Billig
Done: Yes
Result: ~300$ 440x230x260mm 3D printer
Author: @playlogo
Repository: https://github.com/playlogo/billig
Total hours so far: - lost count
3D Printer available: Yes
Bom: Google sheets
CAD: Onshape
About the printer:
- 440x230x260mm printing volume
- 940x410x465mm frame
- Reuses a lot of parts from two “broken” Anycubic Kobra 2 Neos
- Direct drive extruder & dual 5020 part cooling
- Completely enclosed electronics
- Build-in ABL & Nozzle offset sensor
- With a rpi zero & Klipper-Ready
- ~$340 (including the two broken printers)
Take a look at the Design-Notes to better understand my design decisions!
Take a look at the PCB!
TODO:
- Design: PSU-, MB- & PCB-DIN rail mount (not important)
[Written on April 7]
About the journal: So this journal didn’t really work out that well. I started planning the printer and a timeline ~4 weeks ago on March 9., but then got sidetracked by other things (hackboard, pre-final school exams, irl stuff). During this time I constantly thought about it though, and decided to try to convert 2 broken Anycubic Kobra 2 Neos into this one big printer, instead of buying all parts brand new.
After all, this project was a lot of fun and very interesting. Once I got into the “CAD design mood” I really enjoyed doing it, and I’ve also learned a lot about Onshape and how to approach big projects and design parts, that are internally dependant on each other. I’m proud of the final printer :)
April 4th - Friday
4 Days ago I finally started to speedrun the entire CAD design starting with the frame (which I then redid one day later…). I started by converted these drawing I made about two weeks earlier during school into this frame:
As you can see in the sketches, I was initially targeting a CoreXY build with linear rails, but this idea later got ditched in favor of a simple V-Wheel based Belted XY-Gantry to keep costs down.
I also started dissembling one of the broken printers to take measurements of the heatbed, etc.
Time spend in CAD: 2h during the morning (since I’m almost done with school, I don’t have to go to every lesson anymore), 6h in the afternoon, evening and early night.
April 5th - Saturday
A caddy day
On saturday I basically redid everything I did the day before. Instead of bolting the profiles strait to each other using blind joints, I took some inspiration of the Ender3NG, and created these “in-between structures” (see picture). I also converted this sketch (which I created the night before) into CAD (once again, inspired by the Ender3NG, but created from scratch and the final part also ended up completely different)!
I’m very happy with the progress one that day, cause the frame and gantry has been one of these low motivation, hard to imagine progress blockers. Also, the top “extrusion structure mounts” worked first time, and I never had to change them later
Time spend in CAD: ~60% of my time awake (pain, at least I managed to sit outside and enjoy the warm weather for 30min) -> 9-10h
April 6th - Sunday
Another caddy day (ahhhh)
This day was super productive. I’ve designed the entire toolhead, reworked the entire gantry, and finally managed to create a draggable 3 dimensional toolhead in onshape, that allows me to test the reachable positions of the nozzle.
Reworking the gantry was a lot of pain. This is my first time seriously using assemblies in Onshape, and I based the original gantry part assembly on a feature I deleted while reworking the frame (ahhh). This broke my entire gantry when I finally updated it’s context, which I need to do, because I’ve extended it by ~8cm to allow the nozzle to reach all positions. This is a example of the pain I had to endure:
Time spend in CAD: ~75% of my time awake (didn’t even go outside) -> 10h
April 7th - Monday (today)
I really want a break from cad plsss!
Today I fixed a lot of small stuff in the CAD model: I added endstops for X&Y, a X-Motor mount, X-Belt tensioner, changed Y-Motor position from fixed at one end of the extrusion to on the X-Plate, improved dummy models of steppers/lead screws/etc, fixed a lot of small bugs in the CAD model, created the PTFE tube holder and created the electronic housing.
The electronics housing safely mounts both PSU, control boards, rpi zero and power plug. It’s surrounded by acrylic panels, and has two fans at the top to suck in air from the bottom though the entire assembly.
I also updated the BOM and created this document (and it’s now past midnight).
Final version (V2.1 in CAD document history):
Time spend in CAD: Last 7h (had to go to school until 13:10 to get grades of last 2 years and the admission notice for my final 5 tests)
April 7th - Tuesday (1 day after deadline)
Small improvements & fixes: Improved ‘Design notes’, fixed spelling mistakes, added JST cables to BOM, added PCB mount to CAD model
This was a triumph, Huge success
Below is the unused initial version of the journal (from 4 weeks ago)
Status Update: Due to final school exams, hackboard and terminal-craft the timeline has been delayed by one and a half weeks. This means i will be aiming for OpenSauce and not RMRRF.
Journal Overview:
| Date | Total time | Description | Happy with progress ? |
|---|---|---|---|
| 08.3 | 3h | Brainstorming & Gathering & Online research | Yes, finally locked in on one idea. Was really torn between the print farm, module based printer and Billig |
| 09.3 | 2.5h | Documentation & Organization | Yes, really happy: Did all the annoying markdown formatting and stuff |
Timeline:
| Date | Estimated hours | Description | Possible motivational problems |
|---|---|---|---|
| 09.03 - 16.03 | 10h - 20h | Research & Parts selection - Found vendors, lock-in parts for everything, created BOM with estimate expenses, find / create CAD models for individual parts, create dimensionally accurate design specification | Unlikely - I love organizing, planning, and shopping for stuff |
| 17.03 - 23.03 | 15h - 20h | CAD design - covert design specification into CAD (and find a dark theme for onshape) | Maybe - Staring at a CAD design for multiple hours, multiple days strait can be … exhausting |
| 24.03 - 27.03 | - 10h | Implement “Should-have” features | Unlikely - Improving a finished Design should be really motivating, cause you see what you’ve achieved |
| 28.03 - 31.03 | Buffer |
Total expected hours: ~45h Real-life multiplier: x1.5 -> 68h -> ~3h per day -> Realistic
Features:
| Must-have | Should-have | Probably not enough time |
|---|---|---|
| (400mm)² for X&Y, Z should have 200mm+ | Filament runout sensor | 2 Build-in filament holders (Prusa Core style: inset into case, on the left&right) |
| CoreXY with Belts | LED-Bar under Bed for status, etc | Build-in filament weight sensor (using one of these) |
| Enclosed (for ABS) | Exhaust air filtration using activated carbon | External Multi-filament switcher (Pico-MMU, 2 filaments) |
| Direct drive | ||
| ABL using cheap BLTouch clone | ||
| Temperature Sensor inside & Temp-control fans |
March 8 - 3h
Brainstorming about goal. Final 3 candidates:
- Print farm: Similar to this - Why not: Basically would only copy their design and scale it down, due to budget only 2 integrated printers -> kinda useless
- Module based: 250x250x100mm modules with only the heated, joinable in one direction, rack & pinion system on the sides, hotend on a “crane” (picture explains it best) - Why not: Budget would only allow ~2 modules -> Print volume way to small
- Billig (this): There seems to be no big (~(400mm)³) enclosed printer for under 1k -> Should be doable with only 300$ when cutting corners
Billig will be a mix of:
- Prusa XL (frame design)
- Voron 2.4 (artistic style)
- Ender 3 NG (enclosure design)
Accepted tradeoffs:
- Longevity: Will be using the cheapest parts for everything
- Print speed: Won’t be fast due to size
- Power draw: Will need A LOT of energy to heatup the entire chamber
Initial design ideas:
- Printbed consist of 4 smaller (and cheaper) print beds: ~ 40€ total
March 9 - 2.5h
Well, this document…