RatRig vCore 3.1 500x500x500mm
Assembly Instructions
https://wiki.ratrig.com/en/build-guides/v-core-31
Full Printer Bill of Materials
Big Tree Tech Octopus Pro User Guide
https://drive.google.com/file/d/1KF6O0um4_sSIqKhdXKNUiDSKOCfCdVy5/view?usp=drive_link
When completed it will be a large format, high temp, high speed printer.
If the custom bits prove too much, I’d be fine finishing the printer as a bone-stock Rat Rig, so if you need me to order a RatOS compatible extruder assembly to finish it, that’s fine I can do that. I’d just be happy to have another running printer. And if it doesn’t run, oh well, it can’t be worse than it is now. It’s sat 10% completed in my garage for like 2 years and I don’t have any spare time in the near future.
Notes from Mike Burngasser 16OCT2026
- I stopped last at https://ratrig.dozuki.com/Guide/02.+Z-Axis+Assemblies/159?lang=en
- My notes say I stopped at Step 10, though I think I assembled the printer past that point. You’ll have to look at the physical frame parts and see where I was in the assembly.
- The printer is a Rat Rig vCore 3.1 in 500x500x500mm size. It has enclosure parts printed.
- Aftermarket and Non-Standard Parts:
- Y-Gantry – lightweight but hopefully the same shape as the original version, so should not change assembly much.
- Liquid Cooling on Stepper Motors – not necessary for normal operation <60ºC for filaments like PLA and PETG, but will allow enclosed operation at higher temps for ABS and engineering filaments. Will unlock much faster motion system operation and high temp printing without burning up stepper motors. Also cool as hell to liquid cool a 3D printer.
- Extruder – HextrudORT (https://miragec79.github.io/HextrudORT/) with Goliath hotend (https://docs.vzbot.org/goliath) – Hot diggity dog this is one heck of a hotend. This is a severely custom setup, so good luck. This is probably the toughest part of the printer. I strongly suggest using ChatGPT to help with initial Klipper setup for this part, given it will be a different distance from the print bed and way different flow rates than the default extruder options RatRig offers in it’s RatOS Firmware. If you can’t get this beast of a hotend working, I understand. Let me know <admin@smashgoods.com> and I’ll buy one of the stock extruders used in RatOS firmware so we can make the install work. After the printer is assembled I/we can maybe try this extruder later. It’s easier to troubleshoot something that’s already working. But look at the thing it’s a monster, totally worth trying.
- Raspberry Pi 4B 8 GB RAM vs HP Mini-Computer. We will use the Raspberry Pi 4B to run the printer itself. This is the “brains” of the computer that acts as a controller to make all the steppers move. But you have to connect a computer to the Raspberry Pi to operate it. You can use a classroom computer or the Dell mini-computer I’ve included here: HP EliteDesk 800 G3 Mini 65W Core i7-6700 @3.40GHz 8GB RAM 128GB NVMe.
- If you want a monitor and keyboard and mouse dedicated to this printer let me know and I’ll buy them. Probably best to just make it a full printing workstation rather than sending data to the printer and having a headless printer with no way to control it except plugging in another computer or laptop. I can pickup a cheap monitor on Amazon for $80 and a VESA compatible monitor arm to clamp to the printer for $18. Plus a cheap keyboard and mouse. Let me know when you get to this point and I’ll buy the monitor/keyboard/mouse <admin@smashgoods.com>.
- CPAP Tube cooling for hotend (https://www.reddit.com/r/3Dprinting/comments/1ffm0fw/just_got_done_adding_a_cpap_fan_for_remote/) This is a fan into a tube which blows over the parts for cooling. It’s lighter than mounting a fan to the hotend (so faster motion on the hotend without artifacts).
- Beacon3D Bed Probe (https://beacon3d.com/product/beacon/)
- Nozzle Mounted Accelerometer – Only needed during initial setup for adjusting input shaping calibration. I think you just attach it under the nozzle if I remember correctly, then take it off after calibration.
Tips
- Use ChatGPT or Claude to help. Way faster than digging through the internet.
- If you need parts just email me <admin@smashgoods.com> and give me the address and name to send them to. I’ll ship them right over.
- If you have to skip some of the heavily modded aftermarket stuff, that’s fine. A working printer is better than a perfect set of parts in boxes. We can always get it working then tinker with upgrades later. Or just let it run without all the upgrades. Either way is fine.
- Seriously, don’t worry about breaking anything. I don’t care. It’s been sitting in pieces for like 2-years now under my stewardship, so literally nothing you can do to it would be worse than the current situation. At this point it’s all sunk costs to me, so just enjoy the process and if we have a working printer at the end, great. If not, I’m no worse off and really don’t care.
Size Matters!
- It’s large. Make sure it will fit through doors after assembly. Be careful where you assembly it because it might not make it through a standard sized residential doorway when you’re done.
Feel free to use it for a while after assembling it. Then email me <admin@smashgoods.com> and I’ll pick it up and put it to use in my print farm. I always have parts to print for customer facing products, so it will get plenty of use.