Show HN: My Pen Plotting Journey | Hacker News Reader

Show HN: My Pen Plotting Journey

adamfuhrer.com

235 pointsadamfuhrer89 comments

So, I understand the appeal of having something use pens to plot such things but… If I were to just use a regular printer to print those things (art, drawings, …), would the result be really different ? I have no pen plotter nor printer, so… I don't really understand what would be the main differences…

A printer will usually leave a dot pattern to reproduce shapes, with a resolution fine enough that everything will be sharply defined.

The blackness of a laser printer is a bit less qualitative than ink, because it's shinier from a large variety of viewing angles.

Here if you zoom it a bit, you can see a very slight wobble in the pen tracks because it catches a bit of the paper's grain, and depositing ink, the paper "drinks" the ink which fattens the lines a tiny bit.

This is more noticeable on the drawings with a lot of pen lifts/drops, where both the lift and the drop leave a dot a bit larger than the line between them.

The one with gradients made with lines closer and closer is especially eye-catching to me because all of those imperfections adding to produce this "worn-out" look in the darkest parts of the gradients.

Some paths overlap a bit and if you look very closely there are more than one nuance of black because of this - in some other places, the lift/drop are close enough that a bit of ink seems to travel by capillarity between the lift and the drop, resulting in two touching lines that were separated in the program..

The ones having a lot of circles show other imperfections, with a bit of ovalization in the circles, and the paths generated to fill the circles with black missing a few parts..

What I like a lot is that the result shows all of those little details that accumulate and produce this imperfect look, without needing to simulate it in Photoshop or another software if you were to print it with a regular printer.

> Here if you zoom it a bit, you can see a very slight wobble in the pen tracks because it catches a bit of the paper's grain, and depositing ink, the paper "drinks" the ink which fattens the lines a tiny bit.

I think you're misattributing things. Plotters use stepper motors and so have a minimum distance they can move along each axis. Due to this, they don't produce perfect lines at an angle and do introduce similar artifacts to what you'd see on a screen.

IME older plotters use DC motors and optical encoders rather than steppers, and do seem to produce perfect lines at angles. They can't do curves perfectly, as even when you specify an arc or bezier curve, the plotter breaks it down into small straight segments.

the step resolution is such (80 steps/mm) on the axidraw v3 that this isn't really an issue. From their product page:

* Native XY resolution: 2032 steps per inch (80 steps per mm).

* Reproducibility (XY): Typically better than 0.005 inches (0.1 mm) at low speeds.

You must be right, there also must be mechanical steps or wobble at play here. I was hesitant because my 3D printer (lower-end than an Axidraw) seems capable of smoother angled/curved lines than what we can see here. On the other hand plotters I've seen (a long time ago) seemed to not eliminate all vibration in the pen.. but I did not see a mid to high end recent plotter running.

FDM 3D printers squish molten plastic onto the previous layer, and that probably helps balance out the limited "resolution" of stepper motors. Also I'm guessing the inertia makes the extruder movement a bit more continuous, after all it's enough to cause artifacts like ghosting when printing at higher speeds.

That's disappointing. I had assumed these devices were analogue and able to draw true curves. This makes me not so excited about them.

No true draftsman

An analog one could be built with 3 phase motors, but that's another project.

It's also not that uncommon for people to build intentionally bad plotters (I've done it), because the results when you stick a picture through the process have their own charm.

Similar to a 'prepared piano'. By making your instrument unique you introduce interesting variation and improvisation.

Plotters can make big art [0] cheaper than large-format printers, can be higher precision [1], and produce much purer colours (except pure C, M, Y, or K on a printer, but most colours are not those). The results also look qualitatively different up close, and are to me somehow more appealing.

Printers are more versatile within their limitations, so for many types of art they are better, but for what plotters are good at, to me they are clearly better.

[0] Or woodworking templates, blueprints, or whatever.

[1] E.g. a straight line is produced by continuous movement between the two points, with no pixelation or quantisation.

On point 1, there is also a cost to doing registration on large scale stuff. I have the XL Axidraw and am limited to 11" x 17" so if I want to go bigger I have to set up registration marks and make sure they're aligned.

Only for that style of machine, I think (not entirely sure what you mean). Flatbed or large format (paper drapes down each side and gets moved back and forth) plotters don't have that requirement. My A2 flatbed holds the paper in place electrostatically, and nothing can move once that's switched on; you position it where you want and press a button, then smooth it down. The Axidraw style plotters seem quite limited in comparison (and the cheap ones very imprecise).

I'm not visualizing what you have but having the bed static certainly makes sense. But any plotter where the tool moves and not the source will have this issue.

If the plotter is big enough to hold the whole piece of paper (or move the paper through on its own) there is no registration to worry about, and flatbed and large-format plotters do that.

Flatbed ones are like this: https://www.flickr.com/photos/anachrocomputer/5183771083, https://www.raspberrypi.com/news/control-vintage-roland-pen-...

Large format ones are mostly used for vinyl cutting nowadays, but they look like something like this: https://www.signmaster.co.uk/hardware_item/graphtec-ce7000-s...

Right, that's (the vinyl cutter variety) not wildly different than the Cricut (which I mentioned before, and can also pen plot)

I guess I'm thinking larger than 17" and the two flatbed ones you linked would suffer from the same problem (except that the first probably has no way to do larger than its bed)

One upside to a plotter is you can work with different media, both in terms of materials (e.g. chalk or paint) but also what you are plotting on to. For example, you can put certain types of marker in and draw directly on to glass or ceramic tile which might have some interest in terms of making gifts.

It's a fair question! I've thought about that a lot, as someone who has plotted maybe ~200 pieces of their own work (and generated plots for ~500-ish).

In person, it is very obvious that you're looking at something created by a physical pen. The lines have a glossiness to them, a slight pressure, etc. It's an artifact a printer couldn't have created.

Process-wise, it's a fun challenge too, but that's a different thing altogether.

Serious question, Can this pen effect be simulated, and still be printed with a regular printer ? Would there be a difference then ?

Only if your printer also slightly embosses (they don't anymore really .. dot-matrix and daisy wheel certainly can but then you get resolution problems), can take any ink you can run through a pen (they can't.. or at least they don't.. maybe old ribbon based printers could...). There is a quality to a pen plot that is not reproduced with current 'printer' technologies.

I have an AxiDraw Mini that I use with a sharpie to label thinks like zippered storage bags, because I am OCD that way. The only reason I'd use a plotter over a printer is if printing on heavy card stock that won't feed through a printer, or if using something like a metallic ink pen for effects you simply can't get with a CMYK ink set.

Plotters are fun, it's like a creative collaboration with a robot and you can hand it any pen you want.

Concept of Pen plotters is more useful in 2D manufacturing and things like laser cutters.

For anyone who wants to use the Axidraw without being directly attached to your laptop, I've written a bit about how to use a Raspberry PI to wirelessly plot your art: https://medium.com/p/f9e0a872138e

That's really helpful and I've thought about doing this because I don't have a dedicated space for my axidraw and it's kind of a hassle to move around (I have the XL)

I use it for art a bit, for creating really nice notebooks for organization. If you're into these things, I'll also say that the Cricut (a cutting / craft tool) also does pen plotting and while it's a much smaller space (max 12" wide, possibly infinitely long) it can be purchased for much cheaper and is a bit more versatile.

I fastened mine to board with a metal plotting surface (I picked up a cheapo 'metal whiteboard' on amazon). When I'm not using it I slide it sideways behind my desk. It's worked out well, it's a nice .. subjectively level surface. I can using my plotter on pretty much any small table at all as the board will make it bigger...

This also helps so that I don't constantly have to worry about accidentally bumping the table and causing the drawing surface to move in relation to the potter or visa versa.

Does the page work on iOS for others? I get black empty spacing after the description on both Safari and iOS.

Figured out why, it loads ~80MB worth of images.

https://pagespeed.web.dev/analysis/https-adamfuhrer-com-pen-...

Thanks. Just reduced the size of the images quite a bit

For me it just took a long while to load but eventually the content shows up

Same, is there some kind of compression proxy we can put the site through?

Can reproduce too

The images are scretched vertically (800x4032) on Safari. It displays correctly on Chrome though. Please add width: 100% to your existing class. Full CSS after modification below:

    [_nghost-ecl-c2] img[_ngcontent-ecl-c2] {
        margin-top: 60px;
        width: 100%;
    }

Giving me Hans-Georg Rauch vibes. (http://www.hans-georg-rauch.de/espresso/federzeichnungen.htm...)

Hey thanks for sharing, I really like what you do, both in gen-art and in photography.

You wouldn't have an RSS feed by any chance? I'm trying to avoid social media but I'd love to continue reading about what you do.

Really appreciate it! Unfortunately I don't at the moment. Big fan of RSS as well so I get the sentiment

Looks great! I was gifted a pen plotter 6 months ago and wrote a short post on my setup and workflow https://shahinrostami.com/articles/my-pen-plotter-setup/

A fun thing to do with pen plotters is to use a non-exact medum.

Here's Lucia He - an artist working with plotters and watercolor

https://twitter.com/Licia_He

e.g. https://twitter.com/ZeeZee_ETH/status/1628435706275037186

Peter Struycken [1] is a Dutch artist who produced a lot of works with pen plotters [2]. He is the brother of Carel Struycken [3]. He is befrended with Walter Lewin [4], who also owns a collection of his art works [5].

[1] https://en.wikipedia.org/wiki/Peter_Struycken

[2] http://pstruycken.nl/EnDyn.html?D,tag=P&w

[3] https://en.wikipedia.org/wiki/Carel_Struycken

[4] https://en.wikipedia.org/wiki/Walter_Lewin

[5] http://pstruycken.nl/EnDyn.html?L&l&ColWLewin

Pentel features an Axidraw in their ad for their self-feeding Orenz Nero mechanical pencil:

http://pentel-orenznero.jp/

I'm impressed that it works in an Axidraw. It probably helps that many of the strokes were very short so the Orenz Nero reset itself each time the pencil was lifted. I wonder how the Axidraw maintains optimal pressure with a pencil where the lead wears down enough that the pencil needs to get closer to the paper (which is how the lead holder retract works in the Orenz Nero).

I only have an AxiDraw Mini, and I'm not sure if it works the same way as the full-sized machines, but the pen is raised and dropped by a servo and gravity, the machine is not applying any pressure, only the weight of the pen itself is. It's good enough with a Sharpie in my experience, and I guess the Orenz mechanism is sensitive enough as well, but I haven't tried my own Orenz Nero in it as I generally want a permanent result.

> generally want a permanent result

I've often thought Tibetian-style colored sand mandalas would be a fun way to use such devices.

Of course, you'd need a lego-sorter-style device to separate the sand into different colors afterward.

> Of course, you'd need a lego-sorter-style device to separate the sand into different colors afterward.

Well that nerd-sniped me. Maybe a very small vibratory feeder so you can handle individual sand particles? Would require the sand to be fairly homogenously sized, but that's nothing some sifting can't fix. One of those usb-microscopes for checking sand color perhaps? Then you get to the point where you want it going fast, which might be tricky...

Maybe something similar to microfluidic devices but using acoustical vibration to transition sand in and out of a non-newtonian fluid state.

To the degree that different colors of sand have different physical properties I wonder if it would be possible to use differences in vibration and/or electrostatic properties to sort as a whole rather than evaluating each grain.

https://physics.stackexchange.com/questions/479163/what-kind...

Probably a better fit for a 3D printer with the hotend replaced with a screw pump.

This is super cool…thanks for sharing. I own an axidraw from a very expensive failed side project and they’re a lot of fun.

I need to try p5.js some time. Any tips for where to start with that?

Check out the coding train on youtube.

i collect links to plotter-related projects, code, manuals, et cetera here:

https://github.com/beardicus/awesome-plotters

in case you find this stuff as fun as i do.

Again regarding the choice of pens: How does the plotter behave with a softer tip? I'm thinking of the Tombow Fudenosuke pens - they have a wonderful soft tip, which allows for calligraphy in the hand of humans.

When used by a plotter, by changing the Z depht it would be possible to have very interesting dynamic variations, wouldn't it?

I can see how easy it would be to break the tip too, so better buying a bunch of those.

The tip of the Winsor & Newton fineliners are quite hard actually and work pretty well. Although the tip does wear out after repeated use (before the pen runs out of ink), so might not be the most ideal pen for the job. Also, the servo I use with the AxiDraw is the default one it comes with and doesn't apply any added pressure on the page.

The Copic Multiliner might be a good option then. They are just great in my opinion (But I use them for traditional illustrations), although a bit pricey.

Thanks! Will definitely look them up

Beautiful work, thanks for sharing. I'd love to try it myself. Could you elaborate a bit on how you convert your P5 code to .gcode?

Some of these (the wavy lines ones) remind me of Barbro Bäckström's work:

https://www.artsy.net/artist/barbro-backstrom

My family has one of these on the wall (quite dusty - as it's from the 1970s :) ), and the 3D effect is great.

Looks like that plotter is quite pricey. Can anyone recommend something cheaper to experiment with?

A few options generally:

* I got my AxiDraw as an impulse buy for a Black Friday sale. They go on sale around then

* Search AliExpress for "AxiDraw". There are cheap clones for ~$130 shipped

* Thingiverse/etc have some DIY plotters in various form factors: Stationary like an AxiDraw, polargraph (hanging from two points vertically), little plotter vehicles that "feed" a paper through by rolling over it...

* Old 1970s/80s retail plotters (i.e. HP). These are sometimes more trouble than they're worth, both mechanically for repairs and software-wise. Serial port versions are more rare than HP-IB versions. The drawingbots Discord has good vintage info here

As someone who bought a ~$150 knockoff plotter, I wouldn't recommend them unless you're unsure and just dipping your toe into the hobby. The plot quality will suffer -- even small amounts of backlash or slop in the mechanism and pen carriage will result in irritating and unfixable offsets in finer detailed plots. The bigger issue is actually software support -- all the hobbyists shell out for the Axidraw, so it's the only well-supported unit on both an art-software-workflow side and plotter-driver-software side.

Find an old flatbed HPGL-compatible one, from ~1985-2000. You may have to wait for one to show up near you, you may need a USB to serial (DB9) adapter [1], and you may have to jury-rig a pen holder if official pens are no longer available, but the cost will be a few 10s of dollars. Look for one with manuals and pens if possible. Graphtec, Roland, and HP are good brands.

Plotters are really fun, and HPGL is easy to generate with code.

[1] Or get a thin client with a serial port (I have an HP t630) and put Linux on it and use it as a plot server.

You could also go down the DIY route and build one yourself. I did just that and am really happy with the outcome. Check out https://ben.akrin.com/plottybot for a great design and instructions

The video of the AxiDraw is very satisfying:

https://shop.evilmadscientist.com/productsmenu/890

I built one myself. https://framedbyher.com/the-story/ I can share more in depth guide if you'd be up for that.

https://www.brachiograph.art/ explores the low end of cheap experimentation with pen plotting. It's a really charming project.

$700 USD for a AxiDraw V3/A3 doesn't seem too crazy. This is precision, purpose-built equipment.

Are you able to elaborate on what you were expecting or hoping for?

It's pretty crazy if it's just to generate some pictures for fun, especially when there are alternatives. I have an A3 flatbed Graphtec plotter with a precision of 0.01mm [1] that I got for something like NZD$40 (>20 years old, but perfect condition).

[1] Not a typo, but I don't have a way to check it. I use it in its "low accuracy" 0.025mm mode.

Yeah wait till they see what CNC machines cost!

I bought a Vigotech VG-X4 and did get it to work.It was around 200 dollars.

However there were a few issues - bit fiddly to construct (the same might be true of the axidraw i guess) and windows only. Found some software online to drive it on linux.

The one I was gifted (https://shahinrostami.com/articles/my-pen-plotter-setup/) will have been more affordable https://idrawpenplotter.com

There's software to use pens on a 3d printer to draw on paper on the bed, and it wouldn't need to be a very high specification on to turn out acceptable results

Didn't see a purchase link. Would love to buy one.

Thank you so much for sharing about the pens. Your work is incredible and the pictures really pop.

Thank you!

Not entirely sure, but it looks like a laser engraver with a pen holder could do this.

People have attatched pens to 3d printers and done this!

This is really cool! I see the plotter the OP got was like $700. Is there any way this is different than a $200 3d printer from Amazon with a pen mounted where the hotend would be?

It has a head designed for fitting writing instruments. I expected some kind of adjustable pressure mechanism, but I'm not seeing it in pictures or in the description. The closest I found was

    The pen holder fits a wide variety of pens, including Sharpie fine and ultra-fine point markers, most rollerball and fountain pens, small-bodied whiteboard markers, and so forth. It can even hold a fountain pen at a proper angle of 45° to the paper. You can also use implements that aren't pens, such as pencils, chalk, charcoal, brushes, and many others. However, you'll get the best results with instruments such as fountain pens and rollerball pens, which do not require the user to apply pressure.

at [0].

[0] https://shop.evilmadscientist.com/productsmenu/890#

The adjustable mechanisim on the axidraw is nothing but a screw. Essentially there is a right-angled channel you press he pen into and then you tighten a set screw that pushes the pen into the corner.

This design is simple to produce however it causes registration problems if you attempt a multi-pen (multicolor, say) plot, where the pens have different diameters. In the past when faced with this i've 'fattened-up' the narrower pen with tape wraps.

It should be no different, both use stepper motors and gcode for movement.

Very impressive work, would love to see the source code!

I built my own pen plotter - it is such an engaging piece of technology! I hope to design a super size plotter someday, just need to find the time!

The first one with the overlaid halftone squares really works well with these deep black ink pens ! The dictionary of color combinations on the first picture on the page is a real treasure too. Thanks for sharing. Edit : ooh, all the images did not load at first, it's even better than I thought :o

Can you plot the picture of the phase space from The Three-Body Problem TV show which they had on the wall?

Good job! I'm literally in the middle of building something similar with an old laser engraver.

If you want to try what could be the top-of-the-range of non-rotring pens, instead of the W&N you could use the Copic Multiliner. They're pretty hard to find in Europe, not sure in US. The flow and general feel is just great.

Thanks for sharing. When asking on Twitter how to get started the community suggested an Axidraw as well. Inspriing!

wow. those are beautiful. didn't expect to see that this morning!!!

Unknown pleasures!

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