thrust washer is actually a split "C" clip made of either polypropylene or nylon/UHMW plastic. It's size is shown with a reference:
www.wwdsltd.com/files/Q9-25DFrictionClutchShim.jpg
Another view of it installed:
www.wwdsltd.com/files/Q9-25CFrictionClutchShim.jpg
Interestingly, the XR-Q11 drive appears to have a spring-loaded friction clutch in this position, virtually eliminating any problems like this due to wear.
www.wwdsltd.com/files/Q11-ToneArmDrive.jpg
(Links updated)
After some extended use, it appears that one more item required attention. The cueing clutch had been functioning flawlessly. The tone arm clutch had begun slipping, preventing the arm from positioning reliably. It would stutter at times, and not make proper position. Refer to the factory exploded view diagram:
The tone arm slip clutch driver "friction pulley" (Item 25) had lost traction. I previously mentioned that applying silicone grease to the clutch disc (Item 10) was indicated in the factory directions, but commented that this was a BAD idea. I now better understand why. The "pulley" is actually two rubber discs, like flat washers or tires, sandwiched into the cutout space in the drive shaft/gear (Item 23) with a thrust washer (Item 24) between the shaft and the upper tire. The lower tire had taken a set/distorted from 40 years of being sandwiched in there:
www.wwdsltd.com/files/XR-Q9-30ASpring.jpg
It could have been reversed, but I felt that another thrust washer (not in the factory parts diagram) needed to be added to the lower end of the stack, just like the one on the upper end. This helps apply even pressure to the discs and allows better engagement of the "friction pulley" rubber discs.
www.wwdsltd.com/files/Q9-25BFrictionClutchShim.jpg
The thrust washer is actually a split "C" clip made of either polypropylene or nylon/UHMW plastic. It's size is shown with a reference:
www.wwdsltd.com/files/Q9-25DFrictionClutchShim.jpg
Another view of it installed:
www.wwdsltd.com/files/Q9-25CFrictionClutchShim.jpg
Interestingly, the XR-Q11 drive appears to have a spring-loaded friction clutch in this position, virtually eliminating any problems like this due to wear.
www.wwdsltd.com/files/Q11-ToneArmDrive.jpg
(Links updated)
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After operating about 10 hours, set for 7" disc size and on "repeat" mode, I calculated it operated about 140 cycles. The unit was shut off and tone arm drive mechanism removed for measurements.
NOTE:
The centerline distance between the center clutch drive gear and cueing clutch driven gear was checked. Due to the arrangement of the mounting frame it is apparent that the gear sizes could be altered such that the drive ratio would decrease from approximately 2.26:1 down to 1.26:1. This would have been a very good idea during the original design, but would require a fairly reasonable effort to modify existing gears and graft on new plastic gears of the correct pitch diameter. These would be about 27 : 22 mm.
The current state of the table in question following the alterations outlined above is that it functions as designed, with reliability. Again, individual results can vary, but the cueing clutch weakness seems to be the most predominant failure mode, and both XR-Q9 and XR-Q11 models may benefit from these adjustments. The XR-Q11 seems less likely to suffer the tone arm clutch weakness of the Q9, but if one does, a similar method might be employed to resolve it.
NOTE:
- As was indicated previously, a separate ground wire was added so that the original (soldered on) ground could be left intact on the table chassis and the mechanism could be grounded via one of its mounting screws. The only other electrical connection is a 5-pin connector to the main board. With that simple augmentation, removal and installation is much easier. The unit had been removed and installed so many times that anti-seize compound was applied to the mounting screw threads to avoid permanent damage to the die cast table frame (steel machine screws into soft metal). This may be a good practice regardless of whether the mechanism is removed only one or dozens of times.
The centerline distance between the center clutch drive gear and cueing clutch driven gear was checked. Due to the arrangement of the mounting frame it is apparent that the gear sizes could be altered such that the drive ratio would decrease from approximately 2.26:1 down to 1.26:1. This would have been a very good idea during the original design, but would require a fairly reasonable effort to modify existing gears and graft on new plastic gears of the correct pitch diameter. These would be about 27 : 22 mm.
The current state of the table in question following the alterations outlined above is that it functions as designed, with reliability. Again, individual results can vary, but the cueing clutch weakness seems to be the most predominant failure mode, and both XR-Q9 and XR-Q11 models may benefit from these adjustments. The XR-Q11 seems less likely to suffer the tone arm clutch weakness of the Q9, but if one does, a similar method might be employed to resolve it.
There may be concern regarding the source of this specialized "C" clip used to shim and bolster the tone arm friction clutch rubber discs:
www.wwdsltd.com/files/Q9-25CFrictionClutchShim.jpg
As is frequently the case, the Grand Scheme (fate, if you will) often provides solutions as necessary. The manufacture and sale of these tables was around 1980. Coincidentally, that was approximately the same time when the proliferation of personal computers began. It would seem that the Chinese dutifully provided us with an ample supply of Sansui Tone Arm Clutch (STAC) repair parts. Within some of the cheapest, lowest-quality PC parts these STAC parts have been waiting to be harvested for our present use. Don't make the common mistake of selecting a high-quality part, since you could be confounded by actually finding real, metal parts instead. With little more than a scrap CPU processor heat sink or small case cooling fan, and with nothing else but an Exacto knife, the STAC "C" clip can be removed from its storage place to be relocated to its rightful place on the Sansui turntable (center of the photo):
www.wwdsltd.com/files/Q9-25EFrictionClutchShimSource.jpg
It fits nearly perfectly.
www.wwdsltd.com/files/Q9-25CFrictionClutchShim.jpg
As is frequently the case, the Grand Scheme (fate, if you will) often provides solutions as necessary. The manufacture and sale of these tables was around 1980. Coincidentally, that was approximately the same time when the proliferation of personal computers began. It would seem that the Chinese dutifully provided us with an ample supply of Sansui Tone Arm Clutch (STAC) repair parts. Within some of the cheapest, lowest-quality PC parts these STAC parts have been waiting to be harvested for our present use. Don't make the common mistake of selecting a high-quality part, since you could be confounded by actually finding real, metal parts instead. With little more than a scrap CPU processor heat sink or small case cooling fan, and with nothing else but an Exacto knife, the STAC "C" clip can be removed from its storage place to be relocated to its rightful place on the Sansui turntable (center of the photo):
www.wwdsltd.com/files/Q9-25EFrictionClutchShimSource.jpg
It fits nearly perfectly.
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Amazing. You really are getting to the nitty gritty of this tonearm mechanism. How did you know about the c clip in the fan?
OK. I never took the label off on any of them.
It's been faithfully repeating on a 4:25 cycle for 36 hours. That's about 500 trips around the block, and it hasn't faltered yet. I'm beginning to think it's not going to fail again for several more years, at least. Statistically, that's a 99.99% quality rate. The bottom cover has been installed and a different piece of vinyl set up for a 4:10 cycle (33 RPM, 7" disc size, Repeat mode). so that it should get another 350 or so cycles before I'll feel confident that I won't see this unit again except in photos.
Sounds like you have this problem totally figured out now. I'm totally impressed with the level of time and dedication you put forth to repair this unit. Now people can finally enjoy the automatic features of the Sansui XR-Q9 Turntable for years to come. Thanks for taking this problem child on. Fever
Lwrs10
Super Member
Fantastic thread. I've been through all of this with mine.
If I remember correctly, I used a faucet rubber washer to replace the spacer. And roughed up the copper side of the clutch with sandpaper above the rubber "ring". That fixed the clutch side.
Then I had issues with the optic stuff not working correctly. I had to cannibalize the optic board out of some other model of Sansui table.
Then had to realign the optic tone wheel. That took hours to do.
Also had to replace a few of the buttons/switches from the other parts table I had.
It's been a solid table since though.
If I remember correctly, I used a faucet rubber washer to replace the spacer. And roughed up the copper side of the clutch with sandpaper above the rubber "ring". That fixed the clutch side.
Then I had issues with the optic stuff not working correctly. I had to cannibalize the optic board out of some other model of Sansui table.
Then had to realign the optic tone wheel. That took hours to do.
Also had to replace a few of the buttons/switches from the other parts table I had.
It's been a solid table since though.