Any experience with this hotend?

[www.ebay.it]

I was looking for a 2 filament mixing hotend (I tried a switching system with y splitter, but the retraction and loading and filament shaping required were not very easy to work with). Wondering if anyone has tried this one and can confirm it is mixing not switching?

I don't fancy the diamond it seems over the top for me.

Another question on this topic, the e3d cyclops 2in1out with 1 nozzle is described as switching not mixing, so is the junction between the two filament paths in the heatbreak or heater block? If it's in the heater block why isn't this considered a mixing hotend?

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Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

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DjDemonD
Another question on this topic, the e3d cyclops 2in1out with 1 nozzle is described as switching not mixing, so is the junction between the two filament paths in the heatbreak or heater block? If it's in the heater block why isn't this considered a mixing hotend?

I’ve wondered that myself. The mixer is in the block, and, in their engineering drawings ( [wiki.e3d-online.com] ) they call it a “mix block”.

Chimaera/ cyclops seem to use the same cold end. The chimaera hot end looks close to a v6 but the heat breaks are smooth not threaded (for assembly reasons I guess).

I’m kind of interested myself, but there do3snt seem to be a lot out there on how well they work. I do wonder if the relatively large volume of plastic held in the mixer area each side of the nozzle is a problem though: is it prone to clogging when the plastic degrades with heat? I wonder also if it takes ages to purge when changing extruder- leakage from the side you’re not using.

Well from what I gather from Deckingman/Ian on Duet forum who's a bit of a diamond hotend expert, he runs a mix ratio of 98:1:1 for single colour printing to ensure the non working extruders are always extruding a little, which addresses the plastic degrading in the non working side/s. He also uses firmware retraction which retracts all extruders (but by 1/3, in the case of diamond, as much per extruder) to prevent molten plastic being pulled into the mixing zone as it would be if only one (the working) extruder where to do all the retraction.

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Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

Quote
DjDemonD
If it's in the heater block why isn't this considered a mixing hotend?

If you extrude multiple colors at the same time they will remain seperate while leaving the nozzle producing a "toothpaste effect". The print is just two colors sitting next together, not a homogenous mix.

I think the term mixing extruder is slowly being used only for hot ends that can actually produce a blended output, generally via a motor-driven impeller mixing the plastic in the melt zone.

[youtu.be] Is interesting on the mixing topic.

Thanks that makes sense. This is going to cause confusion a bit like direct drive extruders (meaning no bowden tube) rather than ungeared.

Perhaps it might be worth suggesting standardising the terms one example might be:

Switching: non working filament is retracted out of the active filament path to switch between filaments. Requires some element of managed retraction to avoid jams when reloading inactive filament.

Non-switching: multiple filaments remain loaded and can be heated simultaneously and can potentially be extruded simultaneously, but thorough mixing cannot be guaranteed or expected.

Mixing hotend: capable of extruding simultaneously more than one filament and blending them convincingly.

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Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

Switching - Prometheus style

Mixing (or 2in1) - Cyclops - A N Other

Active mixing - ??

There is a trick to reducing or nealry eliminating toothpaste effect.

"Non switching" is miselading as you can still user a static mixing (or 2in1) hotend to switch, albeit with normal retraction lengths of 1-1.5mm instead of 50mm+

my tuppence

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Flex3Drive.com

The 2in1 hotend you linked is a bit suspicious to me.
The Y-splitter path has two sharp corners, the filament might get stuck when unretracting.
Also the cooling surface is dubious.

The printed Y-splitters usually have a smoother filament path. I wonder why they didn't CNC a smooth curve in the coldend instead of drilling in an angle?

Re naming: I vote for
2in1out or y-splitter
mixing
active mixing

The splitter path maybe have two sharp corners but they're in the heater block so they're not handling solid filament.

I wouldn't attempt to use that cyclops style hotend by trying to retract the non printing filament, I'd set mixing ratio of 99:1.

Fair enough on the definitions it would be handy to try to make it all a little less confusing.

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Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

2in1 and y-splitter are different, as a Y splitter does not have 2 channels. Hence my differentiation between what are two very different beasts.

But i do understand some might see a blurred line between the two. Ultimately I think it is up to manufacturers to determine how they classify and describe their product, and of course the community can debate thereafter.

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Flex3Drive.com

Doesn't mean we can't try to influence them a little to be clear in describing what they are offering, as y-splitter and true mixing are distinctly different products with different uses.

The confusion with something like e3d cyclops though is does it mix or split? Can you extrude from both sides at once (I'm not bothered if the colour truly blends).

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Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

@DjDemonD - Yes I totally agree about clear descriptions. Although not sure much value or credence can be taken from ebay adverts as to the veracity or accuracy of their descriptions. After all they are the ones that gave us the all metal JHead

When you have a 2in1 mixer like a Cyclops, the ability to extrude from both sides at once is not down to the hotend itself, but more the simultaneous control of the 2 (or more) extruder motors, ie 2into1 ala mixer. The degree to which they do or dont blend is design related but principle design objective is the same. This is opposite of the Y splitter where loosely speaking, only one motor/filament can be driven at any time. In other words, pull one out before the other can go in.

or maybe its just the way my brain is wired

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Flex3Drive.com

Quote
Mutley3D
@DjDemonD - Yes I totally agree about clear descriptions. Although not sure much value or credence can be taken from ebay adverts as to the veracity or accuracy of their descriptions. After all they are the ones that gave us the all metal JHead

When you have a 2in1 mixer like a Cyclops, the ability to extrude from both sides at once is not down to the hotend itself, but more the simultaneous control of the 2 (or more) extruder motors, ie 2into1 ala mixer. The degree to which they do or dont blend is design related but principle design objective is the same. This is opposite of the Y splitter where loosely speaking, only one motor/filament can be driven at any time. In other words, pull one out before the other can go in.

or maybe its just the way my brain is wired

I would disagree with this, it certainly is down to the hotend as if the Y split is in the melt zone then it is essentially a mixing hotend, if the Y split is in the cold end it is a Y splitter or switching. Of course there may be some ambiguity, the melt zone geometry may make it impossible to simultaneously extrude from both paths but then it is a definitely a Y splitter (even if the Y split occurs in the melt zone).

I think it is probably important that manufacturers clear up as much ambiguity as possible, but I feel like this is unlikely to happen. As for the E3D cyclops/chimera/kraken systems, I get the feeling they were forgotten about quite some time ago in favour of the V6 / titan product lines.

Well maybe they just aren't that popular. When it comes to multi-colour printing its hard not conclude its quite a lot of trouble, and a pot of paint and a brush afterwards might be easier. I gave the y splitter a go but wrestling the firmware and slicer to produce the right output, then adding in wipe and prime towers etc.. was just too much trouble for me, as I mostly print mechanical parts and rarely print "art" objects.

I can see the point to having multi-material for support/print or different materials for perimeters and infill. But then it seems the most satisfactory, but by no means cheapest way, to do this is with dual x carriages, with independent z-probes to ensure no nozzle level issues.

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Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

Totally agree about independent X carriages being the best option. Which firmwares are ready to go with tha? Pretty sure reprapdirmware does, are there any orhers?

RRF

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Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

Some draws (not very clears) [www.banggood.com]

Quote
DjDemonD
Well maybe they just aren't that popular. When it comes to multi-colour printing its hard not conclude its quite a lot of trouble, and a pot of paint and a brush afterwards might be easier. I gave the y splitter a go but wrestling the firmware and slicer to produce the right output, then adding in wipe and prime towers etc.. was just too much trouble for me, as I mostly print mechanical parts and rarely print "art" objects.

I can see the point to having multi-material for support/print or different materials for perimeters and infill. But then it seems the most satisfactory, but by no means cheapest way, to do this is with dual x carriages, with independent z-probes to ensure no nozzle level issues.

Or a secondary lifting nozzle.. IDEX seems far too complicated to me and does not remove the chance of the second nozzle colliding with prints.

@ Origamib - When I say y-splitter I refer explicitly to those single (standard) nozzle setups, which in fact doesnt even refer to the hotend, but the setup configuration, where there is a distinctly Y shaped splitter supporting two filaments that are fed one at a time.

OR are we sayiung the same thing. A hotend with a Y split in the cold end? That would be in my book a Y splitter. Split in the hot zone (or capability to run both filaments at same time) thats a mixer.

@DjDemonD - perhaps no one has made it easy for users yet, I agree dual filament printing is a PITA with current tool chains. I think Deckingman has taken this forward to some degree with his efforts.

Edited 1 time(s). Last edit at 07/18/2017 04:51PM by Mutley3D.

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Flex3Drive.com

Quote
Mutley3D
@ Origamib - When I say y-splitter I refer explicitly to those single (standard) nozzle setups, which in fact doesnt even refer to the hotend, but the setup configuration, where there is a distinctly Y shaped splitter supporting two filaments that are fed one at a time.

OR are we sayiung the same thing. A hotend with a Y split in the cold end? That would be in my book a Y splitter. Split in the hot zone (or capability to run both filaments at same time) thats a mixer.

@DjDemonD - perhaps no one has made it easy for users yet, I agree dual filament printing is a PITA with current tool chains. I think Deckingman has taken this forward to some degree with his efforts.

Yes, I think we are just saying the same thing!

Deckingman has a great set up, but a 3kg print head is not a game changer just yet. To be honest, I see no reason to use FDM as a colour printing option... Inkjet powder printing is miles beyond what any FDM machine can do with colour, so why bother? Anything else is just a gimmick or could be printed in separate block parts and stuck together.

Multi materials though, that is legitimately useful! Breakaway or soluble supports to make difficult/impossible geometries is the future. In this sense though reprap is falling behind... Very few reprap machines have this set up, and most are for expensive commercial printers like BCN3D or ultimaker.

Edited 1 time(s). Last edit at 07/19/2017 03:24AM by Origamib.

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VincentM
Some draws (not very clears) [www.banggood.com]

To me the drawings didn't clarify anything.

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DJ
The splitter path maybe have two sharp corners but they're in the heater block so they're not handling solid filament.

IMHO the Y-splitter is in the heatsink and the hotend is the silicon covered round piece. It is connected by a classic 6mm stainless screw. Hard to imagine they squeezed two PTFE tubes in there to meet in the hotend?!

Edited 1 time(s). Last edit at 07/19/2017 02:26AM by o_lampe.