Otari MX5050BII-2 RW/FF slows down and stops -- tension adjust howto??????

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Blue Jinn

Blue Jinn

Rider of the ARPocalypse
Hello,

Basically rewind or ff slows down to a crawl and then stops close to the end of the tape (depending on which way) or if you start a tape, get about 4 minutes in or so, you can't rewind reliably, sometimes it will start to rewind, or just not move at all if you hit rewind (brakes will go off, motors will engage, but you have to ''help'' it by hand. Removing the tape from the tension arm and holding it so the switch stays engaged is the only way to get a 100% sure RW or FF.

this is driving me nuts. I bought this from a dealer, told him a bout hte problem he said the 'hold back tension' is too high.

The only adjustment I know of is the tension springs on either reel. I don't have the fancy scale (or a crappy one either) but the adjustments aren't subtle either, there are four positions for the spring, so I could (and pretty much have) tried all 16 combinations. A few that are too loose and the tape won't spool properly. I don't seem to find any electronic adjustment for the motors, (which provide additional back tension) unless there is some adjustment I'm missing or don't know about? My parts machine (which is fully funcitonal, just has missing feet and more head wear) doesn't do this, but hte expensive supposedly refurb'd machine does and it is driving me nuts!!!!!
 
WHAT TAPE ARE YOU RUNNING? Sorry about the caps. Possibly you have tape that is experiencing sticky/shed. Now days when I hear someone bring up transport problems its mostly do to crappy tape
 
It's not the tape AFAIK. I get the same problem with

Quantegy 031 (backcoated) on 7" reels -- ok I know, white box, but I bought it by the case, so I'm confident it is Quantegy not Ampex, and it doesn't exhibit sticky shed on this or other machines I've used it on. Also:
Ampex 632 (not - backcoated) on 10.5" reels
Scotch 177 (?) used but not back coated -- although sheds a lot of oxide, and squeals...
Ampex 641 (not backcoated)
Quantegy 632 (not backcoated)

I'm wondering if it could be the actual springs. I don't know much about the mechanics of springs, if they get brittle or something and stiffer?

For Miroslav, I don't see tensioning in that link, but thank you, I can use that info anyway.

EDIT: Looks like I posted on this about a year ago. Same thing again, although 7" plastic reel caused me problem this time. Last night as before, plastic reels seemed to do OK. Also, I tried a quick FF/RW and 4 min in RW, with metal reels and the Otari shims installed and that seemed ot work once. I'm going to try that again a few times. Weird, reel weird....
 
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OK, maybe time maybe not time for an oops I shoulda known better. Well, I can't explain the Scotch 177, unless it is LOL.* The 031, I'm guessing is either slightly out of spec (which is 031 by definition) on width, or the tension arm is slightly misaligned or both. Because the one piece I was using sheds oxide like heck on a fast wind, and hangs up the take up reel on playback. (not sticky shed, but seems to get sheared off (FW) or hungup (PLAY) by the tension arm.) Metal reels, however, do much much better with the shim in place, so I'm going to take a closer look at that tension arm. I hate to say this, but the plastic reels seem to work and fit the best for some reason. Nothing vital on any of these particular tapes. Just albums recorded on my A-3300SX. (Yes I did use the 031 on the Teac, which is supposed to have 1mil not 1.5 mil tape. )

An after market tension arm (flat piece only, not the guide) is $30US from Antham. The new USA Otari dealer (aheadtek) website is currently down.

*loss of lubricant

More to follow...
 
Sometimes the machines we used to have would get tape wrapped around under the reel tables and cause that sort of thing...
 
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