Mega X Hot-End Fan Box Remix

We received a donation of 2 Mega X machines in our campus maker space. We wanted to level them up so they don't feel bad that they aren't our Prusas 😁. We won't compare the Mega X to our Prusa XL — there's no contest. However, we needed to expand our large printing capacity, and free printers are hard to argue with. This is one of several remixes we created on our quest to optimize these printers.

In this chapter, we focused on the hot end, which, in our view, left a lot to be desired in the stock machine.

Partitioning and debulking the hot end

We really hate the big, boxy hot end cover on the Mega X. You can't monitor the print very well, and just stuffing all the fans and the hot end unit into one volume is inefficient. No wonder the fans are loud! We couldn't prove it, but the fact that we needed to replace the hot ends on both machines suggested this configuration led to fatigue for this element.

We started looking for a redesign that acted more like the Prusa hot end: partitioning each element to optimize performance, focusing the fans for best effect. There are a LOT of hot-end reboots. Most are aesthetic responses to the pathetic hot end box, though many of the better ones allow for improved visual access to the nozzle. The more advanced ones did partition the elements, but these typically were geared toward creating a direct drive with the extruder hitching a ride with the hot end, a solution we rejected. It wasn't promising. 

Until we found this amazing work by AlexMu, which became the basis for this remix. We needed to tweak the design, but this was the essential solution.

Integrating a cable guard

We liked Delian Kanzler's cable guard, but wanted to avoid additive solutions. We were going to mash Delian's guard up with AlexMu's cover… but it pays to read the licensing: Delian's did not permit remixing. So we modeled it from scratch, using a modified quadrant of a hard-edged quad-ball. The angles of the guard suggested a new pattern for the cover grill, so we introduced a nice Prusa-inspired hexagonal pattern that shared a visual vocabulary.

We printed the new hot end in orange PETG. Several elements need support to print: your mileage may vary.

This and the other parts of our rebuild can be found in the Collection Mega X Remix.

UPDATE

31 July 2025: Inconsistent hole placement. As we were putting finishing touches on the build, we discovered that the top holes adjacent to the cable guard shift by a millimeter or so from one machine to another; so much for Anycubic's quality control! We found this model worked perfectly on one machine. On the second one, where the holes shifted back by about a millimeter, we simply drill-reamed a new hole to match that new position. So be on notice: your mileage may vary. If we get enough feedback, we might reconfigure the hole into a slot to account for the variation.

• I combined a cable guard inspired by Delian Kanzler with the front cover for an integrated solution (remixing is not allowed by Delian's license, so the cable guard was modeled from scratch with a simplified geometry).
• To match the look of the cable guard, I replaced the parallelogram design with a honeycomb grid on the front cover.
• I created a hole in the rear inserts to accommodate the large fastener on the Mega X hot end mounting plate.
• I created a large radius curve in the top clamp to reduce interference with the tube connector.
• No changes were made to the front insert and the really well-done fan duct. They are here for convenience, but full credit is due to AlexMu.