Bondtech (or similar) extruders
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@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.
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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.......
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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.
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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.
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@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).
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@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
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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.
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@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.
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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?
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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.
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).
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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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@bpislife said in Bondtech (or similar) extruders:
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.
Thanks for that. Re the mixing hot end - I've been using them for years. Loads of stuff on my blog https://somei3deas.wordpress.com/blog/
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@qdeathstar said in Bondtech (or similar) extruders:
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.
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).
Thanks. Ref the flexion, TBH I'm looking fr something that doesn't grind the filament away in the first place - clearing it from the hobbed bolt is the lease of my problems.
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i think any time you use a hobbed bolt that bites into filament you are going to get small chips that accumulate on the hob bolts teeth, reducing its ability to bite the plastic till it can’t provide enough grip to push the filament and simply grinds on it. Keeping the hobbed bolt clean should help make sure you can get a consistent byte.
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@qdeathstar said in Bondtech (or similar) extruders:
i think any time you use a hotbed bolt that bites into filament you are going to get small chips that accumulate on the hobbs bolt, reducing its ability to bite the plastic till it can’t provide enough grip to push the filament and simply grinds on it. Keeping the hobbee bolt clean should help make sure you can get a consistent byte.
Fair comment. I guess the ideal extruder would have 2 (or more) hobbed bolts plus a mechanism to keep them clean. AFAIK no such extruder exists so I'm inclined towards the Bondtech with 2 hobbed bolts over the flexion with a single hobbed bolt and cleaning mechanism. For "normal" use, that is to say without retracting and un-retracting the same piece of filament, I don't really get any build up on the hobbed bolt though.
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It never really made a splash but the belt-friction extruder (Vaeder or something like that) of some while back seemed to be a novel solution for pushing filament without having to bite into it with sharp teeth.
Simon. Precision Piezo Z-Probe Technology
www.precisionpiezo.co.uk
PT1000 cartridge sensors NOW IN, just attach to your Duet board directly! -
@djdemond said in Bondtech (or similar) extruders:
It never really made a splash but the belt-friction extruder (Vaeder or something like that) of some while back seemed to be a novel solution for pushing filament without having to bite into it with sharp teeth.
Yeah, I wondered about those. As you say, it never made a splash and I can't find much info. Bit concerned about how much pushing power they might have compared to a hobbed bolt.
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Well the one I saw some time ago gripped the filament between about 5 cm of belt, so I would expect it to be fairly tight. The big plus would be you could drive it as hard as you wanted, even if it slips, you won't grind it to nothing.
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Update on this. Long story short but Martin Bondéus from Bondtech kindly sent me a BMG unit for evaluation. I've just got around to doing the tests and writing up my findings. Results and associated video are here https://somei3deas.wordpress.com/2018/05/11/bondtech-bmg-vs-e3d-titan-extreme-retraction-torture-test/.
It might surprise you ...........it did me!
