Wanhao Duplicator i3 MOSFET Fix
February 11, 2020
A couple weeks ago I was running my Wanhao Duplicator i3 to make some parts for a project (more details coming soon!) and was greeted with the acrid smell of burning plastic. After opening up the printer and poking about, I determined that the culprits were two terminals that had shorted out.
I did some research and it turns out that this is actually a relatively common problem for 3D printers. The terminals short out because they aren’t rated for the current that is drawn by the hotbed. In my case, the terminals for both the hotbed and the extruder had shorted out.
Not wanting to spend $100+ on a new main board for my printer, I went to work desoldering the terminals. I purchased XT60H Bullet Connectors and an ANYCUBIC MKS MOSFET and connected them to the main board as shown in the diagram below. The bullet connectors are rated for 60 amps and the MOSFET takes the load off of the board.
I also printed out a mount for the MOSFET. The model can be found on thingiverse. Admittedly, it was one of the simplest things that I’ve ever designed. I will leave the horrors of how I printed out the mount with the MOSFET installed and unmounted to your imagination.
With these fixes in place, my Duplicator i3 hopefully has several more years added to its lifespan. I am excited to put it through its paces in the coming weeks!
~ JHE
