Bumbag customizable electronics enclosure system

Common placeable components are here , find other placeable components in this collection , or search for tag bumbagcomponent .

NOTE: The base enclosure is only compatible with the VC4 BOM V1 electronics enclosure (the version that has three side-mounted 50x15 cooling fans). It is not compatible with the new VC4 BOM V2 electronics enclosure with a single 120mm cooling fan in the lid, as this is 2.5mm taller and has different side panel mounting centres. I will publish V2-compatible base enclosure variants soon.

Important Documentation!

You can't just print this model - it's a user-configurable system. Please read this documentation carefully, particularly before asking questions.

Concept

The bumbag system allows you to use PrusaSlicer to arrange things like PCBs, power supplies, USB hubs and cable management just how you want it, then print an enclosure with all the mounting posts and other fixtures included. You can visualize how your layout will look and move things around easily. You don't need to know how to use CAD - it's all done in PrusaSlicer.

The bumbag system has been designed to extend the electronics enclosure attached to the rear panel of the RatRig V-Core 4 3D printer. This is often referred to as the “backpack” - and so the bumbag is an extension that typically goes beneath the backpack. Americans call this a fanny pack, but that sounds a bit odd to British people.

While the bumbag has been initially designed to integrate with the V-Core 4 backpack, the placeable components can be used with any enclosure with a 4mm thick base and 3mm thick walls. The original bumbag has an external height of 60mm which includes a 4mm thick lid, leaving 52mm between the base and lid. Placeable components will typically be designed to this specification, and wall cutouts are typically centred vertically to suit the 60mm external height. The outer width and height of the enclosure must be an even whole number of millimetres for alignment compatibility with placeable components.

Printables Models

This Printables model provides the enclosure shell that can extend the RatRig V-Core 4 electronics enclosure, and a few placeable components that are very specific to the V-Core 4. General-purpose common placeable components are here , find other placeable components in this collection , or search for tag bumbagcomponent .

Remixing and Sharing Layouts

If you want to share a particular layout, please do so as a 3mf PrusaSlicer project file that has not been merged * . This will allow others to tweak the layout for their needs. Single STL remixes of the bumbag enclosure are discouraged: this defeats the concept of being able to move things around. Please always include a link to this Printables model when you share your layout. [ * see below]

Designing Placeable Components

There are some specific subtle requirements and challenges to designing placeable components that work properly. In time I plan to publish a guide for this. Until then, if you need a specific placeable component, I will consider designing it, or try to provide guidance on a case-by-case basis. Please message me, ideally by mentioning @tg73 in a message on the v-core-4-mods-discussion channel on the RatRig community discord .

Heatset Inserts

Where heatset inserts are required, the standard RatRig heatset insert hole profile is used, which suits standard RatRig heatset inserts with a M3 or M2.5 thread. The standard heatset insert sizes are:

- M3 x 4.6mm diameter x 4mm length - M2.5 x 4.6mm diameter x 4mm length M3 is used as standard unless a component requires a different size. For example, the holes on a Raspberry Pi are sized for M2.5.

The base requires 8 of M3 x 4.6D x 4L inserts (4 for the lid screws and 4 for attaching the original backpack side panel which is reused. All standard mounting posts require heatset inserts.

Getting Started

Download this Printables model, the common placeable parts model , and the this USB hub mode l. Paths starting enclosure/ come from this model, paths starting components/ come from the common placeable parts model.

This guide is written for PrusaSlicer 2.8.0. If you want to print with a different slicer, I recommend laying out your bumbag in PrusaSlicer, then exporting as a single STL, then print that STL in using the other slicer. Laying out a bumbag in another slicer might be possible, but this is not a supported or documented workflow.

A bumbag enclosure is designed to be printed as a single part. The V-Core 4 bumbag is 350mm wide. If you don't have access to a large enough printer, you can try designing the bumbag using a preset for a large printer (for example, a RatRig V-Core 4 400), exporting as a single STL, then cutting that STL up using your normal printer preset. You will have to work out how to glue the parts together after printing - there is no specific support for this in the design.

The basic steps are as follows:

- Start with an empty project in PrusaSlicer. Make sure you are using a printer preset that is large enough. The screenshots show a RatRig V-Core 4 500.

- First, let's add the bumbag base. Use Add (CTRL+I) and select enclosure/bumbag_130.3mf . The base model has two alignment guide parts, the long thin strips indicated:

These are used to align certain placeable parts. The alignment guides are very thin, so they don't show up when sliced.

- Now we'll add a USB hub. Use Add (CTRL+I) and select components/device/waveshare_usb3_2-gen1-hub-2in-4out.3mf . The placeable component for the USB hub, along with the required mounting posts, is added:

- The objects list now looks like this:

The USB hub object has several parts:

- 4 post parts. These are “normal” parts. Each one is a mounting post.

- 4 cut parts. These are negative parts. Each one cuts a cylinder into the base of the enclosure to make space for a heatset insert and M3 screw.

- The usb3… part. This is a modifier part, but does not have any special settings. This is the 3d model of the USB hub itself which is useful for alignment and considering cable routing. As a “does nothing” modifier part, this will disappear when sliced.

- Let's move the USB hub somewhere else:

- Click on an empty area of the build plate (or press ESC ) so that no object is selected:

- Important: if you simply click on the USB hub, you will select only the usb3… modifier part, which will look like this (other objects go dark grey):

Instead, you must SHIFT+CLICK so that the whole object is select, which will look like this:

- Important: placeable parts that need to be aligned to the enclosure edges are designed to align when moved on a 1mm grid. Always use the cursor (arrow) keys to move placeable parts. Don't click and drag with the mouse.

- Once the USB hub is selected, make sure the mouse cursor is somewhere over the main view of the model (inside the red box below). If the mouse cursor is over the object list, the cursor keys will not work as expected.

- Now use the cursor (arrow) keys to move the USB hub, and PageUp/PageDown to rotate it. The cursor keys will move the object by 10mm, SHIFT+cursor key will move the object 1mm. The USB hub should move along with its posts. If the posts don't move, then you have not selected the whole object (see above).

Move the USB hub to roughly this position, in the orientation shown: