
Why Paper Jams Persist - ohjeez
https://www.newyorker.com/magazine/2018/02/12/why-paper-jams-persist
======
jws
Exciting fact: Similar jams happen in hot steel rolling mills too. The YouTube
videos are just prettier:
[https://www.youtube.com/watch?v=DVZ1DY0r4y4](https://www.youtube.com/watch?v=DVZ1DY0r4y4)

In general the rolling mills call it a "cobble" when a whole or partial bit of
steel escapes the rolling mill. Lots of exciting videos.

~~~
djsumdog
That's pretty insane. Wow, look at those coils of hot metal. It's interested
how much of it is still hot after they clear the jam and run it through.

I remember years ago hearing about how the US mint misprinted over a million
and had to destroy it (and on the Colbert Report, he joked about how them
destroy it by burning it in front of poor people). We were talking about it at
a party and someone asked, "surely they noticed? Why didn't they shut it
down?" An engineer in our group said, "Have you ever been in a factory? It's
so fast!" He worked in a toothpaste tube factory where you'd see hundreds of
tubes come out every minute. If something went wrong, you'd have to wait for
the whole pipeline to clear. Fab shops in China are even more insane.

I wonder if the mill would just sell those sheets at a reduced price as low
grade/for non-visible construction or if they re-melt them down and run them
again.

~~~
bartread
On the speed front, I concur. Back in 1998, when I was on summer break from
university, I worked in a wines and spirits bottling plant. One day the
labelling machine started applying wonkey labels to the wine bottles and a
couple of hundred had gone through before the guy running the machine had
noticed.

They weren't wildly misaligned, but far enough from true that we had to wash
them off and run them through the line again. Took a couple of us most of an
afternoon to sort it out.

~~~
giarc
At what point is it just more economical to sell them at a reduced price to
restaurants (where the customer might not see the label)? I'm sure the guys
(you) peeling the labels are probably the lowest paid in the factory but a few
staff doing the work for the whole afternoon adds up.

~~~
djrogers
At $10/hr for 2-3 people, assuming they could clear up 30 bottles an hour
you're only talking $1/bottle. I don't think that small of a discount on a
bottle of wine would encourage a restaurant to buy a veblen good that didn't
look perfect.

[1][https://en.wikipedia.org/wiki/Veblen_good](https://en.wikipedia.org/wiki/Veblen_good)

~~~
giarc
This is totally an n of 1 type story, but perhaps relevant nonetheless.

I worked at a bar during university during a time where the popular beer sale
would be "28 bottles for the price of 24". The bar owner would send me and a
few guys in a truck to a beer store in another town to buy as many cases as
the truck could handle. This was illegal as we would sell it at the licensed
bar (all liquor was supposed to be purchased with the license, for which the
sale wasn't applicable too). So the owner was willing to risk legal action for
4 free beers (x50 cases or whatever).

The point is... restaurant owners sometimes go to great lengths to save a few
dollars.

------
zwieback
It's even worse in our low-end inkjets, which are made of plastic parts and
toy motors and are still expected to duplex-print on the cheapest crap paper
imaginable. Our FW devs spend a lot of time perfecting the PID loops and mech
sequences to make this happen. But do we get any thanks for that? Noooo...

Love that New Yorker article, though. I grew up reading this magazine in the
80s but drifted away. These great articles straddling tech and culture became
too few and far between.

------
nwah1
This is why I love the New Yorker. You don't see enough of this kind of long
form journalism, shedding light on seemingly mundane issues that you'd never
imagined could be so interesting.

The historical perspective, in particular, was great. But what took this to
another level was detailing just how big the challenges are, and how
enthusiastic the engineers are in trying to solve them. Even giving a sense of
vicarious excitement from the descriptions of their attempts at problem-
solving.

~~~
djsumdog
I dunno. I think this is one reason I stopped reading the Atlantic/Harpers/New
Yorker. I mean, it is better than sensational TV where they take 45 minutes to
get to the punch line where they could have explained it in 5 min. It's not
even 40 min of interesting facts or history; just mostly commentary and talk
to draw things out.

I do realize this article is different; there is a lot of historical fact and
context which helps create a narrative. It has its advantages. Maybe I'm just
getting old. I read a lot of novels and I'd rather spend the time on that type
of narrative in a novel or even a non-fiction book than a news article.

People may criticize the YouTube generation, but it has helped in content
creators who get a lot of information over in a very concise way (Kurzgesagt
In a Nutshell, Smarter Every Day and Wendover Productions come to mind).

I think the opening of the historic paper jam made me want to fall asleep. The
later office space references and Xerox design became more relevant. Even
then, I feel like I don't read these articles the way I did back when I bought
a physical Harpers from the book store. It's a lot of content, and in the
scrollable world we just end up skimming more these days.

~~~
hycaria
>People may criticize the YouTube generation, but it has helped in content
creators who get a lot of information over in a very concise way (Kurzgesagt
In a Nutshell, Smarter Every Day and Wendover Productions come to mind).

Reading the same info (in a non-narrated way) would be much faster. Also it's
often concise over exactitude or neutrality. I can't sit through these videos,
boring or caricatural. At least the New Yorker is sold as an enjoyable
distraction, and I find great pleasure in reading nice writing.

------
interfixus
Many, many years ago I had a student job with a small company doing industrial
document finish, enveloping, and large-scale mailings. Apart from a still
eaily induced paper eczema, the one thing I took with me was a rather
comprehensive facility with the black magic of paper handling. Not an ounce of
explicit science in it, but an awful lot of _feel_ : When and how much to air
and flex; where a grounded length of copper wire could work wonders; how much
or how little moistening to apply, and where; how too touch the stream of
paper and somehow know by the feel of the tip of your finger whether something
would probably jam within a minute, and which tiny speed-adjustment up or down
would probably forestall the disaster; when to to loosen or tighten this or
that set of rollers because nightshift and the air getting cooler et cetera et
cetera.

To this day I never just bang a fresh stack of paper in the printer tray. The
full gymnastics of airing, flexing, feeling, airing and flexing again. I'm
often laughed at. But my papers never jam!

~~~
giarc
I've seen people do this before, I always just assumed it was to make sure the
pages weren't stuck together, and therefore reduce the chance of 2 sheets
being pulled together.

~~~
interfixus
Well, it is, sort of. But in a fast moving production line, it could make a
huge difference in jam propensity whether the sheets were fed by somehow with
a nice touch or not.

------
smacktoward
We take sheets of dried wood pulp, stack them so loosely you can always see a
few that aren't 100% aligned with the rest, then feed them through a series of
unlubricated rollers inside a machine that's usually indifferently maintained
and clogged with dust, all while deliberately exposing them to heat and static
electricity and spraying their surface with goopy ink or powdery toner.

The surprise isn't that they jam occasionally, it's that we ever get anything
printed at all!

------
reaperducer
Coincidentally, just last night I was telling my wife how impressed I am with
my work's copier/printer machine.

It's about the size of a 1980's copy machine, but my department easily prints
a minimum of 5,000 color pages with it each day. Some days it's double or
triple that. Sometimes with staples.

We go through five massive toner carts each week. They're about the size of a
fire extinguisher.

In six months, I've seen exactly ONE paper jam.

I told her I thought maybe they'd figured out this whole printing thing
finally. But I guess TFA says I'm wrong.

~~~
mathiasben
What's the make and model?

~~~
reaperducer
Don't know the model, but it's a Kyocera. Before this job, I'd only been
exposed to that brand as one of the cheap printers for the Commodore 64. I
guess it's come a long way!

------
DubiousPusher
I enjoyed the article. Just want to point out briefly that the explanation
given in the article of how airplane wings create lift is incorrect.

[http://www.explainthatstuff.com/howplaneswork.html](http://www.explainthatstuff.com/howplaneswork.html)

~~~
giarc
I think they just messed up what side is flat, right?

~~~
aidenn0
No, symmetric airfoils generate lift just fine, and if you were going to spend
half your time upside-down, you'd use one.

Making it asymmetrical merely makes it more efficient to generate lift in one
particular direction (similar to how glasses lenses are asymmetrical to reduce
distortion).

Furthermore, pretty much no airfoils have flat sides, in nature or in
engineering[1]

The wing, when placed in airflow, disturbs the air in such a way that the
pressure on top of the wing is lower than the pressure below the wing,
generating net lift. This isn't a very satisfying description of lift, since
it just begs the question of "how/why does it disturb the airflow in such a
manner" and the short answer is "we put different shapes in a wind tunnel and
measured" with the longer answer being "you don't know enough math to get a
good intuition of that"

[edit]

After reading the article, the article _did_ get lift right for the case of
the paper though. Jets of air behave exactly as they say, and you can feel
something similar by touching the back of a spoon to the stream of water from
a sink; it will get pulled towards the stream of water (or just put a piece of
paper on a table and blow over it). A few planes use blown flaps[2] to help
get a similar effect (the introduction of a jet of air, which "hugs" the wing
helps direct the airflow of the larger mass in the direction you want).

1:
[https://en.wikipedia.org/wiki/Airfoil#/media/File:Examples_o...](https://en.wikipedia.org/wiki/Airfoil#/media/File:Examples_of_Airfoils.svg)

2:
[https://en.wikipedia.org/wiki/Blown_flap](https://en.wikipedia.org/wiki/Blown_flap)

~~~
efraim
>Because the top side of an airplane wing is flat, while the underside is
curved, the air above moves faster than the air below, and the wing rises.

That's what the article says, but it's usually the underside that is flat and
the top is curved.

~~~
aidenn0
In reality usually neither side is flat.

~~~
travisjungroth
A flat bottom wing gives you nice stall and landing characteristics. Very
small, 2-4 seat, trainer airplanes have them. (Cessna 150, J3 Cub)

~~~
aidenn0
I wouldn't call the Cessna 150 flat, as it has visible lower-camber, but you
are right about the J3 Cub; it's super flat on the bottom.

------
xefer
I'd like to see another article on why in 2018 every meeting seemingly has to
start with 5 minutes of fiddling with the screen projector.

~~~
shard
Is that still a thing? For small meeting rooms (less than 10 people) our
offices have large screen TVs (60 inch maybe?), and for larger meeting rooms
it looks like there are NEC projectors (I just checked 1). I don't recall a
project issue within the last 6 years.

~~~
asterius
Projector fiddling has been replaced with VTC fiddling. I hate Polycom/Skype
with a far greater passion than any printer.

------
24gttghh
I still hate printers, and their jams, but I must reluctantly appreciate the
engineering behind them after reading this.

This seems quite clever:

'Corrugating is when we put an intentional wave in the sheet, like in a piece
of corrugated cardboard,” Vicki Warner explained. “It adds stiffness.” The
plan was to corrugate the sheet lengthwise by running it over a line of
rollers turning at variable speeds before “flying it” into the stacker. If a
physical fix was necessary, a part might be 3-D-printed and installed, on-
site, by one of the engineers.'

~~~
jeremy7600
I have been a part of this process at Xerox.. it works quite well.. I've been
involved in a number of different aspects of it as well. I've been the source
of some of these fixes, I've been the source of some of the issues, and I've
been involved in the investigations to solve them. Xerox has a few different
labs for testing different things.

The "stub point" is a common thing, and can be very, very difficult to
pinpoint. They had one specific finisher that kept jamming when you printed to
the top tray. It didn't jam 100%, it was pretty intermittent. Well, this
finisher had been in another lab for a few weeks or so and they couldn't find
the source of the jams or a pattern to them. I had the finisher installed on
one of my machines in the 3 days I'd solved it. There was a small stub of
plastic on a flag for a sensor. The flag sits in the paper path, and when its
moved, the sensor changes state. So this flag has an pretty smooth surface so
as to not catch the paper, but somehow this one got a little nick in it.
Enough to cause a jam when a sheet ran right into the nick. I filed it down
and the machine never jammed again.

We had another issue with a printer at a customer site and the issue dealt
with static electricty. a 30kv ESD gun and the inside of a printer.. we still
never solved the issue.

------
thisrod
I'm surprised that Xerox pays engineers to do all this, when so many companies
would pay their lawyers to make it someone else's problem when an odd type of
paper stock jammed in tropical weather. Making custom parts and flying out to
fit them in production machines? I thought technicians only got to do that
during wars. I suppose you might do it when the machine is the one that prints
the price labels for Walmart, though.

~~~
Avshalom
I don't know about Walmart but here at Target we just use some random small
business Epsons for the signing and Zebras (previously Monarchs) for the price
strips and stickers

~~~
ComputerGuru
Zebras are indestructible. It’s what Amazon uses in their warehouses for
everything. I was looking for a label printer and my options were a new dymo
label printer from 2015 or a zebra released 15 years prior. The zebra still
won.

~~~
skrebbel
They're also a lot of fun to code against, if you're like me and have a thing
for ancient serial cable text protocols designed by electrical engineers.

~~~
ComputerGuru
I haven’t coded against the Zebras but I have against their counterparts from
Epson with ESC/POC and fully concur. It’s like a throwback to the 80s or early
90s.

------
alricb
> (Before railroads transformed the transportation of lumber, logjams had to
> be addressed by “jam breakers”—experts who spotted and removed the “key
> logs” jamming up the river.)

River transportation of lumber kept going long after railroads came along. Jam
would be broken using dynamite sticks.

Here's a movie on the driving of logs on a river in the 1950s:
[https://www.nfb.ca/film/drave/](https://www.nfb.ca/film/drave/) Driving only
stopped in the 1980s on that river.

~~~
djrogers
Rivers are still in use for moving log booms today - you can see them on the
Fraser river and other places in and around Vancouver BC - although they tend
to be more orderly, with strict regulations around the logs being properly
boomed and contained..

------
minikites
The "Secret Life Of Machines" episode about the photocopier is also
illuminating:
[https://www.youtube.com/watch?v=S2NIAD5qn7E](https://www.youtube.com/watch?v=S2NIAD5qn7E)

~~~
djsumdog
Wow, that's really interesting. I didn't realize that's where the term
"blueprint" came from.

------
Ftuuky
I work for a major ICT provider that sells about everything enterprise
related, from servers to storage systems, laptops, scanners, etc. In terms of
customer support the printers are the absolute worst: usually it's always a
critically important since they're used to print the labels for factory
outgoing and if they stop for one hour it's millions of euros lost. This means
the ticket will be Priority 1 and everything needs to be solved within minutes
or else people will freak out since there's a whole factory plant jammed with
cars, tires, whatever, that can't leave the factory without the printed stamp.

------
preinheimer
I wonder if we could go jam-free with Continuous Stationary (
[https://en.wikipedia.org/wiki/Continuous_stationery](https://en.wikipedia.org/wiki/Continuous_stationery)
). That paper with the holes on both sides from the 80s, and some legacy
systems today.

It seems really helpful, but I'm not sure which problems discussed it would
actually solve.

~~~
PotatoMatch
Had a dot matrix printer that used continuous paper. Notorious for jamming.
Usually something getting stuck on the little holes, or the perforated sides
tearing mid-print.

~~~
astrodust
The worst was when it lost traction, shredded the holes, usually in a tangle
of paper.

There'd also be cases where it kept pulling on the holes but those separated
and got gummed up really badly.

When you try and tug the pages out they're all perforated so you get, at best,
a single page. It can be a lot of work to clear a jam.

Most people think of dot matrix printers as slow, lumbering things that would
take measurable time to print a single line. The industrial ones, enterprise
grade, made by companies like IBM were dizzyingly fast, pages per minute, so
if a jam happened it was usually severe. Most had multiple print heads to
speed up printing.

These also used much wider paper than normal for things like accounting
reports. When they jammed, they _jammed_.

------
GrumpyNl
Inst this easy to solve by not feeding sheets, but from a role and cut after
printing? Cheaper production and transportation.

------
leandrod
Page wide, Precision core.

