Of Diamonds and Quadens

A side by side comparison of the Quad head and Diamond Hotend.

My remix of the Quaden
​https://www.thingiverse.com/thing:4072369

Just a brief synopsis of my experience with the Diamond hotend and recent effort to convert my Crane Quad into a Quaden (Bowden) setup.

By late summer I was getting frustrated with my Crane Quad and decided to try a Diamond (3 color) Hotend. I purchased the hotend, 3 BMG clone extruders and motors. I added a ribbon cable to extend the motor cables up to the top of the Crane frame. I also purchased a crimping tool and some of the odd 2 pin connectors used my M3D for the fans, heater and thermistor. Sourcing the 2 pin connectors proved to be a bit of a challenge but I eventually found some on Ebay.

I had no previous experience with Bowden rigs so there was a bit of a learning curve on basic stuff like loading the filament, removing it without getting it jammed in the throat of the extruders or leaving a partly melted clog inside the heat sink end of the tube, etc..  But once I got past those basics, and found a reasonable retraction setting the Diamond Hotend performed pretty reliably. I do think there is still significant room for improvement in my settings.

Late in the year I was noticing more and more people on the Crane Quad group having good experiences with Quaden rigs.  Also, there are times when I wanted to have a 4th color available. So in early December I ordered a 4th BMG clone and motor. When the parts came I reworked the motor mounts to make them easy to move around on the frame and to give me direct access to the opening for service.  I also did a remix of Sindarious’ Quaden hat and plugs. Assembled it all and about a week ago tried to give it a test run.

I tried several iterations of Extruder mounts before creating a remix  design that allows quick removal and ease of service.

https://www.thingiverse.com/thing:4052294

The Quaden assembly itself seems to work pretty well. The filament feeds easily and slides through the assembly fairly smoothly.  There is a certain amount of drag imposed by the internal pathways designed into the Quad head but the Quaden modification does not seem to add any additional drag.  However, when I tried to load filament with the nozzle in place, I ran into the same old issues of having the filament catch on the top of the PTFE sleeve in the nozzle. After far too much monkeying with this and the frustration of having to relocate the smallest hex key I have ever used, I decided that none of the 4 nozzles I currently have are in good shape.  So this brings me back to another frustration with M3D. They charge $25 for a nozzle and $12 for replacement inserts (the part that actually fails). At the time when I looked, M3D was out of stock on inserts, and of course shipping for a single nozzle is another $7. So one nozzle alone would set me back $32, more if I get replacement inserts. And once I get those parts, I would still have the prospect of burning up a bunch of time rebuilding a couple nozzles with the new inserts.

To put this into perspective, let me compare this to the Diamond Hotend. The Diamond is a remarkably simple assembly. It consists of 3 E3D style heat sinks screwed into a large brass nozzle.  The heat element and thermistor plug into holes on the top of the nozzle. The only fiddly part is a brittle (crumbly) fiberglass heat shield that sits on top of the brass nozzle to reduce heat creep. Most hotends don’t even have that heat shield. 

I recently tried to use soluble (PVA) filament as supports and managed to cook the PVA into a sticky mess in the Diamond Hotend, this was parly what inspired me to try out the Quaden. So after a week of fiddling with the Quaden and getting frustrated, I decided it was time to clean the Diamond. This proved to be a pretty straightforward task.  I set the nozzle on an old CPU heatsink on the bed, connected it to the quad wire harness, heated it, removed the heat sinks, use guitar strings of various diameters to floss out the filament path from the top and bottom and put it back together. The whole process took a fraction of the time than I have spent just trying to clear a single channel in a Quad nozzle. Again the remarkable simplicity of the Diamond design is that the heat sinks provide a direct path for the filament into the nozzle. No tight radius turns, no flaky PTFE tube that can rotate out of the path or push out of the nozzle.

Did I mention that that a replacement diamond nozzle cost $15? And if you are really daring, you can get a clone from China for $6. 

With all this in mind, I am more than a little hesitant to throw another $25 at M3D (plus shipping) for what is essentially a disposable and definitely not an easily serviceable part.

I do think the Quaden upgrade is a VAST improvement over the wimpy direct motors that come with the Quad. And eventually I will stop grinding my teeth over this and buy another nozzle.  But for now, I am going to set it aside and enjoy the relative reliability of the Diamond Hotend.

The Quaden executing its first print.

I should add that an upshot of all of this messing around with the Quad is I added a quick change tool change bracket to the machine and holders for the Quaden and Diamond heads so swapping them or other tools is now easy peasy. That small upgrade is probably the best improvement I have made to this machine yet.

Creality Quck Tool Changer
https://www.thingiverse.com/thing:3369444

Crane Mount adapter
https://www.thingiverse.com/thing:3728176