E3D-V6 1.75mm Toolhead for Lulzbot Mini

I modified the original Lulzbot Extruder body to fit an E3D-V6, 1.75mm hot end. I made the modification because trying to use an E3D-V6 in a standard Lulzbot Extruder body made the Nozzle sit approximately 5.5 to 7.0 millimeters too low. While it would work this way it required firmware editing of Z-Max to avoid crashing into the wiping pad or bed. It also made switching between other Lulzbot Mini tool heads a chore because it required a custom firmware edit and upload through Arduino, each time a change back to use the E3D-V6 tool head change was needed. Since I use other 1.75 Lulzbot tool head designs I have made which have the identical Lulzbot Nozzle heights or when I use the standard 2.85 single extruder tool head, I didn’t want to go through the Arduino firmware edit and consequent upload at each change back to use the E3D-V6 toolhead.

                *What was done*

I deepened the socket in the “open Hardware design” of the “Lulzbot Mini extruder body and made a new bushing/shim block that would fit the E3D-V6 at a lower point. I also put M3 holes through the lower base of the extruder body, leaving room for M3 nuts or M3 inserts on the inner and outer sides. (I found it unnecessary to use retaining nuts on the M3 screws, because the fit is tight against the inner groove at the top of the E3D-V6). I did make some cosmetic clearance cuts to the fan mounting clip on the E3D-V6 fan shroud so it would have better clearance of the Lulzbot single extruder mounting base and I changed the fan from a 24vdc 30mm x 30mm fan to a 5vdc 30mm x 30mm fan.

One unexpected thing is that when I deepened the socket in the extruder body, it actually created a small gap that lets you see how tight the top of the E3D-V6 hot end is inside the socket viewable through the small opening that can be seen below the idler side of the Extruder body, (kind of a neat thing)!

The Extruder body has a 4.00mm filament pathway hole that is just wide enough to slide a short piece of 4.0 OD x 1.75 ID PTFE/Teflon tubing into the inside center hole of the 1.75mm E3D-V6 hot end. I suppose you could just leave out the Teflon tubing if you were using a 2.85mm ID E3D-V6 hot end, or enlarge the filament pathway hole in the extruder body.

To double check the finished mounted E3D-V6’s hot end total length to the nozzle tip, I made a measuring tool, which fits up against the bottom of the Lulzbot tool head mount. I have attached a picture in the files to show how it is used (showing it in place on a standard Lulzbot Mini single extruder tool head), kind of a no brainer. Just put it in the same spot on your finished modified E3D-V6 tool head. I mounted my first design to a Lulzbot Mini and was able to use it without any changes other than editing the E Steps to 1000.

I’m using a Z offset of 1.40 to 1.43 the original Lulzbot firmware Z offset was 1.20 and I wanted a little tighter first layer for good sticking. You can play with that setting but you should not have any issue with the Lulzbot Mini Single Extruder original firmware ‘ZMax” setting causing the Nozzle tip to go crashing into the Wiper pad if you use the measuring tool.

One last note, I used a .05 nozzle on the E3D-V6 and used the Standard Lulzbot Mini 2.85 filament presets, “NOTE:” just cut the printing speed in half, for a much nicer print allowing the extruded filament time to lay down and stick better. I didn’t edit or change any of the Lulzbot filament profiles from 2.85, or the nozzle size from .05, I just left it at that. I did change the line at the beginning of the ABS profile startup GCode which shows retracting 30mm of filament prior to the wiping segment to 5mm, because of the difference in the feeding rate of 1.75mm filament instead of 2.85mm.