Prusa i3 Bear Upgrade V2.0
This is an aluminum frame conversion for the Prusa i3 MK2, MK2s, MK2.5 and MK3.
Josef PRŮŠA has created numerous of incredible 3D printers and its latest Prusa i3 MK3 is capable of very impressive print quality for a very low price. A huge thanks to him and all its team!
One of the down point of the Prusa i3 MK2 and MK3 is the rigidity of the frame. A very good project has solved those problems by using 3030 extrusion aluminum : Prusa 3030 Haribo Edition. So why another conversion build? Check the next section ;)
Why another conversion build?
Here are the features that explain why I decided to create another printer upgrade.
- Use as much as possible original parts (no need to print a new RAMBo cover nor change any cable, rods or firmware)
- Compatible with MK2, MK2s MK2.5 and MK3
- Let user choose between two versions :
- Highly detailed manual
- Use more aluminum and less printed parts (3D printed parts can crack and are less reliable)
- Use Openbuilds hardware :
- Single platform of multitude compatible hardware parts
- V-Slot offers more possibilities for printed parts and customisation than T-Slot
- Open source with powerful community
- Easy to square and build
- Worldwide shipping plus several other shops selling these parts
- Other type of aluminum extrusions can be supported thanks to parametric design (check Fusion 360 files)
- 3D printed parts designed using advanced techniques like selective infill, clean vertical holes, sharp angle...
- Open source by providing STL, STEP and Autodesk Fusion 360 files
WARNING: Full Upgrade MK2S, MK2.5 and MK2.5S
We are currently working on reducing the number of versions of the Full Upgrade kit. MK2S, MK2.5, MK2.5S will be merged to MK3 frame. Most of the official distributors are already selling only MK3 frame.
How to use MK2S, MK2.5 or MK2.5S on MK3 frame
- Use this Y belt adapter: https://www.thingiverse.com/thing:3468567
- You will need a new Y belt because MK3 frame is slightly longer. Will be a good opportunity to refresh your old belt. Here is the reference to use with the belt:
GATES LL-2GT RF 6mm Width 2mm Pitch 660mm long. Belt From Prusa store works perfectly as well.
- Use all MK2S/MK2.5(S) parts except Y rod holders and build helper.
- You need to use the 106mm build helper
Full And Half upgrades
The Prusa i3 Bear upgrade is proposed in two versions: full or half upgrade.
- Half upgrade : upgrade your MK2/MK2s/MK2.5 frame to MK3 type
- Full upgrade : has a redesigned and stronger Z axis for all MK2 and MK3 printers but is more expensive
Here is a comparison table to help you choose :
|| Half Upgrade
|| Full Upgrade
|| MK2(s) and MK2.5
|| MK2(s), MK2.5 and MK3
|Y axis rigidity
|| ♥ ♥ ♥ ♥ ♥
|| ♥ ♥ ♥ ♥ ♥
|Z axis rigidity
|| ♥ ♥ ♥
|| ♥ ♥ ♥ ♥ ♥
|| ♥ ♥ ♥ ♥
|| ♥ ♥ ♥ ♥
|| ♥ ♥ ♥
|| ♥ ♥ ♥ ♥ ♥
|| $ $
|Number of V-Slots to cut
|| 6 (4 different lengths)
|| 7 (4 different lengths)
|Number of V-Slots to tap
|Can I place the printer inside an
enclosure and PSU outside?
|No, PSU rigidify the Z frame
|Capability to increase Z axis height?
Half upgrade use the same v-slots and printed part for MK2(s) and MK2.5. However, the full upgrade has 3 different versions, one for MK2(s), one for MK2.5 and another one for MK3.
Several printed parts are shared between all these versions. This makes easier to move from half to full upgrade, or full upgrade MK2 to full upgrade MK3.
Go to HALF upgrade page or FULL upgrade page (on my GitHub).
Where can I purchase the hardware?
Official distributors are selling a kit with all screws and extrusions ready for the upgrade, you will only need to print latest 3D printed parts.
All distributors are following specifications to ensure you will have a perfectly squared Bear. All distributors are using professional machines dedicated to cut aluminum extrusion (like CNC machines). In case your extrusion is out of specifications, you can get a replacement for free. We have created a dedicated support channel in case customers have more technical questions or need information for a custom build.
By purchasing a kit from official distributors you are supporting the development of the Bear project, thank you very much!
Openbuilds hardware distributors
You can also purchase parts separately worldwide. Checkout my list of distributors here : Openbuilds stores list
Here are the places were the Bear project is the most active. Do not hesitate to ask if you have a question :
Checkout the best optional parts for you Bear : Optional Parts
Manual, Drawings, BOM, Sources
Everything is available on my GitHub : github.com/gregsaun.
Support my work
The Bear project is made possible thanks supporters. Here are some way to support me:
Become my patron with Patreon: patreon.com/gregsaun
A tip via Paypal: paypal.me/gregsaun
A tip via Thingiverse: thingiverse.com/pekcitron
Big thank you in advance <3
Thank you to all my Patreon : 3DPrintronics, Ahmed, Albe Gouws, Anders Svendsen, Apton Ika, Arnaud CHRISTEL, Bearpaw93, Christopher Lee, Christos Goulas, Corey Dryja, Cristian Toma, Daniele Malinconi, Darren Furniss, David Pesce, Doug Palmer, Erich Jermann, Espen Fjellvær Olsen, Evan, flobler, Grigori Palamartšuk, Hector Gonzalez, Jason Marcus, Jimmy Lee, Joan Torner Corrons, Joel Weinberg, Jonathan Ryer, Josh Carter, Joshua Jones, Jotham B, JTa, Kevin Smith, mark leino, Matthew Humphrey, Miguel Castillo, Mike Phelps, Nathan Trop, Orlando E Moran, Patch Best, Peter Boardman, Pierre Allegraud, QcRetro, ra100, RC-CnC, Richard Bateman, Riot, Ryan Lobbins, SamE0717, Schwiizer, Scott Rini, sleene, Stanislav Kljuhhin, Stephan Kohls, Steven Clark, Steven Daglish, Ted Rathkopf, Tomáš Vydra, Total Dramatist, Tree of Broken Hearts, Tyler Townes
Thank you to all that have send me a tip on Thingiverse and PayPal.
Thank you to everybody from Facebook group and The 602 Wasteland community.
Thank you for having purchased a kit from an official distributor.
Thank you to all official distributors for taking care of the kits and customers.
Thank you Jason from LDO Motors for the quality manufacturing and relationship.
Thank you Openbuilds for your hardware, community and state of mind.
Thank you for making the community alibe with all your comments, issues, pull requests, optional parts, make, pictures, etc.
Thank you to David Ogles, Flobler, Jason from LDO Motors, Matthew Humphrey, Nathan Denkin, Orlando from All3DMakers, Sleene, Termlimit, Vertigo295 for helping me developing the Bear project.
Here are a list of sources I used to build this project :
Huge thanks to these projects, without them this project can not exist!