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Vintage Tape (Audio), Cassette, Wire and Magnetic Disc Recorders and Players Open-reel tape recorders, cassette recorders, 8-track players etc.

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Old 5th May 2020, 1:30 pm   #1
ThirstyBob
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Default Sony TC-270 Fast Forward slows down

Hi all. First time post for me.
Got the TC-270 down from the attic after 26 years. Powered on ok but didn't initially play. After a good clean out of the gungy old grease and a re-grease, the mechanics began to then, bit by bit, work. Lubricated the reel shafts and all pulleys, cleaned the various rubber wheels and associated reel contact surfaces, replaced main motor belt and counter belt and roughened up the brake material surfaces. Did all the mechanical adjustments as per the service manual. Everything then seemed to work ok. EXCEPT, on Fast forward the take up reel slows down to a stop when almost full (inch or so left on the 7inch supply reel). Rewind works fine and "flys off" as expected when emptied. I have stripped both reels and "brushed" the clutch material but this has made little to no difference. I think the take up reel clutch is slipping when under load (take up pulley continues to drive). What can I use to replace this thin clutch material. Or am I barking up the wrong tree. Any ideas would be appreciated
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Old 12th May 2020, 2:53 pm   #2
DMcMahon
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Default Re: Sony TC-270 Fast Forward slows down

Could well be the Tape Up clutch slipping.

Not familiar with these particular Sony reel table clutches, maybe a felt or cork replacement might help.
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Old 19th May 2020, 2:41 pm   #3
ThirstyBob
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Default Re: Sony TC-270 Fast Forward slows down

Thanks for the reply and suggestion DMcMahon. Sorry for not getting back on sooner but following your reply I got hold of a Salter Little Sampson Spring Balance (1.5kg x 25gm) and measured the F.Fwd torque and it was somewhat lower than recommended in the service manual. (Should be 1200+-100g.cm, was 1050g.cm). Not a great difference but it did start to slip above 1050g.cm torque. So, I've ordered some wool blend felt. Will give that a go when it arrives and report back. I'd read somewhere that the acrylic felt was too hard (and thin) so I've popped for the wool blend (might be too thick!!). Gluing it down and getting it to stay in place might be interesting. Super Glue maybe?
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Old 22nd May 2020, 12:20 pm   #4
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Default Re: Sony TC-270 Fast Forward slows down

Before getting too far into the clutch, check the following:

-The tape! Some tapes have noticeably more drag than others. Philips from the early 70s for one. Sony's own tape is almost all crap, the PR150/200 in the red and green boxes respectively tends to run very sluggishly and squeal. That brings me onto the dreaded sticky shed - this can result in everything grinding to a halt but I am sure you'd have seen that. Sony's back-coated black tape is notorious for this.

-The guides. Guides that show wear down to the brass base metal will add a surprising amount of friction, particularly the cylindrical ones if they develop flat spots. Usually they can be loosened and rotated to expose a fresh surface. The Sony units tend to have a fixed guide/lifter between the heads that wears down.
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Old 22nd May 2020, 6:42 pm   #5
ThirstyBob
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Default Re: Sony TC-270 Fast Forward slows down

Hi Ben. Thanks for the advice.
The tapes and tape unit had been untouched for 26 years. It did most definitely exhibit sticky tape syndrome when I first managed to get the unit operational. When I first experienced the increasing sluggishness and even slowing down when just playing tapes I searched the internet. Thanks to various posts on this forum (probably many by yourself) I learnt about sticky tape which explained why I was getting so much debris being dumped on every contact surface. I've used the same tape to get the unit running and it seems to have stopped depositing debris so I'm happy it's no longer the cause of the slowing down. I do, however, have loads of tapes I'm going to listen to and suspect that it's something that will haunt me for the foreseeable future.
The slowing down at the end (about 1cm on supply) during F.FWD is really only an irritant but it needs sorting so will still give the clutch a go (I like things to be right). I will also look at the various contact points and see if I can rotate them as I hadn't thought of doing that so many thanks.
Richard.
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Old 24th May 2020, 2:31 pm   #6
ThirstyBob
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Smile Re: Sony TC-270 Fast Forward slows down

Quick update.
Took the Take Up Reel table assembly off again and dismantled it. This involves, one by one, carefully removing the E-type Circlips and releasing the spring pressure holding the various washers in place (do this in a clear plastic bag if possible) and separating each clutch component. The clutch that does the work during fast forward is the last one to be accessed by removing the 3rd Circlip. On my previous attempt, at the beginning of May, I'd roughened up the plastic surfaces with a fine grade sandpaper and brushed up the felt. At the time I thought that would be o.k. but in hindsight I think it made things worse as all that does is reduce the contact surface area of the felt to the hard plastic. Comparing the new wool blend felt with the installed felt there seemed to be little difference, so I decided not to replace the felt. Instead, I polished out the sanding marks, brushed up the cloth again and reassembled. Sadly it made things worse (down to 500g.cm F.FWD torque)!!
Back to this forum and found someone who had cleaned the plastic clutch surfaces with Acetone and brushed up the felt. I took it to pieces again and then cleaned the clutch contact surfaces with Acetone which seemed to take off the shine and clean out any of the muck that I had put in by polishing. Reassembled and bingo - F.FWD torque now at 1350g.cm (a little above spec). Put a full 7" tape on and Fast Forwarded it - fixed. The second time I did it though it did slow down and this was definitely due to sticky tape as there was loads on the various posts.

Conclusion:
1. Clean things before taking drastic actions.
2. Read this forum.

Thank you to all contributors to this thread and contributors to the forum.
Richard.
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Old 24th May 2020, 6:59 pm   #7
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Default Re: Sony TC-270 Fast Forward slows down

Any tape that has sticky shed needs binning.
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