What would cause a tape to run off the heads?

[Eldorado]

I've found that one of my tapes played in one direction starts to run off the pinch-roller/heads after a few seconds. The tape is being pushed outwards, away from the deck. If I go to fast wind in the same play direction (even as the tape's starting to move out of line), no problem. If I wind further into the tape (I haven't established the minimum point yet) it plays fine.

Is this problem caused by a warped reel? Looking down from the top as it plays, the reel isn't completely straight. The takeup reel is fine though.

[vinyldavid]

Same problem I have on my teac A-6010, only it does not work on both directions.

The supply reel is not giving tension to the tape, and therefore, it wobbles and moves off of the heads/pinch roller.

add some tape tension by lightly putting your finger against the supply reel and see if that does not correct it. In your case, it sounds like a relay, because it works in one direction but not the other. Mine is in the motor caps somewhere because the durn motor does not work under any circumstances.

[Scorpion8]

First off, are we talking cassette or reel-2-reel? And is it one specific tape only, or on all such tapes?

[Eldorado]

Sorry mate, I wasn't explicit, as we're in the reel-to-reel section. It's an open reel tape.

I now think it's a reel problem (no pun intended). Because I've just started the same tape after it played all the way through onto the take up reel. If I then play that reel (turned around) in the direction that caused the problem before, it plays fine. That's the reel that looks straight. The other reel is visibly off when it plays.

[Scorpion8]

Sorry mate, I wasn't explicit, as we're in the reel-to-reel section.

I was just about to edit my post and guess that since you posted in the reel to reel section, ergo therefore .... :D

Hold a ruler up to the reel in question and watch it as it turns using the ruler as a straightedge guide. It should be pretty obvious if the reel is warped, but it seems like it'd have to be very warped to run the tape off the heads in so short a distance.

[TheReeler]

I don't understand at all when it happens. There are more than one possible causes where a tape gets out of the pinch roller/capstan.

- Too much torgue tension
- Too much back tension
- The tape itself is in bad shape
- The tape is too thin
- Pinch roller and/or capstan is in bad shape

Tro to watch the moment where the tape goes out. Which is the first step?.
Is the tape goes out from the pinch roller/capstan? Or is the tape gets out from the head guides?.

[Eldorado]

Ah hell, I don't know the name of the part. What do you call the metal arm that guides and gives tension to the tape right after it plays out of the reel? Anyway it looks to me like it comes out of the groove on that arm first and everything goes haywire from there. But it could be that it comes out because of way the pinch roller is pulling it through, I suppose. Chicken, egg, I can't really tell, even after watching.

My best guess from what I've seen so far is that that single plastic reel actually is sufficiently warped on its outer edge that it's causing the first part of the tape to run out of line and come off the roller.

[TheReeler]

Do you have a webcam and/or a videocamera?. Just make a video an upload it to youtube showing exactly whats happen in first place *reelspin*

[Eldorado]

Not at the moment. I can't take video, except maybe from my old digital camera. But I'm not familiar with how to do it and upload it, and haven't got time at the moment to work on that. I'll do it at some later stage (don't hold your breath) if I get the chance. But thanks all for the help and suggestions so far. I really appreciate it.

[Eldorado]

Thanks again for all the advice. The tape problem appears to have cleared up now. I make absolutely sure that there is good tension on the take up reel and that enough tape is wound on there. It seems to play fine every time now.

Two other small problems are also resolved, the VU meters are running in balance now, although I didn't do anything to them, and the minor crackle during adjustment of output and headphone volume was fixed with contact cleaner.

I finally had a look at the inside of the deck, and, well, it looks old in there, but I can't see any huge problems. I didn't get long to look at it, but I'll have another shot at the weekend, and maybe post some pictures.

Now I want to get a head demagnetizer and build up my tape stock. Unfortunately my bidding failed at the weekend so I have to wait for more tapes to come up. And I need to find a seller for the demagnetizer who will ship from the US (unfortunately, US Recording doesn't).