JGAurora Z 605S (Prusa I3) Modification for Flexible Filament Printing




Introduction: JGAurora Z 605S (Prusa I3) Modification for Flexible Filament Printing

About: I've been writing software since I was in the 6th grade, and working with mostly-digital electronics since High School. These days my career consists of software development and architecture that is focused...

The JGAurora Z 605S is a Prusa i3 clone kit, that includes a Bowden extruder which can not print flexible filament, like Ninjaflex, Ninjaflex Semiflex, generic TPU/TPE, and other flexibile filaments. The filament ends up wrapping itself around the motor shaft in the extruder.

To solve this problem I purchased a Flexion Extruder which was designed by the inventor of Ninjaflex filament. I quickly discovered that this extruder would not work with the JGAurora's x-carriage extruder mount. This article will show you how to construct a new mount that will work with the Flexion on Extruder.

Even if you are using another Prusa i3 clone -- or an entirely different printer design, the files attached to this article will be useful to you in making a 3D printed or Aluminum mount that matches this Extruder. In fact, you could probably make the mount as described here and use it with few changes with most printers with small changes.

It is possible that the manufacturer of the Flexion Extruder may support your printer already, or that in the future they may offer a mount for the JGAurora Z 605S that will be less work than making your own, so be sure to check his website for updates. Until such time I hope that this will be helpful to you.

Step 1: Materials Needed...

It goes without saying that you will need a 3D printer -- specifically the JGAurora Z 605S if you will follow these instructions exactly. The rest of this list may need modifications to adapt to a different printer.



In addition to this, you will need to following tools:

  • Various Drill Bits
  • An 8-32 tap
  • A 3mm tap (I have a metric tap kit from Lowe's that starts with 3mm and goes up about 6 sizes)
  • A drill press
  • Various metric bolts - leftovers from your JGAurora Z 605S kit will work, or from your existing mounted extruder
  • Metric hex wrenches in sizes 1.5, 2.0, and 2.5
  • A band saw - though this may not be needed if you use u-channel instead of aluminum square tubing

Before Starting

Be sure to read through the documentation on assembling the Flexion Extruder...maybe a couple of times. It may be found here: https://flexionextruder.com/support/i3-style-print...

Step 2: Cutting and Drilling the Mount...

Use a hacksaw or a metal cutting band saw to cut a piece of the aluminum square tubing 69mm long. You can print out the attached PDF template to see all of the cuts and drill marks. The template is attached in a number of other formats. If you have a laser cutter you may wish to use the .dxf, .plt, or .pwj5 (LaserCAD) version of the file to cut an acrylic or plywood template to make it easier to drill holes, etc.

(Note: I original planned to use a laser-cut acrylic box instead of the aluminum mount, but after assembling it I decided that it had too much flex and would likely not produce good 3D prints.)

Important Notes about the Template

When drilling the holes keep the proper orientation in mind! The Bottom template needs to be FACE DOWN on the bottom of the square tube. If you can read the text, you will be drilling the holes wrong and the extruder will not fit properly.

The side templates are meant to be placed on the sides of the square tube with the text facing outwards. The square notch always goes to the top left corner!


Use the template to drill the holes in the Aluminum Square on a drill press. Be sure to use the right drill bits -- especially where tapped holes are required. I used 8-32 for the motor support bolts. Use whatever you have on hand for that. The fan that ships with the JG Aurora Z 605S is attached to the original mount using two 3mm bolts. You can also use 4mm bolts (they will fit through the fan mounting holes) if you'd prefer. Just remember to drill the holes to the proper size for the tap you will use. The remaining holes are used only to pass things through. For me, I think I used a 5/32" drill bit for the holes through which a 3mm bolt would pass, as well as for the holes used to attach the mount to the X-carraige. Use what is closest to the size on the template. And, for the screw driver access holes, make them big enough for your screw driver shaft to fit easily. You can do without those holes, but it will be easier to attach the mount to X-carriage with them there.

Cutting the Notch and the Top

Cutting the notch out of the top left corner, and cutting the top off of the Aluminum Square Tube will be easiest with a band saw, with a metal cutting blade and a fence. You can probably do this with a hacksaw, but it will be very time consuming.

When you are done with cutting and drilling your mount should look like the one in the photos. It is shown in the image below after being attached to the X-carriage, and while attaching the fan to the front face. (Notice how the notch prevents the mount from interfering with the limit switch.)

Step 3: Assembly...

Attach the Flexion Extruder to the Stepper Motor

Follow the instruction from the Flexion Extruder website to attach the extruder to the stepper motor.

Attaching the Hot End

Follow the instructions from the Flexion Extruder website to assemble the hotend - just remember that the barrel must go through the bottom of the mount we just made. In this step (assembling the hotend), you will need your heater cartridge, your 100k thermistor, and some kapton tape. It is easiest to install the heater cartridge (and tighen the set screw) first. Then insert the thermistor into the smallest hole. You can CAREFULLY use the screw provide to lock down the thermistor, but it is very easy to damage the wires. I bought a set of 5 and have already ruined 2 setting this up. :) Use kapton tape to help hold the thermistor wires to the heater wires and to keep them up away from the build plate.

Use two short 3mm bolts to attach the now assembled hotend to the mount. Those two holes in the bottom of the mount on the sides of the barrel hole are there for this purpose.

Attach the Mount to the X-Carriage

You can now attach the mount to the X-Carriage. You may use the screw driver access holes on the front side of the mount to help install the screws (the same screws that held the old extruder mount in place) through the mount and into the plastic X-carriage.

Attach the Extruder

With the mount in place and the hotend affixed to it you can now place the Extruder (mounted on the stepper motor) onto the mount, aligning the PTFE tubing from the hotend with the extruder as shown in the build instructions for the Extruder. Adjust the leveling screws underneath of the mount to take any pressure off of the back end of the stepper motor.

Attach the Fan to the Extruder and the mounting block

Use the fan, heatsink, original bolts, washers and guard from the old extruder to mount the stepper motor (and Extuder) to the mounting block attached to the mount as part of assembly of the hotend. (See the photos.) This completes the Extruder attachment.

Attach the part cooling fan

Finally, using the original hardware, attach the part cooling fan to the front face of the mount, with the directional spout pointing just under the nozzle. (NOTE: As shown in the photo this step can occur at any point after attaching the mount to the X carriage.)


The last step will be to test everything and then to do wire management. I used zip-ties and flexible wire wrap to manage the spaghetti mess of wires. You will see this in the photos. The wiring will be the same as it was previously, though it will likely need some re-routing and containment. If you have problems with the stepper motor pushing the filament out of the extruder instead of taking it in, see my previous article on this printer: Budget 3D Printer Fixes and Enhancements

Step 4: Printing...

With the new extruder fully assembled, try printing normal and flexible filament.


I found that in order to print PLA, I had to completely loosen the set screw that presses against the cam (see documentation of the Flexion Extruder on their website for details in how it is supposed to work. Unlike the previous extruder, I could not push and pull filament into and out from the extruder. I had to power up the printer and use the Prepare|Move Axis|Extruder menu item to load and unload filament. With the tension set properly both PLA and ABS printed well. The manufacturer of the Flexion Extruder told me that they are in the process of adding detailed instructions to their site on how to properly set tension using their extruder.

Flexible Filament

Ninjaflex Semiflex printed with no other changes required. I used blue painters tape on top of the glass (or aluminum) build plate. The less fill you use the more flexible your object. The "disc" looking object I printed (to be explained in a future article) was printed with 25% fill. I re-printed it with much greater flexibility at 5% infill. No adjustment to the tension dial was needed, and the set screw remained backed out enough to not engage. I printed with the nozzle at 222 C, and the heat bed turned off.


Ninjaflex filament printed great. I printed at 230 C with the heat bed turned off, and the Flexion Extruder cam set to "1" on the dial. Here is video of the printing and another of the final product:

Overall Impression

While I still have a lot of testing and experimenting left to do (which may mean new comments or steps added in the near future), I am happy with the Flexion Extruder on this printer. I plan to test Ninjaflex and other flexible filaments soon and will provide an update. Though this article is not intended to be a review of the extruder I should point out that the manufacturer has been very good to work with from answering my pre-sales question to providing guidance after I made the mount and installed the extruder.

If you plan to print with flexible filament, I hope this article will prove helpful. If you find it helpful for a different printer, please post a comment telling others which printer was close enough that the instruction still apply!

3D Printing Contest 2016

Participated in the
3D Printing Contest 2016

Be the First to Share


    • Pocket-Sized Speed Challenge

      Pocket-Sized Speed Challenge
    • Metalworking Contest

      Metalworking Contest
    • Maps Challenge

      Maps Challenge



    4 years ago

    23 April 2016 @ 10:00 PM CST: I just updated the assembly page with a lot of photos. I hope this will be helpful. I've also corrected a number of mistakes (missing words, etc.).