Eastman Amphora AM1800 aka Taulman "n-vent"

Discussion in 'Filament' started by jet, Jun 23, 2016.

  1. jet

    jet Well-Known Member

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    SDS and technical data is here:

    http://www.eastman.com/Pages/ProductHome.aspx?product=71100831

    Using just the Eastman "Guide to printing" with some Taulman "n-vent" and I'm pretty happy with the test prints. Primary layer height of 1.9, temps of 240/70 and my 20x20x10mm cube is coming out 19.8x19.88x9.7mm. Glass adhesion is better than layer adhesion, I snapped a razorblade in half trying to take one off at 60C, if I want til it's between 30-40C I can take of the print except for the bottom layers which stay on the glass. Right now it's set to 8 bottom layers, maybe I should I try 4 or 12?
     
  2. R Design

    R Design Well-Known Member

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    If you're in a hurry then lift off the glass bed.

    It cools faster and you can see underneath when the part starts to separate from the glass. And you know where to slide the palette knife in.

    I've got two glass beds and simply swap them if I'm really in a rush.
     
  3. jet

    jet Well-Known Member

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    I was just wondering about that... I have several pieces of boro glass left over from my Mendel projects, should be easy to cut it down to fit.
     
  4. Paul Winter

    Paul Winter Well-Known Member

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    @jet
    Thank you for the info on the filament, it's great to know about these things in advance :)

    But if it's sticking that well, beware of the glass surface coming up with the print, even if you have left it to cool. Two borosilicate glass plates later, and I ended up just using a 6mm Aluminium plate as my build surface. Not sure how that fits with a BigBox, though.
    But the PEI-coated Aluminium bed-plate looks cool, trouble is I only found out about it after I bought the 6mm plates :)
    But a removable plate is the way to go in my opinion. Makes for easy part removal without risk of damaging the printer, preserves bed-levelling, and improves throughput if you have more than one of them. Or you could have different surface treatments depending on what you want to print.
     
  5. jet

    jet Well-Known Member

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    Letting prints cool to room temp before removing them is working for now. I scrape the glass clean with a flat razor then wipe it with a microcloth before each. I've got enough spare borosilicate glass and Al plates lying around from Mendel projects I can try some variations.

    My real product for the customer is going to be in PEEK, I'm still sourcing affordable PEEK filament so I can make a quote.
     
  6. jet

    jet Well-Known Member

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    I've been using a retraction distance of 4.5mm (per the Eastman guide) and it's worked fine for single prints. When I switched to multiple prints of the same object I started having filament stalls. It looks like the filament cools enough to jam, I dropped to 2.25mm retraction and the stalls went away and the prints still look good.
     
  7. R Design

    R Design Well-Known Member

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    I won't pretend to understand retraction until I've understood it all and none of the gurus have covered all the bases.

    However many seem to suggest that appropriate retraction distances are dependent not only on filament type and temperature but also upon the internal architecture of the nozzle (and no doubt upon retraction speed itself!).

    So I don't think the table you refer to makes much sense if it doesn't cite a nozzle type/brand/model.

    Richrap has often said something like "never more than 2mm" whilst talking about a v6 or a Volcano, I forget which.

    Still hoping in vainly that E3d (who make the darned things!) will weigh in on the debate one day.

    Fits your data anyway.
     
  8. mike01hu

    mike01hu Well-Known Member

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    Essentially, retraction reduces the pressure in the melt chamber so that no filament is extruded, preventing blobs. If the melt is very liquid then more retraction my be required to draw filament up the nozzle but, as you may be aware, pulling back too far will draw the softened end back into the heat break where it can stick and cause a jam. The amount of retraction is going to vary according to the type of filament, the nozzle diameter, the nozzle temperature and the time taken between retraction and the start of the next extrude. As you can see there are a lot of variables, so suck-it-and-see is the best way, as science does not seem to provide a solid answer!
     
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