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Discussion in '3D printers' started by Carl Feniak, Sep 29, 2014.

  1. Carl Feniak

    Carl Feniak Journeyman
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    If true that could cause issues with close parts and dual nozzles. (different layer heights for side by side objects)
     
  2. CapnBry

    CapnBry Well-Known
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    Did I miss where you posted what size your motor is? Mind posting the specs again? I use a 40mm NEMA 17 (300g) for Carl's direct drive extruder at 0.6A and am curious just how light you can get with the Titan.
     
  3. wackocrash5150

    wackocrash5150 Well-Known
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    Luckily I only have a single nozzle. So I splurged and picked up both S3D and a BLTouch today. I imagine i'll be on the hunt for a direct extruder plate STL that supports both a generic mechanical endstop AND the BLTouch ... lol
     
  4. Elmo Clarity

    Elmo Clarity Journeyman
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    • 13Ncm(18.4oz.in) holding torque
    About 5.6 oz.

    Do a Google on short body NEMA 17
     
  5. TechGirl

    TechGirl New
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    I've just tried using different layer heights on my DaVinci Duo 2.0a. I used 'Auto-configure for Print Quality' settings of 'High' (0.1mm) and 'Fast' (0.3mm) with a brim of 10 lines. I watched as it printed and found that it printed the brim at 0.1mm around the two identical parts, this was followed by three layers of the part at 'High' quality followed by 1 layer of the part at 'Fast' quality. This continued until both parts finished printing.

    I'll try and make a more extensive test using all three layer heights over the weekend and hopefully capture it on video.
     
  6. Spiffcow

    Spiffcow Well-Known
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    How fast are you able to print with that setup? I have a ridiculously heavy motor on mine, and I didn't see any ill effects until printing at around 120mm/s.
     
  7. Elmo Clarity

    Elmo Clarity Journeyman
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    Here is the link to the one I bought on Amazon. They are out of stock on them right now. Just bought another one on eBay for about the same price.

    http://www.amazon.com/Short-Bipolar-Motor-18-4oz-13Ncm/dp/B00PNEQ79Q
     
  8. Carl Feniak

    Carl Feniak Journeyman
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    That should work out as they are multiples of each other. Just thought of it as you can also do this with slic3r but it is a bit of a painful process to setup. I suspect it is easier with S3D.
     
  9. TechGirl

    TechGirl New
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    It's a lot easier with S3D. The auto config will always give you multiples of each other, based on the nozzle diameter. It does the same thing on my Prusa i3 where I use a 0.5mm nozzle rather than the 0.4mm of the DaVinci.
     
  10. Elmo Clarity

    Elmo Clarity Journeyman
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    I have been thinking about this some. What if I stacked the second extruder over the first, but offset so the tube has a straight shot to the hotend? While the tube would be longer, it would not add as much to the width.
     
  11. Carl Feniak

    Carl Feniak Journeyman
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    The tube would be like a very short bowden and should work fine functionally. From a dynamics perspective the raised/offset weight will put torque on the XY bar every time it accelerated/decelerated, though so does my current direct drive version.
    Another option is to mirror them so the two transparent plates face each other and the motors hang left and right. The titan extuder isn't symmetrical so it won't be aesthetically pleasing, but it will make for a tighter carriage.
     
  12. Elmo Clarity

    Elmo Clarity Journeyman
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    So the main offset is in the Y axis and both are on the same side of XY bar?
     
  13. Carl Feniak

    Carl Feniak Journeyman
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    Just an alternate idea if you don't like front & back plate mount option. But yes, the nozzle would be offset in the same direction of the XY bar.
     
  14. AK Eric

    AK Eric Journeyman
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    It may actually account for that based on the right settings. I say may because, it has the ability to actually print multiple parts in multiple processes at multiple steps, based on the dimensions of your machine. Meaning, it'll print 2mm of partA, then move over and print 2mm of partB, then move back to A and do 2 more mm, etc. I've never tried it, but the functionality is there.
     
  15. Spiffcow

    Spiffcow Well-Known
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    I have created a parametric 3 piece bracket generator for V-Slot extrusions and some handy OpenSCAD extrusion modules to accompany it.. If anyone is interested, you can use Thingiverse Customizer on it here: Parametric V-Slot Corner Bracket by spiffcow or you can visit the github repo here: GitHub - spiffcow/r-bot: R-Bot is a collection of modifications for Carl Feniak's C-Bot 3D printer

    Edit:

    I also added C-Bot specific corners that can be printed without supports at C-Bot Bottom Frame Corners by spiffcow
     
    #2445 Spiffcow, May 6, 2016
    Last edited: May 6, 2016
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  16. Spiffcow

    Spiffcow Well-Known
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    So I'm wondering.. How much shaking is "normal" on a typical C-Bot? Mine starts shaking pretty hard around 120 mm/s. I have it on foam pads and the print quality is still "okay" but the bed isn't shaking in unison with the frame, creating some wavy patterns. I'm considering putting a second Z assembly on the front to try to mitigate the shaking by making sure it all shakes in the same direction, but I would first like to know if it should actually be shaking in the first place.

    I'm using the direct drive extruder with a very beefy motor (it's probably close to 1lb in weight). Do I just need a smaller extruder motor?
     
  17. James A. Doty

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    Duct for duel E3D extruder set up.

    Let's hope I'm posting this correctly. Up until now I've been lurking.

    I'm a bit more than a month in to building a C-bot and I've run across an issue.

    There's a parts duct with mount for a single extruder set up in the stl files I downloaded but I can't find a set up for two parts ducts.

    Has anyone designed or found someone else's design for setting up a parts duct for use with twin E3D hot ends?

    Thanks.
     
  18. Carl Feniak

    Carl Feniak Journeyman
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    Yeah, I think it is due to the heavy moving mass. You'll have to clamp down a lot on you acceleration limit to get the vibrations out. That said, if I were to do an extra large build what you said is exactly what I would do: replicate the rear wheels to the front and use the front back lead screw arrangement. Should help in your situation as well for out of sync vibrations, but the root of the issue (large momentum shifts) will still be there.
     
  19. Carl Feniak

    Carl Feniak Journeyman
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    I've designed one, but it needs some reinforcement as it is vibrates too much for my liking. Cooling is good though.
     

    Attached Files:

  20. Spiffcow

    Spiffcow Well-Known
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    Okay cool -- that may be my next project :) Is there reason to do front/back instead of on the sides if I have a second set of wheels on the front?

    Also (and this is kinda pie in the sky, but...) if I were to redesign a bunch of parts for, say, 4040 extrusions, do you think that would make a significant difference? Or is it not the limiting factor here? Of course, it's a lot cheaper to just buy a smaller motor, but less fun :)
     
  21. Carl Feniak

    Carl Feniak Journeyman
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    If I were to use an aluminum plate as a base for the heated bed, then I wouldn't need the Z cross rails at all for the setup!
    Hmm 4040 or C-Beam could make something interesting... perhaps 15 mm GT2 belt instead of 6mm... what devilry are you up to?
     
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  22. Chris Roadfeldt

    Chris Roadfeldt Journeyman
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    I will say that I will never give up my aluminum build plate.... Spreads the heat out more evenly, super flat, countersunk screws so the whole build plate is available for printing and still have my choice of print surfaces if I choose. The downside is that I don't want to run the aluminum surface naked, so I use tape which produces lines on the bottom of the prints. Not a big deal and can be mitigated with wide rolls of tape or even attaching glass to the bed with binders.

    The sandwich I have, ¼ inch wood on the bottom, ½ inch real cork, ⅛ silicon, heater and then aluminum plate worked better than I expected. It's heats up much faster than my Prusa i3's 8 inch plate, which is not insulated, but will be when I get around to C-Botisizing it.
     
    #2452 Chris Roadfeldt, May 7, 2016
    Last edited: May 7, 2016
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  23. AK Eric

    AK Eric Journeyman
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    I have yet to get around to it based on where my printer is placed, but if I could, I'd bolt the back-top of it directly to the wall: I think that would help resolve issues you're describing immensely.
     
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  24. Spiffcow

    Spiffcow Well-Known
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    That's a good point on the aluminum bed.. The cost of shipping probably isn't much different, and the plate itself is dirt cheap. You'll have to have something else underneath to hold the heatbed to it, unless you give up leveling springs in order to mount directly to the extrusions like I did, you probably already have to do that.
    Heh, I wish I had a concrete plan for what I want to do.. Truth is I have too many plans, but not enough time/money/skill to implement them. I was toying with the idea of trying to make an entirely parametric C-Bot derivative where you could choose your extrusion profile along with your build area and have the program generate all your STLs, BoM, etc. I figured it could include several options so you could trade off between quality/cost/convenience without having to trial-and-error it. But mainly it just seems like a fun way to learn software CAD modeling, and might look good on a resume if that skillset is ever in demand :)
     
    #2454 Spiffcow, May 7, 2016
    Last edited: May 7, 2016
  25. Spiffcow

    Spiffcow Well-Known
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    Heh, I feel like an idiot.. I spent half the day trying to think of an acceptable place to bolt it to the *floor*, and it never even occurred to me to just bolt it to the wall like ever other piece of large furniture!

    Update on the shaking.. I'm not printing the same thing so I can't say for certain, but I put the tiny 2020 corner brackets on the narrow corners on the corners along the sides and the shaking has reduced dramatically, along with the noise level.
     
  26. James A. Doty

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    That's a cool looking design though. I'll take a closer look at it later this weekend. Thank you.
     
  27. Carl Feniak

    Carl Feniak Journeyman
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    The small arms mount tot he rear plate, extending down and in each direction. The fans attach with their arms that allow you to pivot the fans to get the airflow angle you want (don't want the to blow on the heater block of the nozzle directly). If you were to mirror the arm to the other side of the fan you could link them with a bar across the front. Might help with rigidity, but they are usable as is.
     
  28. James A. Doty

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    I'm printing cones at the moment but once I'm done with that I'll print the fan ducts you posted and try them out. Thank you for your help. I'll also try mirroring the arm as you suggested.

    My poor Two Up has been printing C-Bot parts pretty much non stop for a month now.
     
  29. IanT

    IanT New
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    Finally got the parts to start my build today. Frame was put together this afternoon.
    Does anyone have any issues of screws coming undone? What are peoples thoughts on threadlocking everything?
     
  30. Elmo Clarity

    Elmo Clarity Journeyman
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    I have had some screws come loose. If I was building from the start, I would use some thread lock.
     

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