technics linear tracking issue

[Radiosky]

Thanks for the feedback
The square rubber band that connects the electric motor to the nylon worm drive is readily available.
The issue for me is the braided fabric drive rope which shuttles the tonearm mechanism across its trajectory.

The service manual lists this as #41 SFUZC05N02E Arm Drive Rope Assembly
The term 'ass'y' implies, I think, its the rope, brass connector that locks to tonearm carriage, and spring all measured and pre-assembled.

Searches for the part number yield 'nada'
The square rubber drive belt can be found. I located via search on SBS2.9

On your SL-7: Did you have a problem with the rubber drive belt or the fabric drive rope?
If rope, how did you remedy?

 

[Radiosky]

From SL-5 parts list:

 

[Chubba]

My problem was the belt.Unless I am wrong but pretty sure I am not on my SL-7 the rope is like fine aircraft cable.

 

[Radiosky]

Aircraft cable sounds like a definite step up. The SL-5 that I have was an entry level product I think, although it performed flawlessly for decades. The drive rope was obviously a weak link.

 

[Chubba]

Any thoughts for a solution to the rope issue?

 

[Radiosky]

Well, it's a challenge without much, if any, published success by others.
I was able to size a stand of nylon fairly close to length and get it onto the spool and pulleys. The nylon is too weakly braided and stretchy to commit to.
I've ordered some radio dial twine that should be more durable and stable. Unless some advice arrives from someone who has attempted before, it will be trial and error all the way.
I think the original crimped brass connector was located asymetrically on the rope. Meaning it may be necessary to try and crimp ferrules once a new rope is in place and the connector is seated onto the tonearm carrier. Tricky.
I like the idea repairing vintage electronics. I think a replacement SL-5 unit could be purchased cheaper than the time I will spend on it but we'll see...

 

[Chubba]

Hope it goes well.Cheers

 

[jupitersspot]

Seems strange to post to this old thread, but here goes. I bought an SL-5 locally for $40 with an Audio Technica cartridge. It's a bit dirty but is playing full records without issue. However, if I use the cueing control to raise the tonearm and advance it using the "Start" button it will proceed to move the tonearm assembly for maybe half an inch, and then will pull the tonearm out of line and stop advancing. Pressing "Stop" will move the out-of-line tonearm back, and once it reaches the outermost position the tonearm will pop back into line and everything is fine. If I do very small movements of left and right the mechanism is happy, but if I try to make long leftward movements (using "Start") it will pull the tonearm out of line and progress will stop. Full excursions to the right (via "Stop") operate fine and do not pull the tonearm out of line.

If you've seen this behavior and fixed it, please share your experience.

I have the service manual (Vinyl Engine) and I'm getting set to open it up and look around.

 

[jupitersspot]

I have more information. The lead weight at the rear of the tonearm is running into the metal frame at the rear of the top lid. There is a little rotational play in the traversing mechanism on the bearing rod, and when the lid is closed the tonearm can pivot just enough (stylus end goes up, weight end goes down) for the weight to run into the metal frame.

The tonearm height adjustment screw does not seem to help here -- it's already in the fully up position. I don't see any other adjustments that would help here. Has anyone seen this issue before and know how to solve it?

 

[jupitersspot]

Has anyone seen this issue before and know how to solve it?

I figured it out. The tonearm rides on a cylindrical bar which is held in place on the inboard side by a screwed-in bracket, and on the outboard side by a bent tab of sheet metal. The outboard tab had been bent down, and once I bent it back everything was happy again.

 

[Hugo65]

I figured it out. The tonearm rides on a cylindrical bar which is held in place on the inboard side by a screwed-in bracket, and on the outboard side by a bent tab of sheet metal. The outboard tab had been bent down, and once I bent it back everything was happy again.

Good to know you've sorted it out. I hope you're enjoying the SL 5. I've got a pair of SL10 and like them a lot.

 

[jupitersspot]

Good to know you've sorted it out. I hope you're enjoying the SL 5. I've got a pair of SL10 and like them a lot.

A pair you say? That's a nice set.
I grew up with an SL-10 in the house; I think we got it sometime around 1980 or so. My dad still has it, but at 81 his listening and hearing are much reduced. But it was because of the SL-10 that I bought this SL-5. Well, that and it was dirt cheap.

 

[Theo A]

Here are some videos that helped me fix my Sl10. They're very helpful, and the belt/dial cord cleaning procedures may help you sort out the problem with yours.
Also, double-check the arm belt for any slack and make sure it moves as the motor turns.

I hope it helps!

The long string/ cord snapped on my sl-5, how can I replace it ?

 

[jupitersspot]

You'll need to get a replacement part first; not sure of the best source for that. Then head over to HiFiEngine and download the service manual for the SL-5 (free with membership). Top of page 9 has steps and diagram that will tell you how to replace it.

 

[Radiosky]

Jupitorspot,
The grease in the track and gearing in these units hardens and becomes unyielding after the many years since leaving the factory.
Mine was getting that way and I got into and cleaned and replaced with grease ( I forget the specifics - it was purchased as a 'Milcot' substitute for an ELAC 40A I was working on)
I also picked up a parts/donor SL-5 that the drive rope was broken on because of this very same issue. I tried repeatedly to fabricate a drive rope out of dial string and jewelry crimp ferrules but eventually gave up because of my ineptitude with the non-OEM materials. Life and other projects were calling.

If anyone figures this out please post!
I think it's doable to successfully fabricate the drive rope but it wasn't me the last time I tried.

Other than that - my original SL-5 I bought in 1983 is still working. It has a rumble but it's been a solid performer. Not many options in P cartridges anymore.

 

[Subchannel]

I see this is an old post, but I´l try anyway:
I have a SL-10 where the tonearm doesn´t move forward. All the buttons works and are measured. Start is working. I´ve manually driven the arm forwards, and when pushing stop/ back the arm moves at both speeds (half/ full) or go back to rest position.
All photo sensors are working, so are the lightbulbs.
Checked the greace on the large gear and wormgear, they work. Pulled out motor leads and checked both directions with 9V battery, works as it should.
There´s no resistance or "life" in the motor when pushing Forward, I´ve tried to move the motor manually when Forward is down, nothing.
Anyone familiar with this?
Thank you in advance.

 

[Hugo65]

I see this is an old post, but I´l try anyway:
I have a SL-10 where the tonearm doesn´t move forward. All the buttons works and are measured. Start is working. I´ve manually driven the arm forwards, and when pushing stop/ back the arm moves at both speeds (half/ full) or go back to rest position.
All photo sensors are working, so are the lightbulbs.
Checked the greace on the large gear and wormgear, they work. Pulled out motor leads and checked both directions with 9V battery, works as it should.
There´s no resistance or "life" in the motor when pushing Forward, I´ve tried to move the motor manually when Forward is down, nothing.
Anyone familiar with this?
Thank you in advance.

A slack old tonearm belt, maybe? That's usually what goes wrong when everything else is right...

 

[Subchannel]

Nothing wrong with the belt(s).

 

[KENWOOD RULZ]

When you used the 9 volt battery on the motor, did you try to hold back the pulley with your fingers on the motor to see if it has any "Balls" ??

Also, is the tonearm slide perfectly clean??

 

[mccalljd]

The long string/ cord snapped on my sl-5, how can I replace it ?

Recently replaced the drive carriage cord on an SL-7. I had to find some radio dial cord approximately the same diameter, and then I removed the old cord and cafreully measured and marked it for length on the new cord. The best way to do that was to lay it stretched out and lay the new cord (also stretched tight) against it, leaving about 3 inches on either end. Since you can't get the crimp open to put the new cord in and crimp it back down, I simply tied it into a knot with both ends at the place I marked it at. To keep it from loosening up, once I had the knot tied for the correct loop length (took a few tries to get it correct), I cut the ends off, dabbed some glue on the cord, and put the knot in the same space on the spring wheret the crimp had been positioned. I had hoped to be able to open the crimped portion of the carriage ferrule (the part that fits in the carriage to drag it along) by driving a small tapered pin through the hole, but the brass is brittle on these things and the crimped portion broke part of the side out. No matter. Once I positioned the ferrule in the carriage and adjusted the cariage and tonearm into place, I carefully dabbed a bit of 3M weatherstrip adhesive on the ferrule at both ends, getting it on the ferrule and the cord. Once it dries for 24 hours, there is no way the ferrule will ever come loose. The unit now works as good as new, especially after replacing the belt and the capacitors on the board. It was a PITA, and I hope I never have to do that again to another unit, but it can be done. Not sure if I was just lucky or skilled enough to do it, but it worked.