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Coaxial8or R2

Coaxial8or R0

Produces colours with one side slightly darker than the other:

4-in-1-out Coaxial Hotend

Inspiration and/or examples of working principle

Navigation

The title tag system is explained here, and the table is updated when a change occurs. Notable logs have bold L# text.

L1 [M][T] Initial design and fabrication optimization	L2 [M][T] 5 inputs were possible?!	L3 [T] 4 material + tube?
L4 [M] Center grub insert	L5 [M] Smallest possible size? - Also possible prior art found	L6 [M] Fabrication Changes
L7 [M] Hotend digitally assembled	L8 [M] Starting on the cover	L9 [R] PCBWay still can't manufacture?
L10 [M] Metal 3D print edition	L11 [M] Asking PCBWay for a brass insert	L12 [M][R] Preparation for Uni round 2
L13 [T] Threads and feedback	L14 [M] Cooling ducts	L15 [M] Carriage Mount
L16 [P] 6028 Fans	L17 [P] All other components	L18 [P] Successful Fabrication and Assembly
L19 [T] Sealing with 2mm ball bearings?	L20 [X] No immediate leaks!	L21 [X] Looking at the state of the grub screws.
L22 [M] M4 Grub + 2mm Ball Edition	L23 [T] An Insert Like The Positron Hotend?	L24 [A] Mystery CNC Price Hike
L25 [T] Hotend hypotheticals: Off-centered inlet approach?	L26 [P][A] Outer Cover and leak detected	L27 [M] Visible indication of full grub tightness
L28 [M][T] Internally groove the heatblock-heatbreak mating surface?	L29 [M] Centrifugal-inlet design with expanding ball plugs	L30 [T][R] Dual heater zones?
L31 [M] 8 in 1 out hotend	L32 [M] Added components to 8 in 1 out hotend	L33 [T] Filament order and issue prevention strategy
L34 [A][B] PCBWay CNC fabrication costs USD$257 - $334	L35 [R] Bowden couplings, collets and compression fittings	L36 [T] Print abrasive filament without abrasion?
L37 [M] Heatsink for Unibody Coaxial Hotend	L38 [M] Finished modelling the Unibody 8-in-1-out hotend	L39 [T] Abrasive filament to smooth internal channels?
L40 [M][R] Simulation software and model optimizations	L41 [M] Thermal comparison between machined and unibody	L42 [T] Next steps
L43 [A] Details page before 11 Jan 2024	L44 [P] Nozzle-block heatbreak fabricated and simulated	L45 [T] Grub screw sleeve?
L46 [A] CNC price keeps increasing	L47 [C] Setting up Marlin Firmware	L48 [M][T] Machined 6-in-1-out not geometrically possible? - Also talks about 8-in-1-out tweaks
L49 [X][P][T] CR600S setup and first test prints - Tests 4-in-1-out hotend - Thoughts on BotObjects 5-in-1-out hotend heatsinks - Direct drive idea - Failed due to leaks so only got 2 short prints	L50 [M] Printed Coaxial Hotend with clamp plate	L51 [B][C][M] Preparing shopping cart and Marlin
L52 [M] Slim Cover and Hotend Holder	L53 [M] 2D plate drawings	L54 [T] Directional fan and new filament strategy
L55 [P][M] Plates manufactured	L56 [M] Heatblock design optimisation - Tip on preventing profile rotation when sweeping in Fusion 360	L57 [A] Heatblock ordered and 1mm PTFE gasket
L58 [T] Potential name: Coaxial8tor	L59 [M][A] Switch to 17HS4023 Nema17?	L60 [M] More ideal extruder mount
L61 [M] Coaxial8or logotype and test model	L62 [R] 42BYGH24S Nema17	L63 [C] Marlin M165 improvements
L64 [M] CR600S+coaxial8or logotype and numbers	L65 [P] Flat files fabricated	L66 [M] Using Fusion's renderer to simulate colours
L67 [P] Coaxial8or aluminium 3D print - Other parts arrived: --- DDE (BMG Clone) --- Nema17 --- BTT EXP MOT --- TMC2226 --- £6 400W PSU --- Bowden couplers	L68 [P][A] Clamp face flattened, motors installed and holder attempted	L69 [M][A] Successful hotend holder and extruders installed
L70 [X][M] Heating Tests and Coaxial8or R1	L71 [M][T] Coaxial8... 4 A Budget? - Backwards compatibility with 4-in-1-out - Why not 6-in-1-out?	L72 [C] Push/Pull V-Tools in Marlin
L73 [A] Dryrun worked. Print powered down.	L74 [X][M] First Coaxial8or prints (single colour)	L75 [M] Removed M2 threads in Coaxial8or R1
L76 [T] More potential features for mixing extruders	L77 [X] Minimal flow rate, medium mixing, maximum leakage. - Tests colour uniformity of 50/50 mix of two colours	L78 [M] Updated pathways and protected cartridges
L79 [B][R] Coaxial8or R1 print costs $47, and failed simulation attempt	L80 [M][T][A] R1 needs to be redesigned.	L81 [M] New coaxialising geometry - "intent" mention from Construct3D founder - Wall thickness analysis
L82 [B] 2pcs of Coaxial8or r1 ordered	L83 [P] Aluminium prints have powder still inside? - and copper gasket industry	L84 [P] Tapped threads and copper gaskets cut
L85 [M] Updated holder and cover	L86 [P] Self-tapped plates	L87 [T] Micro heater on heatsink for a temperature-controlled valve?
L88 [X] Clogged Coaxial8ors	L89 [X][M] Continuing to try unclogging	L90 [T] Alternative geometry?
L91 [M] Coaxial8or r2: Tree Geometry	L92 [M] Streamlined via simulations	L93 [M] Diamond square output
L94 [X][P] Coaxial8or r2 machined and installed	L95 [P] 24V 200W cartridges	L96 [P][T] Logo and potential enhancements
L97 [X][T] Print attempt with Coaxial8or R2	L98 [X] Channel 1 and 8 leak, and aluminium foil around cartridge	L99 [M][P] Mild steel plates
L100 [M] Heatsink holder assembly	L101 [X] It's all grey!	L102 [A][T] Improved start-gcode. Marlin AutoMix colours?
L103 [X] Attempting to calibrate input shaping	L104 [M] R3 - High flow pathway geometry	L105 [T] Marlin - Retract specific extruders?
L106 [M] R3 - Heatblock modelled	L107 [X] Cross-section is a kite	L108 [A] R3 - Heatblock ordered - And reason to sharp ring on the in/out ports
L109 [M] Metal plate hotend holder	L110 [M] Print-in-place cooling duct	L111 [M][P][T] Cover, holder, clamp plate and BMGs

Preface

[2024 - Jan 11]

FFF 3D printing, in general, is looking like it is near the ceiling in terms of possible features. (Do note that this perception is coming from someone that believes that the #SecSavr Suspense [gd0105] can be engineered into this reality.)

However, there was and still is a specific project that I wanted to pursue even before I owned my first printer (the late 2016 CR-10) which was to upgrade it to become a multi-colour 3D printer. I had bought a diamond nozzle kit along with the printer, but it was so large that I never got around to mounting it and setting it up. Since then, I transitioned from a volcano heatblock to the NF THC-01, a 3-in-1-out switching hotend. 

Because I was thinking that I was going to be printing in PETG and PBT more in the future, and there was some PTFE present in the hotend, I decided to start designing the #Revolving Hotend [gd0012], of which I just decided to drop development one day; maybe the glamour of the project finally lost against the scepticism of the design. In all this time, my CR-10 has been in the longest update cycle to date and hasn't printed since probably late 2019.

It also seemed like hope was lost when Deckingman, one of the few remaining hobbyist experimenters for multi-material printing, announced that he was moving on from his 6-in-1-out hotend project. 

Fast forward to the start of 2023 when I'm researching the difference between MGN9 and MGN12 rails and I see this:

Me: Hmm? Why are there so many upvotes?
*Sees wall is the exact same colour throughout*
Me: They said it couldn't be done.

At the time of writing, I currently don't have a multi-material printer, and quite a few of my designs (such as #Teti [gd0022]) are dual colour prints. Conveniently, I bought loads of white filament, and it would be great to just buy 3 more spools to get any specific shade I want, such as the elusive milky green (#b2bcac).

I started the project once Nozzleboss/Heinz provided more details in his project, which was sometime in April 2023.

[2024 - Feb 20] After spending months and finally sending off the heatblock to be printed, I thought of "coaxial8or" as the name for it. Beforehand, this project was called the "Coaxial Hotend".

[2024 - Mar 22] Also look at #Printer Repair [gd0137] for progress updates on the CR600S itself.