Thanks Thanks:  1
Likes Likes:  0
Dislikes Dislikes:  0
Results 1 to 7 of 7
  1. #1
    3D Printer Noob
    Join Date
    Dec 2018
    Posts
    10
    Post Thanks / Like

    Cube 3 Heads keep jamming.

    Hey guys, I recently picked up a new Cube3 printer and am having some issues.
    The heads are constantly jamming, normally I will get it to successfully purge when reinstalling a new cartridge, but it seems to jam the next time I heat it up to print or purge.

    I am feeding a different brand PLA into it, but have had this plastic work succesfully on my other printer.
    Also I have tried with different plastics, changing the feeding tubes and different heads, but all of these eventually end up blocked.
    Any ideas?

  2. #2
    Super Moderator
    Join Date
    Nov 2016
    Posts
    2,024
    Post Thanks / Like
    The long standing belief that that the nozzles are clogging is a myth. The filament is actually getting restricted in the stock bowden tube that has the caterpillar tracks on it. This caterpillar track is called an Over-Mold. they take a virgin Teflon tube and put it in a mold machine, heat up the nylon, and squirt it all around the Teflon tubing with the cavity as you see it when it is withdrawn from the process. What has happened to a lot of cartridges, by my best estimate to date is 50% failure rate, is that the ID of the Teflon tubing is reduced sufficiently to restrict free flow of the filament before it ever gets to the nozzle. This is due to the fact that the tube is restricted and the filament is broadened out by the filament driver. If the print exhibits a lot of pumping back and forth, the problem is exacerbated. Know this; Teflon is not as slick as one would thing when trying to slide PLA over it. It has significant stiction that the drive motor has to overcome. In doing so, it further broadens the filament to a point where it literally gets stuck in the tube.

    Having said all that, of course there are other restrictions that can get in the way. I am no fan of the barrel nuts places on both ends of the Bowden tube. These too are restrictions but by a lesser degree only in that the restriction is only a very short length. However, this is enough to cause breaks and other failures. if, during your rebuilding of the nozzle to clear a jam you turn the barrel nut "just a little further" for whatever reason, you have again created a greater restriction at the hot end barrel nut. I know because I've done it. I've been chasing these failures for over a year now and I stand by what I am putting in words here from experience.

    There are a number of ways to deal with this. Some good and some better. Basically, replace the bowden tube! It doesn't matter with what, just that you have some really bad cartridges and you won't get anywhere until you address this issue.

    If you want to do this the fast way, rip off the caterpillar track! That alone will remove the restriction and give the Teflon part of the tube the chance to go back to its original state. Teflon is good that way. I've recovered some very bad tubing by simply working it to recover its original ID of .086" or close too it (2mm is sufficient). it is a bit tricky, but you want to remove the original tubing from the driver mechanism end. I don't prescribe to this method, but in a pinch, it will work.

    We've been batting around replacement hubs on this forum for the same amount of time I've been chasing these issues. I've finally come to the conclusion that if I can pass a 2mm rod from one end of the filament path to the other, from driver mech. to nozzle, I won't have issues with most 3rd party filament or 3DS filament. The only exceptions are harder filaments that do not work well with the fixed driver gap. That's another story, and a different solution.

    I removed the barrel nuts in my setup. I don't like them and I certainly no longer need them. However, let me make a very strong statement here with regard to your printer's performance if you opt for a 4mm OD bowden tube solution:
    The Cube3 was developed and the configurations are based on the flex of the stock 2.8mm OD Teflon tubing used in the bowden tube and the take-up tube in the cartridge.
    This stuff stretches! And they recipes that 3DS came up with takes this into account. When we all switched over to stiffer 4mm tubes, you will see more "drooling" from the nozzle. These manifest as "blobs", for lack of better terms, at the start/stop of each layer. When the printer goes into slow mode to cover minimum layer time, it becomes even more pronounced. However, it must be said that changing the characteristics of your bowden tube will affect your prints.

    Having said that, I have noted that ABS prints using 3DS ABS come out beautifully. These prints are not severely affected by the characteristic changes in bowden tubes length changes. PLA, on the other hand, causes serious drool. So now that you know, you will also know to look for this.

    I am using the Universal Hub talked about in these forums. I no longer have jamming issues; no longer do I have broken filament in the bowden tube. I still get broken filament at the entrance of the driver mechanism if I am using a particularly brittle filament. However, during printing, not an issue. These particular type of breaks take time and printing simply doesn't give the filament idle time to drive a fracture to failure. Let it sit overnight and the results could be different.

    I said a lot here and there are directions you can go. If you have 4mm bowden tube available and common PC4-M5 fittings, thingiverse has a full set of parts to make a replacement bowden tube and nozzle. You can look in my collection to put the pieces together: https://www.thingiverse.com/Qube3Bot/designs

    These are amazing little printers. You will find references and resources to modifying the print files here on the forum. I find that printing PETG using the Ekocycle slicer to be a very satisfying alternative to ABS. You will find that 3RD party ABS sucks in the Cube3, but run it with an Ekocycle profile, and the parts come out amazingly well.

    If you want to get the most out of your recent investment, I highly recommend you find useful subjects on this forum. You will find that this forum is the no.1 resource for Cube3 printers to date. But be aware; most of these efforts have been evolutionary and you can read a lot of this forum as a blog. Feel free that start new threads as you see fit to keep from loosing good information in a long and diverse thread. Even I loose track after all this time. I will be happy to share the most recent information I have with regard to these little marvels or share the history behind some of the posts that are interesting to say the least.

    One thing I will say is that your experience with your printer is certainly not unique. However, I will also say that depending on your level of effort, these printers can be made to be highly reliable. The only problem remains; these printers utilize a proprietary slicer. And in my book, that is not all bad. We are learning more and more about this printer. I can confidently say that even the little quirk about the bowden tube change can be managed with certain tips and tricks.

    Let us know how you get on with these suggestions and how you wish to proceed.

  3. Thanks Nuclearsheep thanked for this post
  4. #3
    3D Printer Noob
    Join Date
    Dec 2018
    Posts
    10
    Post Thanks / Like
    Thank-you so much for this detailed post, there is alot of helpful information here!
    I have been playing around with the tubes and adjusted the barrel nuts, so I am now thinking I may have actually made them too restrictive.
    I will look into ordering some better fittings and tubing and see what kind of results I get.

    Huge thanks again for your help! I will update my progress here later incase anyone else is interested.

  5. #4
    Super Moderator
    Join Date
    Nov 2016
    Posts
    2,024
    Post Thanks / Like
    Anytime Nuclearsheep. Happy Printing!

  6. #5
    3D Printer Noob
    Join Date
    Nov 2017
    Posts
    26
    Post Thanks / Like
    Just want to chime in here.. You'd want to physically cut up the plastic parts of the nozzle so the bowden tube goes straight down into it (the bowden tube would arc over the top of the printer, e.g. like an ultimaker, instead of the 'S' shape they have it going in).

    And also some objects are prone to nozzle jamming due to lots of retractions 'pumping' the filament.

  7. #6
    3D Printer Noob
    Join Date
    Dec 2018
    Posts
    10
    Post Thanks / Like
    Update: Problem solved!
    I recently got my new bowden tube and fittings in the post and have placed them with a mod from thingiverse. I have had immediate success from this procedure, my prints look great and there is no clicking sounds at all! I would highly recommend replacing the bowden tube to any users out there who plan on using these printers!
    Thanks again Tommydee for your great advice. And in regards to your suggestion MarkRon I have previously cut the plastic nozzle head so that it is vertical, I am sure this is also helping with the feeding process.

  8. #7
    Super Moderator
    Join Date
    Nov 2016
    Posts
    2,024
    Post Thanks / Like
    You are welcome on behalf of all the fine people in this forum who have dedicated time and effort to land at this very same conclusion

    Happy Printing, Buddy!

 

 

Posting Permissions

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