Thanks Thanks:  8
Likes Likes:  16
Dislikes Dislikes:  0
Page 2 of 5 FirstFirst 1234 ... LastLast
Results 11 to 20 of 50

Thread: Universal Hub

  1. #11
    3D Printer God(dess)
    Join Date
    Nov 2016
    Posts
    1,566
    Post Thanks / Like
    Quote Originally Posted by slx612 View Post
    It is common practice, yes slx612.

    I do a lot of printing and I have changed the filament a lot for single prints.
    While changing filament, the handling of the hubs and nozzles inevitably rotates the tube in the fittings.
    This is okay if it happens occasionally, but repeated rotations will cut a groove in the tube.
    When the groove gets deep enough, the grippers inside the fittings will not release the tube.
    And when you force the tube, the metal grippers break inside the fitting.
    This means that you need to trim another 1/4" from the tube and you have to replace the fitting.

    This fitting replacement solution removed the risk of not being able to remove the tube when you want too.
    This is specifically important if you plan to change filaments in the middle of the print.

    Also know that the design of the commercially available fittings were never meant for Teflon.
    It is the 3D Printing industry that decided is was "sufficient" to do what it does.

    My goal is to make filament easy to change and minimize all expenses related to 3D printing.
    Replacement tubing and fittings is something I can do without now.

    Of course, you can adopt this solution on either end. I still use a modified stock nozzle housings to print ABS.

    - - - - - - - - - -

    BTW: not sure you know, slx... I have used this setup for quite some time:
    https://www.thingiverse.com/thing:2351218

    The thing is that I do need to keep a printer available for offsite printing.
    With this cartridge modification, I can pull the Bowden tube; which removes the filament from the nozzle; and the nozzle can be kept in place with original shipping materials; the Bowden tube can be separated from the cartridge and placed in the original cartridge box.

    Additionally, with the cartridge case-cover modification, there is no reason that feeding a full 1kg spool is just as simple if you have a good spool holder.
    This is the one I use: https://www.thingiverse.com/thing:2385588

    Obviously I've been trying to get to a fixed configuration for my printers. At this point, I am very happy with the addition of this option. This particular level of effort to groove the tubing is way above my own personal needs. I can groove tubing with a jeweler's lathe with ease. Therefore, this effort was to provide an alternative means to make the groove for anyone with a set of jeweler's screwdrivers or an eyeglasses repair kit. Making things easy to make is always the challenge for DIY projects

    A note on modifying the cartridge case cover:
    I modified two cases recently. The first I marked and used a rotary tool cut-off wheel. Sort of carving the hole a cut at a time followed by a small drum sanding with the rotary tool. If you even played with the resulting debris, you will notice that this stuff is quite abrasive. You don't want this in your lungs. WEAR A FACE MASK!

    -OR- better yet, use a coping saw, scroll saw, or jig saw. Anything that keeps the waste materials under strict control. I used the scroll saw and it just cut like butter and all the waste was pushed under the working surface. The cleanup was done using a hand file and sandpaper. This method made me a lot more comfortable than the cutoff wheel/barrel sanding process.
    Last edited by TommyDee; 06-14-2018 at 06:50 PM.

  2. #12
    3D Printer Noob
    Join Date
    Feb 2018
    Posts
    10
    Post Thanks / Like
    I do not know much, I only know what I'm reading in forums (this is the one I liked the most) but you're right with my modification you can not do that

  3. #13
    3D Printer God(dess)
    Join Date
    Nov 2016
    Posts
    1,566
    Post Thanks / Like
    I hate loosing track of my own threads...



    Been busy converting all the parts in the scrap pile.
    I am definitely enjoying the Back 2 Basics cartridges.
    Remember that these are universal hubs first and foremost.

    minib2bupdte.PNG

    ...and what's that? A bowden tube container cartridge conversion?
    Actually no, that is a hub rarely used but it is specifically for hard filament.
    Call it a placeholder for -just in case-.
    But it does do a nice job of managing your spare tubes.

    Also did a lot of ABS printing with highly suspect filament.
    Didn't seem to bother the design.
    Learned some really interesting things about ABS along the way.

    The only test left is to run 2 ABS carts at the same time.

    I know I've posted hacks here and there in the "Salvage PC4-M5" thread.
    Eventually I will catch up this thread with official releases.
    In the meantime, feel free to give this solution a shot.

    We should actually thank Alex for this. He was the first to honor us with KISS Carts!
    That is still the best emergency repair kit ever conceived. This just notches it up a few degrees.
    Once you're set up, a new cartridges only needs one print part to adapt the new cartridge to the system.
    The nozzle and its guts are spare; the tubing is sufficient to do the mod.
    The hardest part about this mod is how carefully you want to hack the cartridge cover.
    ...and to decide on whether to break off the clips now or let them break naturally.
    Funny how tough they are when you actually want to break them off!

    BTW, have a mentioned how robust this setup is? I need to write this up on a higher level.

    ...and I haven't forgotten about you, Alex. I need to go price shipping the package with a couple of B2B sets printed.

    - - - - - - - - - -



    Ha! that works. Couldn't figure out how to copy an image to a new post through attachments.

    A few posts that should also be here; above is an overly OCD generated cover mod.
    A quick zip just below center would function just as well.
    The cover serves several functions not least of which is to steady the bulkhead adapter.
    Maintaining the entire periphery does maintain a nice finished look and feel to the cartridge.

    - - - - - - - - - -

    I can release this set as final. These are working nicely in ABS.

    I'm not holding back the STL's. You will find them elsewhere on the forum if you really need them.
    I am just making sure parts are oriented properly for the best chance of success.

    This file has both left and right side set up for ABS.

    abs_nozzle_set.PNG

    https://drive.google.com/open?id=1fW...hJdyoDUXdsCIs5
    remember my file coding L/R A/P 1/2 1/2/3 1/2/3 0/1 0/1 these are the menu choices for prints.

    I don't know why I cannot attach .cube3 files in this forum even inside of zip files. Alex?

    Edit 7/15/18: I've uploaded the STL for this: https://drive.google.com/open?id=1Sk...upJD2UPAOK-htM

    - - - - - - - - - -

    And don't forget, both ends of the B2B solution don't need to be implemented.
    You can still use push-to-connect fittings on either end if your setup is different.

    Now what will happened when you plug a grooved tube into a standard push to connect fitting

    - - - - - - - - - -

    And on that thought... the attached part completes the B2B Nozzle... The B2B Tube-Nut

    I'll let you figure out which is the right orientation (default is left side).

    I printed a pair in PLA 200um, strong, cross, no sidewalks or supports (lp12100) and they came out perfect without a cooling tower.
    Just spread them apart on the plate. Printing one may require a second "idle project".
    These may require a little cleanup depending on the OD of your tube. You want a "free running" fit which means spins on the tube but doesn't wobble (much). I am using a #19 (.166) drill. 4.2mm is working too. This is for tube that has a mean measure of ~4.1mm.
    It should also screw into the housing with very little resistance if not freely. This attention to detail will help you when it comes time to do a filament change in the middle of a print where the nozzle has to remain in place.

    tubenut.PNG

    (see the bottom of this link for the bowden tube download set: http://www.print3dforum.com/showthre...ll=1#post44572 )

    Remember, the short piece of tube you need for the nozzle is 42mm long. In a pinch, trim it off the de-tangler tube in the cartridge case.
    Last edited by TommyDee; 07-15-2018 at 11:50 PM.

  4. Thanks bolsoncerrado thanked for this post
    Likes bolsoncerrado liked this post
  5. #14
    3D Printer Noob
    Join Date
    Jun 2017
    Posts
    15
    Post Thanks / Like
    Great work TommyDee, I just printed this in ABS from a stock cartridge with the files meant for PLA. (Cube3_b2b_tubenut, Cube3_B2B_M6_nozzle, Cube3_B2B_Bulkhead_m6, B2B_Nozzle_abs_la1 something something something)

    For reference I used fittings and tubing from Amazon UK ( https://www.amazon.co.uk/gp/product/...?ie=UTF8&psc=1) and it fits snug as a bug in the appropriate connectors, I was surprised to not be able to find the tubenut with m5/m6 threadings until I jammed the tube in there and realized it's just really not needed.

    For the second Nozzle I end up printing I think it might be worth bobbing a little tiny indentation/circular blob on the insert part that goes into the print nozzle holder contraption to help future drunk me from removing the head from the printer.

    Now to figure out how to splice the original tubing to fit appropriately, thread the threaded barrel nuts and how well this holds up without the circular clips and I'm good to go...

    ABS-PrintHead.jpg

  6. #15
    3D Printer God(dess)
    Join Date
    Nov 2016
    Posts
    1,566
    Post Thanks / Like
    Nice work! Love the color! And yes, I made the M6 threaded tubenuts to try them out but I suspect the original nuts work just as well to bind those M6 threads.

    The version I released on Thingiverse was specifically for an M5 fitting threaded directly to the core which kept the whole assembly simple.

    The only thing I am missing in your assembly is how the 2.8mm OD tube mates to the 4mm OD tube.
    In the previous experiment I ended up with the 4mm tubing going through the fitting to the nozzle tube (2.8mm tube).
    The mate is there just to make sure that the 2.8mm tube in the nozzle doesn't withdraw during pull-backs.
    This can obviously be managed by adding a small segment after the fitting. The core is deep enough to maintain a small piece of 4mm tubing.

    I am finding that I rarely have to remove the nozzle from the hot-end. I begin a test print and cancel (twice) when it begins to print. I then keep my finder against the nozzle housing "flag" while I unscrew the tube-nut. Once I'm clear of the threads, I pull the tube and get the full melt in one go. Normally this is followed by a lot of stringing. You'll get a process down for this. I just wrap this string around my finger. I then trim the melt so that the filament is ready to be changed. At this point, I don't want to do anything with the nozzle. It is hot and I don't like pulling it while hot. Sometimes you have to, but in general, I want to avoid changing the spring's tension parameters. It presses on different elements in the printer than when it is stand-alone. I haven't seen a failure yet, but the possibility is there so beware.
    To store the cartridge, I remove the tube set, trim the filament at the end of the bulkhead, and put it back in the sealed bag. I start the new cartridge by getting filament about 3/4" past the hot-end tube-nut. This I can feed directly into the tube of the nozzle. And as I always forget, -before- I put back the cartridge, finish pushing filament into the nozzle. This will make sure that the next print will begin almost immediately. now replace the cartridge or hub you are using.
    If you need to make sure that you get no color-bleed, let the next print run until it moves the hot-end. Hit Cancel and then Pause. You can immediately resume and it will go through a more thorough purge routine. So far, this method has provided a clean color change in a very specific location on the print... meaning, you can follow parts of this process at any time. The only difference in mid-print changes is that it requires the same chip to resume. However, while in pause mode, you can remove the cartridge and work with it as long as you want. The reason I keep outlining this process is that changing filament mid-print is the true advantage of this method. Planning a filament change mid-print only to be thwarted by a failing fitting will force you to cancel the print. That never sat well with me.

    Have you ever worked with the Dremel diamond grit cutoff wheel?
    I love that little tool. Although the disks are around $10, they work wonders on steel. They don't generate tons of heat like the cheaper cutoff disks.
    I cut a 7/32" drill bit flat on the end and it makes for a great de-chipper for the little knot in the pocket for the ringlet.

    When I get a change, I'll see if I can make a section diagram of what I'm aiming to accomplish with the internal bits.

    FWIW... the ABS version of the nozzle just has a little more clearance in the threads than the PLA version. This allows for free-spinning of the tube nut.

    If you decide to try the grooving tool, keep bicycle spokes in mind. Most bicycle spokes are a common gauge. This is so the threads are easy to make.
    What's good for us is that this size is 2mm exactly. This helps us put tubing in drill chucks so we can cinch down on it.
    But it also works to make the cutting tool for the grooving kit. If you cut the spoke near the head, you can even use the bend to see the orientation.
    Just grind down both sides of the rod until they meet in the middle at a fairly steep angle.
    If you don't have spare bicycle spokes, you might visit your local bicycle advocacy shop (bike recycle shop or group). They'll give you a dozen for free.
    A piece of bicycle spoke is what I use to qualify tubing as well. If it fits too tight, it is going to be problematic on some prints.
    I should be able to push a 6" piece of spoke through the tube just by pushing it through with filament.

    Again, way too many words. Let me know what I should expand upon.

    - - - - - - - - - -

    ...don't want to wait for the printer to cool down?
    Just turn the nozzle CCW and back to CW.
    This triggers the "nozzle present" switch and you are ready to print again.

    Don't do this if you use fittings! It will rasp the tubing.
    Last edited by TommyDee; 07-13-2018 at 10:28 PM.

  7. #16
    3D Printer Noob
    Join Date
    Jun 2017
    Posts
    15
    Post Thanks / Like
    Quote Originally Posted by TommyDee View Post
    Nice work! Love the color!
    All credits to you good sir, the colour on the other hand would be stock 3ds neon green, I've got 8 original carts still to be used

    Quote Originally Posted by TommyDee View Post
    The only thing I am missing in your assembly is how the 2.8mm OD tube mates to the 4mm OD tube.
    That bit hasn't been done yet, that's where it's going to end up getting...interesting. Scalpel/razor blade on the 2.8 to shave it down for direct connection to the "4mm OD/2mm ID" tube and a drill on the internal of the 4 to marginally increase the sizing and potentially alot of swearing/blood later. I did try looking for something like a barb or a 4mm to 2.8mm push fit sadly these things don’t seem to exist.


    Quote Originally Posted by TommyDee View Post
    I am finding that I rarely have to remove the nozzle from the hot-end. I begin a test print and cancel (twice) when it begins to print. I then keep my finder against the nozzle housing "flag" while I unscrew the tube-nut. Once I'm clear of the threads, I pull the tube and get the full melt in one go. Normally this is followed by a lot of stringing. You'll get a process down for this. I just wrap this string around my finger. I then trim the melt so that the filament is ready to be changed. At this point, I don't want to do anything with the nozzle. It is hot and I don't like pulling it while hot.
    Is this a general side effect of the use of this print head setup?

    Quote Originally Posted by TommyDee View Post
    I start the new cartridge by getting filament about 3/4" past the hot-end tube-nut. This I can feed directly into the tube of the nozzle. And as I always forget, -before- I put back the cartridge, finish pushing filament into the nozzle. This will make sure that the next print will begin almost immediately.
    I’ve rebuilt the stock cartridge way too many times to know about this one, forget to manually drive the cart and about 6/7 purges later due to my refusal to undo the 4 screws….

    Quote Originally Posted by TommyDee View Post
    So far, this method has provided a clean color change in a very specific location on the print... meaning, you can follow parts of this process at any time. The only difference in mid-print changes is that it requires the same chip to resume. However, while in pause mode, you can remove the cartridge and work with it as long as you want. The reason I keep outlining this process is that changing filament mid-print is the true advantage of this method. Planning a filament change mid-print only to be thwarted by a failing fitting will force you to cancel the print. That never sat well with me.
    I don’t see myself doing too many transitions mid print, I’ll be aiming to make 2 PLA and 2 PETG carts using stock ABS chips with colours I’ll keep fairly static, atleast for now.

    Quote Originally Posted by TommyDee View Post
    Have you ever worked with the Dremel diamond grit cutoff wheel?
    I haven’t but have a Dremel 3000 and the standard attachments so the closest thing in there would be a grinding disk: https://www.amazon.co.uk/Dremel-3000...ef=sr_1_1_sspa


    Quote Originally Posted by TommyDee View Post
    If you decide to try the grooving tool, keep bicycle spokes in mind. Most bicycle spokes are a common gauge. This is so the threads are easy to make.
    My understanding for the grooving tool is it’s used for the push fit connectors to give 360 motion without the push fits ripping the tubing right?


    Quote Originally Posted by TommyDee View Post
    If you don't have spare bicycle spokes, you might visit your local bicycle advocacy shop (bike recycle shop or group). They'll give you a dozen for free.
    A piece of bicycle spoke is what I use to qualify tubing as well. If it fits too tight, it is going to be problematic on some prints.
    I should be able to push a 6" piece of spoke through the tube just by pushing it through with filament.
    I haven’t quite caught up to the bike spoke need yet, still on the pre reqs of getting all those connectors printed/together which I’m working on at the moment. Speaking of which I’ve amended your M6 bulkhead with PETG wording on it and just had a successful print. 62.5% of the way to two carts…..

    Not the clearest of photos:
    PETG Bulkhead.jpg
    Quote Originally Posted by TommyDee View Post
    ...don't want to wait for the printer to cool down?
    Just turn the nozzle CCW and back to CW.
    This triggers the "nozzle present" switch and you are ready to print again.

    Don't do this if you use fittings! It will rasp the tubing.
    Cheers for the heads up!

  8. #17
    3D Printer God(dess)
    Join Date
    Nov 2016
    Posts
    1,566
    Post Thanks / Like
    Sweet!

    1st of all, you never need to splice the two tubes for my processes. I remember this method from the Fugatech video. I will say that this is a viable means to sphincter the tube in a stock nozzle, it is not required in any of my creations or even its variants.

    To keep it simple for your current level, just cut a piece of 4mm tubing to the length from inside the core to the exit end of your fitting. Use the 42mm of 2.8mm tubing and plug the short piece of 4mm tubing into the core. This is what happens when I plug in the tube-nut using the circlips. Again, with the thru-hole M6 fittings, I could just push the 4mm tube all the way into the core. In your case, you just have this fitting as an interruption. Just fill the remaining void with 4mm tubing.

    I also don't have to change filament too often for color changes in the middle of the print, but more often than not, I find myself having to decide if I still have 3 hours of filament left on the spool. Now I can print and print until it gets low. If it turns out I do need to add filament to complete the print, I just pause and reload more. This happens nearly once a week! And I use this very same method for general filament changes. The only thing I still hold sacred is keeping my ABS and PLA nozzles separated. This is to avoid burning PLA in an ABS nozzle creating some very stubborn carbon deposits in the tip. Not too hard to manage, I only have 2 ABS chips

    Standard Dremel cutoff wheels work very well. I've used them to cut mufflers of my hot rods. On tools, it does weaken the metal due to heat. But for plastics, no problem!

    Maybe I missed impressing the very purpose of all this. My 1st aha moment was wrapping the wire around a groove in the tube to salvage the PC4-M5 fittings. Works great if you make it a permanent connection. Perfect for the hub side of the bowden tube. The evolution was to use the ringlet inside a proper pocket (so it can't roll). That is where I went on to create the threaded tube-nuts so I could manage all the interfaces.

    If you are asking if not removing a hot nozzle is our only limitation, I would say that this is not a critical shortcoming. You can easily remove the nozzle if all you did was warm up the tip so you can remove the nozzle (cancel as it begins to print the test print, for instance). No issues doing this. But if you remove the nozzle after an 8-hour print... it is possible the end will try to elongate once removed from the hot-end. Having a few spare housings is never a bad idea.

    Bottom line about the design, there are several tight clearances around the tube features. This is primarily to make sure that edges of the tube -never- interfere with the driver-bites in the filament during feeding or retraction. So the "sockets" for the 4mm tubes are built-in to make sure they align to the mating tubes. In addition, by carefully managing tube lengths, we make sure the original 3DS design intent inside the nozzle is met. Same with the bulkhead end, I chose to use a tube length of 98-99mm to again minimize the gap between the bowden tube and the feed tube from inside the cartridge. Making the tube easy to remove from the driver is all about removing the internal spool without damage to the tubing. Just pull the tube from the driver assembly. I'll post more on the bulkhead end as I continue this thread.

    - - - - - - - - - -

    The "plug" is 5mm long and the tube-nut seats fully at the "socket" (core).

    socket1.PNG
    socket2.PNG

    - - - - - - - - - -

    BTW: in case you had trouble finding these, these two files have the M6 thread in them already for your M6 fittings.
    Again, I found this method to be somewhat limiting but you are welcome to the files.

    - - - - - - - - - -

    ...and yes, a permanent groove pushed into a fitting will let it rotate freely.
    I've even been able to remove the tube after the fact.
    I just don't know how long something like that would last without testing it.
    The groove probably needs to be just shy of 6mm from the end and doesn't have to be wider than 1/2mm.
    This could even be carved with an hobby knife using a taper for the "upper cut".

    |~
    |
    |
    \
    -
    |
    ---
    Attached Files Attached Files

  9. #18
    3D Printer Noob
    Join Date
    Jun 2017
    Posts
    15
    Post Thanks / Like
    Cheers Tommy, very helpful. Pretty much sums up what I ended up doing last night in the end after a few drinks the whole design just made sense. Shall try one of them out when I'm all done. Almost done with 4 replacements now....

    I skimmed through the forum and notice we still don't have a nozzle replacement, I'm sure this has probably been suggested before but has anyone considered these: https://www.amazon.co.uk/Parker-Ball...Y9R012TGCMEP1H

    That nozzle shaping looks surprisingly familiar....

  10. #19
    3D Printer God(dess)
    Join Date
    Nov 2016
    Posts
    1,566
    Post Thanks / Like
    Excellent out-of-box thinking on the nozzle tip

    I did see someone on Facebook carve one out of brass.
    Never heard the results of that effort.
    Curiosity question is whether or not the thermal characteristics remain compatible with the Cube 3 slicer.

    Then again, one of our own threaded the heater block to M6x1, in place no less!... and threaded in standard nozzle offerings.

    I have a slightly different situation where I do have to buy cartridges for work projects.
    This provides the spares I need. (nono... not that trash can!)

    But I will iterate that to date, I've burned 1 nozzle which went to good use by sectioning it.
    A build-up of carbon in the tip is what ruined it.

    The only thing that justifies the extra effort for the nozzle is specialized filament.
    Carbon filled, metal filled, glass filled... you name it. This is what shreds nozzles.
    I'm going to go so far as to suggest that the driver mechanism will wear faster than the nozzle during normal use.

    What I don't like about nozzles (?) is the fact that they vary in seated depth to such a great degree.
    This is another reason this bowden tube upgrade effort is so important by removing the nozzle from the cartridge assembly.
    Once you pair a set of nozzles, there is no reason to ever separate them for that specific material.
    You can match them 2 ways...
    Have several nozzle you can mix and match to get appropriate seating height (more work than you'd think!)
    Or make the adjustment that cracked so many white hot-end housings right out of the factory;
    This second method just aligns the head to the plate and the wipers.
    I opted for method 1, obviously.
    Method 2 means tweaking the hot end level with the two horizontal screws and being very careful with the two vertical set screws.

    - - - - - - - - - -

    Back 2 Basic Bowden Tube Set is ready for release.

    Making a reliable and successful bowden tube for the B2B solution takes a little attention to detail.
    First of all, the entire project hinges on the fact that you need to be able to cut a groove in a Teflon tube.
    This process has been covered in another thread for now. I will revisit the subject here as well before we put a nail in it.

    Speaking of nails, have you found a used bicycle spoke yet and confirmed it is 2mm in diameter?
    If you are not sure, just push it into the guide tube from the cartridge.
    Does it fit? Is it way too loose? Most likely you only need to worry about making it fit.
    Why do I make so much of a fuss about the bowden tube ID?
    Simple; there is a lot of yap about how determine proper clearance inside the tube.
    One camp will say as I once did; "You want accurate movement!"... meaning you don't want feeds and retracts to have too much slack by letting the filament just buckle within the tube. And there is some truth to this... but our little machine isn't built with that kind of precision in mind.

    As a matter of fact, we've done a great disservice to the design intent of the machine. Indeed! We went and yarded out a tube that stretched nearly 1/2" when the filament was under extrusion pressure. The resulting pressure curve is dampened considerably over the hard line we now run with every one of the hub mods. no wonder filament tends to strip easier with the modified bowden setups over the carefully crafted stock tubing upgrades. One of the best early mods I did was to join the cartridge de-tangler tube and spliced it to a shortened section of stock bowden tube. It maintained that original stretchiness and got rid of the torture route defined by 3DS. Now consider, those of you that follow, and understand the code behind retraction... don't you think they (3DS) took this stretch into account when they programmed the retraction routine? Off course they did!

    How about the other fact: when you run that gushy stock 3DS PLA filament through the rollers a few times, what happens? It gets wide! Much wider, as a matter of fact. If you are running the printer in a nice warm room, you can easily see the filament nearing a 2mm width by the time it reaches the print-head. Diamond infill is the worst culprit for failing mid-print. How do I know that, you ask? I've been diagnosing failed prints better than 2 years now. This is my only printer too (x5!). After I made the call for more precise tubing, it soon became obvious that was the very wrong way to go. And then I examined the stock tubing. It is a strange unavailable size as my sources tell it. It really is suppose to be just a hair over 2mm ID. The OD is just over 2.8mm. The stainless steel tube on the nozzle is exactly 3mm ID. Where the barrel nuts reside on the stock setup, the ID is diminished. As for the source of restriction, the barrel nuts are really bad; as a source of friction, however, it is much better than a full length of constriction along the inside walls of the tube. If you ever noticed, you can build up a lot of heat quickly with PLA/ABS inside a Teflon tube. And all that does is cause the plastics to swell from heat which is what plastic does. Kinda like global warming; cascade effect. This causes all kind of problems from stuck filament to overheated and overworked filament drive motors, wear on the drive mechanism, stripping of filament, and thin to utterly failed prints. All this because someone wants to convince you that "..any 'ol bowden tube will work...blah blah blah..." This is likely true for any hot-end-fed FDM printer. We don't have one of those. We're pushing filament into the tube that really wants as much room as practical. Bottom line, the less restriction, the better.

    Now that there is no need for the bowden tube to go into the hot-end, one would think we could change to another low friction tubing, right? Yea, sure!
    Seriously, I spent a lot of my hard earned money on testing various low friction replacement bowden tubes. Although rated at 4mm OD and 2mm ID, more often than not it came in on the small side of its 2mm spec. And I found that variants of Teflon had way to much friction right off the bat.

    So PTFE is the right material to minimize friction. But the tubes that were undersized still caused issues with some prints. Same issue; filament sticking or stuck in the tube. Sticking causes problems in prints like skips in a layer. This was so random that it took awhile to finally understand the tubing was still the culprit. The only reason I know this was the real reason for the problems is that I blamed the filament only to find the filament worked great once we got past all these little issues.

    You've heard me harp on making sure the ID is -at least- 2mm. I wouldn't go so far as to suggest the next SAE size, but I am saying you should know your tubing source. Again, after significant expense, I was learning that even dedicated 3D printing suppliers were selling what is arguably just more best effort tubing. It is nowhere near their stated specs! If you saw the video on the Capricorn tubing, you'll understand what I meant. However, with Alex's current stock, I highly recommend their dark blue! Why? Because the sample I got -doesn't- meet their spec but they met my requirement of being well over 2mm ID. The lighter blue came in at 2mm exactly. No margin, but the 2mm spoke was a snug fit. This also meets their spec.

    I've purchased all my usable tubing from one guy on eBay in China. His stuff has consistently been 2mm+ID. I've found some narrow sections on closer inspection, but I just trim around them now. I got 4 meters for $5-! I'm sure I can get a 1/2 dozen perfectly qualified pieces for this bowden tube setup.

    And imagine... once you have the right tubing, you won't need more! That is one of the benefits of the B2B project; -PERMANENT- bowden tubes.
    No more rasping the tubing with the fittings, no more tubing stuck in fittings, and no more broken fittings! Why, NO MORE FITTINGS!
    Check with Alex. Ask him if he still has the Capricorn Dark Blue from the spool he sent to me. That is some nice stuff but ask him to check the ID by running a spoke through it

    Anyway, the link is to the tubenut set prints which can be PLA, strong, cross... Will drop on the plate ready for left side nozzle; right side, spin 180 degrees. Should need too much cleanup. Just make sure they spin freely on the tube and in the nozzle housing. Cleaning out the blob in the ring-pocket will help with mating.
    (Crap, won't upload to the forum again! Alex!)
    https://drive.google.com/open?id=192...LJFJbuIdVYICdU

    Tubing can be as short as 17"; 18" preferred; and a 1/2 meter (almost 20") will minimize any influence on the print head.

    For the B2B system, there are 3 separate elements;
    Hot-End
    Bowden Tube
    And to follow - Cartridge Mod

    I just had to get all the above out there for people to make informed decisions.
    Even if you completely disagree, the decision to ignore my advice is still an informed decision
    Last edited by TommyDee; 07-15-2018 at 10:59 PM.

  11. #20
    3D Printer Noob
    Join Date
    Jun 2017
    Posts
    15
    Post Thanks / Like
    Quote Originally Posted by TommyDee View Post
    Excellent out-of-box thinking on the nozzle tip [IMG]file:///C:/Users/Admin/AppData/Local/Temp/msohtmlclip1/01/clip_image001.png[/IMG]

    I did see someone on Facebook carve one out of brass.
    Never heard the results of that effort.
    Curiosity question is whether or not the thermal characteristics remain compatible with the Cube 3 slicer.

    Then again, one of our own threaded the heater block to M6x1, in place no less!... and threaded in standard nozzle offerings.

    I think I might give it a go in the coming weeks once some other projects are out the way. I’m not feeling quite so adventurous with the m6x1 hard mod though!

    Quote Originally Posted by TommyDee View Post

    I have a slightly different situation where I do have to buy cartridges for work projects.
    This provides the spares I need. (nono... not that trash can!)

    Lucky devil, I seem to have a partially rounded motor connector on a particular cartridge so the whole cart is now a dud! And 3DS warranty are …..ass****s now. 3 dud carts they’re not willing to replace.


    Quote Originally Posted by TommyDee View Post

    What I don't like about nozzles (?) is the fact that they vary in seated depth to such a great degree.
    Printing with dual heads = I feel your pain, I’ve had up to 0.5 mm difference on the nozzles so far, outrageous!
    Having to manually adjust the nozzle height with every cartridge is starting to become a minor frustration has auto doesn’t work anymore.
    Quote Originally Posted by TommyDee View Post
    Speaking of nails, have you found a used bicycle spoke yet and confirmed it is 2mm in diameter?
    Not yet, I’ve just finished 4 nozzle replacements for this B2B setup and have been fiddling with the rounded PLA cart all morning. It’s black which I need to print with all day so looks like I’m about to cut and splice the filament into a working cart to get this job done today. Once that’s up and running I’ll look at finishing off the tubing.

    Quote Originally Posted by TommyDee View Post

    don't you think they (3DS) took this stretch into account when they programmed the retraction routine? Off course they did!
    The same retraction methods that make the stock cartridges ooze strings everywhere when it’s deciding to hate you. I think that’s more to do with forcing you to buy more consumables from them as the consumer gets fed up with poor prints!


    Quote Originally Posted by TommyDee View Post
    And imagine... once you have the right tubing, you won't need more! That is one of the benefits of the B2B project; -PERMANENT- bowden tubes.
    No more rasping the tubing with the fittings, no more tubing stuck in fittings, and no more broken fittings! Why, NO MORE FITTINGS!
    Check with Alex. Ask him if he still has the Capricorn Dark Blue from the spool he sent to me. That is some nice stuff but ask him to check the ID by running a spoke through it [IMG]file:///C:/Users/Admin/AppData/Local/Temp/msohtmlclip1/01/clip_image002.png[/IMG]
    I’m UK based and also bound to make a few silly mistakes so I’ll stick with the easy to acquire Amazon stuff and bike spokes just for the moment. Knowing me laziness will kick in and I’ll just give it a go with what I have this moment to get the prints I need finished done today.

    Quote Originally Posted by TommyDee View Post
    Anyway, the link is to the tubenut set prints which can be PLA, strong, cross... Will drop on the plate ready for left side nozzle; right side, spin 180 degrees. Should need too much cleanup. Just make sure they spin freely on the tube and in the nozzle housing. Cleaning out the blob in the ring-pocket will help with mating.
    (Crap, won't upload to the forum again! Alex!)
    https://drive.google.com/open?id=135...zqiYpbeHiTZ-Vg
    Blast, just as I’ve done the whole lot in ABS, I’ll give these a go too!

 

 

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •