CORE One Mini - Odds and Ends: Polishing, Adjustments and Integration Work

This update is a bit different - no single big milestone this time, but rather a collection of smaller improvements, refinements and progress across multiple areas. The kind of work that isn’t always the most exciting to show, but is absolutely essential for moving from a working prototype toward something more polished and complete.

A lot of this phase is about iteration - going back over existing parts, questioning earlier decisions and making small but meaningful adjustments that improve reliability, fit, and overall usability. It’s less about adding new features and more about making everything that’s already there work better together and avoiding potential collisions.

And of course, it’s also about keeping up the flow of updates for everyone following along on this journey - sharing not just the big milestones, but also the in-between steps that actually make a project like this come together in the end. Especially when it seems to be almost finished, there is still a surprising amount of small work left to do.

Assembly Progress & Dry Fitting

A lot of the recent time went into continued dry fitting, as well as incremental assembly and disassembly. At this stage, it’s less about creating new parts and more about making sure everything fits together the way it should.

Some 3D-printed parts went through minor revisions - small dimensional tweaks, tolerance adjustments, printability improvements, and general usability refinements. In parallel, I also adjusted a few of the metal components where needed, as I ran into some challenges during repeated assembly and disassembly that required a bit more clearance than initially expected.

It’s slow, iterative work - but each pass gets things closer to a "final-feeling" build - and leaves my fingerprints all over the shiny metal, as you might notice in the pictures.

Toolhead Collision Checks & Cable Management

The main focus area was the toolhead and its full range of motion. I did not fully assemble the toolhead - only to a point where the major "touchpoints" are reached. This allowed me to spend time verifying clearances and ensuring there are no unexpected collisions anywhere within the build volume.

This includes belts, frame elements and especially cable paths - basically anything that could potentially become a problem later on. So far, everything is looking good, but this step was crucial before moving forward.

For the toolhead cable, I designed a set of custom clips to guide and secure it properly. The upper clip is screwed into the rear profile and back panel and replaces one of the nylon rivets. For the second mounting point, I needed to slightly modify the CoreXY plate to accommodate it (a quick job for the file).

The goal here was not only functionality, but also keeping everything neatly in place - especially since the toolhead cable runs quite close to the pulleys of the CoreXY motion system.

Refining the Metal Work

There were also a few tweaks to the sheet metal parts, especially around the CoreXY plate area, to better accommodate cable routing and improve overall integration. I also refined the routing itself, as it turned out to be quite fiddly to get all the plugs and cables through the sheet metal cutouts without an extra set of hands - especially with the cover for the fan/thermistor cables in place.

Aside from the two side panels, all sheet metal parts are now complete. That’s a pretty big milestone in itself, even if it doesn’t feel like one at the moment.

For the right-side panel, I’m still waiting to verify compatibility with the Prusa USS Drybox before finalizing hole placements - so that part is intentionally still on hold.

Cosmetic & Printability Improvements

I also spent some time on the visual side of things. A few parts got some polishing to move away from the "raw prototype" look and make the custom components feel a bit more intentional and organic. The temporary custom parts were refined and also adjusted for printability - either to allow printing without supports or to include integrated breakaway supports where needed.

The PSU cover in particular got some attention. It felt a bit too plain before, especially with the large “PRUSA” branding removed, so I added a bit more refinement along with some hexagon detailing - because we all know, they are the Bestagons. Still simple overall, but now more in line with the general design direction.

Filament Sensor – Still Not Quite There Yet

The filament sensor has gone through several iterations over the past weeks. The core idea has remained the same, but many small details have changed along the way - geometry, mounting and overall robustness.

I’m still not 100% satisfied with the result, but since I can no longer change the geometry of the CoreXY plate, I will leave this design as a prototype. For the final production version, I will likely move the screw mounting positions and also consider a slightly more rounded cutout for better access to the lever.

At this point, I’d consider the design finalized-ish. It’s always a bit of a process getting these smaller components right, but I’m happy with where it ended up - just the cover is still missing.

Where Things Stand

Right now, the project is in that transition phase between "having all the parts dry-fitted" and a "prototype that mechanically works and feels complete".

There’s still work to be done, but many of the foundational pieces are now in place:

• Mechanical structure and key components are largely finalized

• Sheet metal is almost fully complete

• Assembly is becoming more repeatable and predictable

What’s Up Next

I’m already seeing the light at the end of the tunnel - the finish line is within reach - but there are still smaller and bigger tasks that will take some time:

• Plexiglass parts and overall finishing work (including custom vinyl stickers)

• Sandblasting and painting all sheet metal parts (still deciding on the paint)

• Final assembly and cable management in the bottom section

• And then: software - a custom fork of the original firmware will be needed

Thank You & Support

And as always - thank you so much for all the support from the community. The feedback, ideas, kind words and donations really help keep this project moving forward and make a big difference. You are an amazing community.

If you want to learn more about the project, make sure to checkout the main post "CORE One Mini - The Rocky Road to a Prototype." for the complete background and FAQ.

If you intend to buy a Prusa machine, you can use the referral code "@suit" at checkout in the Prusa online shop. This will give you some Prusameter points and 1 kg of free filament and i'll get some points aswell (which I can use for some free filament). Or you can just download, like and make some of my models here on Printables and even consider to become a member in my Printables club.

I've also set up a GoFundMe campaign to tackle the costs. Thanks to everybody who has donated a few euros already - that means a lot and helps me cover the expenses.