Upgrading the 3.5 with second-hand Core 1 extruder?
I just ordered the INDX for my Core One (And I'm really looking forward to it), but I realized that for the upgrade I'll have to get rid of the entire original extruder, including a collection of nozzles...
I used to have a Mk3.5 before that i gifted to an old friend and since the C1 extruder doesn't look to be that different from the Mk4, I'm toying with an idea to give the C1 extruder to the guy as well and let him build basically a 3.9
Anyone having a similar idea? Is there an expert that had the Mk4 and C1 extruder disassembled side by side and compared them?
RE: Upgrading the 3.5 with second-hand Core 1 extruder?
Same here. My MK3 has been upgraded incrementally to the point that it is now an MK3.5S. My core One is a great machine and I ordered the indx upgrade last night. It would be a shame if I couldn't repurpose the Nextruder as an upgrade for the MK3.5s.
I know the board supports it, so it seems like mostly a matter of the parts to mount the Nextruder on the MK3.5 gantry. Probably upgrading the rods to the MK4 versions would be necessary.
I suppose as more of the INDX systems are sold we'll see more people asking this question.
RE: Upgrading the 3.5 with second-hand Core 1 extruder?
After fighting with ChatGPT I've arrived at this list to upgrade the MK3.5S to an MK4S minus the Nextruder.
🧾 COMPLETE BOM — MK3.5S → MK4 ⚙️ Motion System Motors X-axis stepper motor Y-axis stepper motor Z-axis stepper motors (x2) Smooth Rods X-axis smooth rods (set) Y-axis smooth rods (set) Z-axis smooth rods (set) Linear Bearings X-axis linear bearings Y-axis linear bearings Z-axis linear bearings Belts & Motion Hardware X-axis belt Y-axis belt Idler pulleys (X & Y, if replacing to MK4 spec) Motor pulleys (if not reusing existing) 🧱 Structural / Printed Parts (MK4 Set) X-carriage (Nextruder-compatible) Z-axis top mounts Z motor mounts (MK4 geometry if different) Belt tensioners / idler mounts Y-axis belt holders (if updated geometry) Cable management system (clips, guides, strain relief) Nextruder mounting components (if not already included)
👉 Material: PCCF (preferred) or equivalent high-temp filament
🔌 Cabling & Integration Heatbed cable adapter (if required for MK4/xBuddy compatibility) Cable routing components (guides, clips, sleeves) Any non-Nextruder wiring differences required for MK4 layout 🔩 Hardware (Fasteners & Assembly Parts) MK4-specific screws, nuts, and washers not reused from MK3.5S Threaded inserts (if required for printed parts) Spacers and standoffs for: Motion components Structural parts Cable routing mounts
RE: Upgrading the 3.5 with second-hand Core 1 extruder?
I don't think that AI is on the technical level sufficient to be trustworthy at such task yet... But I went through the assembly manual for respective printers and it appears that you need to buy a bent sheet fan holder and possibly some rubber pads (for bearings and maybe Z-motors) and a set of hex spacers (that go behind the extruder)
+ thicker rods and bearings if you want to go even closer to the MK4, but that depends on budget. Even more expensive option are the MK4 motors, that would make it fully converted, i guess
Everything else seems to be printed, PETG and PC+C.
But now we need to wait either for someone actually trying it, or for a Prusa expert reading this to confirm the idea 🙂