Adding a display/Untethered use


we got our 2 Minis today, great little machines :slight_smile:
However, i was pretty annoyed by the lack of an untethered option - sure, i knew the mini had no display and controls but i thought one could unplug the cable after sending the Print Job - like my 4 years old 400$ Up! mini does…

However, since we use the printers for Kids workshops, it is critical not to have 1 Laptop per printer hooked up and the Print success depending on children not pulling cables or clicking around :slight_smile:

Is there any reprep like smart controller board confirmed working with the Mini’s minirambo?

The alternative will be a pi running octoprint which would have the bonus of slicing right on the machine but is a bit hacky with Running a Server + GUI + touchscreen (we don’t always have wifi on site)

Hope you can help :slight_smile:

There are multiple versions of the Rambo mini board. One has an LCD header. You can upgrade to that board if you don’t already have it and add an LCD, or you can add a raspberry pi and run octoprint and octopi using the mounting holes inside the chassis cover. There are other options as well, but those are the simplest.

The Raspberry Pi and optional touchscreen running Octoprint mentioned by piercet is a good, versatile option. Plug the server into the USB port. Upload gcode files to Octoprint (via the local network) and print. Add a camera to monitor the print and collect cool time-lapses for the kids.

Here are two pictures of the board i have, does it have the header?

We dont always bring our own wifi, so I’d have to connect to a new wifi every time, sometimes there isn’t any at all. The Best Option would be to come up to the machine with a usb-drive or sd-card, much like we do atm with our ultimakers. I’m currently working on that solution but a Controller with LCD would be the easier method right now.

That looks like a minirambo 1.3 board, which does have the two EXT connectors so adding a Fullgraphics LCD module is possible. I don’t know if the code bits for the LCD are in the firmware, but you can add those if you have some firmware editing knowledge without too much trouble, mainly by copying the elements in from the full Taz firmware. The same LCD cable used for the full Taz 6 should in theory fit, though I’ve not tried it. As with any electronics upgrade there is a small element of risk, so proceed at your own risk.

Although I haven’t tried, you could add an external SD card reader to the Pi and make it automount. IIRC Octoprint can be configured to watch an SD directory. I don’t really understand the wifi problem, but you can make the Pi access point: no need for external wifi network.
I would definitely try the Octoprint path first.

Understood. Sounds like an LCD would be ideal.

If you don’t have wifi, using a cross-connect cable (or small hub) with the built in network port of the Pi should also work. Make sure the PC and Pi are on the same subnet.

thanks for now, i’m still working on the pi solution :slight_smile: anyhow, if someone already tried the Smart Controller, i’d love to hear about that! I dont want to do any firmware modifications, so i think this would only work for me if its plug and play…

We have done some experimenting with this, and an add-on is something that is currently in development. You can find more information on it here:

Firmware (still in development, please use with caution) can be found here:

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If you are using the Raspberry Pi and don’t always have a WiFi network available, there is a great solution to this. Kenneth Jiang wrote a great set of directions for setting up the Pi and OctoPrint for just your situation. On boot, the Pi will look for known WiFi networks to log on to. If no known WiFi networks are found, the Pi will automatically set itself up as a WiFi Hotspot. You can then access OctoPrint from any computer by just logging on to the Pi’s hotspot. No need to add a touch screen and no need to run the GUI on the PI (which consumes a lot of resources, slowing down the Pi).

Here are the instructions for the Automatic Pi WiFi HotSpot. The first part of the article is just help in setting up OctoPrint for normal WiFi networking - you can skip that part if you’ve already got it working on an existing WiFi network. Scroll down about 1/3 of the page to find the section titled “Turns your Pi into a Wi-Fi hotspot, automatically” and follow the directions there.

I’ve used this when transporting a 3D printer among different classrooms. It works flawlessly. When we’re at a school where I’ve already put in the WiFi log-on info, it connects automatically. If I’m in a place where there is no WiFi (or the school where the IT guy refused to give us the WiFi password), the Pi just sets up it’s own Hotspot, with no intervention from me.

NOTE: the autohotspot is NOT dependent on OctoPi to work. It should work on any Raspian-Jessie installation.

EDIT - the WiFi hotspot instructions have been confirmed to work on OctoPi 0.13 and 0.14 (which were based on Raspian-Jessie-lite). It does not work on Raspian-stretch based systems. Stretch has changed some of the networking files and directories. OctoPi 0.15, the version currently in development, is based on Stretch, so the WiFi hotspot feature will not work on it. The author is aware of the problem. Hopefully, he’ll do an update when OctoPi 0.15 is released.

Nice find! While I don’t travel with my Taz, I can see how this could come in handy for transportable setups.

Thanks for sharing!

I helped Kenneth debug and improve it (mostly by being good at breaking things… I don’t claim to be good at programming).

I requested Kenneth’s help because the IT guy at the elementary school system where I was volunteering would not give the WiFi password to anyone except for use on the school’s own computers. He didn’t want “unauthorized” devices on his network. The Pi hotspot got us by until one of the kids managed to get the network password. I’ve also used it when doing a 3D Printing demonstration at another school.

Thanks John Mc! This is really interesting, I’ll get into that immediately :slight_smile:

Hi Brent, in your recent youtube-video from CES i spotted some “smart controller” like displays on the lulzbot-minis on the showfloor - are those the ones you were talking about?

I’m still very much interested in adding a controller - we are still on tethered use for our education-machines due to various reasons :frowning:

Yup, those are the ones! We announced them in late Q4 of 2017, and hope to have them available soon. Sign up for our newsletter, and you will get an update when new products become available:

jhackt -

Did you ever try using the Pi running Octoprint as a Hotspot?

At one point, I had the Pi/OctoPrint set up to access it right on a screen we attached to the Pi (an old VGA monitor scavenged from one of the school’s defunct desktops with an HDMI to VGA adapter). I ended up going back to running the Pi as a Hotspot and having them access it via OctoPrint’s browser interface. It meant not as many kids bumping around the printer and the Pi, so less chance of something getting disconnected. We also hooked up a cheap USB camera to the Pi (Logitech C270) so the kids could check on their print via a web browser.

Newer versions of Cura (and I believe some other slicers) will let you send gcode directly to OctoPrint for printing, so you can bypass the OctoPI browser interface completely, if you want. I’ve done that at home. I haven’t decided whether to do it at school. The interface for the newer versions of Cura can be complex. We may decide to stick with doing our slicing on Cura included with OctoPrint. With the addition of the “Full-featured slicer” plugin, it will handle 95% of the things the kids print without having to slice on their ancient laptops.

NOTE: I edited the post where I described the Hotspot feature earlier in this thread to include a warning that the Hotspot feature does not currently work on systems based on Raspian-Stretch (like OctoPi 0.15 now in development)

Brent - I missed the announcement. I received the Nov. 21, 2017 newsletter, and one on Jan 9, 2018, but never saw anything about the new Mini controller. I’ll nose around and look for that announcement. I’m excited about that and the new modular print bed. (I actually bought a complete spare print bed to use in the school where I volunteer - those 5th & 6th graders were pretty tough n the PEI surface when removing prints, until I made some adjustments to make removal easier. I’ll probably sell my spare and go for the modular. Being able to do a PEI replacement without having to disconnect the bed completley will be helpful.)

Not yet - I’ve just been too busy to look any further into the whole pi-situation and kept schlepping two extra laptops for the two Minis. Now, I’ll just wait for the magical gyrfalcon to show up. But I’ll still investigate further into running a printer-farm on octoprint or repetier because I’m currently planing a setup for rapid small part runs based on 4-8 ender 2 or tronxy X1 - style cheapo-printers. But thats a story for another forum…