From: gkwan@balboa.eng.uci.edu (Greg Kwan)
Subject: Re: Re: VCR Maintenance Advice Wanted. Head Cleaners Any Good?
Newsgroups: rec.video
Organization: University of California, Irvine
Date: 11 Sep 92 08:12:21 GMT

I do not normally read this newsgroup. My original post was a followup
to something I saw in sci.electronics. This discussion was brought to
my attention by someone threatening to roast me over open fire. And now,
for your viewing pleasure, I'll explain what I was thinking about when
I recommended separate tape rewinders. People with better things to do,
please `n' now...

Note: I not trying to flame anyone here. :-( I just want to share my
thoughts. I probably shouldn't have shared them in the first place.

Note 2: Rather than following up to both posts, I've chosen to kill
two birds with one stoner post. When flaming me, be sure you get the
attributions correct: >> = Gary, > = Carter, ` ' = me.

Dis: I only worked part time as a tech during one semester of college
and then the following summer, so I don't claim to know much.

In article <las8r8INN5uk@news.bbn.com> ckoch@BBN.COM (Carter Koch) writes:
>In article <4300146@hpcc01.corp.hp.com> steed@hpcc01.corp.hp.com
>(Gary Steed) writes:
>>Is this really true?  I've heard this many times but I haven't heard of
>>a good explanation on why it so bad. In REWIND/FAST-FORWARD mode the motor 
>>is running wide open with only the drag from the tape itself for 2 to 3
>>minutes [I hate wrapped lines--gkwan :-]
>>vs. PLAY mode where the motor is running with lottsa drag from the capstan 
                                                ^^^^^^
 ever try `edit spell'? should be `lotsa'. :-) ;-) :-)

>>holding back the take-up reel for up to two hours.

 Ah ha! That's the problem: playing tapes. Everyone, please stop play-
 ing tapes. :-) Actually, the capstan's job is to provide a stable
 speed across the heads. The take-up reel isn't being "held back"--it
 only needs to provide enough tension so that there's no slack between
 it and the capstan. Too little = `eaten' tape; too much = stretched
 tape. There are test tapes that check that the play & rew/ff tensions
 are within the proper ranges (they're not the same tensions).

>>In most VCR's that I've
>>seen there is no contact with the heads during REWIND/FAST-FORWARD, so
>>there's [they REALLY urk me--gkwan :-]
>>no head wear.

 As is pointed out by others, there are machines that don't retract
 the tape from the head. This, however, was not what I meant when I
 said that rew/ff take a lot out of the machine...

>>From this it seems that the REWIND/FAST-FORWARD function would
>>be a lot easier on the VCR that PLAYing tapes.

 Sure, I suppose rew/ff is easier on the VCR than play. They are,
 however, usually separate operations from play. That means different
 mechanisms are involved. This should be apparent when you consider
 that otherwise rew/ff would take as long as play. Not much of a ff.

>>Although one could be handy if you want to start watching the 
>>next movie without waiting for the other one to rewind. For me I need
>>that time to go to the bathroom anyway. ;')

 Yes, pipelined operation. That's a big plus for me. Guess I have
 better bladder control.


 And now for the tough post... maybe I should visit the restroom first.

>Using a rewinder is not going to noticeably save on any wear to your heads,
>or rubber parts (idler, capstan belt, etc).

 NOT A FLAME! but...

 Could you please elaborate on this? Forget about the head wear and
 tear as that's not what I was talking about. I believe that the
 `rubber' parts will wear faster. Specifically, parts in the rew/ff
 operation need to be driven much faster than in ordinary playing.
 It would seem that this causes quite a bit of wear and tear. Can
 you really say rew/ff contributes nothing to the wear of a VCR?
 Speed kills.

>Rubber idlers and belts will crack over time whether they're used or not.
>It's very rare that you're going to burn out a capstan motor (used to drive
>idler assy's in most units).

 Still, should you stress the VCR ($200 for a cheap one) or a re-
 winder (<$20 for a good one)? I've seen heavily used VCR's where
 there is a very fine black powder coating over the rew/ff mech-
 anisms. This is the rubber worn off from idler wheels, belts,...

>In my shop I can't tell the difference between
>a VCR that has an owner using a rewinder and/or a tape cleaner and another
>that doesn't.  But I can tell whether the owner smokes or has a dog or cat.

 Or cockroaches. Uggh. I always hated being surprised by them.

>    Rewinders don't have the light sensors that detect the end or beginning
>of a tape like a VCR does.  The sensors enable the VCR to stop rewinding
>before the tape is jerked and stretched at the end of the spool.  Rewinders
>jerk and stretch the tape before halting which is not good.

 Very true and good point. The part of the tape being jerked and
 stretched is the leader, though. No big loss. Consider, too,
 audio cassettes. They rew/ff blindly and stop when the tension
 gets too great. Some don't even auto shut off. There doesn't
 seem to be a large movement to remedy this. The leader takes
 the abuse.

 So, _I_ still think rewinders are useful. At 1/10th the cost
 of a VCR, they're not a significant expenditure. I find them
 especially useful for rental tapes. Not only can you watch
 another tape while rewinding, but you avoid having a rental
 tape possibly jamming your VCR. Who cares if the tape is
 stretched? (Well, I would if I rented it after you, but... )

still friends?,
greg

gkwan@balboa.eng.uci.edu

P.S. Did anyone actually read this whole post?
From: artb@hplsla.hp.com (Art Bori)
Date: Fri, 11 Sep 1992 00:22:28 GMT
Subject: Sony Batteries
Organization: HP Lake Stevens, WA