Bondtech (or similar) extruders



  • This has nothing to do with Duet but as there are so many informed users on these forums, I thought I'd ask here.

    I have a particular problem which is that I use a Diamond hot (that is a problem in itself but not the one I need an answer too ☺ ). When using a mixing hot end such as the Diamond, it is necessary to retract all filaments simultaneously. So when doing multi coloured parts one or more of the filaments may not move forward for a considerable time but still gets retracted and un-retracted many hundreds of times. What happens is that these (unused) filaments get ground away by the hobbed bolt. I've just lost another print, 14 hours in to a 25 hour print because one of the filaments got completely ground away and snapped off at the extruder. Obviously I've done all I can like slowing the print speed down, adjusting every variable known to mankind with regard to retraction, setting the spring tension as light as possible etc, etc.

    So I've finally come to the conclusion that I need to replace the extruders - these are E3D Titans by the way. Something like the Bondtech seems like a logical choice as it has two hobbed bolts so in theory, might need less tension. However, as it's a 5 colour hot end, I need 5 extruders. At 100 Euros or so a throw, I need to be pretty sure that any replacement will do the job - i.e. retract and unretract the filament many hundreds of times without grinding it completely away.

    Are there any users here with experience of the Bondtech (or any other extruder) who could advise?

    Thanks in advance.



  • @deckingman
    Bondtech BMG here operating as flying extruder in a delta printer. I had spring loaded and e3d Titans as well before. I would never go back again. My Bondtech BMG works flawlessly for some Kg of filament now and causes no problems at all retracting like crazy (fast and often). I can recommend the Bondtech system. It is worth every penny.



  • Have you looked replacing it with a Zesty Nimble? It might fit your needs. I have one and I like it a lot.


  • administrators

    Bondtech are here at 3D Meetup Sweden, so I'll ask them what they think. I'll also ask them to do a special price for you for 5.



  • @dc42 said in Bondtech (or similar) extruders:

    Bondtech are here at 3D Meetup Sweden, so I'll ask them what they think. I'll also ask them to do a special price for you for 5.

    David, that would be brilliant! I did actually try their contact form and explained a bit about my printer and the issues but didn't hear anything back from them.



  • David,

    If it helps, you could mention that I'd be quite prepared to test and evaluate and publish the results on my blog and YouTube channel.



  • @shadowx said in Bondtech (or similar) extruders:

    Have you looked replacing it with a Zesty Nimble? It might fit your needs. I have one and I like it a lot.

    Thanks for the suggestion. Yes I did look at them and had a few discussions with Lykle some time back. The issue I have is that the 5 heat sinks on the Diamond stick out at angle of about 20 degrees to the vertical. Adding Nimbles to the top of those heat sinks makes what is already a very wide hot end, extremely wide. As things stand, I loose about 200mm in X so to get 360mm of movement, the printer is 600mm wide (outside dimension). I think when I last looked at the Nimbles I'd lose another 40mm a side so 80mm travel in total. I need that 360mm (could do with a bit more) so realistically, I'd need to make the frame wider which is major hassle and cost.



  • @heapstar said in Bondtech (or similar) extruders:

    @deckingman
    Bondtech BMG here operating as flying extruder in a delta printer. I had spring loaded and e3d Titans as well before. I would never go back again. My Bondtech BMG works flawlessly for some Kg of filament now and causes no problems at all retracting like crazy (fast and often). I can recommend the Bondtech system. It is worth every penny.

    Well thanks, that's good to know. Is my assumption that you need less tension on the filament compare to an E3D Titan correct?



  • @deckingman
    That is correct. Also the filament comes more straight out of the BMG. You will experience this this especially with sensitive and very flexible filaments.



  • I've tried the standard MK8, a B2D style dual drive, a titan, and the BMG. BMG wins hands-down. It doesn't flatten the filament at high tensions, the teeth are sharp and don't squish the filament edges, and the gearing is nice enough I haven't experienced noticeable filament grinding even in retract-heavy tiny pillar segments.

    On the Bondtech FB group Martin himself recommended full tension minus one half to one turn for PLA. I think that is because the gear mesh is also controlled by the tension. I have seen no reason to decrease it whereas with my titan (now on an i3 clone) I try to run low tension.

    The biggest difference was that at high tensions on the other extruders the teeth marks were clearly visible with color change on the filament where it goes towards a pastel color. The Bondtech tooth marks at a glance are nearly invisible but VERY easily felt. Those teeth are beautifully sharp.



  • Well from what you guys are saying, it's looking very promising.

    I just had a look online and found a UK seller but they are asking GBP 100 for the basic unit without any extras. That's GBP 500 and if I went for the aluminium bracket and Bowden adaptor, I'd be looking at £140 a pop or £700 in total! That gave me mild heart attack as it's quite a bit more than many people spend on a printer. (Although in fairness, it's not much different to what Titans cost) On the other hand, looking at Bondtech's web site, they are asking 69.90 Euros for the basic unit which is much more affordable. I'll have to see if I can buy direct and if they'll ship to the UK (unless David manages to do some sort of deal on my behalf).

    Another quick question, the Bowden adaptor looks very much like the E3D one and Bondtech indicate that an E3D groove mount will fit. So it is safe to assume that I could use the Bowden adaptors from my Titans? That would save me 6.90 Euros x 5 = 34.50 Euros if I could buy direct or £16.80 x 5 = £84.00 if I bought from the UK supplier!

    Maybe I can recoup a bit back by selling the 5 Titans too.......



  • I have a new bondtech BMG as well i'm using as a flying extruder - I contacted them via facebook chat and they responded pretty quickly - given it's weekend it may have much luck but they're really responsive in general. I anticipate using their extruders pretty exclusively after reviewing the types of issues I have in general(mostly extruder related errors)

    And yes E3d bowden adapters should universally fit here from what I understand.



  • Thanks for that. I'm not on Facebook (or any other social media platform come to that) so I'll try other means. Thanks for confirming the Bowden adaptor thing.


  • administrators

    @deckingman given your use case is pretty unique (1000s of retracts over the same bit of filament) maybe get just 1? You can set it up to test with the bondtech being the one that is unused for the first N layers of the print so it gets a workout.

    Also we need to talk about filament monitoring and pause/purge/restart so that even if bondtech type dual toothed extruders dont work you can have the print pause and you can sort it out manually and then resume (but i wont want to hijack this thread and i don't have the laser monitors to hand yet).



  • @t3p3tony said in Bondtech (or similar) extruders:

    @deckingman given your use case is pretty unique (1000s of retracts over the same bit of filament) maybe get just 1? You can set it up to test with the bondtech being the one that is unused for the first N layers of the print so it gets a workout.

    Also we need to talk about filament monitoring and pause/purge/restart so that even if bondtech type dual toothed extruders dont work you can have the print pause and you can sort it out manually and then resume (but i wont want to hijack this thread and i don't have the laser monitors to hand yet).

    Hi Tony,

    That's spooky - the thought had just occurred to me that I ought to get just a single unit to start with before parting with my "hard earned" on 5 of the beasts (which as you rightly point out, may not be a solution due to my somewhat unique usage case). Also, it shouldn't be too hard to devise a torture test to compare BondTech with Titan back to back.

    Ref filament monitoring - it's all related to the same issue so I have no problem discussing it in this thread (although we can always converse via email if you think it would be better). It'd also be good to test filament monitoring with my other unique usage case which is when I fade one colour into another. So I have mixing ratios, and therefore extrusion rates, as low as 1% of what most users would see. David has indicated that this should not be a problem but I guess it would be good to run some tests.

    But, I have a couple of problems. I only have 2 or 3 spare estops. CoreXYUV plus Z then I use a couple for emergency stop and axis maxima. So even with Duet plus Duex5 I'm struggling with connectors. I guess I could probably disconnect these last two temporarily but I'd rather not if I can help it. The other issue the shear number of conductors that already go to the hot end and extruder gantries. 5 steppers with 4 conductors each, plus all the other associated gubbins like heater, fans, switches, thermistor, lights etc. I think the last time I did a count, it was in the order of 38 conductors. So if I had 5 filament monitors, I'd really struggle to run all the cables - I'd certainly need to change the cable chain which, with all the existing conductors, is no easy thing to do. I could possibly common up a few conductors but not all that many. Just to complicate things, the part cooling fans are 12v but the hot end fan is 24v.

    So as an aside, it would be really good if next gen Duet was a bit more modular to cut down on the number of conductors that have to all go back to the main board 😉



  • Just my 2 cents - I've had my prints fail for the same reason on my switching setup with 2 E3D Titans. Since it had to retract and unretract 70mm of filament every layer, on smaller prints one of the filaments ended up being ground.

    Bondtech extruders have completely solved the issue. Not only do they have a lot more grip, they deform the filament a lot less. Which additionally means less bowden tube resistance. Not that it would be an issue for you though.



  • @mike said in Bondtech (or similar) extruders:

    Just my 2 cents - I've had my prints fail for the same reason on my switching setup with 2 E3D Titans. Since it had to retract and unretract 70mm of filament every layer, on smaller prints one of the filaments ended up being ground.

    Bondtech extruders have completely solved the issue. Not only do they have a lot more grip, they deform the filament a lot less. Which additionally means less bowden tube resistance. Not that it would be an issue for you though.

    That's also very encouraging to hear. Good to know that I'm not alone even if slightly different set ups. BTW I do use Bowden tubes, albeit small ones so filament deformation is an issue to some extent. It certainly increases friction which exacerbates the problem. Thanks for your input.



  • Just for info, here is pic of the latest failure. So switching between gold and white on every layer but retracting all filaments together. At some point during the night, the white filament got ground away during the retractions between each gold spindle (because the white filament wasn't moving forward).

    It should look like the one in the background but a bit bigger. So those white towers should have been about 150mm tall. Wondering what to do it with now that I've aborted it. Frisbee maybe?

    0_1523737316214_failedPrint.jpg



  • i have titan aeros and agree that they leave something to be desired in the power department, i had debated between replacing them with bondtech bmg’s or another interesting extruder, the flexion extruder.

    https://flexionextruder.com

    It has an interesting feature, in that it automatically clears the hobbled bolt, would solve your problem.

    I ended up going with the bondtech, because i have my doubts that the heartbreak on the flexion is up to the task of sinking enough heat away. Documentation on it is also limited and there isn’t a support forum.... that and i know bondtech makes great stuff (i’ve got a bondtech qr that worked great on my delta).



  • I exclusively use the BMG extruders and own a total of 4 of them across 3 printers. They seem to be the only one that can grip a wide variety of materials and don't require any re-tuning for feed rates or anything, even when using ninjaflex and switching right to PC-CF. Heck it even handled ninjaflex in a bowden setup quite well.

    One note is that while they say to set your step/mm to 415, when you calibrate I find 415 to be a good average but find +/- 10mm / step is the tolerance. Once set though you never really have to adjust it.

    I will be curious to see how you make out with the mixing nozzle as I may be upgrading to that soon as I really like the idea of a multi-color print.


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