Tape machine reel motor pulleys | the mind reels and I've got that sync'ing feeling.

March 15, 2006 12:14 PM

What are reel motor pulleys on a reel-to-reel tape recorder and how do I replace them?

I am looking to purchase my first analog multitrack tape recorder. The machine I am looking at, a Fostex R-8 (second-hand, of course) seems to be in good condition. However, the owner has noted that he has ordered new reel motor pulleys to be included in the sale, because they need replacement. I have no reason to believe the machine is, for the rest, not in good shape.

All fine and dandy, but: what are reel motor pulleys? Anyone with more than a passing acquaintance with open reel tape machines out there who can tell me what they are, what their function is, and whether they are difficult to replace? I am reasonably adept at servicing electronics and audio equipment, but I've never actually opened up an open-reel tape machine.

I have searched the web, but with little usable result. Of course, I could just ask the guy, but I don't want to give the impression that I don't have a clue about tape machines - I do, just not enough of a clue to understand what these pulleys do. Also, it would simply be nice to get an independent take on this.

So, thanks a heap, tapeheads, and keep it reel! ;)

posted by goodnewsfortheinsane to technology (10 comments total)

My best guess is that the reel motor pulleys are simply the pulleys that turn the reels via a belt. It's likely if they are in need of replacing then the belts should be replaced as well.
posted by 6550 at 1:33 PM on March 15, 2006

I suspect the nomenclature is off. The pulleys are either metal or a hard plastic, like Delrin. They're driven by electric motors. It seems unlikely that they'd wear out. If they did, then the belts would almost certainly be gone, too, as 6550 says. If the pulleys got damaged somehow, that would make me suspect abuse of some kind; I'd walk away.

Ask if you can see the form he used to order the pulleys. Then look up the part number, if it's on the form.
posted by Kirth Gerson at 1:42 PM on March 15, 2006

There's a gentle introduction to the guts of open-reel machines here.

I'm with KG - I think you're probably dealing with somebody who says "pulley" when he means "belt".
posted by flabdablet at 2:09 PM on March 15, 2006

The Fostex A-8 series were belt driven; I believe the R-8 series, which came out a few year later, were also. It's like a turntable belt - very easy to change.
posted by chocolatepeanutbuttercup at 2:17 PM on March 15, 2006

I wouldn't be surprised if the pulley itself was made out of hard rubber that can crack and start to crumble apart after many years.
posted by Rhomboid at 4:56 PM on March 15, 2006

Thanks for your input so far. So are the pulleys these circular things around which the driver belt(s) run(s)?
posted by goodnewsfortheinsane at 4:59 PM on March 15, 2006

You should expect to see something like this or this. The small one is called the capstan and the pulley is the larger bit that pushes against it, with the tape going in between the two.
posted by Rhomboid at 6:13 PM on March 15, 2006

Rhomboid, that's not connected to the reels, so I don't think that's what we're trying to identify.

goodnews, yes - the belts run on the pulleys, which are wheels with grooves of some kind on their outer circumference that accept the belts.
posted by Kirth Gerson at 8:02 PM on March 15, 2006

Rhomboid: that's not a pulley, that's a pinch roller.
posted by flabdablet at 8:06 PM on March 15, 2006

Ah you're right... I read the post too fast. Disregard me.
posted by Rhomboid at 9:18 PM on March 15, 2006