3D Printing?

Discussion in 'Modelling' started by von Poop, Nov 26, 2021.

  1. SteveDee

    SteveDee Well-Known Member

    When things are going well, you should not need to continually re-adjust offset/platform.

    I suggest you swap your trusted piece of paper for a set of metal feeler gauges. Also ensure that filament ooze is not tricking you into thinking the gap is wrong:-
    Captain Bodgit: My new favourite 3D printer bed leveling method
    von Poop likes this.
  2. von Poop

    von Poop Adaministrator Admin

    Interesting again, Steve.
    Was only last night wondering about feeler gauges
    Nice, shiny dedicated alco-washed feeler gauges maybe, rather than my existing greasy box-full. :unsure:
  3. SteveDee

    SteveDee Well-Known Member

    Pieces of paper are compressible, so not exactly repeatable. With a set of metal feelers, you can keep using the size that gives you best results.
    As long as your platform is not subjected to a serious thump between prints, it should be fairly stable.
    For best results, test your setup with one of those calibration cubes downloadable from Thingiverse. They provide quite a lot of useful information on x/y/z setting and quality.
  4. von Poop

    von Poop Adaministrator Admin

    Yeah, the attention is wandering towards testy stuff. Torture Toaster.etc. Though I still need more reference points to understand what I'm actually testing for.
    But first, I must print this knob successfully.... Rats nest ahoy this evening.

    The platform really has got me thinking.
    Every time I lift this strong magnetic plate, I'm surely tweaking things. Fractions of a millimetre is not a hard measurement to nudge.

    Sprog Alpha returns from uni soon.
    Hoping he'll brush me aside and I can learn from his graphic designy/pootery skills.
    Nice soft brains, these 20-somethings.

    3 successful prints so far.
    2 Nonsense, one genuinely useful/potentially money-earning in use.
    3-4 complete arse-ups. Not a bad ratio to my mind. Was expecting worse.
    More filament needed. Currently PLA+. Got a feeling I should try a few more. (And then contemplation of nylon capable ends. If I could do nylon there's a whole world of fixing things I couldn't before to consider. I enjoy fixing things, and get paid for such.)

    Either of you chaps tried Laser engraving bolt-ons?
    Another area I could earn a few quid with.
  5. Rich Payne

    Rich Payne Rivet Counter Patron 1940 Obsessive

    Did someone mention feeler gauges ? Another one of my dead-end peripheral "collections" :whistle:

    1936 1.jpg


    Can you print "Mottled brown Vulcanite" ?
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  6. von Poop

    von Poop Adaministrator Admin

    One day, mate.
    One day.
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  7. RAFCommands

    RAFCommands Senior Member

    Done Nylon, even more of a nightmare to dial in bed adhesion then got it too good and ripped up print surface trying to get print off. Got it dialled in and mostly use for bearing surfaces.


    Good next step from pla is petg. I use prit stick to smear print surface then print onto that - let cool after print and it self releases. Just refresh with prit stick to print more. To fully remove glue from print surface wash plate in sink warm water and a squirt of washing up detergent. Dry and clean with ipa as before.

    Did not try laser module add on to fdm printer as wanted to fully cut through carboard/engineering plastic sheet and could not trust focus not to damage print surface.

    Used open builds guidance to do a light weight 3d platform using extrusion and printed parts
    3D printed Laser Engraver

    Works well and from there went down the rabbit hole of doing cnc router to allow subtractive manufacturing as well as 3d fdm additive.

    von Poop likes this.
  8. von Poop

    von Poop Adaministrator Admin

    I have a dark feeling CNC routers might be the end result of all this.
    I like routers, while also being healthily terrified of them.
    Magic routers that follow instructions... hmmm.
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  9. RAFCommands

    RAFCommands Senior Member

    You are going to need a bigger shed.

    docs:machines:comparison [OpenBuilds Documentation]

    I built a mini mill to do aluminium versions of the side plates I printed for the laser engraver. Does well approx 150mm x 150mm and 50mm depth Al block light cuts. Quite rigid structure - best use is up to 6 mm ally plates. Uses Matika palm router.

    For wood I built an Ox but if starting now I would do a Workbee and use the Matika again.

  10. SteveDee

    SteveDee Well-Known Member

    Highly recommend you download this file and print: XYZ 20mm Calibration Cube by iDig3Dprinting

    Using your vernier calipers (...you did buy yourself a pair, didn't you?) each side should be more or less the same.
    The quality on each face also gives a clue to axis drive problems. Print one now and you will have a reference against which you can judge your machine and any anjustments you make in the future.

    BTW, are you printing with a Brim?

    So you can test this by adjusting the gap/platform, then remove mag plate without doing a print, then put it straight back and test again.
    von Poop likes this.
  11. von Poop

    von Poop Adaministrator Admin

    Cheers, again.
    Now that I understand what the Brim/raft/skirt difference is, I shall be doing more of that depending on part.
    Half a dozen times trying to print a tiny round knob. Brimmed up, and printed first time... Sigh.

    Thinking fighting a few more prints, then onto calibration ones.
    Don't yet have the mental reference points to fully grasp what I'm looking at. Need a few more failures/theories to start joining dots.
  12. RAFCommands

    RAFCommands Senior Member

    For stuff that has a very small initial contact point to volume eg a sphere a good trick is to look at your slicer software and change the setting for supports rather than use a raft.

    The brim will be produced to cover the entire area of supports, so while these have a small contact area it's augmented by a dirty great brim layer below. If you change the overhang/support ratio to give more supports than the default then it makes cleanup much easier than stripping off a raft with it's many contact points on what you want as a finished surface.

    You do need to have dialled in temps and retractions first though to use supports reliably - the stringy hairs from poor settings will get caught in nozzle passes and can break long thin supports before they can do their job in supporting an overhang in higher layers.

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  13. von Poop

    von Poop Adaministrator Admin

    Kilo of white PLA for £8.63 after ticking 50% token, in case anyone's interested.

    Hoping it'll help being able to actually see what's hitting the bed...
    And maybe with painting little AFVs

    (Fully manually levelled the bed, BTW. Unnerving hitting those wheels, but now suspect there was a fractional sloping off towards the rear. Soft vice jaws printed beautifully after that, and with a skirt. Offset holding after print - user-friendliness ramps up.
    Thanks again to you chaps for assorted tips. Helped enormously.)
    SteveDee likes this.
  14. RAFCommands

    RAFCommands Senior Member

    Smoothing 3d FDM prints is a ball ache especially so for your small print AFVs ready to take paint.

    For prints I usually knock the highest ridges down with abrasive then, depending on size of sub module:

    For large - cover in car filler to raise print lines to ridges - sand smooth and prime


    For Small or intricate detail that negates sanding - use XTC-3D resin filler and prime


    XTC-3D small bottles from Bentley go a long way - the videos show good guide to application - essentially you keep moving the excess drips back up to the top of the surface by a disposable brush until it just starts to cure then leave it to self level

  15. von Poop

    von Poop Adaministrator Admin

    Funny.Was just this moment looking at 'ironing' and considering future finishes.
    The resins are interesting. Reasonable track record with epoxy in general, but think I'm a way off such for this stuff.

    No idea why everyone talks about this sheet of paper business. Cheapness doesn't really justify it. Nice new dirt cheap set of feelers washed of oil in a Xylene/Acetone mix & offset/adhesion seems perfect from first go. They should chuck a feeler leaf in the box.

    My first tip for fellow knowlessmen: Get a nice light colour filament so you can see WTF is going on.
    Started with shiny black, as I assume many do - good colour for many brackety/devicey things, but... you cannot easily see whether it's working, or if it's left any bits of crap on the bed.
    There is a lot of staring involved.

    The eye now drifting towards TPU.
    Soft vice jaws astonishing fit on a hefty WW2-era vice & good for small things, but too brittle in PLA really.

    Worth it so far?
    Yes. Satisfaction level routing a new stair tread using a near perfectly rigid trim router base that fitted first time, made from shiny plastic string: Immense.

    Good book, for bookish types.
    Honest, direct, low jargon.
    Whether he's right, I do not have the skill to tell, but finding it interesting anyway.
    If nothing else, it runs through concepts that aren't necessarily easily found in one place.

    Screenshot 2022-06-27 143538.jpg
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