The bracelet hole is moved to the left side of the shell.
bigger & stronger.
Corners:
Bevelled/chamfered corners for a more comfortable grip on the shell.
.STEP/.stp files
Use the .step/.stp files instead of the STLs for more precision.
V2 rack | 11.03.2025
Rack adjustments:
New aux hole:
Heart shaped press fit mechanism for the aux jack. A little flexible arm holds the jack firmly, but with more tolerance for minimal jack deviations.
New snappy USB hole:
Holds the stick with snappy arms on the sides instead from the top, (was too tight and lead to tilting)
→ Rack can't get stuck anymore, because the movable part is not pushing against the shell after the stick was injected
Allows injection of different kinds of USB sticks.
Harm reduction for the hardware due to less grabbing force.
.STEP/.stp files
Use the .step/.stp files instead of the STLs for more precision.
With this miniature CDJ player, you are spinning the disc before they see you coming.
Extend the USB-stick and AUX-plug rack by turning the disc. And if the mechanism fails to work, you can still use it as a decoration piece for the wall.
Features
Movable discs with retraction mechanism for USB-Stick storage (USB 2.0/3.0 type A)
Multicolored print possible
Micro SD-card (~15mm, ~11mm, ~1mm)
Modular: Removable snap fit disc & rack for colorful combinations
Below you will find some general print setting recommendations for the parts. I was using the good old PrusaSlicer for this guide, so I hope you can find these settings in your slicer of choice.
Note: All three parts could be printed with the same settings. I just figured that the concentric bottom fill layer for the shell might lead to first layer problems, so I'd suggest choosing monotonic/rectangular for the first layer of the shell and the rack. If you have good bed adhesion, this doesn't affect you.
Important:
Position the models as shown on the images.
The clearances are tight (0.3mm, +/- 0.05mm). To ensure a smooth spinning experience, a good calibrated printer is mandatory.
Nozzle: <= 0.4mm
Set the following overall settings for the file. Then, only add modifiers to the disc. The other parts don't need anything extra.
General configuration
Top Bottom & fill layer: rectangular (or whatever works best)
Perimeters: 3 (min. 2)
Elephant foot compensation: 0.2 mm
Infill: 0%
Support: no (perhaps support infill, if your bridging isn't reliable)
Bridging: enabled
Print thin walls: enabled (detect thin walls)
DISC
(the 3mf file has everything set up already)
Select the disc
Right click, add Infilland Layers & Perimeters modifier
Layers & Perimeters → Bottom fill layers: 0
Infill: 100%, concentric (at least the layers around the snap fit joint. I just used a box modifier with 100% monotonic infill for the tip)
SHELL & RACK
Right click, add Infilland Layers & Perimeter modifier
Infill: 0% (Decent bridging capabilities are required. Otherwise, 10-20% Infill of any kind will do. Internal support Infill, such as "lightning" or "cubic support" also works)
Seam: aligned (Try to place the seam somewhere outside the shell, any edge will do; the inner seam is hard to sand off and could make the rack get stuck.)
It is advised to print in separated runs. This saves time, filament, energy & results in a more consistent finish = resource friendly + easy to print!
Otherwise, there are three options to consider:
(Easy) Print all 3 parts separately (or all parts three times, then you have 3 CDJs and can mix the parts)
(Advanced) Print all parts one by one within one session and perform a manual filament change as soon as the other part starts
(Advanced) Print with a multicolor printer:
If you also want to colorize the buttons, choose the file V1-usb-cdj_shell_btns_seperated for the shell, or use the attached usb-cdj_V1_all.3mf file. Then apply a color change to the button objects (not tested yet & not recommended).
Assembly & Retouch
Sand off inner holes, the gear and rails if necessary for a smooth spin. I just took a flat screwdriver and scraped off any blobs and such.
Push the rack into the shell.
Push the disc into the center hole.
Attach a neat bracelet.
Insert your USB stick & aux plug, spin the disc and get ready for the next gig!
Improvements
All printers have different settings, so I can't guarantee that the clearances apply to your print settings right away. But if you run into issues, have questions or if you have suggestions on how to improve the model - I'd be happy to receive feedback!
Design process
My initial goal was to use as little space on the print bed as possible and not having to use support material. It was quite a challenge to find a compromise between detail, size and actual printable properties. In the first versions, I tried to make it a print and place model. But since the layers of the rack and the shell were plotted in the same orientation, the rail couldn't really run smoothly because the friction led to tilting. Internal print failures and stringing were another problem. Now, with the separated snappy rack, you don't have to worry about this and can easily insert it afterward.
However, I would choose a different approach for further development, as the print quality could be improved in some places by a different positioning on the print bed. And of course, the rails would run even smoother if the shell would also be printed horizontally. But that would mean dividing the part and adding snap mechanisms and stuff. This took quite a while already, and I first want to see how this version works for other people.
scullptor
