tetra3dprint / HemeraOdyssey

HemeraOdyssey BETA (v1.0)

Universal E3D Hemera mod for the Prusa i3 MK2 MK2.5 MK2.5S MK3 MK3S + Other variants
This is for advanced users so please fully read this README.md to avoid disappointment, frustration and missguided expectations!
I make no claims about this mod, it simply satisfies the requirement of enabling the Hemera to be used on stock firmware, pass self test and XYZ calibration.

HemeraOdyssey Facebook group

Find me on twitter @ tetra3dprint

What is this mod

This is a universal one fits all mod that enabled the use of the E3D Hemera extruder on a Prusa i3 MK2/S MK2.5/S MK3/S without needing custom firmware (sort of).
It will pass the self-test and XYZ calibration thanks to the geometry matching the stock setup but needs a minimum change to the e-steps that can be done via gcode.
There is no loss in build volume.
It supports both Laser and IR filament sensors.
This is a very maintainable and moddable mod. I encourage and look forward to seeing mods and remixes, remeber to use the tag #hemeraodyssey

This is a BETA mod!

I have to stress this is a beta mod with beta documentation.
Parts might change over the next few weeks, please check everything and don't assume.
I will make a note of changes in the assembly guide where relevant.
You can also check for listed changes here

Documentation is not complete and will be updated daily until this message is gone.
There are probably spelling and grammar mistakes and possibly incorrect links and numbers.
Field testing of parts and printing parts is limited. Some parts might cause problems when printing especially with materials I haven't tested. I will attempt to deal with any highlighted issue in a timely fasion, that said, changes will be kept to a minimum if possible.

Please respect the LICENSE this mod is released under

Please respect the GNU General Public License v3.0 that this mod is released under. This is the same license that Prusa use.

MMU2 Support?

Not yet supported, however it is intended, but will require custom modified firmware which will come at a later date.

No custom firmware (sort of)???!!!

Aside from needing to change the e-steps, this will work with stock firmware but it's not ideal. The menu unload can cause a blob of filament to be pinched off below the hobbed gears. This in turn causes a filament jam that would then need clearing by dismantling the extruder. On the MK3, the e-current will need to be increased slightly because the motor is 1.3A vs stock at 1.0A otherwise a moiré pattern is more visible than usual.

Caveats

I showed a preview of my mod and there was a voice of concern in regard to the center of mass moving forward on the X carriage.
This was mainly because the X motor is now positioned forward compared to stock.
The concern is that this now unfavorably loads the z axis bearing and in turn reduces the life of the bearings and smooth rods.
I have not been able to find data that supports or refutes this concern, however it does appear that the extra loading is within spec.
So what does this mean? It might, or might not reduce the life of your z axis bearings and smooth rods.

The x carriage is slightly heavier than stock so this could manifest as more ghosting from x movements. Print settings can be adjusted to counter this.
Here is a weight comparison of fully assembled variants of extruders: -

Lots of coffee and filament consumption

In making this mod I've used several rolls of filament and drank lots of Grumpy Mule coffee. If you like it and want to support me in some way (obviously no obligation) maybe consider buying me a coffee here :)

Huge thanks to

Vlastimil Hovan on twitter
Vlastimil has kindly beta tested my mod, printed several variations and tried them out on his machines. He has also has given invaluable suggestions and feedback that have made their way back into the design.
Not only that but he has created the first official mod (Z Tops) for my mod that enables the use on the MK3S variant, so huge respect and thanks to him.

Grégoire Saunier #BearUpgrade on twitter
Grégoire has not only been inspiration but has also been kind enough to offer some guidance here and there that kept me on the straight and narrow :) so huge respect and thanks to him.

Blender Source Files

I used Blender to create the files for this mod so only the blender file and STL files will are available.
The blender file is available at the root of this repo here HemeraOdysseyBlenderFile.zip

Sources

• Prusa: http://www.prusa3d.com
• E3D Hemera: https://e3d-online.com/
• Grégoire Saunier : https://github.com/gregsaun/
• Blender 3D: https://www.blender.org/