Bondtech Extruder for Prusa MINI  

RE: Bondtech Extruder for Prusa MINI

i have most of the mentioned problems and observations with my prusa-mini , too.

very interested in a solid solution to get hassle-free printing with correct temperatures and good output.

i updated to 4.3beta firmware with same behaviour, still have to use too high temperatures and get inconsistent first-layer.

also hat the same observations mentioned before with the super-pinda update.

i liked to have all that time not spend on fidlling with a "prusa", but must still follow this (and some other) treads to see if anybody finds a final solution to all this fiddling with hotend/extruder problems.. hope to see such a posting you here

RE: Bondtech Extruder for Prusa MINI

Has anyone actually done before/after prints of the Bondtech Extruder upgrade?  I'm having a lot of issues with uneven extrusion, layer lines, and bubbling on retraction, but I'm not having problems with hotend clogs or the stock extruder slipping or grinding filament.  So I'm not sure if the Bondtech will actually make a difference for me.

Has anyone actually gotten print quality improvements from the Bondtech?

RE: Bondtech Extruder for Prusa MINI

@tex

I've been having a lot of issues with layer lines, or rather z-artifacts, the line seems to appear for one single extrusion but not an entire layer. I've been trying a multitude of things to try resolve the issues I'm having with my printer, see here

I just noticed mention on the earlier pages in this thread about changing the retraction settings. I recently tried changing the Retraction "Length" to 2mm and adding "Retract on layer change" and this has made a huge difference which I wasn't expecting to be honest.

I've been repeatedly printing this 20x20x20 cube as a test print, and finally all of the z-artifacts I was getting are gone. I then tried to reprint a board game insert component i've been trying to print and it was not perfect but was miles better. Wondering if I should continue to tweak the retraction settings further, as it does seem to have helped. Suggest trying to make those changes in Prusa slicer and see if it helps you.

RE: Bondtech Extruder for Prusa MINI

@nizmox

Thanks, I will give that a try.  I have to lower my retraction way down to around 1mm to get rid of massive holes on unretractions, and I still have z-banding.  But I haven't tried adding retract on layer change, perhaps that will help.

After talking to Prusa support a handful of times, they finally decided to send a replacement hotend.  My extruder literally clicks and is full of gear dust (not filament dust - actual gear grinding), but they seem to think my problems are hotend related and not extruder related.  We'll see if it helps.

RE: Bondtech Extruder for Prusa MINI

Posted by: @tex

Has anyone actually done before/after prints of the Bondtech Extruder upgrade?  I'm having a lot of issues with uneven extrusion, layer lines, and bubbling on retraction, but I'm not having problems with hotend clogs or the stock extruder slipping or grinding filament.  So I'm not sure if the Bondtech will actually make a difference for me.

 

Has anyone actually gotten print quality improvements from the Bondtech?

For me I think it made a difference for some filaments (glow in the dark, ivory white) which seemed to be very unreliable before. I think it grips better and less likely to slip.

I tweeted a before and after pair of benchys and I could only tell two differences.

It is definitely a lot better at gripping the filament which I imagine improves retractions and consistency on extrusion. But then also, it's scarily good at gripping the filament, so much that (see this other tweet, also sorry I am too lazy to save and upload the images here) if your hotend is clogged it will probably break one of the olives on your boden tube.

RE: Bondtech Extruder for Prusa MINI

Would anyone know what would cause the Bondtech extruder to chew up filament, no matter what filament brand or type.. I use, after about 2 hours into a print I hear clicking then I notice that the filament isnt extruding.. after stopping the print the gears have chewed through the filament causing the issue.

I have the tension screw backed of 2-3 turns from fully tight.. and it will print ok for a while, but a print longer than a couple of hours it starts clicking..

RE: Bondtech Extruder for Prusa MINI

You need much less tension. As with a bowden system retraction is much more as on direct drives. So if you get to a position in your object with only smal segments to be printed, followed by retraction it can happen the same segment of filament passing through the gears multiple times, flattening the filament. The cross section of the filament becomes oval instead of round. It does not fit through the bowden couplers anymore, so filament is blocked. Than the grinding starts...

I had extreme problems with this. Solution was to tighten the feeder to the minimum preassure needed for reliable transport and replace the ideotic 3-part bowden by one piece with push trough couplers (used adapters for m6 push throgh). You have to adjust very carefully the tension, esp. than changing from PET-G (weak, lower tension) to PLA CF (hard, a bit more tension) and vice versa.

RE: Bondtech Extruder for Prusa MINI

Posted by: @oliver-andre

You need much less tension. As with a bowden system retraction is much more as on direct drives. So if you get to a position in your object with only smal segments to be printed, followed by retraction it can happen the same segment of filament passing through the gears multiple times, flattening the filament. The cross section of the filament becomes oval instead of round. It does not fit through the bowden couplers anymore, so filament is blocked. Than the grinding starts...

I had extreme problems with this. Solution was to tighten the feeder to the minimum preassure needed for reliable transport and replace the ideotic 3-part bowden by one piece with push trough couplers (used adapters for m6 push throgh). You have to adjust very carefully the tension, esp. than changing from PET-G (weak, lower tension) to PLA CF (hard, a bit more tension) and vice versa.

This makes a lot of sense, as the issue is worse the higher up the Benchy goes, and is worst when it is doing a lot of retractions. 🤔

RE: Bondtech Extruder for Prusa MINI

Is there anything special we need to do with the new 4.3 firmware if we have the Bondtech Extruder beyond just set the esteps in the starting gcode in PrusaSlicer?  Will self test, leveling, etc still work ok without anything special?

RE: Bondtech Extruder for Prusa MINI

Posted by: @jeremy-12

Is there anything special we need to do with the new 4.3 firmware if we have the Bondtech Extruder beyond just set the esteps in the starting gcode in PrusaSlicer?  Will self test, leveling, etc still work ok without anything special?

In my experience 4.3 works as well or as badly as before, it's the same. Other filament is great, Prusament is not. 😢

I have tried retraction settings of 2mm, retract on layer change, having the extruder tension knob as loose as possible before it clicks, the only thing I find that helps reliably is a temperature of 240, and even that isn't always perfect.

RE: Bondtech Extruder for Prusa MINI

@jeremy-12

If you add the gcodes to Prusaslicer, any model you slice through Prusaslicer will work just fine.

With regards to bed leveling, if you use the stand Prusa Mini bed level option, this is not using a sliced model so you are going to need to run those two gcodes bondtech provides before you do this, otherwise the gearing on the extruder will be incorrect. At least that is my understanding.

RE: Bondtech Extruder for Prusa MINI

Actually sorry I meant to say first layer calibration, not bed leveling. Apologies.

Bed leveling and selftest will not be impacted as they do not extrude any filament.

RE: Bondtech Extruder for Prusa MINI

Actually I much prefer to compile the firmware myself, editing eSteps (and PID) directly in source code. It is not only first layer calibration you need to correct eSteps, but also load/unload filament you should have correct eSteps for (unless you want to manually select "purge more"). So print the bondtech gcode after every restart is not very comfortable. Anyway, with 5 Prusa mini (one original, 4 clones) not having all the same feeder (so different eSteps...) I do not want multiple profiles with different start-gcode. So much more comfortable to have the eStep for each printer stored in it´s firmware, so same profile/start-gcode for all minis.

RE: Bondtech Extruder for Prusa MINI

In a matter of days I will be receiving my Prusa mini+ kit version, and already have on hand Bondtech extruder and heartbreak as I'm interested in printing flexible as well. Have bought the upgrades based on several videos and review online that suggested the upgrade overall for better performances. Having read the entire thread I am now really doubtful about both standard extruder and heatbreak as well as the Bondtech combo, which one should I mount?

RE: Bondtech Extruder for Prusa MINI

@n1ckfra

You dont need the Bontech parts for flexibles. In fact, given the experiences I've encountered, the Bondtech may have had a role early on, but at this point it only serves to foul the MINI. I'll post some of my recent flex prints when I get home. I have unused Bontech extruder and heartbreak sitting in my desk too. No plans whatsoever to install at this point. My MINI prints beautifully.

RE: Bondtech Extruder for Prusa MINI

@24kjames

Thanks! Looking forward to see your prints! 

RE: Bondtech Extruder for Prusa MINI

As a general principle, I would always try the stock hardware first before making "improvements". Remember that forums like this have a natural selection profile for folks with problems. I suspect (with zero data) that the majority of Mini owners has no issues. You can always replace parts later in case you run into issues.

In full disclosure I do have the Bondtech extruder installed, or rather the Trianglelab clone. I'd be hard-pressed to claim I can see any improvements. I did have one case of grinding filament before I installed the Bondtech but that may well have been a case of the screw tightened too much.

I also have the upgraded heatbreak but it's sitting in the drawer as I never had any hotend issues. Maybe I got lucky but in my hands this has turned out to be an amazing little machine right out of the box, which is a pleasure to run. The only mods I made that seem to have a visible impact on performance or rather ease of operations are replacements of the brass couplers with standard PC4 fittings, which makes it a lot easier to remove the bowden tube if needed, including replacing the housing for the filament sensor with one that has a PC4 adapter; plus I'm using nickel-coated copper nozzles on all my printers. And I'm using the BCZAMD gold-plated steel sheet for all materials.

RE: Bondtech Extruder for Prusa MINI

@n1ckfra

Here you go.

And this gif is supposed to be animated, but maybe the forum doesn't currently support .gifs. idk.. It would be nice if it did.

RE: Bondtech Extruder for Prusa MINI

@24kjames

Thanks for the effort of putting your results over here! Will definitely consider stock version at first, do proper testing of it and then decide. Already have some flexible on hand, can't wait to test it.

RE: Bondtech Extruder for Prusa MINI

@24kjames

clicking on the gif enabled the animation