This is a model to replace the spool holders on the Elegoo Centauri Carbon 2.  I don't know that it will fit the Centauri Carbon with the Canvas system, but it does fit the Centauri Carbon 2. 

This package consists of two bases and two spool holder shafts.  Either base will work with either shaft.  One shaft is for spools up to 74mm wide and the other is for spools up to 80mm wide.  I haven't run into a 1kg spool wider than 74mm yet, but included a wider one as that is similar to the size used on the original Centauri Carbon single spool holder.  This is NOT a drop in replacement for the Centauri Carbon single spool version.  There are other models out there that do a better job than I can.

Simply unscrew the two screws that hold the base of the spool holder for the Centauri Carbon 2 Combo and re-use those screws with these bases.  I used PETG with 5 walls and 25% grid infill.  This is clearly overkill, but I like to overbuild things.  The narrower base works fine.  I just like chunkier parts.  The fit between the base and the shaft may be tight.  I few taps from a hammer will make everything go together.  I'd rather be too tight than too loose.  

The two indentions in the length of the shaft are for PTFE tubes (completely optional, but should help reduce wear on the shaft.

WHY replace the factory spool holders?  The 3rd or 4th time you come back to a spool on the floor, tangled filament, and a failed print, and you'll have your answer. :)

There are no restrictions on this model, other than if you make a useful remix, please post it under the same license.  The only people who will want this model own a 3d printer, so it's not a model that you could sell anyway.