Printserver¶

Sooner or later you'll come to the point that you want to use additional software like OctoPrint to control your printer.
Yes, it's not necessary as you can control it directly using the printers control unit and it's advisable to stay in the same room and monitor the printing process to be able to intervene as soon as something is going wrong - but we all know how it is..

So having the possibility to not only send gcode commands directly to the printer for e.g. executing a PID tuning but also to use certain plugins or additional hardware to e.g. monitor the printing process isn't the worst idea.
In case you're already using some kind of home automation software, you could also send yourself a fancy notification when the printing process is done.

Sounds tempting? Ok, so you'd need additional hardware for that to run the desired software on.

If you want to use Klipper firmware with your printer you'd need additional hardware to run Klipper and e.g. Mainsail on it anyway.

So let's have a look what might be an interesting and reasonable priced solution for that first.

Hardware¶

In the following I'll mention some solutions which can be used as an additional host which runs some sort of Software like OctoPrit or Pronterface or which can be used as a host for a Klipper installation.

Raspberry Pi¶

When you start looking around for a system the desired software should run on, the first thing you'll come across surely will be the Raspberry Pi (in the following named as "RPi").
The RPi is a little computer which became pretty famous since it entered the market.
It's a Broadcom SoC 64bit ARM system with LAN (and WiFi within the newer versions) and a microSD card reader onboard which keeps the desired OS. It offers GPIOs to directly connect hardware like sensors to it and it draws only a little amount of power.
Pretty much all of the regular software for 3D printing like the beforementioned OctoPrint or Mainsail or so are available as specific RPi image which makes it pretty easy and flawless to install even if you're not an expert. Just install the Raspberry Pi Imager, create the specific image, copy it to a sufficient microSD card and you're good to go - the installation will take a few minutes only.
And as handy as it is - it might not be the best solution, especially these days.

Prices for the RPi went up to a ridiculous level (afaik at least in Europe and the US) - if they're even available at all.
Also you don't want to get yourself an old RPi2B for example, it should be a RPi3B at least (referring to OctoPrint a RPi Zero 2W also works, it uses the same Broadcom SoC like the RPi3) - a RPi4 would be even better and advisable. Not only because of the pure processor power or the RAM - both is sufficient even with the RPi3 for example, but mostly because of the reason how the USB sockets are connected to the CPU. Afaik, up until the RPi3 the Broadcom BCM2837 only offers one USB port itself. This one port is split up by using a SMSC LAN9514 hub chip to get four USB connectors out of it and it also uses the LAN port.

If you're asking yourself now "What the heck is this guy talking about - I have four USB connectors available there, so what's the problem?" - well, let me try to explain it to you very simple:
Imagine you connect your RPi3 to a monitor and plug in a mouse, keyboard, your 3D printer and a webcam to the USB sockets and maybe you also use the LAN connection (because everybody who knows wireless uses wires ;) ). Then you start your printing process sending the gcode file to the printer and start to observe the printing process using the camera. Then all of the information are running across the same one and only USB port of the SoC (the main CPU). That means that most likely you'll find yourself noticing some kind of stuttering during the printing process and/or the stream of the webcam.
That doesn't occur because of a lack of RAM or CPU power (what people use to assume) - that occurs because of the architecture and the bottleneck "one USB port at the SoC". So you can see it like a four lane street going down to one lane - as soon as there's (much) traffic on all of those four lanes, you'll get stuck in the traffic where it goes down to one lane.

So does that mean you shouldn't use a RPi? No, not at all, it works absolutely fine - just be aware of the fact that it might not be the best solution for your money during these times where they became pretty expensive.

RPi Zero (2) W¶

Instead of using the regular Raspberry Pi, you could also get yourself the RPi Zero (2) W.
If you want to use it for KLipper, I'd recommend to get the Zero 2 W as it's quadcore CPU is more powerful.
However, as it seems to be quite difficult to get in these times, you could try running Klipper with the older single core Zero W as well - it just might be that it's not powerful enough to run the webcam stream. I've heard that it might not even be capable of running Input Shaper, but I'm not sure if this is true or nt, so maybe do a little rersearch on your own before you buy it.

Other SBC¶

If you can't or don't want to get an RPi but still want to stick to one of those tiny tinker SBC (single board computer) units, you can check out the market what's available and comparable to a RPi, like an "Orange Pi", a "Le Potato" or so on.
However, I'm not going into further details here as I personally don't use them and therefore can't give reliable pieces of information about which boards exactly might be a good substitue to a RPi.

Old "Regular" Hardware¶

If you have old hardware laying around like a laptop or so, you can also use that. Don't worry - even if it's pretty old in most of the cases it still would be sufficient. Install a Linux OS onto it and then install the desired software.

However, as much as I appreciate and love to re- and upcycle old hardware in general, one thing has to be mentioned: the amount of power they're drawing due to their old and mostly energy inefficient chipsets.
It might not really come into account if your prints last only a few hours and after finishing them you turn everything off. But as soon as you think about running those machines pretty much 24/7 you should keep in mind that they might draw a lot of power which sums up at the end. Right now here in Germany we're paying about 0,40€/kWh, so it really matters just looking at the financial side of that - not to mention the ecological aspect.

Thin Clients¶

Now - get ready for the real deal: Thin Clients!
Ok, might be a bit exxagerated, but I really love those fellas.
Especially if you want a host for running Klipper on, Thin Clients are my number one recommendation.

If you've never heard of them, let me give you a quick introduction:
Thin Clients are computers which are often used by companies for e.g. setting up workstations for their employees or to have some kind of information desk or screen running somewhere.
They have a small build factor, don't draw an excessive amount of power and usually come with connectors for LAN, USB, a monitor and so on.
Especially newer models (like only a few years old) have hardware built in which would be even powerful enough to replace your daily driver for surfing the web, watching videos, writing stuff and so on. Generally speaking: the newer and bigger they are, the more they have to offer usually - I'm talking about energy efficient quadcore CPUs here and the possibility to put in up to 32GB or even 64GB of RAM, swapping in a SSD (2.5", m2.SATA or m2.NVMe - that often depends on the age actually) and even run virtual machines (tip: ProxmoxVE) or containers (tip: Docker). Of course you could also just install a LinuxOS like Ubuntu or a headless Ubuntu Server and install your desired software directly there.

The (imho great) point is: you can get a pretty powerful and energy efficient machine which is a true x86 platform for just a little amount of money as companies use to sell them pretty cheap most of the time. You probably have to look out for a certain model a bit longer sometimes as they use to be sold out quite fast, but it would be worth it.
Anyway - even if they're usually available for a fair price, I want to mention that it's advisable to not buy the very first offer you can find. Even though they're still cheap most of the times compared to a RPi4 for example, certain companies know about the potential and that people like to use them for tinkering around, so some companies call for much higher prices than others.

NAS / Server¶

If you have a NAS or a server up and running already, you could also install the printing software onto that. In this case I'd assume that you already know what you're doing and that you don't need any advise though.

Creality Sonic Pad / BigTreeTech Pad 7¶

These ones are a nice and handy solution for the Klipper users as these are SBC units with a touchscreen in a nice enclosure.

The BTT Pad 7 is especially interesting when you want to swap out the stock mainboard and use a BTT board instead.
Afaik the BTT Pad 7 is also somewhat 'easier' to flash and configure than the Sonic Pad, but I didn't really do firther research on it, so maybe better check and compare yourself.

Old Android Devices¶

Yes, you've read correct: certain software could also be installed onto your old Android device like your smartphone or your tablet. Namely especially OctoPrint has to be mentioned here.
I personally would not recommend it as a host for Klipper though - you can use an old Android device as a KlipperScreen though.

I won't go deeper here though due to my lack of experience with this solution - you'll find many information about this around the web. One of those sources of information I'd like to mention though is the video of Thomas Sanladerer: How to run OctoPrint on your phone! and the GitHub repository of feelfreelinux: octo4a.

Besides the possibilty to use your old android device as a printserver, you can also use it as an additional screen for software like OctoPrint. That means that you don't install e.g. OctoPrint itself on the android device - you install an app which connects with the running instance of OctoPrint and gives you a nice UI on your smartphone. By doing so you could mount your old phone at the printer and interact with OctoPrint using your touchscreen or just have certain information displayed at the screen.

However, it should be mentioned here that it seems to be a bit like gambling to find the right device which connects with the USB chip being used at the printers mainboard and that can be charged parallel to being connected to the printer as well. It might even occur that the mainboard might get affected somehow if one applies 5V to it through the USB-C connector.

AndroidTV Boxes¶

You could also use one of those AndroidTV boxes like those T95 models and install Linux/Armbian onto them. These devices often come with 2GB RAM & 16GB flash or 4GB RAM and 32GB flash and use different kinds of quadcore CPUs. As there are many different versions which using different CPUs out there, you'll have to do a little bit of a research on your own how to install a Linux OS onto the belonging AndroidTV box regarding the chip being used.

If you're living in the US, you can also have a look at the Inovato Quadra - it's a T95 AndroidTV box which comes with a LinuxOS already being installed and it's about 35$.

Software¶

When it comes down to the software that should run on the printserver, you can choose between different solutions.
It also depends a bit which kind of firmware you're running.

My personal opinion on this:
- If you're running the stock one which is Marlin based, just go with OctoPrint.
- If you're using Klipper firmware, you can stick to OctoPrint, I'd recommend the usage of Mainsail or Fluidd though, as they're basically made for Klipper.

Yes, you could also look out for different software, but because the abovementioned programs are commonly used you'll find a lot of information about them and also many plugins for enhancing the capability even more. I'd recommend to do a little websearch on that, you might want to start with this article though: Ocbico: Mainsail vs. Fluidd vs. Octoprint - A Comparison

How To Install¶

So in case you want to use hardware like the abovementioned Thin Clients, you probably don't know how to set it up and install the software. You'll find many guides and tutorials for that out there, so let me just mention the following:

• For installing OctoPrint you can start your web research at All3DP: How to Install OctoPrint on Linux/Ubuntu.
• If you want to install on an SBC, you might want to have a look at All3DP: How to Install OctoPrint/Klipper on an SBC: Tutorial.
• Check out KIAUH as it isn't an installation script that makes everything a lot easier only for Klipper but also for OctoPrint, Mainsail, Fluidd and so on.

Camera¶

As mentioned in the RPi section, if you connect a webcam directly to your printserver, I'd suggest to use a webcam which only offers a low resolution like 480p (640x480) as you don't need 4K for monitoring the printing process. Of course a more powerful hardware can also handle a higher resolution though. Even though you can use 720p or even 1080p as well most of the times, I personally think 480p is totally sufficient when it's just about monitoring the print process.

Preferably use a cam with a wide angle view and a fixed focus, so that you can see the whole area of the bed and there's no autofocus which gets irritated by the movement.

If you want to create a time lapse video from your printing process, keep in mind that it's a pretty resource consuming task (CPU power, RAM and storage usage). So also here using a low resolution like 480p is adviseable, but might not fulfill your needs if you want high resolution videos.

However, I also would like to mention or even recommend general IP cameras (WiFi/LAN) which you could use. Also here it doesn't have to be a cam for a hundred bucks - a cheap one will do the job just fine. They often already come with the option to create time lapse videos and store it onto a microSD card also.
If you like to tinker a bit, maybe get yourself a cheap ESP32-CAM module.