Y Adapter for 1.75mm filament dual extruders and single nozzle

thingiverse

I've tried various adapters from other posts, but none have worked for me. So, I decided to create one myself. Several things helped improve the design. Here are some key points: 1. A wider 3mm diameter inlet tunnel receives filament, preventing damage when feeding filament from PC4-M6 fittings. 2. The 2mm diameter outlet tunnel feeds filament, avoiding hits on PC4 or PTFE walls when feeding filament from the adapter. 3. Avoiding sharp curves and S-curves in the tunnel enhances performance. 4. Using a PC4-M6 fitting with a 4.3mm bore works well, as PTFE fits snugly against the inbound or outbound tunnels. 5. A PC4-M6 fitting with a 2mm bore also works if you enlarge the hole slightly using a small round chisel. 6. I tested the adapter with retracted filament that forms a bulging end and found it worked well. 7. I also tested it with a small roll of filament, which curved the filament in a smaller diameter. The M6 threads may be a bit tight, so you might need a wrench to screw the fitting in securely. On November 24th, 2017, I printed my first dual-filament piece and was pleased with the results. I'm using Marlin 1.1.6 with the single nozzle option. Since Cura 3.0 doesn't support single nozzles, I removed references to T1 (the second hotend) from the g-code. I'm also working on a Y-adapter using M3 snap rings instead of PC4-M6 fittings. I'll post it soon.