1. Got a question or need help troubleshooting? Post to the troubleshooting forum or Search the forums!

Glazing, filling in gaps post processing.

Discussion in 'Projects' started by collin, Nov 1, 2014.

  1. collin

    collin New Member

    Joined:
    Mar 21, 2014
    Messages:
    313
    Likes Received:
    86
    So, im working on some parts for work right now that require smooth surfaces. I am prototyping a resin shoe for a carbon fiber winding machine. basically the part is a block with little valleys in it that the fiber travels through and gets soaked in resin. so its important these valleys are very smooth.

    my question to you guys is: what do you do to smooth parts. im not talking anything atheistic im talking about maybe a glaze or enamel you recommend with pla/pha.
     
  2. Printed Solid

    Printed Solid Volunteer Admin
    Staff Member

    Joined:
    Feb 21, 2013
    Messages:
    1,605
    Likes Received:
    1,002
    You probably need to consider outsourcing some inserts even for a prototype. You can do something like EA smoothing, priming/sanding, and/or spray lacquer, but I wouldn't really expect any of those to last more than a very short period of time against carbon fiber. You could conceivably 3D print an overall structure in plastic, but then have the bearing surfaces metal printed or machined and then coated with something harder.
     
  3. Ziggy

    Ziggy Moderator
    Staff Member

    Joined:
    Feb 20, 2013
    Messages:
    707
    Likes Received:
    530
    Maybe print the part in ABS and smooth it using acetone vapor?
     
  4. collin

    collin New Member

    Joined:
    Mar 21, 2014
    Messages:
    313
    Likes Received:
    86
    see that was what i was thinking. actually note to printed as well, the pla/pha does actually react to acetone but only slightly so the acetone must be applied to the surface directly, and it really only works on rounded edges, but non the less its an option.


    any ways, here is what im dealing with any ideas?
    http://imgur.com/a/9TLJo
     
  5. Printed Solid

    Printed Solid Volunteer Admin
    Staff Member

    Joined:
    Feb 21, 2013
    Messages:
    1,605
    Likes Received:
    1,002
    It looks like that's just a case of not having enough infill so you're not getting good compression at the top layers.
    Gently sloping parts like that can be a little tricky because you don't really have any top layers. I.e. you can't correct the issue with more top layers.
     
    2 people like this.
  6. Mike Kelly

    Mike Kelly Volunteer

    Joined:
    Mar 11, 2013
    Messages:
    6,967
    Likes Received:
    2,275
    Looks like under extrusion. Possible causes:

    Filament diameter out of spec and needs to be more accurate
    Step per mm are wrong and need to be recalibrated
    Clog in the nozzle
    poor cooling on the cold part of the hot end and it's causing material swelling before it can reach the nozzle.
     
    2 people like this.
  7. collin

    collin New Member

    Joined:
    Mar 21, 2014
    Messages:
    313
    Likes Received:
    86
    Well I just put a .6 mm nozzle on and changed the value in my slicer (simplfy3d)
     
  8. collin

    collin New Member

    Joined:
    Mar 21, 2014
    Messages:
    313
    Likes Received:
    86
    I know this
    I know this to be true. I think it must be that I've changed out my nozzle for a .6mm. I did change in in my slicer but maybe it was mislabled idk. I'll do a little more digging whut I get home
     
  9. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
    Staff Member

    Joined:
    Feb 21, 2013
    Messages:
    22,556
    Likes Received:
    7,226
    Changing the nozzle certainly affected mine. Significantly. It may be related to the 'some nozzles over extrude' issue...
     
  10. 1d1

    1d1 Active Member

    Joined:
    Feb 21, 2013
    Messages:
    418
    Likes Received:
    216
    If you Must salvage that part, tiny tools and bondo is a technique used by some restorers for frames, etc. but it requires sanding and shaping after application. It works a treat, but it requires practice. Personally, I'd find a way to get it to print better...
    Good luck!
     
  11. collin

    collin New Member

    Joined:
    Mar 21, 2014
    Messages:
    313
    Likes Received:
    86
    Its looking like my best bet is to reprint the part with my original nozzle.
     
  12. collin

    collin New Member

    Joined:
    Mar 21, 2014
    Messages:
    313
    Likes Received:
    86
    Hey check out pressure+acetone post processing of that piece.

    surprise! acetone works on pla pha surprising well because only the pha. so I dipped a cotton cloth in acetone and just rubbed it until it wore down to this. it only took a couple minuets. its a slow moving process so its not very easy to over-do. very controlled process. IMG_20141106_152421691.jpg
     
  13. bamhm182

    bamhm182 Active Member

    Joined:
    Mar 17, 2014
    Messages:
    167
    Likes Received:
    86
    Another thing that I would recommend with Simplify 3D is changing the number of solid layers on the top/bottom under the layer controls of your profile. I was having similar effects, but changed each of these to 5 and they're gone. Yeah it uses more filament, but I've been printing like a madman and I bought a few new spools 2 weeks ago, still got a bit left on the black one I've been using almost exclusively. I figure I can spare a few layers being full if it means it looks a bit better.

    Before I found out that acetone was primarily only useful for ABS, I tried using it on a few PLA prints. I'd get widely varying results from the same filament, which I found weird. Overall I deemed acetone as not very useful for PLA.
     
  14. Galaxius

    Galaxius Well-Known Member

    Joined:
    Jan 18, 2014
    Messages:
    632
    Likes Received:
    342
    I read somewhere you can vapour bath PLA using MEK?
    @Mike Kelly ?
     
  15. Printed Solid

    Printed Solid Volunteer Admin
    Staff Member

    Joined:
    Feb 21, 2013
    Messages:
    1,605
    Likes Received:
    1,002
    MEK does do some smoothing. It works pretty well as a solvent weld for PLA. I believe it's highly carcinogenic or something. It's been generally avoided in the workplace AFAIK since I've been a practicing engineer so I have it categorized in the 'don't use that it's bad' compartment of my brain.

    Ethyl Acetate does work pretty well in vapor for PLA. Here's my blog writeup: printedsolid.com/smoothPLA and some others who have tried it http://fabsterdam.com/3dprinting/smoothing-pla/

    I've also reviewed smooth-on's part smoothing epoxy which is OK. http://www.printedsolid.com/xtc-3d/

    Colin's method is actually a stroke of genius (or dumb luck, but I'll go with the former :p).

    It's not nearly as aggressive as ABS acetone vapor polishing or even the ethyl acetate on PLA, but it definitely works. As he points out, PHA IS soluble in acetone, but I think when you try something highly potent like vapor smoothing, you loose the PHA, so direct smoothing with a cotton ball or soft cloth is a must. His pic shows a pretty coarse print, but I've been trying it out on smooth (100 micron and below) prints and the layer lines completely disappear even under some pretty high magnification. I'm spending time with family today and expect to be insanely busy with cyber weekend sales, but after that I will get a good blog post up on that method (giving Collin credit of course).
     
    2 people like this.
  16. Peter Krska

    Peter Krska Active Member

    Joined:
    Nov 30, 2013
    Messages:
    766
    Likes Received:
    229
    Smoothing PLA. I've seen people use those Rock Tumblers. It seems to smooth PLA as good as anything else.
     
  17. Mike Kelly

    Mike Kelly Volunteer

    Joined:
    Mar 11, 2013
    Messages:
    6,967
    Likes Received:
    2,275
    PrintedSolid is also on the end of the "Chemicals are bad, avoid at all cost" spectrum.

    I think having a family to look out for will do that to you :)
     
    2 people like this.
  18. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
    Staff Member

    Joined:
    Feb 21, 2013
    Messages:
    22,556
    Likes Received:
    7,226
    Better living through Chemistry is my motto.
    Sadly, substitute MEK (since real MEK is bad) is not a good polisher.

    I have not found the one solution yet, but still playing with it.
     

Share This Page