The pleasure is all mine, this project benefits immensely from your involvement. This is planting several seeds for improving the gondola, thank you as always.

The photos and video show my very first drawing with this setup. The pen lift still needs some adjustment: you can see that the pen doesn’t always lift off the paper at the right moment.

https://drive.google.com/drive/folders/10kbSwDSyQu5ssncqoqmOgL8We2ZReyiv?usp=drive_link

Interestingly, the original build also uses a slight tilt to help with pen pressure. I’ve included a photo with a spirit level so you can judge the angle of mine for yourself. I’ll leave it to you to decide whether to call it almost vertical or slightly tilted 🙂 So far, this design seems to work at that angle.

One downside is the noise from the sliding pen holder rubbing against the inside of the housing. I’m still thinking about how to reduce that. I can also see why you chose a static gondola, given your concerns about fresh ink and precision.

I looked at [this design on the V1 forum](https://forum.v1e.com/t/polargraph-addition-to-my-wall-mounted-pen-plotter/53504/46) too, but it seemed more complicated than I needed.

I don’t have as much time for the hobby as I’d like, but I’ll definitely keep experimenting and sharing what I find. And yes, it’s been a pleasure exchanging ideas with you too. Thanks for being so open to discussing these changes! 🙂

I’m surprised that moving the pen rather than the paper would solve this issue, I suppose you can keep pushing the pen further until it hits. Would you mind sharing your design? It could be that the wall you’re on isn’t perfectly plumb too, the slightest deviation can have an impact with the plotter perfectly vertical. In general I do know “pen contact” is a bit case by case based on the deployment, you solution might make this a non issue. There are several reasons I went with a static gondola, I was worried about it rubbing fresh ink, and I thought a pen mechanism could lose a bit of precision. I’m really curious about your design.

I do use precise v5 pens a lot, I have a gondola design specifically for them so I can swap them on multi day/multi color deployments without losing registration. Please do keep sharing all the stuff you discover or redesign, thank you very much for the improvements you contributed, and your work testing everything. It’s very nice in 2026 to have fruitful human interactions online :).

Take care!

Hi Ben, thanks for such a detailed answer!
I used PILOT Hi-Tecpoint V5 pens, which I believe match what you use yourself. Even so, I couldn’t get them to draw without tilting the paper.
I probably should have taken the easy route and just accepted the tilted paper, but it was too interesting a problem to pass up. So I made a gondola that keeps the pen at 90° to the paper and lifts and lowers only the pen, not the whole gondola.
This setup works really well with fineliners, although they dry out quickly when the plotter sits idle with the pen uncapped.
Thanks again for such a great project!

I Santry, good to hear from you!

You’re right about the servo connection! My wiring diagram had a mistake and shouldn’t have worked. I fixed it, thank you very much for catching that.

You’re right about the fan too. 40mm does open more options, including fancy Noctua ones. I bought several 30mm ones figuring one would be good, but they were all a little noisy, so I lowered the voltage to make it quieter and that was that. That ship had sailed for this iteration. I run the plotter where quiet matters but in a public space it would be imperceptible, there is a lot of ambient noise in big open spaces.

The lines getting curved near the edges is almost certainly a calibration issue. And calibration on this plotter is only measuring the distance between the motors, and making sure your gondola starts at half of that horizontally and vertically. Are you certain that you got the measurements and initial positioning right?

Measurements and positioning are all referenced from the center of the motors, and to where the tip of the pen would hit the paper.

It’s very exciting that you got the thing moving and drawing even though it’s distorded :).

As far as the gondola tilting in extreme positions, this is ok, it’s actually designed with the tip of the pen at the center specifically to make tilting not affect drawing. Now of course, depending on the position, it’s never perfect, but I haven’t found this tilting to be an issue ever. I definitely had miscalibration isssues that created the curves you are seeing though :).

As far as the pen hitting the medium without enough pressure, it’s a multifactor issue, and you’ll quickly figure out a formula that works for you.
1. what pen are you using, how much pressure does it need to start flowing?
2. the gondola’s weight can be adjusted (likely increased) to make it behave better in these extreme positions
3. the gondola’s belts have several positions then can take when they attached, you likely want them the furthest
4. you might be able to cheat a bit by padding the drawing surface against the wall at the bottom so that it’s not perfectly vertical. If you look at the Dragon photo near the top, you can see that the way I’m holding the paper makes that happen. It helps but it’s not necessary, I’ve done perfectly vertical plotters. There isn’t a lot of pressure especially in these bottom positions, but you can always find a happy arrangement that works.

Hi Ben! Hope you’re doing well. I’ve finished assembling the mechanical and electronic parts and got the plotter up and running.

I’m not very familiar with wiring-diagram conventions, but on the actual board, the servo wire connection points are row of holes lower than shown in the diagram.

As for the fan, the SUNON MF30101V2-1000U-A99 seems like a good choice. It isn’t completely silent, but the noise definitely isn’t bothersome. A 40 mm fan would offer a much wider choice of models, although it would require redesigning the enclosure. There doesn’t seem to be any real obstacle to doing that, but I’m not sure it would be worth the effort.

During testing, I ran into a couple of issues. First, horizontal lines curve downward near the top of the drawing; the closer they are to the center, the straighter they become. Second, there is very little pen pressure near the bottom of the drawing. Given your experience with these machines, do you have any idea what might be causing these issues?

Also, is it normal for the gondola to tilt this much when it reaches the far left or right side?

https://drive.google.com/drive/folders/1rFBOILTPBqkQpNB1WdD0asqqIv0hP2kQ?usp=sharing

Indeed, it’s updated, thanks for noticing.

Everything’s good. I was on vacation in an area with no cell service anyway, but I’m back now and continuing with the build.

One other small thing I noticed while following the assembly instructions: they don’t mention the password for the Wi-Fi network created by the Raspberry Pi. It’s included in some of the other instructions, but I think it would be useful to add it here as well.

I can’t believe it’s the first I hear about Hugo, it looks pretty great. This might be too much of a feature degradation for me, I do like comments and an occasional dynamic thing, but it’s definitely giving me pause. Thank you for mentioning it :).

Hey Santry,

apologies for the radio silence. I ended up migrating a whole bunch of things I had accumulated over the years which left little time for anything else. I did catch your earlier comment which got caught between 2 waves of this blog’s migration (sorry!). I did reorient all the parts to be in their “print friendly” orientation by default, thank you for this suggestion. “Print friendly” is in quotes because some of them don’t have an obvious orientation. I refrained from giving too much guidance on printing because I find that it varies widely between people’s expertise and hardware. All in all these are pretty vanilla print which should do well with default settings.

I also integrated your threaded design in the parts, I put them in an “alternatives” folder and I’ll refer to them in the instructions. They could very well become the default, I just want to make sure they get used without issues first.

Thank you for all your work and commentaries, it’s really awesome to have a second pair of skillful eyes on this :). Sorry again for my late response.

I think I may have already left a comment, but it seems to have disappeared. Here is a link to an alternative version of the weights with threaded caps: https://drive.google.com/drive/folders/1XSbi0pZu3_wDEL9UPEnahQ6-bSnOhFL1?usp=sharing

Also, I found that Adafruit has published the PCB files for their board here: https://github.com/adafruit/Adafruit-Perma-Proto-Bonnet-PCB

This might be useful if anyone has trouble buying the board for some reason.

Very nice about the progress :). What makes you think the Pi is overheating? Are you seeing anything in the logs to that effect? I’ve ran many Pi in many extreme conditions and I don’t think I ever had one do that. To further convince yourself, you could check the logs, read the sensor continuously, maybe blow a fan on it, or run a CPU stress test to see if you can drive the issue manually regardless of the PlottyBot software stack (which isn’t particularly demanding on the CPU to begin with). My first reaction would be to look at the circuitry before anything else, and see if the Pi dying correlates to any particular action being taken (maybe it happens randomly when the servo motor is engaged, or maybe it’s a stepper motor that does it). I hope this helps somehow.

I got all the way to the servo motor part!

My only issue is my Pi is overheatting and essentially dieing. It happened twice 🙁

I thought maybe too much voltage was entering the Pi but after checking the voltage with a multimeter the voltage read 5V. I am going to check my wiring with your circuit diagram.

do you reccommend any solution?

The instructions were clear: it was easy to understand what to print and in what quantity.

A small improvement would be to save the STL files in the recommended print orientation, so future builders do not have to rotate them manually before slicing.

Most of my feedback is about the cylindrical weights. I think it would be useful to mention that they print well with tree supports from the build plate only. This uses less filament and avoids internal supports, which can break loose and spoil the print. That happened to me on my first attempt.

I was also a bit worried about the rounded bottom and bed adhesion, but it printed better than expected. Still, I think adding a small flat spot on the bottom would make the part easier to print and would give a cleaner outside surface. It would also probably allow the part to be printed without supports at all.

I also have some doubts about the small eyelet thickness, although since you have been using the plotter for a while, I assume it is reliable in practice.

One possible future idea: a version with a threaded cap, so there is no separate small lid that can fall out or get lost. If I have time, I may try to model this alternative.

Hey Ben,

That’s great news, I’m really happy to see this. At first glance, the V2 page looks clear and understandable.

I’ll start printing the parts and hopefully get the missing electronics from the store soon. I’ll leave comments on the instruction page as I go, unless you think there’s a better place for build notes and questions.

Thanks a lot!

Hey Santry,

It’s not complete yet, but I’ve made some good progress here:
https://ben.akrin.com/gondola-plottybot-v2/

That’d be great — I’m in. Happy to build it straight from your documentation and give you honest feedback along the way, so you know the instructions actually make sense to another maker and not just to you. That’s really the point of a good build guide anyway, so I’m glad to be the guinea pig.

I haven’t bought anything specifically for this yet, but I’m not starting from scratch either. I’ve got a few stepper motors left over from other builds, some belts, odds and ends of electronics, and a 3D printer. Flashing microcontrollers is familiar territory too, so the firmware side doesn’t worry me.

What does the parts list look like on the new version? If you can point me at the motors, the board, and whatever specific hardware you ended up going with, I can start sourcing the gaps while you work on the docs

Hey Santry,

well the new version is significantly different than the previous one. These gondola ones are fairly easy to make really. There’s barely anything mechanical at all, the gondola doesn’t have much to it, belt tensioning is as easy as adding weights until they’re straight, calibration is nothing but measuring the distance between the motors. Electronics and the software have changed, although I did make the later backward compatible.

Since I did take a bunch of pictures last year when I posted this, how about I try to put an actual documentation together and you can be the first one to use it? I would hope to have you review it thoroughly as you build, so we can refine it. I can’t promise anything because time is tight, but let me see what I can do in the next few days.

Do you have any of the parts yet?

Hi Ben,
I’m trying to pick a DIY drawing robot / vertical plotter to build, and I’ve been going back and forth between your Gondola PlottyBot and the Makelangelo. Your approach won me over.
Even the first version feels more modern and maker-friendly to me: Raspberry Pi control, a web interface, sensible build logic, printable parts. It reads like a project I can actually understand and modify, not just a kit I assemble and hope works.
I noticed you mentioned a second version with possible improvements. If you have any rough notes, sketches, or lessons learned about V2 that aren’t published yet, I’d be really grateful to see them before I start — especially around mechanics, the gondola, belt tensioning, calibration, electronics, and any software changes. Even messy notes would help.
Your documentation is already some of the best I’ve found for this kind of project, so anything extra on the newer version would help me avoid mistakes and start in the right direction.
Thanks for publishing this — it’s genuinely inspiring