Cassette slowing down

  • Thread starter Thread starter justinchannell
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Justin,

You are definitely on the right track, and making a 'justi-fiable' effort to get the right info from the source, unfortunately, it bears out some translation as to what "ring diameter of 7.8cm" actually is in 'merican.

As I said, I've refurbished a few cassette mechs in my day, and the belts used will all vary slightly, based on model. F/I, the belt I've used to refurbish a Tascam 234, the rackmount/dbx/4-track/cassette, [probably the Tascam model closest in design to the Vestax],... was about 7" total length.

Mind you, all the repair belts I've ever seen here, [Los Angeles, California], were cataloged on total length,... with appx 7" being total length,... and don't ask me how that equates to "ring diameter".

Leave it to the Euro's to confuse the issue with metrics!

Justin, I defer back to my original statement, that you'd be best off to remove the old belt and measure it, in TOTAL length, and then subtract about 3/4" to 1" from the total length of the USED belt, as by definition, the used belt is s-t-r-e-t-c-h-e-d o-u-t.

Justin, I too have always wondered about belt dimensions for cassette repair belts, and the truly best source is the old belt. Once you've measured the old belt, then www.electronics.com should have exactly what you need,...

and you may want to peruse the entire catalog for some stuff that could round out that $15 minimum. They have tons of stuff on the website and in their 'print' catalog.

Good Luck!

PS: Just-do the right thing: remove the belt and measure it!
 
PS2: Radio Shack will probably NOT have this item, sorry!

And, fyi, just-think of the 'total length' measurement I'm referring to as "circumference", [and yet I still don't know what the "ring diameter" is that the Vestax rep was talking about].

Sure, I know what 'diameter' is in normal cases, but I don't think we 'mericans measure our belts on 'diameter'. We seem to use 'total length', which equates to 'circumference'.

A 7" belt would be average, but you'd do yourself a favor to measure your actual belt,... less the stretch,... with the new belt to equate to roughly 3/4"- 1" less than the old one,... total length/circumferential measurement.
 
The guy at Radio Shack told me about a nearby electronics shop with flat belts. So I called them and the guy told me I'd have to bring the belt in, even after I read those dimensions off, and he'd give me one slightly shorter.

Now, because I'm not experienced with this, I need to take the belt going from the right capstan(those are the capstans, aren't they?) to the counter off right? To go about doing this, I'd just slide it off, right?

Also, I saw one of those Vestax 6 tracks on eBay... it didn't have the ability to record, however.
 
Well Justin,...

It would be hard for me to give you an exact yes or no on that question, sight unseen. I can't say how much disassembly will be required to get the belt off/on.

BTW, I know Vestax had a few models, so what's your Vestax, a table-top-portastudio-like unit, or a rackmount unit more like the Tascam 234? Inquiring minds want to know.

As disassembly goes, a flat tabletop-type Portastudio is a little easier to get at the belt than a rackmount or component-style unit.

Just-be sure that the capstan belt is the "flat rubber belt", about 3mm wide, about .5mm thick, and some unknown length that should be somewhere appx 7" long.

Other than the capstan belt, all the other belts I know of in the typical cassette mech would be "square" belts of some shorter length, [although I can't comment directly on the Vestax].

FYI, The capstan belt goes between the motor "pulley" and capstan "flywheel". The motor/pulley should be obvios upon visual inspection, and the capstan/flywheel is the large metal cast wheel with the capstan attached to it on the other side, [inside of the cassette compartment]. The capstan itself is that "little-metal-shaft-thingy" that spins and drives the tape, as the "pinchwheel" contacts it.

Guess I'd be remiss if I didn't mention that [just-fyi] the FF/RW motion is driven by a second motor, which engages the cassette "hubs" to spin by a little "clutch" that pivots between the right and left hub. On this clutch are two little rubber "tires".

So, fyi, if you ever experience problems with the FF/RW function, the "clutch-tires" [in technical lingo] should be replaced. Just-fyi, the "clutch-tires" are measured on outer diameter [OD], inner diameter [ID], and Width [W]. BTW, as I've probably mentioned before, the FF/RW clutch/motor removal is a more heavy duty disassembly than the capstan-belt replacement.
 
Okay, would the capstan be one of the two prongs which wind the cassette? Because that's the only belt I happened to see after taking the top off.

Also, yes it's a tabletop Portastudio esque machine. I saved an image of one off of eBay, if you wish to see it.
 
Yeah, pls do.

Pls post the image, if possible.

Anyway, I can't speak directly to the Vestax, sight unseen, but it doesn't sound like you've gotten the capstan belt isolated yet, visually.

You'll definitly need to remove the bottom cover, not the top, or at least I'm pretty sure of that. You'll definitely need to locate the actual flywheel. It's a large cast metal wheel, probably about 2"-2.5" in diameter, and maybe 1" thick, around which you'll see the capstan belt, a flat rubber belt.

The capstan is a single "prong", located in what's otherwise the bottom-right of the cassette compartment. Locate the actual capstan and pinchwheel, and proceed from there.
 
Okay, well I don't think what I was seeing was the correct belt then. :)

I think I'll just give my sister's boyfriend a call and ask him to show me where it it's at.

Also, there really isn't cover to the machine. More like a top and bottom. It's pretty hard to explain some of this stuff... I wish I had a digital camera or something. :)

I attached the image I stole off of eBay to this post...
 

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Okay, I found two belts upon another inspection: one that connects to the the right prong that turns the cassette wheels (I don't know what they're called... sorry) and one underneath of the cassette playing mechanisms. Should I take both of them off and change them, just to be safe?
 
I had trouble with my old Fostex X-15 4 track. It would always stop on me. I would have to open it up and physically turn the weighted (flywheel) to get it going again. One night I got tired of it and threw the SOB out. Life is too short to mess with crap that doesn't work. Computer is the only way to go for me now.
 
I heard one of the Fostex recorders was rereleased with a larger flywheel, so maybe you got one of the ones with the smaller flywheels.

My computer is too slow and too much of a hassel to record on for me. That's why I like my 4-track better. If need be, I can go record anywhere I want, as opposed to having to be around my computer.
 
Yeah, you're right about that. I think mine was one of the originals. Hell I bought it about 16 years ago. I remember thinking "damn, I can do anything with this thing" 4 whole tracks to play with. How times change.
 
Justin,

Thanx for posting the image. Your Vesta-Fire is much like a cross between the Tascam PortaOne and the Tascam Porta03. This is a handy little 4-track, that's in need of some minor maintenance. It's definitly an early/mid-80's design, and replacement of the belts is a common and well known issue with decks of this age. If you replace the belts, it will probably run like new.

The tape transport section is of the mechanical variety, which is a little more mechanically complex than the solenoid-driven designs of later years. As you've probably noticed, there's lots of little levers, cams and springs in there, which makes repair a bit of a complex task, but still doable if you're careful. I believe, in most cases, the capstan belt would be accessible by removing the bottom cover, and accessing the mechanics through the bottom.

You'll have to identify the capstan and the capstan flywheel, and proceed from there. Moderate disassemby will be required. Good luck.
 
Well, I think I have the capstan belt. I unscrewed the cassette mechanism and underneath of it, there was a belt running from a gear under the motor, to the flywheel (determined by checking it to see if the capstan moved with it), and to another gear. I'm quite positive that this is the belt. I'm going to try to get a replacement from the electronics store ASAP!

Quite simple, actually. :)
 
Well,

I replaced the belt and bought some new tapes...

...and it's still doing it.

Any more ideas?
 
Ooh, sorry to hear that. You made the effort on the belt, which was good.

We'll have to assume that it's the correctly sized belt, one that's taut and snug, and not one that's loose and sloppy. Anyway, good job on the belt.

Sight unseen it's very hard to tell why your cassette's ailing. In general, the belts usually do this. Beyond that, it's a highly mechanical unit, and the headstack and pinch roller has to come all the way up to firmly contact the tape and capstan. [pinch roller contacts to capstan].

It could be a mechanical issue, that would be virtually impossible to troubleshoot on a bbs. The other thing that crosses my mind would be the motor, but I don't want to send you on a wild goose chase on the motor, without any independent verification of some sort. I'd also be interested to verify the power supply unit is supplying a steady voltage and current, as wild fluctuations of the power could cause cassette speed to be unstable.

These are all hypothetical ideas about technical repair of cassettes, not necessarily binding. It might be best to have an actual tech check it out in person. There's something more tangible that you'd get by having a qualified tech check it out in person.

You've done an admirable job so far, but maybe a pro-tech could shed some light on the issue. Good luck. Hang in there.
 
Now it seems as though it's speeding up!

http://www.showchoir.com/~justinc79/everlong.wav

My new guess is on one of these three possibilities:

1. The motor is dying.

2. Wrong belt size.

3. Something's going wrong with the pitch control setting.

Ugh... this is really beginning to anger me. I'm about ready to chuck it and buy something else on eBay, as opposed to putting even more money into it.
 
You'd be justi-fied in doing that. It's very cool to have been given this unit,...

and I think it's fixable, but yes, there are better units out there. I highly recommend Tascam Portastudios, and mostly other Tascam analog gear.

Regarding the clip, I think it sounds like the same thing as before,... that you're getting wild speed fluctuations on record and playback.

Did you ever get an exact belt size? You got a diameter of 7.8cm. Did you ever do the math? What's the formula for circumference? Sorry Justy, I'd have to look that one up!

Go consult the geometry books, and tell me the circumference of a circle with a diameter of 7.8 cm. They may measure belts in Germany on diameter, but in the US they're sized in circumference.

If you don't have the correctly sized belt, of course it could still be the problem. Size matters, despite whatever you may have heard. Just-because I'd say it's probably approximately 7", that is not enough info to source a belt of the correct size.

As I said before, I'd recommend measuring the old belt, then getting something roughly 3/4" to 1" shorter, to account for wear, and roughly how stretched the belt seemed to be. That, or do the math on the circumference of a circle with a diameter of 7.8 cm.
 
I'm sending my mother back to the shop (I'm stuck at home and can't go there) because the belt is nearly the same size as the original. I'm going to send back both belts with a detailed note to get something smaller.

I hope that's the problem and that I was ready to pull my hair out over nothing. :)
 
You have to consider that the belt you have is old and stretched out,...

and get one that's slightly smaller, enough to be a snug fit again. A belt that's loose is going to slip, and a belt that slips is going to sound like that.
 
Well, I got a smaller belt... same problem :-(

But now I notice that when I try to rewind, the player jams up until I hold down the rewind button. Maybe whatever powers the left prong that turns the cassette (whatever it's called:) is getting stuck somehow thus explaining why the speed is warbling.
 
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