this old RCA VR688HF VCR has been a good one over many
years but i have had to clean the 4 heads and all tape contact
surfaces a number of times. also had to adjust the tension a
few years ago (had to loosen it, rather than tighten it, opposite
of what i expected). had a number of problems lately with the
only belt slipping off but i have been able to keep it usable by
applying belt dressing. i was in the process of trying to find a
reasonably priced replacement belt when it developed the
present problem. it has now damaged two tapes and am now
experimenting on the third tape after splicing it. the present
problem is that it winds multiple loops around the pinch roller,
when it loads a tape. i've removed the glaze from the pinch roller
with a pencil eraser and vacuumed the abraded material. nontheless,
it still wraps multiple loops around the pinch roller, when loading
a tape.

i am trying to salvage this VCR because it has a highly desirable
feature of "commercial advance".

should i invest in a new belt and a new pinch roller for such an
old VCR, or should i give it up???

"nucleus" wrote in message
...

this old RCA VR688HF VCR has been a good one over many
years but i have had to clean the 4 heads and all tape contact
surfaces a number of times. also had to adjust the tension a
few years ago (had to loosen it, rather than tighten it, opposite
of what i expected). had a number of problems lately with the
only belt slipping off but i have been able to keep it usable by
applying belt dressing. i was in the process of trying to find a
reasonably priced replacement belt when it developed the
present problem. it has now damaged two tapes and am now
experimenting on the third tape after splicing it. the present
problem is that it winds multiple loops around the pinch roller,
when it loads a tape. i've removed the glaze from the pinch roller
with a pencil eraser and vacuumed the abraded material. nontheless,
it still wraps multiple loops around the pinch roller, when loading
a tape.

i am trying to salvage this VCR because it has a highly desirable
feature of "commercial advance".

should i invest in a new belt and a new pinch roller for such an
old VCR, or should i give it up???

Are you certain that the problem is not with the takeup reel? Also, did you
clean the capstan as well? It's fairly unusual for the tape to wrap around
the pinch roller, it's more likely in most cases for it to wrap around the
capstan.

Agreed. Have you thoroughly cleaned the pinch roller, or checked to see if
it's gummy/sticky?

It also seems likely that the takeup might not be running fast enough. So
the tape piles up, so to speak.

On Oct 9, 5:47*pm, nucleus wrote:
this old RCA VR688HF VCR has been a good one over many
years but i have had to clean the 4 heads and all tape contact
surfaces a number of times. *also had to adjust the tension a
few years ago (had to loosen it, rather than tighten it, opposite
of what i expected). *had a number of problems lately with the
only belt slipping off but i have been able to keep it usable by
applying belt dressing. *i was in the process of trying to find a
reasonably priced replacement belt when it developed the
present problem. *it has now damaged two tapes and am now
experimenting on the third tape after splicing it. *the present
problem is that it winds multiple loops around the pinch roller,
when it loads a tape. *i've removed the glaze from the pinch roller
with a pencil eraser and vacuumed the abraded material. *nontheless,
it still wraps multiple loops around the pinch roller, when loading
a tape.

i am trying to salvage this VCR because it has a highly desirable
feature of "commercial advance".

should i invest in a new belt and a new pinch roller for such an
old VCR, or should i give it up???

'Commercial advance' is the reason for a VCR? Check out PC based DVRs.
The computer I'm writing this on records about 15 hours a week in HD
while also surfing the web or watching other HD video. Our VCRs are
now paperweights. But if you insist on the VCR, William's and Brenda's
comments are right on.

G²

G²

nucleus wrote in message
...

this old RCA VR688HF VCR has been a good one over many
years but i have had to clean the 4 heads and all tape contact
surfaces a number of times. also had to adjust the tension a
few years ago (had to loosen it, rather than tighten it, opposite
of what i expected). had a number of problems lately with the
only belt slipping off but i have been able to keep it usable by
applying belt dressing. i was in the process of trying to find a
reasonably priced replacement belt when it developed the
present problem. it has now damaged two tapes and am now
experimenting on the third tape after splicing it. the present
problem is that it winds multiple loops around the pinch roller,
when it loads a tape. i've removed the glaze from the pinch roller
with a pencil eraser and vacuumed the abraded material. nontheless,
it still wraps multiple loops around the pinch roller, when loading
a tape.

i am trying to salvage this VCR because it has a highly desirable
feature of "commercial advance".

should i invest in a new belt and a new pinch roller for such an
old VCR, or should i give it up???

This is one cause of such a tape wrap

cog on the jockey/idler assembly rubbing against
chassis,consequently removing drive from the take-up spool

Depending on the actual calendar age of the VCR (not how much it's been
used), there may be a rubber(y) tire on a plastic hub, in the center of the
mechanism below the cassette, which drives the reels.

The worn and aged belt may be the root of the problem.

I suspect that an aging tire may be the problem, and the reason the tension
needed to be reduced.
Replacing the tire and belt (and pinch roller) may be complicated. Finding
the correct replacement parts may be time consuming. The widely used term is
idler tire, although you may need the actual physical size of the parts, to
order new ones, which would likely require removal of the existing tire.

If the VCR is a later version, it may not have an idler tire.

A test jig is typically used to check the available torque that the reels
can deliver.
A modified empty cassette case can provide the same function, with a piece
of heatshrink slipped over the center IR emitter.

--
Cheers,
WB
..............


"nucleus" wrote in message
...

this old RCA VR688HF VCR has been a good one over many
years but i have had to clean the 4 heads and all tape contact
surfaces a number of times. also had to adjust the tension a
few years ago (had to loosen it, rather than tighten it, opposite
of what i expected). had a number of problems lately with the
only belt slipping off but i have been able to keep it usable by
applying belt dressing. i was in the process of trying to find a
reasonably priced replacement belt when it developed the
present problem. it has now damaged two tapes and am now
experimenting on the third tape after splicing it. the present
problem is that it winds multiple loops around the pinch roller,
when it loads a tape. i've removed the glaze from the pinch roller
with a pencil eraser and vacuumed the abraded material. nontheless,
it still wraps multiple loops around the pinch roller, when loading
a tape.

i am trying to salvage this VCR because it has a highly desirable
feature of "commercial advance".

should i invest in a new belt and a new pinch roller for such an
old VCR, or should i give it up???

On Sat, 09 Oct 2010 17:47:39 -0700, nucleus wrote:

this old RCA VR688HF VCR has been a good one over many years but i have
had to clean the 4 heads and all tape contact surfaces a number of
times. also had to adjust the tension a few years ago (had to loosen
it, rather than tighten it, opposite of what i expected). had a number
of problems lately with the only belt slipping off but i have been able
to keep it usable by applying belt dressing. i was in the process of
trying to find a reasonably priced replacement belt when it developed
the present problem. it has now damaged two tapes and am now
experimenting on the third tape after splicing it. the present problem
is that it winds multiple loops around the pinch roller, when it loads a
tape. i've removed the glaze from the pinch roller with a pencil eraser
and vacuumed the abraded material. nontheless, it still wraps multiple
loops around the pinch roller, when loading a tape.

i am trying to salvage this VCR because it has a highly desirable
feature of "commercial advance".

should i invest in a new belt and a new pinch roller for such an old
VCR, or should i give it up???

Replace take up reel drive.



--
Live Fast, Die Young and Leave a Pretty Corpse

thanks for all the replies. problem appears to be belt related.
trying to get a new belt but encompassparts.com says belt
is "no longer available". anybody have a source for old VCR
parts?


On Oct 9, 7:47*pm, nucleus wrote:
this old RCA VR688HF VCR has been a good one over many
years but i have had to clean the 4 heads and all tape contact
surfaces a number of times. *also had to adjust the tension a
few years ago (had to loosen it, rather than tighten it, opposite
of what i expected). *had a number of problems lately with the
only belt slipping off but i have been able to keep it usable by
applying belt dressing. *i was in the process of trying to find a
reasonably priced replacement belt when it developed the
present problem. *it has now damaged two tapes and am now
experimenting on the third tape after splicing it. *the present
problem is that it winds multiple loops around the pinch roller,
when it loads a tape. *i've removed the glaze from the pinch roller
with a pencil eraser and vacuumed the abraded material. *nontheless,
it still wraps multiple loops around the pinch roller, when loading
a tape.

i am trying to salvage this VCR because it has a highly desirable
feature of "commercial advance".

should i invest in a new belt and a new pinch roller for such an
old VCR, or should i give it up???

You haven't mentioned where you are, in the U.S.A. maybe?

A search engine will give results for VCR BELTS

I haven't bought any belts recently, and there have been a lot of changes in
the parts and service/repair industries in the last decade (most of 'em not
good for repair folks).

When VCRs were most popular (and replacement parts were in demand) there
were an abundant number of suppliers of belts and various other VCR parts.

Belt distributors printed cross-reference manuals with VCR models (also
audio tape and various other units) and the specific size/type of belt for
each function.. loading, capstan etc.
Some of the early VCRs had lots of belts inside them, the latest models may
have one, or none.

What I mentioned earlier about needing to measure tires also applies to
belts, since the lookup-by-brand/model listings are most likely obsolete,
and many rubber parts will likely have been discontinued, due to lack of
demand.
You will likely need to know the cross-sectional (thickness) and
circumference of the belt, assuming it is square, also the width if is a
flat type (decimal inches or mm).

One method for approximately measuring the circumference was to place 2
pencils inside the belt, and spread them apart until the belt just formed
around them. Old belts are typically loose, so ordering a belt of the same
type and size with a slightly smaller circumference was a regular practice.

You can download a 2006 cross-reference manual here, although I don't know
if Adams Radio or any other seller still offer these products (some web
pages are left in place as an archival reference display of sorts).
http://www.adamsradio.com/page12.html

You might find more info in the Repair FAQ
http://www.repairfaq.org/REPAIR/

--
Cheers,
WB
..............


"nucleus" wrote in message
...
thanks for all the replies. problem appears to be belt related.
trying to get a new belt but encompassparts.com says belt
is "no longer available". anybody have a source for old VCR
parts?

On Mon, 11 Oct 2010 09:28:48 -0700, nucleus wrote:

thanks for all the replies. problem appears to be belt related. trying
to get a new belt but encompassparts.com says belt is "no longer
available". anybody have a source for old VCR parts?

You get the belt measurements and research a replacement based on that.



--
Live Fast, Die Young and Leave a Pretty Corpse

On Oct 11, 2:05*pm, Meat Plow wrote:
On Mon, 11 Oct 2010 09:28:48 -0700, nucleus wrote:
thanks for all the replies. *problem appears to be belt related. trying
to get a new belt but encompassparts.com says belt is "no longer
available". *anybody have a source for old VCR parts?

You get the belt measurements and research a replacement based on that.

--
Live Fast, Die Young and Leave a Pretty Corpse

Try http://www.iglou.com/studiosound/index.htm
It looks like they have the belt & pinch roller you need.
Your VCR is old enough to use their make/model index.

Mike
WB2MEP

Mike WB2MEP wrote in message
...
On Oct 11, 2:05 pm, Meat Plow wrote:
On Mon, 11 Oct 2010 09:28:48 -0700, nucleus wrote:
thanks for all the replies. problem appears to be belt related. trying
to get a new belt but encompassparts.com says belt is "no longer
available". anybody have a source for old VCR parts?

You get the belt measurements and research a replacement based on that.

--
Live Fast, Die Young and Leave a Pretty Corpse

Try http://www.iglou.com/studiosound/index.htm
It looks like they have the belt & pinch roller you need.
Your VCR is old enough to use their make/model index.

Mike
WB2MEP


Such supplies are likely to be contemporaneous with your VCR and so unlikely
to have much life in them either. Consider cutting your own as they tend to
be quite large cross-section, square for round cross-section replacement
does not usually matter.

good suggestion. where can i get such material for "cutting my own"?
i have substituted a rubber band for the belt, it has solved the
problem
functionally but it is not the right size or durometer and eventually
may
damage the bearing surfaces of the pulleys.

On Oct 12, 3:33*am, "N_Cook" wrote:
Mike WB2MEP wrote in message
Consider cutting your own as they tend to
be quite large cross-section, square for round cross-section replacement
does not usually matter.

nucleus wrote in message
...
good suggestion. where can i get such material for "cutting my own"?
i have substituted a rubber band for the belt, it has solved the
problem
functionally but it is not the right size or durometer and eventually
may
damage the bearing surfaces of the pulleys.

On Oct 12, 3:33 am, "N_Cook" wrote:
Mike WB2MEP wrote in message
Consider cutting your own as they tend to
be quite large cross-section, square for round cross-section replacement
does not usually matter.


Every time I passed bike / motorcycle/ car / lorry facility that changed
tyres I asked for any scrap inner tubes. Cut a working band from each a
dumped the rest in the garden shed. I now have a range of diameters from
about 1 inch to 10 inch. Often a slightly diagonal cut is possible for
intermediary diameters.
Details of "bean slicer" etc on my tips files off below, for reducing
thickness for flat bands etc.
No wasting time now on fruitless www hunts

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://diverse.4mg.com/index.htm

Your assumption that new rubber parts haven't been produced in 15 years may
be correct.

NOS is a term that I've been familiar with for decades.

As I suggested, experience is the key. The OP's recent fixes by abrading the
pinch roller and applying a miracle-in-a-bottle compound to the belt, didn't
express to me that he was experienced in repairs.
I did fail to detect the tighter than a frog's ass (cheap) pitch in his
voice, though.. otherwise I wouldn't have bothered offering any suggestions,
backed by actual experience (twice).

Considering the vast number of magnetic tape transports (and other small
machines) that are likely to exist presently, my guess is that many spare,
replacement rubber parts are still being produced (expensive photocopy and
various other machines).
A new, $80 fabric reinforced photocopy machine belt probably won't fit a
dumpster VCR though.

Excluding cheap throw-away products, there is a lot of commercial grade
equipment wordwide, that's still being supported. I would expect that much
of it was manufactured in Japan, not China.

The last new replacement belts, idlers, tires and pinch rollers I purchased,
were packaged in sealed plastic bags.
I wouldn't hesitate to use the unopened ones that I still have for a repair
of something worthwhile.

I've seen new mono, portable, audio cassette (and mini cassette)
recorder/players in stores for less than $25 (maybe $19.99 I forget
exactly), but I wouldn't spend my time to repair one.
If you want me to, I'll buy one just to take apart, to see how many rubber
parts are in it, in addition to the pinch roller.. if you want me to.
That's just the nice kind of guy I am (and I don't know if stores have a
problem with picture-taking on their premises).

When my cheap portable, frequently used, audio cassette failed again, after
replacing the belts several years earlier, I bought some used Marantz PMD
units which utilize belts, which work fine.
The PMD 670 I have, doesn't use belts since it uses a CF card for storage,
and the counter isn't mechanical (or is it?, heh).

If I were doing repairs for others today, I'd buy replacement rubber parts
in plastic bags. It's not as if the belts I noticed recently were
expensive.. many, at a glance, are less than $1.
If I needed to cut a rubber part (not a belt probably), I know where to buy
new rubber sheet stock (plumbing supplies), and if that wasn't adequate, I
might even purchase a new innertube or other item made from rubber, and save
the effort/time of cleaning the material before I cut it.

I don't care to research the matter, but I wouldn't be surprised that
servicers of vintage equipment would know where to get new, not old,
replacement parts.

One can still purchase new vacuum tubes if they know the proper sources,
just as one can buy newly manufactured pistons for antique engines.
Russian tubes might not be authentic for a vintage amp, but if the amp isn't
a museum piece, it really doesn't matter.

That little tumble I took from the turnip truck, took place long ago. All
the rest of us aren't young inexperienced dopes stumbling around in the
dark.

I would expect the strength and durability of a new, even 10 year old belt
sealed in a bag to be slightly greater than a piece of age-unknown,
innertube material that as been flexed constantly, severely abraded from
under-inflation, contaminated with oil from air compressor air, exposed to
extreme heat and cold, etc.
Mudflap, yes.. belt in a commercial ENG camcorder, no.
I could, of course, be very, very wrong.

--
Cheers,
WB
..............


"N_Cook" wrote in message
...


"N_Cook" wrote in message
...

Such supplies are likely to be contemporaneous with your VCR and so
unlikely
to have much life in them either. Consider cutting your own as they
tend
to
be quite large cross-section, square for round cross-section
replacement
does not usually matter.





AFAIK stockists of flat belts etc for tape systems, R-t-R and cassette
,use
the word new in the sense of unused as in NOS= new old stock , ie 15 or
more
years old with very little life left in them. Many of my customer are
quite
happy keeping there old decks going with sliced inner tubes and neoprene O
rings as pulley tyres, (sometimes one will do but usually 2 or 3 to get
the
right sort of packing )- I'm quite upfront with them. I have a method that
will last me out, can you say the same about your sources ?
Even one of those awkward thin tyres on a 45/33rpm speed change jockey
assembly of an ancient record deck is going still with modern material,
NOS
of those ? don't make me laugh

Wild_Bill wrote in message
news

Whats this with plastic bags for preservation. First you get brown oiliness
of the plasticiser? (from the plastic or the band?) in the bag after some
years and then they perish as "in the field".
I store salvaged bands in open cardboard boxes with a good sprinkling of
talcum
powder, or over suspended cardboard cones that then show automatically the
sizes, again dusted with talc. Every now and then a rogue one goes gooey but
it does not set the
remainder off like an infection.