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FF/REW fix ctf-8282,9191,1000 RXA-581, NOT DIY

markthefixer said:
And so far, IIRC no UNCRACKED clutches have come in here.
Click to expand...

There was me thinking that I was VERY unlucky to have bought TWO ct-f1000's that suffer from this problem!!!

I wonder if the amount of use a deck has had is the biggest factor in the failure of this part or could time alone take its toll?
 
pauls1 said:
There was me thinking that I was VERY unlucky to have bought TWO ct-f1000's that suffer from this problem!!!

I wonder if the amount of use a deck has had is the biggest factor in the failure of this part or could time alone take its toll?
Click to expand...

Nope. It is the most stressed part in the deck of that material. Nylon dries out and becomes brittle. That small part of the design was ill-conceived. The stress has little to do with usage, it is continuous over the years. The metal sleeve becomes the strength member.
 
I'm bookmarking this one. Luckily my CTF-8282 is working fine. But how much longer remains to be seen.
 
Thanks for your response and answer.

I have now removed the the clutch part from the axle and the clutch itself stays together without the "inner" clutch spring pops out. The clutch assembly spins freely when I remove the up and down spring(as Mark called it) and it seems there isn´t anything that the clutch binds to.

So, at the moment I believe it is a lack of torque in the ff/rewind motor. I have when I remove the belt to the time counter a good speed in the rewind direction, the ff direction is still slow even if the small all time engaged brake is removed. But the clutch is never activated as the tape comes to an end in either direction.

I have only changed the tape sensing micro switch, could some of the other switches make a difference upon the voltage to the motor?

Thanks for your help and support!

Regards
Thomas
 

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markthefixer said:
Surprise!!!! Sproingggg.......
That tight friction fit between the post and the top button got WEAK!!! The assembly now does NOT float over the arm, instead the force of the big spring causes everything to bind - and tear up (formerly irreplaceable) expensive rubber on the drive motor's tire. Some early fixes tried to drive the frozen idler by increasing a spring size elsewhere, to increase the force of the motor drive tire onto the idler. Fail. Tear up that drive wheel really quick. Another fix tried to LIFT the binding surface of the botton of the idler ABOVE the arm. Fail. Still kills that drive tire.
View attachment 204854



The problem? Look at the post, there's a vertical CRACK in the post, and the part of the button that went down inside the post now just expands the post, rather than generating friction. The nylon dried out and lost some strength, and there IS a lot of tension there, so the nylon just split. The fix, a brass sleeve made out of brass tubing. Reinforces the entire post, the nylon is no longer in tension, it is in COMPRESSION. PASS.
Of course it's a lot of fun cutting something smaller than a pencil eraser, making sure the ends are square (not tilted or wobbly) and getting rid of any burrs inside which would make it impossible to get on, and any burrs on the outside that would make it impossible to get the idler B on. We're talking clearances of 0.001 inches. A lot of machining is 0.005 clearance... AND THEN, to make life miserable, KEEP from knocking the tube out of ROUND while doing all of this... fun...
but I figured it out. Die makers files, stuff like that...
View attachment 204859




BUT TANSTAAFL: there ain't no such thing as a free lunch..........
That sleeve increases the diameter of the post, and we DO get a freebie, the spring holder (green circle) clears it (edit - NOPE!! it gets bored out too because the button's outer wall expands). BUT the B idler doesn't fit over it. OK, easy enough... open up the hole in the B idler to restore the original clearance (the RED circle) - the sleeve isn't THAT thick..... well... close but no cookie...... LOOK AT THE BUTTON, on the Left.
Here comes the HARD part.
View attachment 204852


See the "halos", the green circle with the red circle inside of it, we'll get back to them. There is a tall nub that fits INSIDE of the idler B post, THAT'S the friction fit. The green cylinder drawn above it means that not only is the diameter correct, it is the all important friction fit surface that we must PRESERVE AT ALL COSTS.

Then there's the wall around it, forming a groove that the idler B post fits into, OR USED to fit into, until the brass sleeve was added.... OUCH.... so, options: 1. remove the wall, or 2. increase the groove's width (make that wall thinner) WITHOUT hurting the inner surface of the groove. Now we're back at the "halos", the red circle is the outer face of the groove, that must be made wider. The distance between the red halo part and the green halo part will end up being 0.008 inch ( eight thousandths of an inch ) when I'm done cutting..... So, I made another tool. It was a real %^$#^%%^%$ to make.... If I ever have a fire, I'm gonna grab that tool BEFORE the computer....

Note: the shavings around the button and in the groove are the result of stopping in the middle of the groove cutting to take a picture.

Success: this is what a good clutch looks like, the button is holding it all together without the assistance of the center shaft. So far I have done two. I will do these clutches like I do the STV-2H, STV-3H, STV-4H diodes. I get and fix the broke ones...
View attachment 204855


and this is what good versus bad looks like when on the arm, the one on the left is good, the one on the right is binding.
View attachment 204870

this picture was taken FIRST, before the clutch on the right was repaired, all the other pictures are THAT CLUTCH being repaired.... I now have NO binding clutches.
Click to expand...
markthefixer said:
The ctf-8282, ct-f9191 and ct-f1000 cassette decks are built like tanks, with one exception:
The FF / REW idler clutch. It's failure kills the deck's ability to Fast Forward and Rewind tapes.

The idler clutch is allowed to move in two directions (top/bottom of deck, left/right), and depending upon whether the driving tire is turning clockwise or counter clockwise, the idler comes to rest, wedging between the motor drive tire and either the cassette tape supply reel drive or the takeup reel drive and causes that reel to turn - thus Fast Forwarding or Rewinding.
View attachment 204931


This first (exploded assembly) drawing is of the arm and idler clutch assembly from the ct-f9191 service manual.
View attachment 204845

But this thing is more than just an idler, it has a clutch (idler "B", RNK-187) built in, to presumably reduce rubber wear when the cassette refuses to move, so instead of tearing up the rubber, the nylon to felt clutch joint slips. This clutch pack(idler "B", RNK-187) is the upper white wheel with the vertical grooves for friction. The motor's tire (looks a bit like a pencil eraser) turns on these vertical grooves. The lower idler with black tire (idler "A", RNK-188) is what hits the supply and takeup reel drives for the cassette.

View attachment 204846


This is a view of the partially disassembled arm, with the clutch pack (idler "B", RNK-187) on the left. Note the rather strong spring standing better than 1/2 inch tall. On top of that is the spring holder. In the center is the idler (idler "A", RNK-188) that contains (or is supposed to contain) the force of that spring. You can see the black tire on the bottom, and the felt friction/slip material on the flat surface that the post sticks up from. On top of the post is a button that presses on quite tightly, with a friction fit to the post. this friction fit is strong enough to contain (when new) the force of the idler B spring.
View attachment 204847

With the force contained, the idler a/ idler b assembly is floated OVER the supporting arm by the spring cup and spring shown on the right side, shown ON the shaft that the idler a/b assembly turns on.

That's how it's supposed to work. Time had a surprise for us.
Click to expand...
 
I have learned quite a bit in how to recover clutches that have been mistreated by ad-hoc repair attempts, as well as which clearances to watch like a hawk, as well as a few more to adjust - depending upon how things measure up....
Also even though I am still "on hiatus", I have NOT left clutch owners in the lurch, I am not on hiatus for clutches or STV diodes.
 
I just fully serviced my 9191 with the belt, pulley and tires from wjoe and still have no RW or FF, the motor does not even turn, can i test the motor on its own ??
 
it's a 12v motor, so disconnect it's two power wires (document which came from where FIRST) and sub in a power supply to test the motor. Then reverse the polarity and see if it runs the other direction as well.

BUT a locked up clutch WILL stall the motor, so push the idler away from the motor tire and see if the motor will turn on it's own before disconnecting any wires.

Oh, and if there's any more postings on this problem, please start your very own thread!!

(plus you got lucky I popped in and saw this. still on hiatus)

-----------------------------------------------------

edit October 2017

User Parastat (credit where credit is due!!) has discovered that INCREASED drag from the mechanical counter is a factor to blame for Rewind struggling.

http://audiokarma.org/forums/index.php?threads/ct-f9191-ff-works-great-rew-struggles.469551/

testing for this can be done by removing the third belt, between the tape movement sensor and the mechanical counter - then see how the ff and rew work. Flush counter with faderlube to correct.
 
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As usual, and excellent thread and tutorial. I found that the clutch in the CT-F6262 is nearly a clone of the ones depicted here, and the same methods can be applied. Three years ago I performed the same kind of "fix" for CT-F6262 with tubing reinforcement and refitting the mating parts. Hobby shops often have the tubing in sizes necessary for this purpose, and if that fails there is always the internet.
 
I am new to the game! Just obtained a 9191. Are you accepting these for repair? Thanks so much!!!





QUOTE="markthefixer, post: 3609359, member: 6768"]PM sent. saying more in a thread will turn it into an ad and get it deleted.[/QUOTE]
markthefixer said:
This has been moved up to the front, too many people are missing it.:



The ctf-8282, ct-f9191 and ct-f1000 cassette decks are built like tanks, with one exception:
The FF / REW idler clutch. It's failure kills the deck's ability to Fast Forward and Rewind tapes.

The idler clutch is allowed to move in two directions (top/bottom of deck, left/right), and depending upon whether the driving tire is turning clockwise or counter clockwise, the idler comes to rest, wedging between the motor drive tire and either the cassette tape supply reel drive or the takeup reel drive and causes that reel to turn - thus Fast Forwarding or Rewinding.
View attachment 204931


This first (exploded assembly) drawing is of the arm and idler clutch assembly from the ct-f9191 service manual.
View attachment 204845

But this thing is more than just an idler, it has a clutch (idler "B", RNK-187) built in, to presumably reduce rubber wear when the cassette refuses to move, so instead of tearing up the rubber, the nylon to felt clutch joint slips. This clutch pack(idler "B", RNK-187) is the upper white wheel with the vertical grooves for friction. The motor's tire (looks a bit like a pencil eraser) turns on these vertical grooves. The lower idler with black tire (idler "A", RNK-188) is what hits the supply and takeup reel drives for the cassette.

View attachment 204846


This is a view of the partially disassembled arm, with the clutch pack (idler "B", RNK-187) on the left. Note the rather strong spring standing better than 1/2 inch tall. On top of that is the spring holder. In the center is the idler (idler "A", RNK-188) that contains (or is supposed to contain) the force of that spring. You can see the black tire on the bottom, and the felt friction/slip material on the flat surface that the post sticks up from. On top of the post is a button that presses on quite tightly, with a friction fit to the post. this friction fit is strong enough to contain (when new) the force of the idler B spring.
View attachment 204847

With the force contained, the idler a/ idler b assembly is floated OVER the supporting arm by the spring cup and spring shown on the right side, shown ON the shaft that the idler a/b assembly turns on.

That's how it's supposed to work. Time had a surprise for us.
Click to expand...
 
I think I put this in wrong section. I am new to the game! Just obtained a 9191. Are you accepting these for repair?

Thanks!!


QUOTE="markthefixer, post: 3603192, member: 6768"]This has been moved up to the front, too many people are missing it.:



The ctf-8282, ct-f9191 and ct-f1000 cassette decks are built like tanks, with one exception:
The FF / REW idler clutch. It's failure kills the deck's ability to Fast Forward and Rewind tapes.

The idler clutch is allowed to move in two directions (top/bottom of deck, left/right), and depending upon whether the driving tire is turning clockwise or counter clockwise, the idler comes to rest, wedging between the motor drive tire and either the cassette tape supply reel drive or the takeup reel drive and causes that reel to turn - thus Fast Forwarding or Rewinding.
View attachment 204931


This first (exploded assembly) drawing is of the arm and idler clutch assembly from the ct-f9191 service manual.
View attachment 204845

But this thing is more than just an idler, it has a clutch (idler "B", RNK-187) built in, to presumably reduce rubber wear when the cassette refuses to move, so instead of tearing up the rubber, the nylon to felt clutch joint slips. This clutch pack(idler "B", RNK-187) is the upper white wheel with the vertical grooves for friction. The motor's tire (looks a bit like a pencil eraser) turns on these vertical grooves. The lower idler with black tire (idler "A", RNK-188) is what hits the supply and takeup reel drives for the cassette.

View attachment 204846


This is a view of the partially disassembled arm, with the clutch pack (idler "B", RNK-187) on the left. Note the rather strong spring standing better than 1/2 inch tall. On top of that is the spring holder. In the center is the idler (idler "A", RNK-188) that contains (or is supposed to contain) the force of that spring. You can see the black tire on the bottom, and the felt friction/slip material on the flat surface that the post sticks up from. On top of the post is a button that presses on quite tightly, with a friction fit to the post. this friction fit is strong enough to contain (when new) the force of the idler B spring.
View attachment 204847

With the force contained, the idler a/ idler b assembly is floated OVER the supporting arm by the spring cup and spring shown on the right side, shown ON the shaft that the idler a/b assembly turns on.

That's how it's supposed to work. Time had a surprise for us.[/QUOTE]
 
I just want to confirm that Mark is a great guy and helped me with my fix. I sent him my seized idler and he fixed and sent it back to me.
I had some issues with the install after the fix and he continued assisting me. It is now working properly. The assembly with the two brakes was not set properly. I manipulated it and now it sits properly.

The take up lever when I pressed play was not working. Mark replied as:



Take up lever? The FF operating control?

Or the play does not rotate the take up reel?

Take the cassette out, and fake the cassette presence microswitch
located in the top of the cassette well, it is the center microswitch feeler
(the other two are record inhibit and CrO2)
push the feeler up and press play. Does the take up reel TRY to turn and stop
or never move?

The take up reel is driven from the massive capstan flywheel, with the idler B * tire
that swings to fill the gap between the take up reel drive half of it's clutch and the
capstan flywheel
It has a spring for tension - that's probably what happened
because there ALSO is a BRAKE on the other side of the take up clutch - ** BUT **
that brake ALSO brakes the supply reel AT THE SAME TIME.
Thus no tape spills out, unless the leverage of the capstan overcomes the supply reel brake.
BOTH the brake and the tape up drive idler are actuated by the BIG solenoid
and they are mechanically interlocked behind the appearance plate (panel assy rxx-160)

so the easiest explanation is the spring RBH-236 isn't pulling it in, or the tire is slipping.
so long as the capstan motor is turning (the tape presence switch starts it IIRC, no deck
working here to check that right now)



* idler B page 89 in the paper manual, idler A is the FF/REW clutch assy I worked on
 
I'm at the same time glad and dismayed to find this fix. Understanding the passage about the importance of getting tolerances correct... It's very unlikely that I'll be able to do the job right. And I noted before being kindly directed to this repair that my inner shaft is indeed cracked. I had replaced the WJOE tire and thought that might do the trick. Now I see the repair will be quite a feat. I've already put more time into this machine than I can ever hope to charge the customer. Argh. I'll report on my results. I may just try the ill-advised path of fusing the two parts. I'll have to read this over a couple more times to get the idea. Thank you very much.
 
tomwil said:
Wow, Mark, get writeup!
1) Is it possible to glue the button (RR Idler Bearing RNK-189) to the post (FF Idler A RNK-188)? Even if that post is cracked, it would still hold the retaining spring button via the glue.
I know it would probably be impossible to separate those parts again, but would there be a reason to separate them again in the future?
Again, thanks for a great writeup!
Click to expand...

And did you end up gluing these parts in the end? It might reduce the life of the black tire, but would it still last quite awhile? Just checking back.
 
JCHaywire said:
I'm at the same time glad and dismayed to find this fix. Understanding the passage about the importance of getting tolerances correct... It's very unlikely that I'll be able to do the job right. And I noted before being kindly directed to this repair that my inner shaft is indeed cracked. I had replaced the WJOE tire and thought that might do the trick. Now I see the repair will be quite a feat. I've already put more time into this machine than I can ever hope to charge the customer. Argh. I'll report on my results. I may just try the ill-advised path of fusing the two parts. I'll have to read this over a couple more times to get the idea. Thank you very much.
Click to expand...

LOOK at the first post - I FIX the clutches, (with sleeves and special tools to get the cuts right), through the mail. PM ME. I can't say more in the forum, it would get this thread disappeared.

From now, henceforth, any"indvidual" that GLUES the damn clutch and THEN sends it to me for work when it isn't working right - gets charged DOUBLE because of all the time I have to spend undoing the glue job.

And afterward - be SURE the tape movement sensor shaft and the mechanical counter are clean and lubricated - PLENTY of times AFTER the clutch fix this becomes noticeable.
 
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