Bear extruder and X axis (BearExxa) 1.0.0

Changes

Bear Extruder and X carriage

• Tighter PINDA mount
• Reinforce square nut pockets and hex pocket of x_carriage
• Add compatibility to 2.85mm 3D print filament for cable_guide_back
• Reduce tolerances around v6 heatsink
• Small improvements and bugs fixes

BearMera (E3D Hemera)

• Introduce compatible mount for E3D Hemera called BearMera
• Add an optional part to support Volcano (designed by Florian Daeubler)

Note: Prusa's filament sensor and BLTouch supports are planned for the next release.

Bear X Axis

• Re-orientate clamps to offer more room for E3D Hemera
• Self centering of X stepper
• Reduce hex pocket size of x_end_idler_tensioner
• Reduce chances of warping of the x_end_motor arm
• Clean up Fusion 360 sketches and features

Bondtech X Carriage

• The Bondtech X carriage received the same reinforcements as the Bear extruder X carriage.

Other

• BearExxa is the new short name for "Bear extruder and X axis"
• Make easier to navigate into github and download files
• Improve documentation for alternative extruders
• Optional parts from community now listed on guides.bear-lab.com

Compatibility

Please check compatibility section of the main repository page.

Parts that needs to be replaced since release 0.7.0-beta

Here is a list of what you should replace or not from Bear extruder and X axis 0.7.0-beta

Motivation or problem	Parts to replace
Want to use the E3D Hemera extruder	all parts
Your PINDA mount is getting loose	extruder_body and extruder_cover
Your X carriage has some cracks around square nuts	x_carriage and x_carriage_back
You are using a 2.85mm filament to guide the extruder cables	cable_guide_back_a and cable_guide_back_b

Special thank you

• To E3D-Online for being very supportive and having sponsored the development with a free Hemera
• To Florian Daeubler for precious help on documentation, support as well as developing the E3D Volcano adapter for BearMera
• To My Patreons for being very supportive during the BearMera development
• To David Ogles for his excellent support to the FB community
• To "The 602 Wasteland" community for their support and help
• To Twitter 3D printing community for their encouragements
• To Bear upgrade FB community for their support and help
• To Tom Jackson for having tested the BearMera and shared a lot of impressive print
• To official distributors for their support and work
• To LDO Motors team and Jason Yiming Bao for their support and work

Bear extruder and X axis 0.7.0-beta

Changes

Extruder

• Supports the new IR filament sensor introduced with the Prusa MK2.5S/MK3S hardware.
• Added an official nozzle fan duct (shroud).
• Refined heatsink space for smoother airflow.
• Insertion and removal of E3D V6 made easier.
• Improved heat resistance of the PINDA mount.
• Stronger holes for hotend fan screws.
• Improved heat resistance and airflow the lower portion of the extruder.
• Full length of X axis use for MK2.5S (it has been reduced on original MK2.5S extruder)
• Printing filament path made easier and cleaner.
• Small improvements and bugs fixes

X Axis

• Refined X and Z bearing pockets diameter to avoid over-tightening the bearings.
• Refined X carriage thickness to better match slicing values.
• Increased X carriage and cable guide back stiffness.
• Made cable guide easier and cleaner to print.
• Fixed issue with selective infill on X carriage back.
• Lowered tolerances of the lead screw nut holes.

Optional parts

• Official support of E3D Gates idlers.
• Applied refinements from Bear X carriage to Bondtech Bear X carriage.
• Created X carriage back to accommodate larger filament sensor cables.
• Updated reverse Bowden cover to accommodate the IR filament sensor.

Other

• Created a custom tool and guide for cutting perfect PTFE tubes.
• Improved BOM, description, images and download links.
• Added more documentation to https://guides.bear-lab.com.

Compatibility

This extruder and X axis are matched to each other and '''cannot be used separately'''. As a unit, they are compatible with both Original Prusa and Bear Upgrade frames.

MK2.5(S) and MK3(S) compatiblity

• This Bear extruder version supports the new IR filament sensor introduced with latest Original Prusa MK2.5S/MK3S extruder.
• This Bear extruder version is compatible with original Prusa firmware for daily use. However, (XY)Z calibration and selftest require a dedicated firmware for these steps only.
• The older filament sensor used in MK2.5 (non-S) and MK3 (non-S) is not compatible with this Bear extruder version. However, with the exception of the filament sensor, this extruder is fully compatible with MK2.5 and MK3 firmware.

Why the Bear extruder isn't totally compatible with MK2.5S/MK3S firmware?

The original Prusa MK2.5S/MK3S hotend was raised by about 7 mm. This placement increases the ambient temperature around heatbreak and heatblock which could leads to clogging, heatcreep, inconsistent layers, extruder body melting, reducing part cooling efficiency, longer retractions, more fragile X carriage, etc.

We then have decided to keep the same hotend position as our previous Bear extruder to provide best printing experience and reliability. Because of the difference with original Prusa extruder, we provide a customized firmware to pass Selftest and (XY)Z Calibration. At the exception of these steps, the original Prusa firmware is completely compatible with our extruder.

The firmware is available here: https://github.com/bear-lab-3d/Prusa-Firmware/releases/

How the Bear calibration firmware is made?

• The Bear calibration firmware has very minimal modification from the original Prusa firmware. Those changes are described in the release: https://github.com/bear-lab-3d/Prusa-Firmware/releases .
• Those modifications have been tested and some bugs have been reported to the community firmware.
• The modifications are reviewed and code quality is taken with care.
• We automated the build to avoid human errors.

Parts that needs to be replaced since release 0.6.0-alpha

Unfortunately, all parts have been improved and we recommend to re-printed them all. However, changes on X ends are intended to improve assembly and you don't need to update them unless you have problems with the Z axis.

Special thank you

• To Florian Daeubler for testing hotend cooling.
• To David Ogles and Nathan Denkin for the precious review of the assembly guide.
• To Josh Jones for the work on the Bear calibration firmware.
• To Vecko Kojchevski for help and inspiration on PTFE tube cutter and X carriage.
• To David Pesce, RH_Dreambox, Robrps, Stahlfabrik and anyone from the issue #20 for design and research of the nozzle fan duct.
• To Matthew Humphrey for its optional E3D idler design.
• To Bear upgrade FB community for their support and help.
• To "The 602 Wasteland" community for their support and help.
• My Patreons for their help, support and testing.
• To official distributors for their support and work.
• LDO Motors and Jason Yiming Bao for their support and work

0.6.0-alpha

Improvements

X Ends

• Moved the X pulley closer to the X motor to prevent the motor shaft from being bent.
• Improved the X end idler mount to accommodate a misaligned belt and larger idler pulley.
• Increased the stiffness of X end idler mount, however it now requires a 15mm to 15.8mm long dowel pin replacing 14mm pins.
• Improved nut pocket holes.
• Improved selective infill on both X ends.
• Improved fitting of idler mount in the X end idler to ensure best possible alignment.
• This new version is compatible with the previous one (0.50-alpha).

Extruder

• Greatly improved hotend cooling. The cooling fan has been moved and exhaust has been opened.
• Reworked the filament sensor pocket and cover:
  • Improved filament path to ease insertion.
  • Improved protection of the laser sensor.
  • Moved the cover screws to allow a more compact reverse bowden setup.
  • Added light leak protection.
  • Adjusted clearances.
• Reworked the belt clamps on X carriage to eliminate belt slipping.
• Simplified removal of the X carriage back bottom.
• Improved screw holes on the X carriage back.
• Improved spring tension of the extruder idler

Optional parts

• Reduced the size of filament sensor cover for reverse bowden setup.
• Allow the use of drop-in tee-nuts with the reverse bowden v-slot mounts.
• Updated the BOM for the extruder idler with bearing to use a dowel pin instead of Bondtech shaft.

Other

• Improved BOM, description and images.
• Now on Thingiverse!
• Switch to semantic versioning: semver.org.

Bug fixes

• #17 Centered mounting hole to hold X carriage and exturder body is off by 0.2mm bug.
• #18 Hex nut pocket for POM nut is not tight enough.
• #19 Try to find a way to not have the shroud's hex nut falling down.
• #21 Unable to remove filament from bowden cover when filament sensor kick it because it is the end of the filament.
• #22 Quick assembly image is showing GT2 instead of 2GT.

Compatibility

This extruder and x-ends are matched to each other and cannot be used separately. As a unit, they are completely compatible with stock Prusa MK2.5, MK3, Bear Upgraded MK2.5, and Bear Upgraded MK3.

Parts that needs to be replaced since release 0.50-alpha

Unfortunately, all parts have changed and need to be re-printed.

Special thank you

• To Matthew Humphrey for helping me to improve hotend cooling
• To Nathan, he is preparing an awesome assembly guide!
• To Bear upgrade FB community for your support and help!
• To "The 602 Wasteland" community for your support and help!

0.50-alpha

Improvements

• Added MK3 compatible X-carriage and X-axis motor mount (in addition to MK2.5)
• Reduced X axis idler failure rate by using 20T idler (previously 16T idler)
• Added clamps for Z-axis bearings to provide better fit with easier installation, increased stiffness, and easier bearing replacement
• Added zip ties for PINDA and nozzle fan cables to be able to replace them without disassembling the extruder body
• Optional: reverse bowden to improve smooth movement of filament before entering the extruder. If you are using MMU2, you can get the filament sensor cover from the reverse bowden system
• Improved tension of X-axis smooth rods
• Smoother cable guides and reduced possibility of pinching cables during assembly
• Improved fitting of extruder cover and body in the bottom
• Improved vertical holes print quality and precision
• Filament sensor cover gets a nicer shape

Bug fixes

• #12 extruder_body needs a 4mm brim
• Fix issue where opening the project on F360 might result in a crash

Compatibility

This extruder and x-ends are matched to each other and cannot be used separately. As a unit, they are completely compatible with stock Prusa MK2.5, MK3, Bear Upgraded MK2.5, and Bear Upgraded MK3.

Parts that needs to be replaced since release 0.40-alpha

• extruder_body.stl
• extruder_cover.stl
• filament_sensor_cover.stl (only aesthetic)
• x_carriage.stl
• x_carriage_back.stl
• x_end_idler.stl
• x_end_idler_idler_mount.stl
• x_end_motor.stl
• You will need a 20T idler, 6 extra M3x10 screws and 4 extra M3 hex nuts

Special thank you

• To Nathan, he is preparing an awesome assembly guide!
• To Bear upgrade FB community for your support and help!
• To "The 602 Wasteland" community for your support and help!