Wanhao Duplicator i3 V2: Flexion Extruder Install

Printing with flexible filaments such as TPU provide a whole new set of project opportunities. The problem with these filaments is guiding them through the filament path without them squirming their way out. The great team at Diabase Engineering which includes one of the inventors of Ninjaflex, solved the problem.

The Flexion extruder controls the filament pathway and compression in a very elegant solution. The kit includes a full extruder replacement of every part except the stepper motor. Take a look at the video installation and the challenges that go with installing this great piece of kit.

I was able to print a replacement bike handle for my daughter. It took a few tries to print (mostly due to a difficult design on my part) but works great.

You'll notice a seam about 1/4 of the way through the print. I did get a jam in the extruder but was able to measure, reslice and resume the print the next day.

Wanhao Duplicator i3 V2: Micro Swiss All Metal Hotend Install

I'm starting to get into some of the higher temperature filaments including PETG and decided to splurge on the purchase of the Micro-Swiss All Metal Hotend. The temperatures that PETG melts at are very close to the breakdown temperature of PTFE, the tubes inside the stock hotend.

The slotted design of the cold block also allow better support of the thermal tube and more efficient coupling of the aluminum upper portion to the heatsink and fan. I also sprung for the CNC machined lever which provides better stability to the intake path with much less slop than the stock plastic version (not that we don't love plastic here).

Enjoy the walkthrough installation video below and share your experience in the comments.

Wanhao Duplicator i3 V2 - Stepper Tuning

The stepper controllers on the Melzi board inside the Wanhao Duplicator i3 V2, Monoprice Maker Select and Cocoon Create are incorrectly tuned for the stepper motors. The Wanhao Google group again has some great information on the symptoms here. Using that information, I created a video on how to research the data on your own stepper motors and correct the current being sent to them for cool and quiet printing.

X, Y, E Motors - 42HS34(L)-0954-JA05
Z Motors - 42HS34(L)-1204-JA05

Decoding model numbers
42           HS   34(L)      - 095            4
Diameter(mm) Type Length(mm) - Max Current(A) Number of connectors

HS = Hybrid stepper, in case you wanted to know

My Results
Stepper MotorMax AmpFactory VREF (v)Correct VREF (v)Correct Amp (90% max)X0.9500.8170.6840.855Y0.9500.7770.6840.855E0.9500.7850.6840.855Z1.2000.7890.8641.080
The variable resistors/potentiometers are too coarse to achieve 3-digit accuracy with any regularity, my final number were slightly off my targets but well within tol…

Wanhao Duplicator i3 V2 - PID Autotune Process

Temperature control is critical in 3D printing. Unfortunately, the Prusa i3 clones typically come with PID temperature control disabled. Using any program that can talk to your printer directly including Octoprint and Repetier host, you can setup PID and use the built-in auto-tune process to get much better temperature control.

The following video walks through the process on my Monorprice Maker Select (a clone of the Wanhao Duplicator i3).

PID Autotune process for Wanhao Duplicator i3 V2, Monoprice Maker Select and Cocoon Create.

1. In any system that provides terminal access to your printer via USB (Repetier host, Octoprint, etc) enter the command M303 S230
2. Wait for process to finish and gather Kp, Ki and Kd values
3. On the printer; go to Configuration - Extruder
4. Set Control to PID
5. Set DT/PID P to the value of Kp
6. Set PID I to the value of Ki
7. Set PID D to the value of Kd
8. Go BACK ⏎

Wanhao Duplicator i3 V2 - Grounding Upgrade

My 3D printer was showing a +/- 10 degree swing in hotend temperature around the 245 C mark. I read up on the Wanhao Google Group and found an interesting thread that attributed the issue to improper grounding of the sensors on the Melzi board.

I created the video below while I was doing the upgrade for others to follow.

An important step I left out of the video was to switch to PID mode and do a PID tuning after this step.

Connections are as follows:
ETEMP GND to power supply GND
HOTBED to power supply GND
Processor capacitor to power supply GND

Disclaimer and warning: Follow these directions at your own risk. No guarantee to fix your problems and you may destroy your printer or yourself. Disconnect the unit from mains power before doing any work.