Spool Holder for Anet A8

Here we have a spool holder I designed to fit requirements I felt weren't fully addressed by other spool holders. Certainly not the best spool holder there is, but hopefully not the worst either. (It fits my needs just right since installed...)

I assume it could fit several other printer models, and you can customise your own if you are familiar with OnShape; my models are public over there. --> Link to OnShape models <--

Inspirations

• General design: Anet A8 Spool holder - reuse Anet parts
• Back brace: Anet A8 Spool Holder & Brace
• "Spool cone": Parametric universal spool holder

Requirements

1. As simple as possible
   • No fancy slats or patterns
   • No ball or needle bearings
   • No printing supports
   • etc.
2. Prints as fast as possible
   • Low support %
   • Less overall surface area
3. Easy and speedy installation
4. Limits the axial forces to "push out" the "spool cones"
5. Requires as little plastic as possible
6. Does not rely on tight tolerances (or as little as possible)
7. The possibility to easily screw / affix something if it isn't solid enough
8. Nottoo ugly

Comparative Remarks

The remarks I had on other designs were essentially as follows:

• The weight and friction does not justify a bearing (not on an A8 at least, it's notfancy enough and plenty strong; I've seen minepull up a half-full spool from the floor)
• The models I've seen use too much surface area in contact with the axle, which is why I chamfered mine to approx. 2mm wide to lower friction.
• I needed more clearance at the back of the holder since the display board on my A8 had longer connector pins, which required spacers to affix the acrylic back panel. You can see the brass inserts used as spacers in my pictures...
• The moment (torque) created by the weight of the spool needs only a countering moment from the lower end of the holder, not something that goesunderneath the printer's panel. That "under-arm" limits the easy fitting and the number of printer models it could actually fit. However, not having this feature means a back-brace is mandatory for stable operation.
• Fancy "spool cones" design just adds surface area, hence plastic used (sidewalls do take more plastic than infill generally) and printing speed. That said, since I wanted mine with a lesser "axial angle" (reason below) it ends up having a higher volume (hence weight) than the inspiration above. (eh, can't have the cake and eat it too) Plus, mine wasreally quick to design. ;-)
• "Spool cones" too angled just makes the axial "push-out" force higher so I made some with less angle (i.e. more parallel to axis). It fits a lesser range of spool hole sizes, but I don't use miniature spools. I aimed at 55 +/- 5 mm.

You may like to know...

• Should the pegs of the back brace brake off, or you want to use screws right away, the pilot holes at the back of the brace are there just for that; drill through and use pins or screws
• The braces pegs and the holder holes havethe same diameter; expect drilling the holders with a 1/8 inch drill bit. I always prefer to rely on that rather than on my printer's ability to make nice fits.
• The holders are mostly 8 mm square cross-section. In hindsight, I'd probably go with 5 mm cross-section to save time and plastic. You can have fun in OnShape to fix that; I don't need another spool holder!
• The design does allow to use the stock "spool holder threaded rod" that comes with the A8. However, as the spool unwinds it'll always have a tendency to "screw away to the right", especially since I made the contact area smaller and more subject to interact with the threads. I recommend you use a straight 8 mm rod of your choice instead. Or at least file round grooves in the rod to fit the holder's bearing surfaces. You can use the nuts to limit motion, but they end up creating friction if they touch to the holder... Well grooves are always good in any case to prevent any side-ward motion while limiting contact surface (hence friction). If you look carefully at the pictures you'll see it's what I did.
• The rod clips were inspired from the metal ones you usually have at the back of washing machines, holding tubes. The ones in this design are easily installed with two fingers.
• This design puts the spool slightly more forward than the first design in "inspiration" above, in order for the spool to unwind more directly into the extruder, even as the spool is practically empty.However this means that a tangled filament preventing the unwinding may have the extruder pull the spool forward and over easier than with the other design... Let me know if you witness this issue, and if you think the other design may have prevented that better... For reference, a mock up of the holder of the "inspiration" section is "hidden" in the OnShape design

Please!

Let me know what you think of this design, keeping in mind;

• Constructive criticism is always welcome (the other kind, not so much)
• This design was made in 1-2 evenings; there is bound to be some flaws
• Pros & cons of this design vs. others is quite good at making all the designs being compared better!
• If you do make your own mod from within OnShape, please let me and the community know with the "remix" check.

Print Settings

Printer Brand:

Anet

Printer:

A8

Rafts:

No

Supports:

No

Infill:

10%

Filament: Hatchbox PLA Post-Printing =============

Drill / widen the holder holes with a 1/8 inch drill bit

... Or change the OnShape model why not!

Category: 3D Printer Accessories