Elegoo Centauri Carbon Toolhead Cover SM-33 Ed.

Note! Additional magnet hardware required!

What/Why:

First of all, in general, a lightened tool head cover reduces toolhead mass and inertia, which can improve VFAs and printing speeds after you re-run input shaping (MANDATORY). 

Sander De Groot made some huge gains in the Elegoo Centauri Carbon Toolhead arena. Mainly the fan mounting, their nifty slot for the 8mm magnets at the bottom, and a cover that is magnetic. This was a pain point in the original design, potentially having to unscrew the front cover for nozzle swaps. And the fan posts breaking easily. NBD, we had to start somewhere!

Retaining this brilliant fan mounting, magnetic function and support areas by Sander De Groot I was finally able to craft my vision, a single sided lightened toolhead cover with the looks of SM-33 - my favorite "I ain't heard of no at-attin" droid. It could probably still use some refinement. But it trims the weight down to 45g including magnets (38g-ish without), and even drops the weight further due to removing the side "guide" screws from the OG design. They're unnecessary. 

Printing:

I printed mine in Black ASA. I have a creality chamber heater to print it around 50-60C, 265C Nozz, 100C bed. 0.4 to 0.6 nozzle. 0.30 layer height for 0.6, 0.20 for 0.4. 2 walls recommended. This is about a net weight of plastics of around 39g for the original SM-33 cover and 34g for the slim (with a 0.4 nozz). 

Hardware/Assembly:

I will take magnet size requests if you have some magnet sizes in stock. I plan on uploading a version with the 6 mm lower magnets, but let me know if you need anything else.

You can reuse the stock fan screws, and stock rear cover screws. But you will need (5) 8x2mm magnets, and (2) 5x3mm magnets. For the magnets, orientation is critical! Be sure to test magnet orientation BEFORE gluing! 2 8x2 magnets are REQUIRED at the top of the front cover. 

NOTE: There have been issues for others with lower strength magnets. To avoid this you can buy the ones I purchased, here:

You can purchase both here:
https://a.co/d/0akJvFw

https://a.co/d/dpAYKxh

Once the magnets are glued, in place...

• Disconnect the fan from the old extruder cover, unscrew it with a small phillips driver. 
• Slide the fan onto the 2 pegs on the new extruder cover, this stops the fan from rotating. Screw the original screws into the new posts. This will secure the fan to the pegs. 
• Unscrew the mid-cowl cover (4 screws), place them in a bag somewhere for safe keeping. 
• Unscrew the rear cover (3 screws), replace the rear cover with your new printed one, and screw the 3 screws back into place on the toolhead. 
• Plug the fan back into the toolhead lead. 
• Snap the front cover in place with the magnets - and you're done assembly! 

Now RE-RUN FULL Auto-Calibration, including:

• Input Shaping 
• PID Tuning
• Bed Leveling

After this, you should be good to go!

Other Notes:

I had made an SE3D toolhead cover in the beginning that I wasn’t the biggest fan of myself. I struggled trying to make a magnetic design that I was proud of, that encapsulated the magnets more than just gluing them in. With the flood of models (hyper weight ones like Andrews) I ended up giving up. I’ve got 3 kids, wife was mad for me staying up late, and I was exhausted.

Enter Sander De Groot - they designed everything I was looking for in a toolhead cover: Lighter weight, magnetic, fan mount that doesn’t suck (no offense SE3D - you started the craze!), and has integrated support. While the magnets are still ideally glued, they hold up SUPER well. I had to give it a shoutout because I took it and was able to complete my vision. A toolhead that was slimmed down, still magnetic (ie easily removable for maintenance and hotend swaps), and looked cool.

I will be adding more tweaks as I go along. Every time look at it there’s something else I want to change. It could use a fan cable clip so that’s next on the agenda, as well as some further pockets/hollowing.

Updates:

Updates 12/22-2025: Added 0.4 & 0.6 nozzle profiles, ASA, 2 walls, 10% infill, 0.20 or 0.30 layer height respectively.

Updates 12/26/2025: Added extra braces for the Slim version, if you fan isn't secure enough. I have a version that spans the fan screws or a single tab that you can bolt thru to secure the side of the front cover to the fan. 

Updates 1/6/26: Completely gutted the Slim Version and made the new “Demogorgen” (v2)! Seemed appropriate timing and looks wise.

• Added the quad jet pack! 
• Added a slot for the LED mod as noted in the comments from @Darkwolf7887
• I also reinforced the side a little more because of cracking issues.
• Front cover comes out to 18.5ish grams which is INSANE. Saves another 6-7g from my first slim version. 32.5ish F&R (not including magnets or screws)
• The file is very large so I am working on that.
  • EDIT - Gotta pay to play - there was no getting around that loft/sweep geometry
    • Recommend importing the STP file - the STL is insanely large

Please add tree supports under the air channel lofts (or see print profile). I feel like we need like a TPU/ASA blend. Excellent layer adhesion but rigidity and light weight :D

Updates 1/22/26: It's come to my attention that not all magnets are made equal. Some people even having covers fly off mid-print. Mine haven't had an issue (and I added my magnets that I have), but in the interest of nobody having bad experiences, I have made a new rear cover to add:

1. A retaining guide/pin to secure the top magnet area between the pin and the main toolhead body. 
2. An additional 8x2 magnet to keep the top magnet area secure
3. Lightweighted sides to offset the magnet and pin material
4. Backwards compatibility for ALL SM-33 Covers

Updates 2/2/2026: I apologize I've been so sick these past few weeks. I did make some progress testing and have a few findings...

• H2D A1 nozzle mod (Pedro/Makerworld) - LIST OF COMPATIBLE COVERS:

  1. SM-33 Original (Front)
  2. SM-33 Slim (Front)
  3. toolhead-cover-back-lightend_step_8and5mags_MORE_SECURE (Rear)

   

  • The Demogorgen V3 (or 2.6.3) is sadly NOT compatible with the A1 nozzle mod. It fits, but the ducting sits below the Nozzle. I am running my SM-33 Original with decent results. 
• I made a new Demogorgen V4 - I printed it before checking fitment in the assy but turns out the new ducting interfered with the fan.
• For whatever reason my magnets reversed their polarity on the rear cover which is a huge PITA. Because it means I can't use ANY of my front covers without wrapping them with electrical tape. 

Updates 2/11/2026

Removed Demogorgen and profiles. It doesn't fit the H2D/A1 mod and is flawed with the ducts being too low. Will Create a separate Demogorgen V4 page in the future. 

Demogorgen Notes:

First of all this was a community request, so it is EXPERIMENTAL. I indulged in creating a new model similar to a BIQU jetpack. These are my findings. There is more potential in this, so if you are willing to wait, I will be coming out with more models. 

VFAs:

• I have tested the VFAs, and added an image above with results. I can get up to 70mm/s without VFAs on the low speed end (an improvement from 40-45). 

Cooling:

• The cooling leaves something to be desired. It does work but I see no improvement over my "SM-33 Slim" Cover. The rear ducts have more flow than the fronts, mainly because it's a single opening blower and the flow biases towards the rear of the blower.
• I'd like to add a better design in the future that has modular ducts, and a 2 into 4 design to mitigate the preferential flow (hugging walls and not splitting). 
• I also found the ducts sit low and the angle of them is too flat (slightly angled down but not enough). Future designs will angle this down slightly.
  • If you're feeling crafty you can dremel out the bottom of the ducts to allow air to exit sooner and aim below the nozzle