In a previous blog I wrote about my trip to the Lulzbot factory in Loveland, CO. While I was there I decided to upgrade my Taz 5 to print dual materials. To do this will require the dual extrusion tool head from Lulzbot. With this tool head I want to print more complex prints with dual colors and print with dissoluble PVA.
My first impression was that it would be difficult to calibrate and tune. In the end I was proven right when I took the extruder to IT-works and received professional help from Jamie Leben in calibrating the whole setup.
The dual extrusion tool head is essentially two standard heads crammed front-to-back on a metal chassis. This puts the second extruder in front of the other, compared to the side-by-side configuration you see in other dual extrusion 3D printers.
Another difference is the amount of visibility clearance to see the print. With the standard extruder, you can comfortably see the print from a normal angle. The visibility with the dual extruder is almost zero by comparison. I have to crank my neck down and use a flashlight to see underneath the tool head to see the print in progress. This lack of visibility also means you may not see errors in the print until it is too late.
Installing the dual tool head is a task that may take a hour or two of your time, and calibrating will take a few hours more. The dual tool head is definitely a upgrade for advanced 3d printers.
The hardest part that I could not get right was adjusting the height of the front (T1) extruder. With the Taz 5 you have to use a piece of paper to adjust the height of the extruder, which is a major weakness of the printer. The second extruder quadruples the difficulty of installing this dual extruder. You have to turn a screw underneath the front of the extruder to adjust the front, which can be a tight fit with a 4 mm Allen Key against the build plate.
The next part was the firmware. You have to flash the printer firmware, than upgrade to Cura 19.12 to print with the dual head.
Calibrating the printer was another kettle of fish that ultimately sent me to IT-Works to fix.
I found out there that that the dual extruders had another weakness apart from the print visibility. The micro blower fans that cool the hexagonal hotends may be under powered for dual extruders.
When you combine the compact design of the dual extruder with the close proximity of the two hot ends, heat creep can cause extrusion issues. Jamie Leben of IT-Works showed me a tester his team developed to test the strength of the micro blowers. There may be a quality control issue with the micro blowers in the dual extruders. When I looked at the Lulzbot site for replacement micro blowers, they did not have them in stock. It would be interesting to see if others have had this problem. If so, please contact 3D-PT in the comments below.
After taking the dual extruder to IT-Works, I was able to start 3D printing with both heads. I wanted to test it out by printing with PVA support material from Wenotion and in another blog I’ll review PVA filaments. I did get some good results by printing PVA and colorfabb PLA /PHA. I have also been playing with the 3D modeling required to print with two colors, and that will also be covered in a future blog.
Overall the Lulzbot dual extrusion tool head is something for advanced 3D printers who seriously want to expand the capabilities of their printer.
This printer will require extra tools like a flashlight, scotch pad (to clean the nozzles) and extra patience to work with.
If you have also had an issue with the dual extruder or micro blowers, please leave a comment in the blog below.