Twicx's Dual E3D Direct-Drive Extruder

Discussion in 'E3D-v6 and Lite6' started by twicx, Mar 6, 2014.

  1. Josh

    Josh Administrator
    Staff Member

    Joined:
    Feb 26, 2014
    Messages:
    183
    Likes Received:
    39
    If you want strength I would increase the wall thickness, how many perimeters are you currently doing?
    Personally, I have avoided honeycombs, they are quite slow to print - why not try rectilinear with a fill of 50%? Avoid 100% - strange things start to happen and just for interest, it actually makes the part more prone to crack propagation. you should not really go above 90-95%..
    I would stick with 0.25 layers
     
  2. twicx

    twicx Well-Known Member

    Joined:
    Mar 6, 2014
    Messages:
    161
    Likes Received:
    0
    Ok, I'll try rectilinear on about 85%. 4 perimeters?
     
  3. Josh

    Josh Administrator
    Staff Member

    Joined:
    Feb 26, 2014
    Messages:
    183
    Likes Received:
    39
    Should be absolutely solid.
     
  4. Eaglezsoar

    Eaglezsoar Administrator

    Joined:
    Mar 7, 2014
    Messages:
    267
    Likes Received:
    0
    At 85% infill it should be like a tank!
     
  5. twicx

    twicx Well-Known Member

    Joined:
    Mar 6, 2014
    Messages:
    161
    Likes Received:
    0
    Yeah, see i need it pretty dense, but i know at those higher densities, you can get layers separating from each other. I had great ambition last night to have another go of it, but when you get out of work at 6 after a day of meetings, even the idea of turning on a laptop is a mammoth task.

    Tonight, I have the gcode ready to go, I've the house to myself, I'll order pizza, and give this another go.
     
  6. Eaglezsoar

    Eaglezsoar Administrator

    Joined:
    Mar 7, 2014
    Messages:
    267
    Likes Received:
    0
    Yes, indeed those high infills will cause separation. I will not normally go over 50%. Enjoy your pizza!.
     
  7. twicx

    twicx Well-Known Member

    Joined:
    Mar 6, 2014
    Messages:
    161
    Likes Received:
    0
    do you think ~80% would be enough to keep it pretty dense so its strong enough, but sparse enough to avoid separation?
     
  8. Eaglezsoar

    Eaglezsoar Administrator

    Joined:
    Mar 7, 2014
    Messages:
    267
    Likes Received:
    0
    That question is iffy, my answer must be to try it once and if the layers separate, take it down to 50%. It is worth a try to use the 80, try to keep all drafts away from it while printing.
     
  9. twicx

    twicx Well-Known Member

    Joined:
    Mar 6, 2014
    Messages:
    161
    Likes Received:
    0
    Ok, so a few little problems last night.

    Firstly, I couldn't seem to get any ABS to print. It was a feed issue, in that it just wasn't feeding at all. At 240C, when I did manual feed through repeteir host, it would feed fine, but it wouldn't feed during normal print, regardless of things like feedrate etc. I tried cleaning the nozzle, but no such luck. I had a few problems with the hot end being to close to the bed, but even when it was fixed, no such luck. I think it's possible that 240 is too hot and it's clogging a little, but I don't know if 220-230 is too cool. It's something I have to try. I also think I would benefit from stronger compression springs for the bed, but I wont get to the hardware shop to get them till next week at the earliest. Any suggestions on things I could try, as always, is appreciated.

    Now all this brought me back to my actual application of ABS. I've said it before and I'll say it again, I hate ABS. I'm using it here purely out of necessity. PLA is such a nicer material to print with, less temperamental, better for the environment, cheaper etc etc. Once this carriage is done, I'll never use ABS again. The problem is that I just need the carriage in ABS so it wont melt when I go to print in PLA. However, I would wonder if I would get away with PLA. Because of the design of the extruder carriage, and moreso the design of the E3D hot end, I might be ok with PLA.



    Attached is a very rough section of the new extruder. As you can see, the extruder holds the hot end at the top, and once it gets to the ribbed section of the hot end, it's cooled by a 12V fan that's about 5-10mm from the hot end. I know PLA gets soft and maliable around 80-90C, but I wonder would the fan cool it enough so that the top part of the hot end, where it's held to the carriage is below that point of melting. IF it was, I could very possibly get away with PLA, which to be honest, I'd prefer, because I've always had excellent results printing it at 100% infil. This would be a preferred solution immensely, BUT, I'm not familiar enough with the E3D to know if it would be cool enough at the top. Can any of you guys shed some light on it based on me printing PLA at 180-190C?
     

    Attached Files:

  10. Chavaquiah

    Chavaquiah Active Member

    Joined:
    Mar 1, 2014
    Messages:
    31
    Likes Received:
    0
    (Again the caveat that my experience is very limited, but...)

    I think PLA would be too risky. It's not that it will melt but, from 60ºC on, it starts getting soft and, with time, it will deform badly. Now, with proper cooling and without an enclosure for the printer, the top of the E3D will remain cool. However, convected heat from the bed and heat from the motor will probably be enough to push PLA past the limit. Not to mention the risk of the fan stopping unexpectedly (happened to me with a failed print that filled the area with strands of plastic).

    I'd like to encourage you to solve the ABS problems. I used to hate it, just like you and for very similar reasons. Now that I can print reliably with ABS, I tend to not care so much. As a matter of fact, with a E3D hotend, I'm getting better textures with ABS than with PLA. At least with the cheap and nasty material I tend to buy.

    Nowadays, I print ABS on kapton tape rubbed with vinegar. Bed at 115ºC for the first layer but dropping to 80ºC afterwards. For pieces with very thin areas on the first layer I use hairspray - the cheapest most awful brand possible, bought from Spain at €2.50 for a jumbo sized can. I also used to get great adhesion with UHU glue.

    As for the (lack of) feed, could it be there is an obstruction in the nozzle? Did you try to let the filament cool down below 150ºC and then retracting it?
     
  11. twicx

    twicx Well-Known Member

    Joined:
    Mar 6, 2014
    Messages:
    161
    Likes Received:
    0
    Yeah I gave the nozzle a good clean and got a bit of gunk out of it. Its sticking fine, and I'll probably go back to printing it on kapton with hairspray so I'm not having to remove the glass to clean it so often. Part of me thinks that since I changed the thermistor on the hot end, its too hot, so dropping it to 220 should still be hot enough to print, but not too cool that it won't stick.

    You might be right about the whole heat deforming thing, but there's no harm checking. I'll keep at it with the abs, but if I don't get anywhere soon, I'll just get it printed somewhere else.
     
  12. twicx

    twicx Well-Known Member

    Joined:
    Mar 6, 2014
    Messages:
    161
    Likes Received:
    0
    Ok, so I made some progress, then hit a snag, then made some progress, then hit a snag. UGH!

    First thing's first, problems with the bed are now zero. I'm printing onto Kapton on aluminium, with hairspray, and its sticking fine.

    The problem now is with the hot end. It feeds for a bit, then stops feeding. So I took the whole extruder apart and gave it a good cleaning. I'm trying to eliminate problems, but I'm now wondering if either a) I don't have enough (or too much) tension between the hobbed pulley/fillament/bearing OR, I've the pot for the motor too low.

    The guide I was always given for the pot is start at about 1/4 turn clockwise, then slowly adjust it up till it doesn't skip. But now I'm questioning that.
     
  13. Eaglezsoar

    Eaglezsoar Administrator

    Joined:
    Mar 7, 2014
    Messages:
    267
    Likes Received:
    0
    I wish I could help but you are at a point now where only experimenting with different adjustments is about your only recourse.
    Best of luck to you in getting this to work.
     
  14. twicx

    twicx Well-Known Member

    Joined:
    Mar 6, 2014
    Messages:
    161
    Likes Received:
    0
    Right, so good news!

    Density 85%, .25mm layers, 5mm brim, bed @90C, hot end at 245C, printed on Kapton, no glass, with Tresemme super mega freeze hold number 5 death grip hairspray (or whatever its called), 4 perimeters, 6 solid shells

    After all that, the base of the extruder is FINALLY printed. It worked out nicely actually. I had to keep a close eye on it for about the first 6-7 layers, because the extruder would go back and forth between skipping, and not feeding enough. I constantly tweaked the pot back and forth, leaving the feedrate in Repeteir host at 100. Once I found the sweet spot, there was no other problems. Print speed for the first 4 layers was 40%, then up to 50%, and it all went just fine.

    So hopefully by next weekend, I'll get the other parts printed, but I've a lot on over the next few days.
     
  15. Eaglezsoar

    Eaglezsoar Administrator

    Joined:
    Mar 7, 2014
    Messages:
    267
    Likes Received:
    0
    85% density? Wow, that should support 3 tons!
     
  16. twicx

    twicx Well-Known Member

    Joined:
    Mar 6, 2014
    Messages:
    161
    Likes Received:
    0
    Yeah, it's pretty damn solid! But I had to do that, because there's a part in the middle where the two hot ends are held that's about 7-8mm thick. It's the weakest point, but it's the pivot that'll take the weight of the 2 motors, and they're not light.

    In anycase, it'll also have another little support piece, so it should be pretty strong. The other benefit of all this is that when it comes to printing other nice materials that require a higher temperature on the new setup, I should have a much clearer idea of the setup to use.
     
  17. Eaglezsoar

    Eaglezsoar Administrator

    Joined:
    Mar 7, 2014
    Messages:
    267
    Likes Received:
    0
    Now I understand why you made it so strong.
    Great job!
     
  18. janny68158

    janny68158 New Member

    Joined:
    May 17, 2014
    Messages:
    1
    Likes Received:
    0
    The printing in china have the good sources about the printing products,you can have a look at.
     
  19. twicx

    twicx Well-Known Member

    Joined:
    Mar 6, 2014
    Messages:
    161
    Likes Received:
    0
    [​IMG]

    So its been a little while since I've gotten to do an update, but I've made progress! That's now the base part with the two locks for the hot ends in place. Fits nicely and they're pretty damn level which I'm pleased with!

    I figured out that there were 2 reasons it wasn't feeding right. It was a combination off too much tension at the feeder, and not enough power at the driver. But it looks to be feeding ok now. I have maybe 2 or 3 parts left to print, but its finally starting to come together.
     
  20. Eaglezsoar

    Eaglezsoar Administrator

    Joined:
    Mar 7, 2014
    Messages:
    267
    Likes Received:
    0
    That looks really good and the fact that they are level is great! So many require shims etc.
    Good job!
     

Share This Page