u/suit1337

Hello there,

I stumbled upon this paragraph and it left me a bit confused, since my basic chemistry knowledge taught me otherwise.

>The G in the acronym PETG stands for Glycol which is added during the manufacturing process. Glycol modifies the properties of PET [...]

https://prusament.com/materials/prusament-petg/

To my understanding, the "G" in PETG does not simply stand for glycol, as is often claimed (and not just by Prusa). As confusing as this may sound, the "E" already stands for glycol - while the “G” actually stands for "glycol-modified copolyester" (and not "contains glycol").

Stick with me for a moment and let's start simple with good old PET.

PET stands for Poly Ethylene Terephthalate. It is produced from the monomers ethylene glycol and terephthalic acid (or dimethyl terephthalate). So the "E" effectively refers to ethylene glycol (also called monoethylene glycol or MEG). Since the common name for this substance is simply "glycol", the "E" already indirectly represents glycol. Chemists may also refer to the broader family of MEG-derived compounds collectively as "glycols".

Now to PETG. The common explanation is that glycol is "added during the manufacturing process". But that is not really what happens. Instead, part of the ethylene glycol is replaced with another diol - most commonly CHDM (cyclohexanedimethanol).

If the ratio of MEG to CHDM shifts further toward CHDM, the polymer may then be classified as PCTG, which some people might know as the "bigger, stronger brother" of PETG.

And finally, if the ethylene glycol were entirely replaced by CHDM, the result would essentially be PCT, yet another polyester.

Since I’m not a chemist, I’d genuinely appreciate feedback from someone with an actual background in polymer science to shed some more light on this - and, of course, correct me if I'm wrong.

TL;DR:

PCTG is a modified version of PCT with partially added (ethylene) glycol - but PETG is a modified version of PET with partially replaced (ethylene) glycol (or respectively, the G stands for "modified by an additional glycol / diol component").

Am i wrong?

Hey everyone, the bi-weekly update on the CORE One Mini progress is here. This week was mostly focused on wrapping up the exterior side of the project - especially plastics, fitment refinement and pushing the sheet metal and enclosure work closer to completion. A lot of small decisions in earlier stages came together this week, so it feels like a meaningful step forward - i'd almost stay it was too easy :)

Full breakdown here: Plexiglass, Polycarbonate and Paint

TL;DR

• "Plexi set" has been made - though one is is PC instead of PMMA
• Front handle shortened by 70 mm
• manually refinished with my awesome paint mixing and painting skills :)
• Prusa USS Drybox helped with testing the right side panel
• Final sheet metal part was lasercut (but not bent yet)

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For the main project page, full updates and FAQ head over to Printables and read CORE One Mini - The Rocky Road to a Prototype

If you want to help the project: 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 + a free Spool of Filament and for me some Prusameter aswell (which I can use for some free filament). Or you can just download, like and make some of my models here on Printables or 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.

Hello there, i hope you all had a nice weekend. Just a small sneak peak, what I'm doing right now.

Even though the weather was exceptionally nice here in Austria and i spent quite some time outside, i still got some time to make progress with the CORE One Mini.

Big thanks to u/Tommy_Prusa3D - who sent me a Prusa USS Drybox to play around with - of course I immediately put it to use: i tested a bunch of different spools and at least the spools i use fit perfectly fine (including, of course the Prusament Spools).

Most my time went into refining the side panel geometry. It’s a tight fit, but it should work - the radius of the PTFE tube is pretty tight, so I don't expecty to feed very brittle filaments, but for good old PLA or PETG, this should be totally fine.

Since the design is mostly locked in, bigger changes that would squeeze out a few extra mm will have to wait for a potential future "production" version - there is still room for some extra space, but it is too late for this design.

I also checked the acrylic parts and made a quick test piece for the vent cover - it is rather cute when put ontop of a regular CORE One. Finding the right tint/opacity is tricky, but the scrap piece i've found works, even if it's a bit darker than the original - and my local source should have this tint in stock.

Current state still looks a bit rough: paper/cardboard templates + bent 3D prints held together with tape - but those contraptions did the job. Next up will be a proper sheet metal version.

I've also prepped a cutoff template to trim down the stock door handle - easier than making a new part and especially color-matching the paint, since the part is not that big.

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For the main project page, full updates and FAQ head over to Printables and read CORE One Mini - The Rocky Road to a Prototype

If you want to help the project: 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 + a free Spool of Filament and for me some Prusameter aswell (which I can use for some free filament). Or you can just download, like and make some of my models here on Printables or 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.

Diejenigen, die nicht nur bei uns in r/3Ddruck herumlurken werden es vielleicht schon gesehen haben:

Es gibt ein neues Update zum CORE One Mini auf Printables (in englischer Sprache):
Odds and Ends: Polishing, Adjustments and Integration Work

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TL;DR:

Ein zentraler Punkt war der Toolhead: Hier habe ich mich intensiv mit Freigängigkeit und möglichen Kollisionen beschäftigt. Zusätzlich wurde das Kabelmanagement weiter verbessert - insbesondere im Bereich der CoreXY-Plate, wo der Bauraum recht eng ist. Dafür kamen auch neue, speziell angepasste Clips für die Führung des Toolhead-Kabels zum Einsatz.

Auf der Hardware-Seite ist die Blechbearbeitung inzwischen nahezu abgeschlossen - abgesehen von den beiden Seitenteilen, allem Anschein (wenn es DHL nicht versemmelt) sollte ich morgen eine Prusa USS erhalten. Der Filamentsensor hat ebenfalls seine finalen Iterationen durchlaufen und ist jetzt mehr oder weniger “final” (ja, bin lazy - immer noch nicht ganz).

Neben den funktionalen Themen gab es auch ein paar optische und praktische Anpassungen: Einige Teile wurden hinsichtlich Druckbarkeit optimiert und leicht überarbeitet. Und das PSU-Cover hat ein kleines Upgrade bekommen - jetzt mit Hexagon-Pattern, damits nicht so fad und nackt ist.

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Wenn ihr das Projekt unterstützen möchtet:

Solltet ihr eine Prusa-Maschine kaufen, könnt ihr beim Checkout im Prusa-Onlineshop den Referral-Code „@suit“ verwenden. Dadurch bekommt ihr Prusameter – sowie je nach Druckermodell noch etwas gratis Filament dazu und ich auch (die ich wiederum gegen Filament eintauschen kann).

Alternativ könnt ihr auch einfach meine Modelle auf Printables herunterladen, liken oder drucken oder Mitglied in meinem Printables-Club werden.

Außerdem habe ich eine GoFundMe-Kampagne eingerichtet, um die Kosten des Projekts etwas abzufedern. Vielen Dank an alle, die bereits ein paar Euro beigesteuert haben – das hilft wirklich enorm.

With the INDX bomb dropped in the past few days, I hope this progress update is still exciting to you. For everyone wondering what to do with the Nextruder after your INDX upgrade - build a CORE One Mini :)

Full article as always on Printables:
CORE One Mini - Odds and Ends: Polishing, Adjustments and Integration Work

TL;DR:

This update is a collection of smaller refinements rather than one big milestone. Mostly dry fitting, iterative assembly and tightening tolerances.

Key focus areas were toolhead clearance and collision checks, cable routing and small mechanical adjustments - especially around the CoreXY plate to keep wiring clean in tight areas. Custom clips were added for toolhead cable management.

On the hardware side, sheet metal work is now essentially complete (aside from the two side panels), which is a significant step even if it’s not very visible. The filament sensor also went through its final iterations and is now “finalized-ish”.

There were also some cosmetic and practical tweaks, including improved printability of parts and polishing details like the PSU cover - I've added Hexagons :)

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For the main project page, full updates and FAQ head over to Printables and read CORE One Mini - The Rocky Road to a Prototype

If you want to help the project: 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 + a free Spool of Filament and for me some Prusameter aswell (which I can use for some free filament). Or you can just download, like and make some of my models here on Printables or 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.