SM-33 Hinging Lightweight ECC Toolhead Cover - Updated - No magnets required

Another Centauri Carbon toolhead cover...?

For those of you who hate magnets, this toolhead cover resolves that issue with a 3-bolt design (or 5 bolt) and evolution of my original SM-33 Magnetic adaptation of the SE3D toolhead cover.

Lightweight!

Lightweight... Making it completely 3D printable reduces weight FURTHER and makes it possibly one of the lightest in the SE3D lineup, aside from removing it entirely. Should be around 38-39g + 3 back cover screws.

Lightweight helps reduce VFAs (visual fine artifacts) on large highly visible walls, and will increase printing speed in during on the low end without significant VFAs. This cover can do about 70mm/s on the low end before seeing VFAs. (stock is 40-50mm/s). On the high end, it's about 140-150mm/s+ for reduced VFAs. Stock I think 160mm/s + in my testing. Some applications require lower speed printing (such as TPU, some PETG, etc.) so a slightly higher low speed printing band is nice. Or really tall models that you don't want to catch a warped edge knock over, lower speeds is nice.

As with any of the covers, recalibrating the vibration compensation is essential to take advantage here.

Hinges! Printable! Better Cooling!

Features:

This front cover slots into 2 proven, built in hinge pins at a 15deg angle on the bottom (still easily removable), and then either a supplied alignment pin on the top, secured with screws, or you can still do 8mm magnets in the pockets. This should still allow for the fan leads to be connected and flip the cover up. 

On the original SM-33 magnetic cover, the magnets on the bottom had the potential to reverse polarity while printing ASA (High bed temps ~100C). The top magnets NEVER had an issue, so I've left 8mm magnets on top as an optional feature on this cover. And probably will be what I still use. 

UPDATE

- I've added a version that can use M3 Fine/Coarse button head cap screws - 6-8mm in length, to secure the front and rear cover to the pin. Of course, once installed, you'd only need to remove the front screw to take the cover down, in the future. I have not printed this but I'm confident in the geometry, based on the best 3d printing tricks in the book. 

Cooling Details

On this cover I increased the cooling duct lengths and made them equal length on both sides of the nozzle. I also made sure the angle of the ducts angled downwards towards the bed more. This still has more airflow than my flawed Demogorgen quad duct and should be adequate for most printing applications. 

ECC1 Compatibility

For now it is still only compatible with the ECC1 NON-Canvas. I'm still working on magnet placement for the hall sensor on the new cover. So to be clear, it is not currently ECC2 or CANVAS compatible. But I am planning on making an adapter that won't require reprinting this cover. It will just mount to the back of the fan. 

Like it or lump it

I'm not planning on adding an LED. I like the improved open viewing space in front of the nozzle. And I'd rather have better cooling than a light. If that is something you'd like to add, feel free to modify the stp files attached and remix. Like most things I design, I design for myself and share them with the world. 

Initial Setup

One last note, when you initially install the rear cover, it may hit off the stepper motors until it homes the first time. This is normal. Once it homes (back cover hits the stepper), you shouldn't have a problem again. This is the same with the stock cover, if the cover wasn't on, the machine would ram the PCB into the stepper motor (it's been done) :(

Hardware

You need:

• The 3 bolts on the back of the Original Centauri Carbon Toolhead Cover (that covers the PCB). Reuse the original fan screws to secure the 24v part cooling fan.

• ONE of the following

  • 4 (four) 8x2 magnets

  • OR

  • 2 (two) M3x6 or M3x8 fine or coarse button head cap screws (BHCS)

• OPTIONALLY

  • re-add the Original 4 side screws, to stabilize the rear cover (mainly while wiping the nozzle)

  • I do not use these screws, and for me, a bit of flex is ok to not damage the toolhead or steppers, in case of light contact initially (see notes above). 

  • Personally, I would run it without them first, let the machine find itself, THEN add the screws.

Access

The hinging/tilting mechanism and open design allows access to all critical toolhead parts such as the extruder, nozzle and extruder preload without any tools. 

PRINTING:

As you already are probably aware, ASA is the filament of choice for these covers, I do not recommend PLA or PETG. Chamber temps alone for printing ASA can get as high as 60C which is over the softening temp of PLA (45-55C). 

You will need to add supports for the pins (I recommend Normal - Snug supports, or Auto Tree Organic, built plate only). They should build off the hinge part up into the pin, on the rear cover. Else try my other favorite supports - Tree Organic. Building off the plate is still fine and may actually work better depending on your filament tuning/support settings. Finally, if you have the ability to print support material on an H2D or X2D, that would work, but this is designed to print on the Centauri Carbon itself... Regardless, ASA for support works fine and breaks off easily. See my attached Bambu studio file (importable to Orca).

This cover is based off my SE-3D magnetic cover. And integrates a swinging hinge design loosely based off my handlebar alignment tool.

Print all parts face down as per my original SM-33 designs (see remix link on this page).

REVLOG

2026-09-21 - Updated the rear cover to add optional tabs again for stabilizing the rear cover. Added new pin geometry that can be secured with screws or magnets. Also added chamfer on the back of the cover to alleviate the rear cover smacking the lever arm during the homing routine. (still does it but more gently, at least in open centauri).