Fancy Bowden couplings and fake tubing tests

[@BeardedSkunk]

Wow the things you go into, that nobody else mentions and your scientific approach is just great. I keep mentioning you in other 3d channels comment and rooting for the algorithms to promote you so more people get aware and maybe improve or just rehash.

[@Mr3DPrintWizard]

minus much of its was wrong...

[@yura979]

@@Mr3DPrintWizard examples?

[@prongATO]

As an engineer, I appreciate your work. Thank you.

[@LaserUpgradesdotcom]

I'd like more information... Links... On tubing and the fittings including details on the mods done on the fittings and tubing to get the hydraulic fittings to work.

[@gerthalberg9735]

Looking forward to seeing your work on the fans

[@vangelis.gavalakis]

This is why I am subscribed! Fantastic video Alex :)

[@cri8tor]

Until just a few weeks ago, I was very ignorant about 3D printing and all the related paraphernalia. Couple of weeks ago, I purchased what I thought was Capricorn Bowden tubing from AliExpress and now I'm pretty sure its going to be garbage, so I purchased the real stuff right from the Capricorn Website. Your videos have been so helpful and I really appreciate how much time and effort you've given to all of us. Cheers brother

[@yonutz333]

Can you please share the exact model of the hydraulic coupler you used and where you got it? The results are quite promising and your whole argumentation makes a lot of sense ...

[@StrikeEagleCC]

I found these on aliexpress that look the same and should work: insert (GP-4-2) bit.ly/2w7D0ZF and coupler (JS46 4mm -M6x1 ) bit.ly/3a7N6sb

[@jordan177606]

your insert link is broken but I believe you are talking about "10pcs JIANHE GP Brass tubing bushing 4mm/6mm/8mm/10mm Oil pipe fittings/ Compression Sleeve Fitting/ nylon tubing oil core" which is in the same store (JIAXING JIANHE MACHINERY)

[@yonutz333]

@@StrikeEagleCC thanks but both links seem to point to the same item, still need link to GP-4-2. But i might look it up myself since now you gave us model numbers 😏

[@tyob1]

For the extruder, I usually back off the coupling 1/2 turn, seat the (Capricorn) tubing, then tighten the coupling down. It compresses the tubing between the extruder and the coupling teeth. Haven’t had any movement at all luckily

[@DavidMulligan]

This sounds like great advice. I wonder if there is a way to do the equivalent on a BMG style extruder.

[@olafmarzocchi6194]

Is it reversible? Can you do an atomic pull easily? It implies removing the coupling and pull the cold filament out of the nozzle

[@69hytek]

Here's a crazy idea and this could just be the right place to deliver it. What about a push/pull cable sheath? Something like bicycle brake cable, not exactly, but that kind of thing. They're steel reinforced to combat stretch yet designed for flexibility. Pretty sure there are Teflon lined ones too. Just a thought.....

[@casykid]

does the fan cooling at 1:11 have any venturi effect like you teased on the fan videos or just small nozzle on 5015 blowers that are angled at like 45 degrees so you have a lesser angle of wind deformation?

[@SeanCMonahan]

Is that a water-cooled hotend (or, rather, cold end) at 1:18?

[@MrConnor128]

Another awesome video Alex. Thank you for the insight. Sign me up for wanting to see the hydraulic fitting install video!

[@kenlipper874]

Another great video. As a scientifically-minded person I really appreciate the depth that you go into. Keep up the great work!

[@thebeststooge]

I haven't watched the video yet but I agree. My thing is I hope he really dives into the Capricorn tubing because that shit is expensive and if the filament isn't nearly perfect I can see it jamming. I will have to watch this later as I am suddenly busy.

[@alann4808]

Maybe this was your point, but the ratio of Young’s moduli between the tube and filament, I think, only matters in so much as the lower of the two will determine how much retraction/extrusion force you can apply. So, ideally, your Bowden tube would be at least as stiff as the filament. If it’s stiffer, then the filament will stretch. If it’s less stiff, then the bowden compresses. In reality, I assume, both are happening. Complicated.

[@SeanCMonahan]

I'd love more info about the hydrologic couplers you used! What sizes? Where'd you get them? What was the process of drilling out the PTFE tube for the inner compression sleeve? Edit: The barb would preclude using the hydrologic fitting on the hotend side of the coupler, yeah?

[@JoergGebhard]

So good! I would have never thought that the filament stretches the tube!

[@jordan177606]

I kind of want to see the hydraulic fitting video, I think thats the first mention of that on KZbin. The pieces are GP-4-2 for the bushing and JS-46 4mm -M6x1 for the fitting right? the ones sold by Jianhe on aliexpress. I might order some for myself. Any tips on the hole boring thing?

[@jordanscott1394]

Thanks for this in-depth video .. refreshing to see a proper thought out video instead of the standard Capricorn fixes all your issues .. I found it extremely difficult to find information on rectifying the slop

[@olafmarzocchi6194]

Hi, nice and complete overview. Thanks. If you use hydraulic couplings, does it get significantly more difficult to do the atomic pull for cleaning the nozzle?

[@mysfiring]

1:21 - you're trying to reenact the scene in Final Fantasy VII where Sephiroth takes the shroud covering Jenova off?

[@Olson_91]

Hi Alex, to reduce stretching of ptfe tube try to use glass fiber reinforced packing tape (reinforced along tape) example of this tape is Tesa Monofilament. You need to wrap tube paralel to the tape it is tricky but gives awesome results. I personally reduced retraction from 5mm to below 2mm on around 0.5meter bowden.

[@jmtx.]

Just goes to show that the shorter the bowden tube is, the more predictable and controllable your prints will be. Thanks for such an informative exploration!

[@Side85Winder]

I would like to know the size of the hydraulic coupling you used in the video. I am sure i can figure out the how too my self from the quick flashes of video you shown. I use the black top pneumatic coupler they have a much better grip than the blue top ones. The black top also allow the PTFE tube to be pushed through hard up against my self designed extruder gear with out drilling the back out. I would be very interested in this hydraulic coupler for another setup.

[@AlexKenis]

THat was one thing I forgot to compare. Those black 10mm thru-couplers hold really well on the hotend side, and don't develop play very easily, but you need a different feeder to use them on the other end.

[@Side85Winder]

@@AlexKenis yeah i have a self designed belt driven extruder 3.75:1 ratio with a 40t pinion gear. I brought a hobbed gear as well but i like the pinion better because of scrubbing of the curved hobb on the filament shaft and i never had a grip issue unless it was catastrophic. So i use black topped couplers with aliexpress 1.9mm ID tubing. The PTFE tube is cut to the shape of the pinion gear and idler bearing and meets up less than 1mm tollerence. I tried printing TPU on my bowden its working ok. I want to mount the extruder on the right x axis on a cartesian to shorten my bowden that will help.

[@DRIX3D]

hi, do you have the reference of the hydrolic coupler you have used ? Thanks ;)

[@suivzmoi]

you briefly touched on re-priming speed but didn't go back to elaborate. so how much less should re-prime be compared to retraction rate?

[@frodobaggins169]

Thanks for the great video. There is one subject you brought up at the end that is not will understood is hotend temp and flow. I found that my Ender 3 has to print at 230c using PLA + . I stopped using Capricorn Tubing because is would clog too fast and under extrude during a long print. I was not aware of counter fits till now thanks for that.

[@Cairos1014]

Thanks, Alex. Keep that technical detail coming! It's hard to tune a system of you don't know how it works! Something that bugs me is that there is no feedback in the control system for the most important parameter which I believe is probably the pressure at the nozzle? I'm trying to think of a way to achieve that. Maybe a servo motor with power or torque sensing for extrusion drive?

[@olafmarzocchi6194]

Hi Alex, thank you for the testing. Are you aware of couplings suitable for 2.85 mm filament? They are apparently more difficult to source

[@JasonLooseArrowAlso]

Well done, dude!

[@WaschyNumber1]

Is it not possible to use nylon tubing? 🤔

[@markferrick10]

Excellent video Alex. Do you have a comparison pneumatic fitting ( with clip or zip tie to set the teeth ) vs hydraulic fitting with either the real capricorn or the black tubing. Interested if the difference is substantial enough to go to hydraulic. Again, thanks for a real eye opener.

[@A.Achorn]

I'd love to know your retraction settings!!! I'm using cap tubing and I'd like to dial it back from 4!

[@SianaGearz]

Bonus fake internet point says you're trying to figure out the best way to cool TECs for a subambient part cooling fan, or maybe prechilled water heatsink as a source of cold airstream on the right.

[@AlexKenis]

DING DING, You win the fake internet points, LOL

[@thisiskeithb]

10:20: I recognize the retailer's website and would be surprised if they were selling fake products. Did you contact them?

[@AlexKenis]

Hey Keith, no not yet, but I will soon. Yeah the dude is legit, so I left the name out until I figure out what the deal is.

[@Mr3DPrintWizard]

@@AlexKenis the deal is you have no idea anything is fake and your results are as bad as the tests.

[@hound83]

I had an Ender 5 pro that "featured" some really crappy Capricorn tubing from the factory. Could very well be the same stuff you experienced. After i bought a genuine Capricorn from a reputable source my printing quality went up a lot too! (upgraded to a Ender 5 Plus now and upgraded to some real Capricorn too after that experience) Really awaiting the (air) cooling followup from your other part 1 video... :D

[@3sotErik]

Okay, I seen this vid awhile back & I remember you saying where I can get genuine tubes. I don't see a link & cant scrub through the whole vid again. Links please!!!

[@ImSweetKiss]

Triangle Labs for the first one, and mellow store for the second, I guess, where did you get the fake stuff?

[@aurthorthing7403]

Curious how HVAC pneumatic tube would work on these? If you ever go to an older hospital or large commercial building and hear air hissing from a thermostat that you can not adjust... it's a pneumatic control system. They use black tubing that kinda resembles ABS. I don't have a clue as to what it's made from but it doesn't stretch much at all.

[@ianide2480]

I would think that length of over-all tube would be important in this case. For short runs you might get away with pneumatic tube, longer runs and you might not get past the extra friction. This is just a guess though, but friction is the main reason to use teflon tubing.

[@BeardedSkunk]

Because of fear of bowden-slop I mounted my extruder on the center of the horizontal z-bar the nozzle carriage runs on .. just an idea..

[@tablatronix]

hows that working out? I was considering this also as it lets you shorten the tube a little

[@BeardedSkunk]

@@tablatronix haven't seen any negative effects. Also I feel like tpu prints better, but haven't done any before and after tests.

[@BeardedSkunk]

Your X is my Z ... Seen this in this video the first time, least I thought the extruder moved upwards in that one shot. Guess it's a good compromise but haven't found it to hard to design/print a 2nd plastic bar, attach it at either ends of the original bar and maybe save another 3rd length of tube. ,. Would love to see a scientific test of either approach though ... Maybe with std ptfe comparing against fixed couplers and Capricorn ... Though the test combinations seem unsurmountable ;)

[@DJPhilTBCollins]

Regarding tension and compression members: I'm reminded of trying to put the first pole into a dome tent, and how most learn the lesson of putting all the poles in before trying to bend anything.

[@diego1694]

I noticed that your bowden tubes are longer than what they need to be. I would assume that a longer tube means more friction, but also higher radius bends. Have you tested what is the optimal length ?

[@diego1694]

There is also a printed coupling (thing:3837897) that claims to remove all play, would be interesting to see how this compares to the proper hydraulic coupler.

[@sustmi]

This might interest you: kzbin.info/www/bejne/enOYk2dsbJh6gJI

[@TheDgdimick]

I've run into some "counterfeit" Capricorn tubing as well, normally the cheap stuff off of Amazon is counterfeit, so I now pay a bit more, and get the real stuff.

[@Nitram_3d]

I reinforced my bowden with cable mesh and shrink tubing (gluing) photos.app.goo.gl/AasMiSHusymLpfkZA I managed to lower the PA value as well as the retract a fare bit...

[@AlexKenis]

OOO that's pretty clever. I tried gluing PE tubing over the teflon tubing, but it kept breaking loose inside, so I put that thought off till a rainy day

[@jalanjarosz]

This is an interesting idea too.

[@Nitram_3d]

@@AlexKenis Gluing PE and PTFE, in the same sentence... choose your battles... here is my bowden in action kzbin.info/www/bejne/rnSnf4OmpNV0Z7M

[@yogimarkmac]

I was getting excited by the non-Newtonian liquid part and then he just said bye! Now I need graphs of viscosity vs. pressure with hysteresis for different filaments. Oh how will I sleep till then. lol

[@AlexKenis]

Yeah, sorry... I want that data too! I have considered doing just a theory video about it, but it's too easy for someone to call bullcrap if I don't provide testing data and examples, so it's on the list

[@jaro6985]

Good topic, I had no idea about stretch and slop just friction. Maybe consider an Aliexpress affiliate link for the black tubing.

[@patrickweggler]

And I was thinking about remote direct drive extruders to circumvent my retraction issues...

[@ameliabuns4058]

random question but do you have a twitter :P ?

[@Aubreykun]

I don't own a 3d printer, so maybe this is just me speaking from ignorance, but would bicycle brake cable housing work for this sort of setup? I imagine you'd need different couplings since the cable housing has a larger OD due to the steel in it, but you can get ones with the PTFE liner for pretty cheap. (Reason I even clicked is because "bowden cable" is the technical term for bicycle cables, and I'm subscribed for other content.)

[@Aubreykun]

You can also get compressionless brake cable housing but it's far more expensive, not sure if that would be needed for the printer but if you have trouble it may be an option.

[@AlexKenis]

yes I looked into it a little bit and I may see what I can turn up in the future. My first thought was SIS shift cable, but it may not do well in compression, so I've had an eye out for cable with controlled internal tolerance as opposed to just 'nominal diameter'. If anything useful comes of it, I'll post a vid. My original hydraulic couplings were from shimano disc brakes, but i switched to bulk brass couplings because man they mark up the price when the box says 'bicycle'...

[@Aubreykun]

@@AlexKenis Shift cable housing is compressionless as the metal wires that support the housing run along the jacket as opposed to being wound like in brake cable housing. It may not have the correct internal diameter though, as shift cables are thinner than brake cables, so you'd have to test it with a piece of filament to see if it would actually fit. Brake cable housing has a larger ID, and there is compressionless brake housing - but it's a specialty item. Jagwire makes some, not sure who else. In either case you'd be limited to 1.75mm filament... too bad the manufacturers don't make it smaller diameter. Maybe one day when the printers-manufacturers realize they can consistently get away with using shifter housing for a bowden setup?

[@modmike4406]

Nicely done.

[@LiquidForce142]

Great video. You'd make a good teacher

[@olafmarzocchi6194]

Links for hydraulic coupling would be nice. And you may get some money too. Win/win!

[@Nicholas-rm2gp]

Give this a try, it should lock the bowden tube into place. www.thingiverse.com/thing:4269840

[@pnt1035]

I just checked some "Capricorn Bowden PTFE Tubing XS" which I received a couple of weeks ago from AliExpress. At first glance it looks and feels just like the real stuff (whch I also checked) and had the right labels - but the bore isn't concentric at one end, and the internal diameter measures over 2.05mm (I can easily slide a 2.10mm drill all the way in, quite different to the real stuff in which the bore is 2-3 drill sizes smaller). And this wasn't cheap. I've just opened a dispute with the seller :-(

[@avejst]

Great analyze as always Thanks for sharing :-)

[@wishicouldarduino8880]

Haven't seen you in awhile good video

[@RuairiODonnellFOTO]

You tidied up the water cooling? Can't wait for more water cooling video 🤓

[@maximilian.arnold]

Nice!

[@jsimmonstx]

The thing you're calling a "pineapple" is actually called a "ferrel".

[@thelightspeed3d712]

Check your tweets! Bondtech came out with the mother of all fittings! They are the best I’ve seen. Dare I say perfect!

[@ameliabuns4058]

Wait I thought capricorn was a scam

[@GeekinaCave]

For anyone interested I reverse engineered the link of the black aliexpress Teflon Tubing: www.aliexpress.com/item/32354926214.html And this one is similar from Trianglelab: www.aliexpress.com/item/32961383872.html

[@AlexKenis]

Yeah, that's the stuff. Sorry, I may have to post a follow up vid with all the things I cut out for time. THat black tubing performed pretty well even though the tolerance was not quite as tight as Capricorn and the center hole was not quite as centered

[@jirij]

Funny, I was going to post a comment that mine (direct from E3D UK !) arrived with a mis-centered hole and a larger out-of-spec OD, so it didn't fit my reamed hole in a cold end, ... but then you mentioned exactly that. ... E3D sent me a replacement, but the OD was still out of spec. So this is not just some dodgy distributor re-branding fake tubing. See photos (remove the space, damn spam protection): imgur. com/a/QlkOyt8

[@EvileDik]

Fking awesome videos mate, here, have a sub. I'll definitely take a hydraulic coupler mod howto and an order of fries please.

[@winchesterlyon]

If it was never advertised as "Capricorn", what makes it "fake" and why do YOU take "premium" to mean "Capricorn"? Are you of the mind that just because it's blue, it MUST be mimicking the "Capricorn" brand? Do you feel the same way about other things? Do you believe a "black" Japanese "luxury" car is a fake Mercedes because Mercedes luxury cars come in black?

[@Mr3DPrintWizard]

So much misinformation. You can't say it's fake unless you know. You can't use calipers to measure the inside diameter of a tube. That's just ignorance. Your data is piss poor.

[@diego1694]

Why are you being so aggressive ? he explains that either it is fake or the manufacturer changed the specs of the tube drastically, and fake seems the far more likely option.

[@BeardedSkunk]

What's Chrissy's problem, if Alexis did any more in detail explaining/relativ-izing no one could watch this. It's all laid out as open as bearable, we can all notice the parts of the results we deem important... Don't see any mis-information just an excaustive presentation of happenstance

[@Mr3DPrintWizard]

Just because someone uses big words doesn’t make them smart. In this instance because he tested things doesn’t mean he did any of those tests correctly.

[@diego1694]

@@Mr3DPrintWizard Do you think that you look smart with what you are saying here ? if you don't explain clearly why you think he did not the tests correctly you just look like an angry idiot.

[@BeardedSkunk]

@@Mr3DPrintWizard I guess there's always room for improvement but I don't get the mis-information .. he did show he used calipers to measure which is truthful and comparable within the test. The other actual critique you mentioned was he called something fake without testing?... He showed the results and there was a difference of everything against Capricorn original ... Sorry but can you point to a specific thing that's in-accurate or is it justv all: 'you know, if you'd asked me if I'd do a way better job'