
An intro to Pen Plotters - Tomte
http://www.tobiastoft.com/posts/an-intro-to-pen-plotters
======
tobiastoft
Can't believe my old post got picked up! If anyone's looking to get a plotter
I would still highly recommend an old HP 7475A as a gateway drug — they're
relatively cheap, not too big (the size of a large-ish inkjet printer) and
incredibly well made. I've had a lot of fun using the Geomerative library for
Processing.org to play around with my plotters, but really anything goes as
long as you can access your serial port and don't mind reading the plotter's
manual. I generally save the HPGL output to a text file and then use a small
utility app I've written to send it to the plotter. Sometimes I'll check the
output in Cenon.app before wasting any paper or ink.

~~~
Kadin
Though there's a lot to be said for the old HP plotters, if eBay is any
indication, there's a very thin supply and any uptick in interest is going to
cause them to dry up and prices to increase. It looks like that may have
already happened.

One alternative for people who just want to get started today is to buy a
modern version: they don't sell them as "pen plotters" exactly, anymore, but
they do sell desktop vinyl and paper cutters (sometimes a/k/a "die cutters",
although that's an inaccurate name used by papercrafters for historical
reasons) that are very, very close in terms of operation to a 1980s moving-
media pen plotter. And most of them can be trivially adapted to use a pen or
marker in place of a cutter blade.

I have a "Silhouette" brand cutting plotter, which can take two tools, and it
cost me about the same as what used 7475As are currently selling for and
worked via USB out of the box. It'll never challenge the old HP on its great
1980s aesthetics, and the paper traversal speed isn't quite as fast, but it
produces output that seems equivalent and I can jam pretty much any type of
pen I want into its toolholder. It uses a variant of HPGL that's supported by
several open source tools in addition to the OEM software.

The one important note is that you must absolutely avoid "Cricut" brand
cutting plotters, which are unfortunately the dominant modern manufacturer.
They have an awful razors-and-blades business model that revolves around
selling the machines at a discount and then charging users for overpriced
vector drawings through an "app store" type system, and they enforce this by
obfuscating the communication protocol used by the plotters, and abusing the
DMCA and engaging in other bits of sharp practice to discourage 3rd-party
software. Unless you're buying one to reverse-engineer, they are best avoided.

The Roland STIKA line is very well-regarded if you want to spend a bit more.
Can't speak for many others.

I'm hopeful that the current resurgence of interest in plotters will result in
more third-party, open-source software for these current-production commercial
machines, in addition to the older surplus ones. Once the parts supplies dry
up for the older machines, these newer ones will be the easier path forward
for people who want to start playing with this technology.

~~~
hahamrfunnyguy
I have one of the made-in-China cutting plotters from USCutter. USCutter seems
like the Harbor Freight of cutting plotters, but for me the plotter works as
intended. You can swap out the cutters for pens or markers. I paid around $200
for the 34" version.

It's USB and uses HGPL and you can open it up like you would a serial-USB
device and just start sending it HGPL.

I hope interest in these devices from programmers continue, because I'd love
to see an open-source plotting software that's suitable for printing/cutting
graphics on rolls of paper or vinyl. The software available from USCutter is
horrible!

~~~
cybertim
This is exactly what I was looking for. After searching on ebay for the HP
7550/7475a i noticed they are generally only available in the US. Since the
shipping costs and import duties to the EU are really high for US-ebay
products and most of them did not guarantee it would work I started looking
into alternatives.

So I tried my luck on the 'Drawing Machines'... But they are (in my opinion)
very slow, suffer from the same 'do your own maintenance/support' like current
3D printers and brands like AxiDraw, Eleksmaker or Mackerblocks are crazy
expensive compared to the 3D printers which contain much more electronics and
material.

Also looking into their 'boards' I noticed they use different firmwares and
mostly leaned on SVG/Inkscape/Python and i'd rather have the HP-GL to mess
around instead of getting lost into this firmware/library rabbit hole.

Then I stumbled on the Silhouet Curio while looking through youtube videos. It
has so many options.. whole 'home' businesses are build around this device.
Looking closer into the electronics I noticed it uses a proprietary
language/driver. However it does have a small active tech community that was
able to reverse engineer the protocol and created an Inkscape plugin.. but
that will make it on par with the drawing machines, and I'd rather have a
documented protocol from the get go (like HP-GL).

I almost gave up on my dream of owning a plotter and tinkering with fractals
and the HP-GL on a rainy Sunday afternoon. Until I decided to read this thread
that started it all once again and read your comment about the USCutter, this
thing is exactly the right price and seems to actually use HP-GL, awesome, my
search continues.

------
djsumdog
I grew up in the 90s. My dad would tell me about the plotters they had at
work. I remember many of the old dos programs from that era would have
plotters listed in their printer options. (Anyone remember Banner Mania?)

I never actually saw a plotter in person though. We just had an ink jet at
home and lasers at school.

This is a pretty amazing post though. I never knew how plotters worked, or
even realized how elegant their protocol was.

A lot of people talk about how kids will never appreciate x, y, z today. I
remember in high school when a friend of ours got his first CD burner, a 16x.
We had been struggling with 2x/4x burners (I even had an old SCSI burner). We
were both like, "You will never appreciate that."

That's why posts like this are so important. I think a lot of people growing
up will appreciate learning what technology was like; seeing simulations of
old BBSes on 9600 bps modems. Sure, they'll never have that feeling we did of
dialing BBS after BBS and downloading shareware, typing on FIDO net or photo
copying our parent's drivers license so we could download dial-up porn, but if
it's well written about -- it's still something we can pass down to the next
generation of engineers about the way things were and how far we've come.

~~~
dsnuh
Agreed. I was just talking today about how I missed the days of yanking trial
CD-ROMs from magazines to get that next free month with a cardgen. I love
seeing old technologies like this still in use, especially with modern
libraries, etc. It's the perfect mix of nostaglia and discovery. I am picking
up an HP7470 tomorrow and can't wait to play with it.

~~~
monochromatic
I wonder if AOHell would run on Windows 10...

~~~
dsnuh
Guide XYZ has entered the room...

------
qubex
I turned 18 in 1999.

I found a discarded HP plotter from the mid eighties in the late nineties
(about 1996/1997) and successfully connected it to my PC. There I used
CorelTrace! to transform a scan of my father’s signature into a vector file.
Then I was able to place any document the school wanted him to sign into the
bed of the plotter and have it literally inked onto the page.

Excellent, reliable, indiscriminate forgery. (I’ve since owned up to this.)

~~~
julian_t
We did the same thing with the signature of our department head, who was often
out of the office, and was cool with it provided it didn't get him into
trouble.

It was necessary because this was in the Civil Service where you needed a
signed requisition for _everything_ , and previously he'd just leave a pile of
pre-signed forms on his desk when he went away...

------
jdcarter
Most vinyl cutters can use a pen as well. I have a Graphtec CE5000-40 cutter
with a 15" wide bed, and I have adapters so I can stick sharpies of various
sizes in it. Plus it has niceties like a USB interface and plugins for
Illustrator. (Downside vs. an old plotter, of course, is cost.)

EDIT: also don't forget the AxiDraw!
[https://shop.evilmadscientist.com/productsmenu/846](https://shop.evilmadscientist.com/productsmenu/846)

~~~
wlesieutre
Interesting note on the AxiDraw, the way it holds the pen at an angle and
drags it around means it can work with a fountain pen where you need the nib
held with a softer angle relative to the paper (both tines touching, ink flows
out in between). The photo shows it with a Lamy Safari.

I don't think this is the case with regular pen plotters, which look like they
hold the pen vertically and keep it fixed as it draws in different directions.
Some pens will write vertically, but it's not ideal depending on the nib
grind. The bottom corner of the nib is rounded to work at a range of angles,
but the top might have sharper edges that would catch when dragging it upward.

EDIT - I suppose you could make an adapter for a pen plotter that would hold
it at an angle though.

~~~
meatsock
dont forget you would have to prevent the modified regular pen plotter from
dragging the angled fountain pen the wrong way

~~~
wlesieutre
As long as it's not a particularly flexible nib (and most aren't these days)
you can pretty much push it any direction once you have it at an angle. Lucky
for me, otherwise I'd have trouble with down strokes (left-handed overwriter).

------
fogleman
See #plottertwitter for a peek at "our" world.

[https://twitter.com/hashtag/plottertwitter](https://twitter.com/hashtag/plottertwitter)

~~~
GuiA
There’s also a nascent plotter art subreddit:
[https://reddit.com/r/plotterart](https://reddit.com/r/plotterart)

------
2dollars27cents
Building 2d plotters is a fun mechanical design exercise too. It's very
accessible from both a mechanical design + software/electronics perspective.

Shameless self promotion but here's one I built:
[https://www.markjgallagher.com/projects/#/utsushi/](https://www.markjgallagher.com/projects/#/utsushi/)

~~~
joshu
Very nice work! I also use GRBL.

Here's some of mine:

\- belt driven:
[https://www.youtube.com/watch?v=piKsTr9XfFU&t=0s&index=3&lis...](https://www.youtube.com/watch?v=piKsTr9XfFU&t=0s&index=3&list=PL0h5Hh-9o_h-
cT5vb3yNMY0_7Y7Vfb6CI)

\- screw driven:
[https://www.youtube.com/watch?v=8rGjyPqcVbg&t=0s&index=2&lis...](https://www.youtube.com/watch?v=8rGjyPqcVbg&t=0s&index=2&list=PL0h5Hh-9o_h-
cT5vb3yNMY0_7Y7Vfb6CI)

corexy belt:
[https://www.youtube.com/watch?v=Rf1MJxOYzkU&t=0s&index=7&lis...](https://www.youtube.com/watch?v=Rf1MJxOYzkU&t=0s&index=7&list=PL0h5Hh-9o_h-
cT5vb3yNMY0_7Y7Vfb6CI)

~~~
dsnuh
Awesome stuff! The water droplet one looks amazing.

------
paulgb
Here's a good intro to plotting in a JS environment:
[https://mattdesl.svbtle.com/pen-plotter-1](https://mattdesl.svbtle.com/pen-
plotter-1)

And one I wrote for Python: [https://bitaesthetics.com/posts/surface-
projection.html](https://bitaesthetics.com/posts/surface-projection.html)

One of my favorite parts of plotting is the community; there's a bunch of good
tutorials and GitHub repos for someone getting started.

~~~
salgernon
There’s also a community around a python hpgl library called “chiplotle”:

[http://sites.music.columbia.edu/cmc/chiplotle/](http://sites.music.columbia.edu/cmc/chiplotle/)

They’re involved with plotters as part of interactive art displays.

------
dfox
In early 00's I went for cycling/drinking trips with few friends and wrote DOS
program for collecting data from bicicle "computers" (manually transfetered,
obviously), it produced charts in all the glory of VGA mode 12h and had export
to HPGL, because the HP DesignJet we had access to (which was sold as
"plotter", but in fact was giant InkJet printer) understood HPGL. Originally
the input was simply text file with records separated by new line (produced as
a note file on Casio data-bank), but later I wrote DOS immediate-mode GUI
"spreadsheet" for capturing that data (on some random-ish mid-90's
subnotebook).

------
rhplus
This seems like a tangible way to introduce a young child to programming. It
immediately brought back memories of drawing shapes on a grayscale display
with Logo.

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

~~~
JaggedNZ
It's still not as fun as a real turtle
([https://en.wikipedia.org/wiki/Turtle_(robot)](https://en.wikipedia.org/wiki/Turtle_\(robot\)))
But there is a decent turtle lib for python, used in the Rasberry Pi book my
son has and a few online tutorials like:
[https://projects.raspberrypi.org/en/projects/turtle-
snowflak...](https://projects.raspberrypi.org/en/projects/turtle-snowflakes)

------
yitchelle
Back in the mid 90s, the company I worked for used to plot our circuit
diagrams with the pen plotters. It would plot it out on an A3 and takes about
30mins per page. The results were beautiful, almost an art piece.

~~~
hexane360
This twitter account does exactly that:
[https://twitter.com/FogleBird](https://twitter.com/FogleBird)

~~~
azeirah
Michael Fogleman's in this thread, you know? :P

[https://news.ycombinator.com/item?id=16496005](https://news.ycombinator.com/item?id=16496005)

------
ghaff
There was a period of a few years when I used HP pen plotters to make
transparencies for presenting on an overhead projector. There was something
sort of relaxing about watching it work. As I recall, there was also a lot of
screwing around with non-standard serial interfaces.

~~~
oldcynic
_> There was something sort of relaxing about watching it work_

I came here to post exactly this. Not forgetting the almost musical
accompaniment of the stepper motors.

Just as well really, as they weren't exactly fast.

~~~
gnufx
Yes, you could get a reasonable idea what people were plotting on our
Benson(s) from the sound. Many yards of spectra we plotted, even before
Versatec matrix plotters came along.

When we got an A4 flatbed plotter (early-ish 80s), I remember using it to
produce the first computer-generated overhead slides anyone in the group had
seen, but it was also useful in reverse for digitizing plots from papers by
moving the pen and recording points.

------
igpay
Anyone know of a good service for getting custom large format plots from a
machine like this? Looking to make a custom poster in this style but would
rather not invest in a whole machine.

~~~
gh02t
Pen plotters are pretty much extinct in commercial use as far as I know.
They've been almost entirely replaced by large format printers, which are also
called "plotters" but are really just large laser or inkjet printers.

I just tried looking a decent amount and couldn't find anybody offering
contract pen plotter services. Your best bet would probably be to write some
code to simulate the way lines look with a pen plotter and render it into an
image, then print it with a modern large format printer (which plenty of
places offer). They generally have very high print quality and should be able
to print enough detail that it'll look like it was drawn with a pen.

Edit: maybe you can use Inkscape to get the pen line effect? I've only used it
a bit but it sounds like something it'd be perfect for.

~~~
cartoonfoxes
Not entirely. I dragged one out of storage at work a few months back to make a
run of large format ARCH D-size assembly drawings for the shop floor - no
sense in buying a large-format inkjet just for this task. The machine is older
than me by a long ways, but is still in good working condition. AutoCAD ships
with binary drivers for most of the common plotters of the day, so there was
no real effort involved in setup.

I had a good amount of fun watching it go, though as others have stated, they
can take forever to run. The output is gorgeous, and generating real honest-
to-goodness engineering drawings on one is a special feeling.

I have a mind to try some blueprinting with it, if I can find a source of
drafting film and compatible pens.

~~~
gh02t
I wasn't suggesting buying a modern plotter, I was suggesting using a printing
service as modern large format printers are expensive. Similarly I know pen
plotters probably aren't totally out of use, but I can't find anywhere that
offers them as a service you can rent (which was OPs question).

Pen plotters have actually had a resurgence lately among hobbyists with the
proliferation of affordable CNC controllers and stepper motors, but I don't
think many professional shops are operating them regularly. I bet there are
some artists using them however, as well as occasional users like you.

------
stuart78
A nice memory from my childhood (early 1980's) was doing a school trip to some
sort of design shop where they were CAD and getting to take home a crisply
plotted rendering of the US Space Shuttle. In my memory, it was pencil not
pen, but I'm not sure if that holds up.

The 'perfection' of the drawing blew my mind and, as the author points out,
does have a unique character. Definitely one of the early memories that got me
excited about what computers can help us do.

~~~
Kadin
The Space Shuttle drawing is so common that I have to believe it must have
been a sample image distributed with _some_ software suite or plotter. It
comes up everywhere! Especially in old plotter ads.

Sadly I haven't managed to find a clean EPS or SVG version of it, though.

~~~
jaclaz
I believe it was a demo .dwg (Autocad) see:

[https://www.youtube.com/watch?v=iziP0cQhOFY](https://www.youtube.com/watch?v=iziP0cQhOFY)

~~~
stuart78
Love watching that print.

------
mark-r
It was an HP pen plotter that first introduced me to computer graphics.
Sometime about 1974 I think - probably the 7202A [1]. This was before HPGL, I
distinctly remember the PLTL and PLTT commands to start and end the plotting
sequence. The first thing I did for it was to create a font.

[1]
[http://www.hpmuseum.net/display_item.php?hw=83](http://www.hpmuseum.net/display_item.php?hw=83)

------
jankovicsandras
This looks really cool. If somebody needs a free vectorizer, then check out
ImageTracer (Unlicense/Public Domain). I think it would be realtively easy to
convert from tracedata (path coordinates) to
[https://en.wikipedia.org/wiki/HPGL](https://en.wikipedia.org/wiki/HPGL) .

Available in JavaScript (works both in the browser and with Node.js),
"desktop" Java and "Android" Java:

[https://github.com/jankovicsandras/imagetracerjs](https://github.com/jankovicsandras/imagetracerjs)

[https://github.com/jankovicsandras/imagetracerjava](https://github.com/jankovicsandras/imagetracerjava)

[https://github.com/jankovicsandras/imagetracerandroid](https://github.com/jankovicsandras/imagetracerandroid)

~~~
chris_wot
Funny, I’ve been looking into vectorising bitmaps. Try potrace on Linux, and
for a GUI ink trace can do this also.

------
chx
The most insane device in this vein IMO is the Panasonic Penwriter. It's a
four color typewriter (!) and plotter. Yes. It was using pens to write
whatever you typed. And this was in 1985! If it'd been more reliable
(surprise: it wasn't) it would've taken the world by storm. (I think Brother
had one too.)

~~~
hahamrfunnyguy
I wouldn't be so quick to write them off. With the attention this article is
getting, hackers are going to be lining up on eBay to get their hands on one
of these. A veritable penisance of plotting devices!

~~~
chx
If you meant penaissance that'd be excellent wordplay :)

------
taeric
The language reminds me of metafont. And svg. Really cool to see the results.
And now I'm tempted to get one of these. Pretty sure I don't need to spend the
money. Or the time. Really want to, though.

------
rrauenza
A lot of people turn their 3d printers into plotters...here is one example:
[https://youtu.be/sXb9NDqn1Mo](https://youtu.be/sXb9NDqn1Mo)

------
stinos
I had the Lego Technic 8094 when I was a kid, good times. One of the things
you make with it was a very simple pen plotter, but it actually worked for
creating drawings (which could also be programmed into the controller).

Now ships for >500$ it seems: [https://www.amazon.com/Lego-Technic-Control-
Center-8094/dp/B...](https://www.amazon.com/Lego-Technic-Control-
Center-8094/dp/B003JAB4PI)

------
bitwize
PEN PLOTTERS. My dad's HP-7475A was the cat's ass back in the day. I still
remember the sounds that thing made as it turned its carousel, snatched a pen,
and then started making laser-sharp, perfect lines on the page. My dad used it
for drafting.

Eventually I read the manual and learned how to command it using BASIC,
because of course I did.

These days, my dad messes around with 3D printers, so a lot has changed, but
then again a lot hasn't.

------
dsnuh
I ordered a plotter kit off of ebay a few weeks ago with zero instructions. I
finally found an assembly video online in Chinese and managed to get it built,
but still haven't been able to get it to print anything using Inkscape, which
is what was recommended. I'm pretty discouraged and haven't messed with it in
a few days, but this gets me motivated to try again.

------
antod
My first job was AutoCAD drafting in the early 90s with pen plotters. I can't
say I missed them when we replaced them with A1 inkjets and A3 laser printers
(for quick small drafts). Very slow and noisy when you needed to get work
done, but I can see how they'd be a fun retro hobby now.

------
julian_t
This stuff brings back memories... as a junior dev, one of my jobs was to keep
the Rotring ink pens working so that we could plot maps on tracing film on the
Calcomp drum plotter. I later wrote some Fortran code to sort the data in
order to minimize drum movement.

Goodness, but that's a long time ago...

------
johnhenry
I've been wanting to experiment using pen plotters and conductive ink to print
circuits.

~~~
Kadin
That's probably possible, but you may have better luck on non-trivial circuits
using the plotter with a knife blade to cut or a pen to draw masks, and then
do photoresist etching. Or maybe you could draw with a Sharpie directly on the
photoresist paint and then expose it, without masking material. It's worth a
shot anyway.

Plotter-printed photoresist masks were actually a fairly common way of doing
PCBs in lab settings, back in the 80s and early 90s. Later, it became easier
just to run acetate sheets through laser printers, but for a while a
Rapidograph filled with India ink was the cleanest, darkest line you could
get.

Perhaps more usefully today, quite a lot of people use vinyl cutters to cut
thin plastic (mylar usually) to make solder masks. Even the cheaper cutters
can do a surprisingly good job of this, enough to make solder masks for many
SMCs.

------
chrisbennet
My first job out of college in the 80's was developing software that drove a
big(ish) HP plotter for drawing maps for a mapping company.

------
myro
That's super cool

------
cronjobma
This is absolutely fascinating. It got me all excited about pen plotters and
I’m thinking of ordering to hack around with it. Would love to try attaching
water pencils to it for example. How about hacking 10 of these to move a long
a real person’s hand so you can sign multiple pages. This one article is going
to hijack so many of my upcoming weekends...

~~~
Kadin
> hacking 10 of these to move a long a real person’s hand so you can sign
> multiple pages

You may already be familiar with this, but the "Autopen" is a commercial
device descended from older machines which did exactly that.

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

I'm not sure how current ones work exactly, but the 1940s through 1960s ones
used a system of cams running against a template. It's more complex than just
the 2D motion of a pen plotter, as I believe it can also alter the pen angle
and pressure somewhat.

It descends from older devices which go all the way back to Thomas Jefferson,
who used various mechanical aids to make simultaneous multiple copies of
handwritten documents.

[https://en.wikipedia.org/wiki/Polygraph_(duplicating_device)](https://en.wikipedia.org/wiki/Polygraph_\(duplicating_device\))

They are quite clever, although today largely forgotten outside of their
historical connections.

