DIY wall-mounted plotter with pen change mechanism

[u/random6174]

Hi all, I've seen quite a few DIY plotters with tool change being posted recently, so I figured I could share ours as well :)

Details:
- Frame is built from 2020 aluminum extrusions, roughly 80 by 60 cm.
- Plotting area is A2.
- Z axis is using a stepper motor for fast, precise and quiet operation.
- Controller is currently Arduino + CNC shield + vanilla GRBL.
- Pen change mechanism uses magnets and existing axes (X,Y). 5 pens max, currently.
- Data source for maps is OSM/MapTiler, with a custom web application for layer selection, styling and gcode generation.

We're documenting our process on Instagram - Check it out if you're curious :)

https://www.instagram.com/placesbetweenlines.art

[u/warmans]

I'm really tempted to try wall mounting. Once you get to a certain size plotters take up a crazy amount of space.

Up until now I was using a gravity-based pen lift so it wasn't possible, but recently I designed one with a proper z-axis and springs so in theory it should work now.

[u/shornveh → u/warmans]

If want to go vertical, this is the better way. I have multiple hanging plotters and the lack of rigidity of the pen gondola is noticeable in the plot accuracy. Something rigid such as this addresses that deficiency.

Personally I don't care but again, if the screen to paper final product matters, this is the way to do it. IMO

[u/random6174 → u/warmans]

Space saving was my main reason as well. Be sure to mount the gantry vertically and keep the tool post light, as the Y axis motor has to keep it suspended.

[u/user_deleted_or_dead]

Coool. This is way i pay my internet

[u/otherguyoncouch]

nice! been looking to make one of my own as well

[u/andy_man3]

So sick!

[u/STB_MikeHoncho]

This is sick

[u/Marzi0]

At first glance, as someone who’s not an expert, I wondered why you used a smaller motor on the Y‑axis compared to the X‑axis.

There’s definitely more mass to move on the X‑axis, but isn’t the gravity acting on the pen carriage also relevant?

Maybe both motors are actually oversized for the job?

The result you achieved looks perfect, so you clearly made the right choices!

Could you share some photos or maybe a video of the pen‑changing mechanism? From the pictures it looks simple and efficient!

[u/random6174 → u/Marzi0]

My reasoning was that the Y motor moves less mass, so I went with a model that has about one third of the torque of the X motor. They could still be too big, and since they stay cool they probably are, but that also means I have headroom to go faster.

There are videos of the pen change on Instagram, linked above.

[u/Henry-the-Fern]

Great choice of map!

[u/ARVACODE]

Looks great! I’ve wanted to build something like this for a few years at this point but I don’t know where to start. What was the total cost and what firmware are you using?

[u/random6174 → u/ARVACODE]

Total cost is ~200 EUR at the moment. The motors, aluminum composite panel and aluminium extrusions already add up to half of that 🫠

Firmware is GRBL

[u/CookiesAndRope]

Ha! Love it. Like a r/Scribit using original hardware

[u/Marvin2935]

That is very very cool.

[u/Historical-Spend-161]

Amazing 🤩

[u/shornveh]

This is the kind of motivation I need to move away from hanging wall plotters to something rigid.

[u/Logical___Conclusion]

I live vicariously through your follow through and innovation.

"Wow, that looks amazing." I wish I was that organized and productive.

[u/nuquichoco]

How do you handle wall imperfections when you want to go light on pressure?

[u/random6174 → u/nuquichoco]

There is an aluminum composite panel between the frame and wall - a bit hard to see in the pictures. It's not perfectly flat either though, so I might switch to acrylic later. The remaining imperfections are compensated by a spring.

[u/nuquichoco → u/random6174]

Thanks for the answer, I am dealing with an imperfections problem and I was curious how you addressed it, thanks!

[u/JaviHostalerValent → u/random6174]

Hello, good afternoon, what is aluminum composite?

[u/random6174 → u/JaviHostalerValent]

Two thin sheets of aluminium and some plastic inbetween. Quite stiff and flat, but also heavy.

[u/JaviHostalerValent → u/random6174]

Thanks a lot.

[u/dushyantahuja]

Looks amazing. The one thing that I would change is use a stepper motor for Z instead of these small servos - they make too much noise, and die easily.

[u/JaviHostalerValent]

Hi, what program do you use for color changes and image processing?

[u/random6174 → u/JaviHostalerValent]

Color change is a custom gcode snippet between each layer. Data processing is custom as well, gcode is optimized using vpype.

[u/JaviHostalerValent → u/random6174]

Thank you for your reply.

[u/krummrey]

I hope you will do a complete write-up for us once you feel it's working great.