This is an mod for the Wanhao Duplicator i3 plus to change from the existing hotend assembly to a more universal and available E3D V6 hotend assembly, heatbreak and heatsink. Since the part changes the geometry of the hot end, a modified cooling duct is also required.

The mod uses the existing 40mm fans as a cooling fan for the heatsink and part cooling fan, and preserves the existing i3 Plus mount plate.

Captive nuts are used to mount the heatsink clamp and cooling duct to the mount plate, and are also used to mount the 40mm fan to the cooling duct. One will need an assortment of M3 machine screws and square M3 nuts.

Since this part is moving around on the x and z axis, keep it light to keep vibrations low and speed high!

I had this printed in grey resin to withstand greater temperatures, but if you're only printing PLA, PLA should be perfectly fine.

I measured all major dimensions using a caliper:
Distance between all existing screw holes
Dimensions of the e3D v6 heatsink

I designed the existing parts in fusion 360 with the major dimensions and started sketching how they would integrate into the existing hardware.
-One difficulty was figuring out how to clamp the heatsink in place without any screw points or mounting hardware. A collar around the thin "neck" at the top seemed like a good idea.
-Another challenge was ensuring there would be airflow to the heatsink and around it.
-The design must also ensure that the extruder stepper motor can feed filament into the hot end without friction, and also prevent filament jams.
-Lastly, the e3d hotend is a bit shorter than the existing hotend, and that makes the z-height slightly higher, rendering the existing part cooler/cooling duct useless, requiring a redesign. Luckily the existing one isn't great, so this is a bit of an upgrade.

With a design made, it was time for a test print to check tolerance and identify flaws. The collar tolerances and resin print shrinkages took a few attempts to get right.

1. Print all the parts!
2. Remove the existing hot end assembly and disconnect the fans.
3. Purchase screws of appropriate length. I used the bottoming-out feature of my caliper to do this with a bit of wiggle room. They are all M3 screws and nuts. [TODO: document the lengths]
4. Insert a captive nut into the converter.
5. Place an e3d hot end assembly in the collar, and slide it on the wanhao hot end mount plate, screwing it into the captive nut.
6. Screw the heatsink cooling fan onto the collar and into the stepper motor, tightening the collar around the heatsink.
7. Screw the part cooling duct into the mount plate using more captive nuts, and screw the fan to the duct.