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Bear Extruder and X axis 0.6.0-alpha MK2.5 MK3

by pekcitron Nov 19, 2018
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The belt was really, really difficult to fit in the slot...

It’s possible to upgrade MMU2S with this ? Should be the IR sensor compatible with it ?

Changing my comment as I realized after posting that it states right in the thing details that you have to use everything a a whole due to the belts/motor/pulleys being higher than the standard.

I did want to know where people were sourcing the 3mm x15 mm pin? I'm tempted to just take a Stainless steel M3x16 machine screw and cutting the head off to bring it down to length but if there's a better option I'd like to know

Yes you are right for the compatibility. In case of, I have attached two pictures that explain why The Bear X axis is NOT compatible with stock Prusa extruder.

Some of our official distributors are selling the dowel pin. Otherwise you can cut an M3x40 screw to keep the smooth part of it.

Would this be suitable for the MK2.5S? I upgraded from MK2S and wish I hadn't, although I do like MK3 firmware.

Check the new version for MK2.5S: https://www.thingiverse.com/thing:3716110

Bear Extruder 0.7.0-beta MK2.5S MK3S

Hello, I need help, I get a selftest x axis length error, after installing the Bear X axis on my stock MK3. I am also using

Both x endstops looks good for me, no zip ties blocking.

But I encountered a strange oddity when I was changing the x axis:
I had to pull back the smooth rods. Fully pushed in, the distance was ~1cm too short to fit on the z axis lead screws. Is this normal on the stock MK3 or has this something to do with the Z mounts from jltx?

Prusa MK3 fixed Z mounts
by jltx

Make sure the Y tensioner idler is not out of the X end, it should be flushed or inside but not out. Check the image attached.

do you have any plans to make a cable chain option for the x axis? I know some people like them but there are probably an equal number of people that are against cable chains. I like them because it makes it look more professional and more industrial. If you look at any commercial or industrial piece of equipment they almost always use cable chains to protect the wiring.

The problem of cable chain is that it can drag the extruder and create lots of various type of problem. I don't think it is a good idea to use cable chain on a Prusa X axis type.

Is this compatible with the mk3s extruder?

I just finished installing the Bear X-axis, and the thingiverse.com/thing: 3535905 (x-carriage for the Prusa R4 extruder), and the Prusa extruder for the MK3S upgrade (called version R4).

Just follow the Prusa MK3S upgrade manual for the installation.

I have been using it for about 80 hours and it works excellently together.

if you use the bear x-axis, which I recommend, you need the special x-carriage listed above to make it work.

You can print the work in progress, it's available here https://github.com/gregsaun/bear_extruder_and_x_axis/tree/dev, but keep in mind that the final design may change.

No. The developer is working on it. Delivery date unknown.

Attention! the extruder is incompatible with MK2.5s sensor IR.

Bear Extruder 0.7.0-beta MK2.5S MK3S
Comments deleted.

A small nit: On the part x_end_idler.stl (and maybe some others), you have the hex nut capture hole aligned so that the point of the nut is up. It's better to align the nuts so the flats are up. Your way, there's a 60 deg overhang to print which can lead to a poor surface. The other way, with the flat on top, the overhang on the sides of the hole is only 30 deg, with a short bridge across the top, which should print more reliably.

Also, you say that the stock MK3S extruder won't work with these new ends. Why is that?

I tested both orientation and to me the best is to have the 60deg overhang.

Because it dies not support the new filament sensor. Check the new version here: https://www.thingiverse.com/thing:3716110

Bear Extruder 0.7.0-beta MK2.5S MK3S

Bonjour, avons nous besoin de ça:
https://s.click.aliexpress.com/e/cmK4HuWM ?

  • Posted with 3D Geeks Thingiverse Browser App

Bonjour, j'aimerais fabriquer cet extrudeur mais c'est en "work in progress", donc est-ce qu'ils sont bons ?
Et où est la pièce "PC4-M10" de la photo ? Je suis allé sur Github, et la seul pièce nommé PC4-M10 n'est pas compatible avec le lien thingiverse.. Sur la photo il y a deux vis, et sur Github il y a une vis.

EDIT: J'ai eu la réponse à toutes mes questions :-D

Désolé je ne suis pas très rapide sur thingiverse. Je suis bien plus réactif sur le Facebook group ( https://www.facebook.com/groups/prusabearupgrade ) ou le Discord "The 602 Wasteland" ( https://discordapp.com/invite/hYUjSnW ) ou encore sur mon compte twitter @gregoiresaunier .

This X Ends doesn't work with the MK3S Stock Extruder?

Nope, I am working on a MK3S version of this extruder ;-)

I am currently printing your "work in progress" files for the MK3S extruder and the X-Ends.
My MK3S has huge problems with Inconsisten Extrusion.
I hope the Bear Extruder improves it a bit.

Is it possible to install this extruder with BLTouch sensor?

yes I have a remix available for BLTouch https://www.thingiverse.com/thing:3251530

Bear Extruder BLTouch Mount

Thanks Vertigo. Do you plan a version with BMG extruder?

I do not at this time. The official BMG extruder is optimized for SLS printing.

I mean to install Boundtech BMG extruder and BLTouch sensor in the same Prusa Bear X carriage

Comments deleted.

I would like a version that includes the new 3:1 BondTech and MK3S enhancements!

I am currently working on MK3S version, you can download "work in progress" files here : https://github.com/gregsaun/bear_extruder_and_x_axis/tree/dev

Geared extruder will come later ;-)

Comments deleted.

Is there an MK3S version of the bear extruder?

I am currently working on MK3S version, you can download "work in progress" files here : https://github.com/gregsaun/bear_extruder_and_x_axis/tree/dev

Thanks for all your work

Is x carriage the same one used to mount the bondtech? I have an mk3 and saw the mount on githup and it looked exactly the same. I am making sure before I print it.

You have to use this one here: https://www.thingiverse.com/thing:3477926 :-)

Bear X Carriage for Bondtech Prusa Upgrade Extruder

so how does the z endstop work? i have a fine adjustment endstop that mount to the x motor on my printer that wouldnt work with this motor mount so idk how i could get something similar to work

it is made like original Prusa printers, you have to hit the Z mounts on top. You can maybe see this better in my guide here:

First, I want to thank you for your work.
I want to print new x-ends for my mk2.5 full bear. Can I use this x-end with the mk2.5 x-carriage and bondtech extruder?

Bear X Carriage for Bondtech Prusa Upgrade Extruder

Hello, I want to update my Anet A8 and I have seen this magnificent project. Would it be possible to use these pieces for that purpose? Or are they incompatible with my model?

Thank you

I have no idea honestly, I never used an Anet 8. Best for you is to open my Fusion 360 source file and do some measurements inside.

Any plans to make this compatible to new MK3S extruder? Have the problem that I've printed already the x-ends (because I realy want the adjustment für the x-belt) and now with the MK3S upgrade I need a x-carriage to fit with the upgraded stock MK3S extruder. Since it should be easier to maintain and have a new sensor-mechanik, the bear-extruder itself is no more an option for me :-(

For the little analysis I could do, the Bear extruder only needs to add the filament sensor, all the rest is already implemented or better. I have to study the separation of the top (where the motor is attached), I dropped that idea in the past because it will add errors in alignment of the motor. So I will first try to add the sensor in the single body as it is today.

My MK3S upgrade arrived today. What do you think, could it be days, or more like weeks/month until you can design an update of the bear extruder? I don't want to push this, take your time. I only ask to know, if I meanwhile print the original MK3S extruder since i have to disassemble thex-axis anyways to maintain parts anyways.

I looked into your very well engineered source file and it looks realy good. I think I wait for an update for the new filament sensor for the bear extruder :-)
Thank you for your hard work!

Finally printed the extruder. Amazing work! I found the tolerances a bit tight, specifically the gear area; however, i used an exact-o knife and carved it out a bit and it works great!

Maybe you did over extrude a bit. I now have a guide to explain how to setup good extruder multiplier:

Salut et bravo pour le travail. Je m'apprête à monter cette amelioration sur ma MK3 avec l'extruder Bondtech reçu récemment. Une petite question cependant: je vois deux vis M3x10 sur le shema de montage qui vont au niveau des smooth rod X à droite. Quelle est l'utilité de ces 2 vis exactement ? sont elles à mettre avant ou après l'insertion des smooth rod ?

Hello, j'ai tout juste terminé un guide qui explique comment utiliser ajuster ces vis :

Super ! Merci. J'ai réussi à trouver une page en cache finalement qui m'a éclairé sur le sujet ( https://webcache.googleusercontent.com/search?q=cache:yrBPClm35aUJ:https://fr.ifixit.com/Tutoriel/Bear%2BExtruder%2BAnd%2BX%2BAxis/113062+&cd=4&hl=fr&ct=clnk&gl=fr&client=safari ).

En tout cas, testé avec Bondtech upgrade + moteur LDO 0.9 : tout est parfait :). Bravo encore pour le travail et le partage.

Looks like the extruder needs the stock fan duct (HOT!2) and does not work with Prusa R3?

So i need to use the HOT!2 or robrps or RH-dreambox designs, right?

thx for the great extruder and bear upgrade!

Compatible with Prusa R3 or R1. I recommend the 90° one because the 45° is killing the bearings and makes to much stress on the fan cables.

I recommend the robrps or rh-dreambox you can find in this issue on my GitHub : https://github.com/gregsaun/bear_extruder_and_x_axis/issues/20

Will this upgrade work in a stock prusa I3 MK2s? or first i should upgrade to MK2.5????? Thank you very much.

It works on MK2s but you will lose around 5mm of the Y axis. Next version will include the MK2s without this issue.

I'm rebuilding my MK2 clone-ish and seems like this version motor end have extra about 4mm in the holes for X rods... Drill fixed it :D

Hello, any progress for the MK2s mod? Thanks.

Hi friend, thanks for all your hard work. The contributions you have made to this community are exemplary.

I noticed some remixes of your X motor mount that add a support bearing for the motor's shaft. Do those solve an existing problem, or are they more for aesthetics?

Thank you for the king words :-)

Some are saying it solves bending of the motor shaft. However, the latest version 0.6.0 moves the pulley even closer to the motor so it should reduce that issue quite well now. I don't recommend this myself because you might introduce a bad torque to the motor if you are not very careful during the assembly.

Can I just use These x-ends with my stock x-carriage and r3 extruder?

No you can't, the belt path is different. 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.

I keep seeing this mentioned, but what is the difference in the belt path? Also, is the belt path the same from v0.6.0 to v0.7.0? Please forgive my ignorance.

i'm sure there is a reason but why did you keep the air vent grate on the extruder body part. i'm referring to the discharge of the hot end fan, does having them improve cooling? great job on this i'm printing it now

It is to make the body and blind mount stiff. It also avoid the pinda mount to melt with high temperature prints. Note that the printed grid is aligned with the heatsink fins to improve cooling.

Salut ! je viens d'imprimer les pièces et comment dire... les perçages n'ont pas le bon entraxe par rapport au vis trapézoidale que j'ai. Le diamètre du bronze non plus, j'ai un diamètre de 10mm alors que les pièces ont un diamètre de 13. J'ai donc créer une pièce qui adapte mes pièces au tiennes.

Je pense a terme modifier tes pièces pour éviter de les adapter avec des manchons ou autre.. Pourrais tu me fournir les fichier en .sldprt ? au pire des cas .stl

Merci ;) et super boulot ! j'adore le design

Hello, oui mes pièces sont basées sur les pièces de Prusa. Il y a les sources au format Fusion 360 dans les fichiers ici et sur mon Github.

merci je vais regardé !

Are the x-ends and x-carriage compatible with the newly released bondtech extruder for the mk3?

Not yet, I know that Prusa is working on a revised version so I will certainly base my design on it (if it is a good way to do it). However, the filament sensor pocket has been improved over the prusa extruder. I personally never have issue and I print a lot of black PETG. Do you currently have issue with it?

very nice improvement, could you please include https://www.thingiverse.com/thing:3307739 - Revised MK3 Extruder Indirect Filament Sensor - into the part. I would like all the improvements at once since it is so much work replacing the extruder assembly.

This 'Bear Project' is on the cutting edge of reliable improvement. Thanks!

Revised MK3 Extruder Indirect Filament Sensor
by abelsm2

Quick Question , where is the Festo Filament sensor cover , I see it in picture above , but don't see in Zip Files ?

I want to upgrade my clone mk2s. It's built mostly with original parts, except the Z axis, which is using chinese motors with screw rod and thus the trapezoidal nut is a little bit different size. Are you aware (or do you have, maybe) of the modified version of the X parts?
Here's modified version of the original x-ends

Prusa i3 MK2 Clone x-end-motor (brass nut, tom's end stop)

Unfortunately I don't have that and I have not seen remix going in that way. However, you can modify my project, I share my Fusion 360 source with this project ;-)

Hi :D i have print all it , and it very cool . but i miss 1 thing , that is the Hot!2 . I could not find it . So could you please help me where can i find it . Many thanks again .

you can reuse the stock one or check the one in this discussion:

Is it possible to use 16t Gt2 idler ? or shall i better buy a 20t ? could you also please mention the size of the 20T you are using ?

you can reuse the stock one ;-)

What kind of lead screw nut you are using?

This is the POM nut that comes with original Prusa printers.
I have attached Fusion 360 files if you want to modify it.

Hi there, can You make parts to fit Igus RJUM-08 bearings? They are 1mm wider and 1mm longer, I was trying to change it in Your fusion design, but besides updating the dimension of bearings the cuts for them remains the same.

Sorry I don't recommend Igus so I will prefer to avoid doing this. The way I am building this part is a bit tricky because I have parent and children. Do it like this:

  1. Edit the x_carriage part
  2. Open the x_carriage_mkx
  3. Rollback the timeline to combine feature
  4. Get latest release
  5. Put timeline back to the end

In the bom is written "Bondtech gears 1.75mm/5.0mm with its 20mm shaft".
can I also reuse the Bondtech gears from Prusa Mk3 ?

I would love to see one of these prusa extruders that uses the new threaded heatsink. Being able to remove the heatsink and change the PTFE without having to remove the cover would save tons of time.

The objective of this extruder is to offer an improved solution that reuse most of the stock hardware. A more advanced one without all the prusa's constraints will be done later (will be on a different X and Z axis as well).

I am not sure to see which heatsink are you using, do you have a link to share?

I’m not using it yet, but I’d eventually like to move to this:

Same basic dimensions of the original heat sink, but with threaded mount instead of the groove mount. The groove mount is terrible! So hard to insert and remove the heat sink in the current mk3 designs.

ah I see, yes this is interesting, nothing planed for this at the moment but do not hesitate to remix my parts (Fusion 360 project is available in the file list).

I made it a bit better than MK3 on mine but would be better with thread for sure.

Can you share extruder body and extruder cover STEP files please?

I will generate all of them once I have a bit of time, in the mean time could you use the Fusion 360 source file and generate them by yourself?

thanks a lot!

Sorry it takes a lot of time to export STEP files during dev so I will do it later when dev will be mostly done

What infill would you recommend for the parts

Thank you for that. Would this extruder design improve my prints compared to the r3 design

Definitely, it almost totally solve the inconsistent extrusion issue ;-) . Bridging should be improve a bit too.

If you want to improve print quality a bit more check those two optional parts :
Replace the Bondtech idler gear with a bearing: https://github.com/gregsaun/bear_extruder_and_x_axis/tree/master/optional_parts/extruder_idler_bearing
Improve hotend cooling: https://github.com/gregsaun/bear_extruder_and_x_axis/tree/master/optional_parts/hotend_fan

You can also go reverse bowden to smooth the filament movement :

All this will be published on thingiverse soon as well

Fantastic work! Someone has been very busy. 8-)

Someone else has also been busy: https://www.thingiverse.com/thing:3223513

Prusa Mk3 indirect filament sensor for all filaments (transparent, black, shiny, whatever).

Thank you, yes busy since months with this one :-D . Lots of users from bear FB group and Discord "The 602 Wasteland" server are already using it.

I have seen this filament sensor but I also know that Prusa is testing several improvements to fix this issue. So I will wait to see what they are going to propose. In the mean time, I have tested 50 insertions of a clear nylon filament and 49 have been detected successfully! I tried different speed to ensure it represents the reality. I personally never have issue with my filament sensor and I print lots of shiny black PETG.

Can't wait to print this. Had my Full Bear kit ordered for XMAS, so I'm getting a jump on all the parts. This was wonderfully timed.

I hope you will like it :-)

Get a good square for the Bear frame build. I recommend a 200mm long machinist precision square with standard DIN 875. In case you do not want to buy a new square, checkout this video : https://youtube.com/watch?v=FNpAQHrNpNU

Are the POM nuts the same size as all of the brass TR8 nuts?I can't find any documentation on the dimensions for the POM nuts anywhere.