The Barback was a smashing success for fact it was banged out over little more than a weekend hackathon. It’s been to dozens of parties, served countless cocktails and has been on several bike rides. It’s never been recharged, the straps are falling off, in addition to always having been a bit janky, and the code has barely been updated. So it’s time for Barback V2.

I’ve been working the design for V2 for quite a while but never felt ready enough to move onto CAM. The whole thing is designed in FreeCAD, using a combination of Part Design workbench and Assembly 4. This combo works really well for my design and fabrication style. All my parts are ‘flat pack’ designed, where everything is oriented the same way, as if it will be cut from plywood…. because it is going to be cut from plywood.

Preview from FreeCAD.. visualize plywood

But with a couple recent breakthroughs in my FreeCAD workflow I was excited to get back to work on this, finally adding addition structure I felt would stiffen up the entire frame.

Old rendering without additional structure

This earlier shot lacks a central support for the tray in addition to the shoulder support. The area still needs work and it’s pretty flimsy when the frame is detached.

With the design done in FreeCAD being all flat individual parts it was easy enough to lay out for CNC in the Path/CAM workbench.

And then off to cutting….

As this is just the prototyping stage I cut out of some scrap I had leaning against the house, the final packs will be cut from some really nice marine grab plywood I’ve been hoarding, but even so it came out pretty good!

First fit!

okay, okay, that’s some good progress alight! The fit went together just fine, this picture above doesn’t have any glue and it feels relatively secure. The fit test on Sam show it’s still too short, and the shoulder pads are probably still too close together. Despite this it’s still going to be fine to continue prototyping the straps…. so I might as well paint it right?


Aaaand that’s it. From here Sam can work on other design aspects while I work on the next parts of the model. All in all I’m super happy with the progress. Next up for the design I need to detail out battery mounts, which I’m strongly considering switching from RC batteries to Milwaukee-style power tool batteries, flush out the electronics platform/enclosure and figure out the mounting points for the pumps. I also need to finish prototyping the machinable peristaltic pumps, the first 3d printed one didn’t work out, the second revision has been machined out of HDPE and just needs testing.