I just wanted to post a few ideas I had for the development of the concept to ensure that the design process is fully documented.
Above is a perspective drawing the basic shape of the holder design, annotated with arrows. Each arrow represents a different force or load that might be imposed on the holder during use, since this will be important if optimal shape will be an important part of the design.
Arrow 1 represents the weight of the spool that is placed upon the holder, which may vary from 0.25Kg to 2.3Kg. Most of the shape optimisation will be dedicated to holding this load, since it will be almost constant.
Arrow 2 represents the pull from the feeder on the printer, drawing in filament from the spool and pushing it through the extruder. This force may be negligible compared to the weight of the spool but still may be worth considering.
Arrow 3 is related to the use of the spool holder, since filament spools will need to be removed and replaced every so often, introducing force along the length of the spool. However, the way that the spool holder juts out of the printer also presents a potential risk of it snagging or catching on things during movement of the printer, or movement of other things around the printer during everyday life.
Number 4 simply shows the opportunity for different attachments to be added to the holder, enabling it to be mounted on other machines or objects.
Another idea I had for the assembly of the holder (shown below) was to allow the spool holder ‘pin’ to be removable and to use a bearing to enable the spool to rotate more smoothly whilst filament is being pulled from it, by the feeder, during use. This could then be bound together using a single bolt to provide easy disassembly.
My plan is to continue to experiment with topology optimisation (and possibly generative design), before starting to look at stress analysis (static stress for the weight of the spool, but event simulation could be used to simulate the holder snagging or catching something). The assembly of the spool holder can then be addressed in a more focused manner towards the end of the development process.