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3D printed line follower (It Works!) — Parallax Forums

3D printed line follower (It Works!)

RaymanRayman Posts: 13,797
edited 2017-05-15 00:41 in Robotics
Getting close to finishing design of this 3D printed line follower...

Thought I'd post pictures, in case anybody has ideas on how to improve it...

Going for what I guess I'd call a "unibody" construction where there is just one big piece to print.
Then, just need to print the wheels and the ball (third wheel).

The top circuit board is my own with 3.5" LCD, but is same size as Activity Board, so can use that if need to.

The bottom board is also a custom copy of Sparkfun's line follower array.
673 x 709 - 92K
849 x 633 - 99K
737 x 713 - 108K
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Comments

  • RaymanRayman Posts: 13,797
    I added some nibs to retain the ball wheel and the top PCB.
    Added some holes for cables and sent to printer.

    Printer says it's going to take 35 hours to print... That's a long wait!
  • ercoerco Posts: 20,244
    Looks nice. 35 hours to print, YOW!

    I've had fun hacking some $5 line follower kits, I'm sure yours will beat those for speed!

    Please give my regards to Northern Virginia! I was a Woodbridge kid. You're in Vienna IIRC.

  • RaymanRayman Posts: 13,797
    I've seen a lot of dirt cheap line followers that are super fast.

    But, I've also been in a competition at Parallax where there were junctions and they only told you which path to choose right before the race. So, all of those would fail horribly...
  • ercoerco Posts: 20,244
    Lots of serious competition out there!



  • RaymanRayman Posts: 13,797
    Like, I said, none of those has junctions, right? Bot only needs brains when it hits an X or T junction...
  • Nice design Rayman, 35 hours is quite a process. When I see projects like this it makes me want to get into 3D printing.

    Do all finished products have that layered ribbing?

    Does it ever de-laminate?

    Can you get a smooth finish on a completed design?
  • RaymanRayman Posts: 13,797
    There are ways to "post process" 3D printed parts to make them look smooth and shiny.
    I haven't done that though...

    De-lamination and/or warping can happen on large parts, especially with ABS. PLA isn't as strong, but doesn't have this issue.
  • RaymanRayman Posts: 13,797
    Wheel is done :)

    Had to restart chassis print this morning though as build plate was not level enough for this big print and made a mess.

    Looking good now and total print time has updated to 19 hours.
    3264 x 2448 - 1M
  • That looks great! It doesn't look like supports were used, were they?

    I've been contemplating an ultrasonic acetone mister. If I could get my printer to do consistent overhangs...
  • RaymanRayman Posts: 13,797
    I printed it horizontal, so it did need supports...

    Some acetone polishing here probably would reduce friction. But, I think it'll be OK as is.
  • ercoerco Posts: 20,244
    edited 2017-05-13 23:01
    Nice roller! See also http://forums.parallax.com/discussion/166557/robot-mini-ball-bearing-caster

    You could use that, or print that type of snap-in holder on your chassis, sized to fit a ball bearing ($) or glass marble (very cheap). A great benefit of 3D printing is that you can print overhangs (AKA undercuts) which are impossible in injection molding without slides.

    s-l500.jpg
  • RaymanRayman Posts: 13,797
    edited 2017-05-13 22:56
    That's an interesting idea. If this roller has any issues, I'll try it your way.

    Robot is over 50% printed now. I probably should have only done 10% infill instead of 30%. That's probably one reason it's taking so long...
  • RaymanRayman Posts: 13,797
    It's done! Needs a lot of support and brim cleanup though...

    3264 x 2448 - 2M
  • ercoerco Posts: 20,244
    Beauteous maximus! That's a mother of a print, very apropos today of all days.
  • RaymanRayman Posts: 13,797
    It's together! Might actually work...

    The ball wheel and the circuit board are retained by the plastic nibs, so that worked.

    Only minor issue was with the bottom, it appears to have gotten real hot.
    Maybe room was too cold and heated build plate worked too hard to compensate...
    Might have been better to print with PLA where doesn't need heated build plate.
    Anyway, it took an extra bit of work to remove the support from the bottom, especially where the line sensor array goes.

    Now, I have to wait for my custom PCBs to get here...
    Till then, I can use the Activity Board...

    1024 x 768 - 1M
    1024 x 768 - 1M
    1024 x 768 - 1M
    1024 x 768 - 1M
    1024 x 768 - 1M
  • RaymanRayman Posts: 13,797
    edited 2017-05-14 18:18
    Also, I should have maybe left more room to access the hardware for mounting the servos...
    It was pretty tight up against the forward wall there...

    The chassis used ~100 meters of a 240 meter filament spool (that costs $25).
    So, that's about $10 in filament to print. Maybe $15 with wheels, tops.
  • RaymanRayman Posts: 13,797
    Also need to print a 6-cell AA battery holder.
    I've read that my servos easily take 9 VDC.
    With NiMH at 1.2V, six cells gets me to 7.2 V, which seems like a good place...
  • ercoerco Posts: 20,244
    Looks perfect from the top! We all have our best sides. :)

    In addition to line following, this beauty looks like promising a figure 8 candidate!
  • That's a pretty awesome build Ray!
  • Nice, sharp looking. I like how nice you cradled the board.
  • RaymanRayman Posts: 13,797
    Just tested it on driveway.. It works!

    Had to rotate the board 180 degrees though so could access USB port...
  • ercoerco Posts: 20,244
    edited 2017-05-15 01:02
    Need video, or it didn't happen! Driveways are perfect for figure 8s!
  • RaymanRayman Posts: 13,797
    edited 2017-05-16 10:54
    Ok, I made a lame, one minute attempt at a figure 8...




    Modedit: YouTube link
  • RaymanRayman Posts: 13,797
    I just published the design files here:

    http://www.thingiverse.com/thing:2322633
  • Rayman, you need to paste theYouTube link directly into your post. Using the button above just gives a white screen.
  • RaymanRayman Posts: 13,797
    edited 2017-05-16 00:44
    That's strange... works here...
    Does this work:


    https://youtube.com/watch?v=r25Xge8_asM

  • ercoerco Posts: 20,244
    Not lame, that's a great 8 with straight center segments, much fancier than most. You just need to get a sledgehammer and knock that wall out of the way.




    Or maybe just start farther from the wall. :)

    Great job!
  • Way to go Rayman.

    Your gonna need a bigger arena, that bot was born to motivate.

    Got a name in mind yet?
  • RaymanRayman Posts: 13,797
    RayBot, of course :)
  • ercoerco Posts: 20,244
    What else can you 3D print, RayRay?



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