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Heated build chamber

Discussion in 'Mods and Upgrades' started by BjG, Feb 23, 2013.

  1. tesseract

    tesseract Moderator
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    It was a repost and one thing mentioned to help remove the parts when using the slurry was zapping it wiath a few quick shots of one of those pressurized keyboard duster turned upside down and directed and a corner of the part it tended to start the removal easier.

    The stickiness of the slurry could also be adjusted by an imperfect splotchy layer as stated couldn't it or a thinner slurry or even both.
     
  2. tesseract

    tesseract Moderator
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    Only based on what I have heard
    ABS is trickier and tends to lift easier(warp) but does have some flexibility
    PLA isn't as bad but is alot more brittle
    NYLON don't know about lift(warping) but can be much more flexible extremely so but does require a higer extrusion temp by about ~100C degrees.
     
  3. Printed Solid

    Printed Solid Volunteer Admin
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    I think Nylon is fine as long as you have the right build plate material and make sure to bake out the nylon pre-build so it is bone dry. Garolite LE (bakelite) is reccomended for build plate. Google Taulman 618. He has a big writeup for everything he tried.
    I've actually heard the finished parts are great, but haven't tried it yet. I have some in my filament bin, but haven't ordered a garolite plate.
     
  4. JDM_

    JDM_ New Member

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    I don't think nylon has the warping issue as long as you can get it to stick to the print bed. Thats why I'm going to clip a Garolite board over the factory print bed while printing Nylon.
     
  5. JDM_

    JDM_ New Member

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    But we wil find out when RoBo arrives.... lol
     
  6. Printed Solid

    Printed Solid Volunteer Admin
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    I have a massive ABS print running right now that fills up my entire build volume. If it warps badly, I'm going to be buying a garolite plate and testing it out next week. Will report back when I get results.
     
  7. tesseract

    tesseract Moderator
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    What do you think about the abs slurry?
     
  8. Printed Solid

    Printed Solid Volunteer Admin
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    The ABS slurry works REALLY well. It works so well that I avoid using it!
    But with a part this big, you can actually induce thermal stresses that tear the part apart, so the slurry wouldn't help much. Either the part peels a little or the ABS itself breaks.
    If you have some materials science background, we're talking and adhesive vs. cohesive failure issue, but the failure may be inevitable. Hopefully my heated box keeps in enough heat to keep the whole thing together! So far I'm about a little over an inch in and it looks good.
     
  9. tesseract

    tesseract Moderator
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    Ok I do not have that type of background but I will look that up I am all for learning new things even if only at the surface level but a quick comment. In the post I read it was mentioned to use the slurring in a hit in miss process or splotchy meaning large gaps of nothing like finger painting on glass using just the finger tips and not having enough paint to cover even an 1/8 of the glass but spreading it out to cover all of it.

    Is this how you have done it or did you use a single solid but very thin layer?

    Also could the slurry be thinned down even more. I have seen no actual ratios but I would think a ratio even higher in acetone would help resolve the aspect of locking the piece in place. Without the experience of doing it or the in depth chemical knowledge the ratio may require less acetone and more ABS.


    MY GUESS at the difference I think adhesion is the first and cohesion is the second.
    First one may be surface based like paste it simply joins two pieces with an interveneing medium.
    Second may be more chemical like a solvent dissolves and both pieces which then meld them together into a single piece the solvent evaporates and the material rehardens into more of a single item.


    Actuality:
    1. Adhesion is the molecule attraction between dissimilar molecules.
    2. Cohesion is the molecular attraction between similar types of molecules.
    kinda close
     
  10. Printed Solid

    Printed Solid Volunteer Admin
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    I've been BUSY since that last post. Lots to report:

    First: I ended up having to restart that print several times due to filament blockage followed by an airprint. I can't tell you how discouraging it is to go to bed, come down the next morning, and find your printer head just moving around in air 3" above the part.
    On the third try, I babysat the heck out of it. After every 2-3 hrs, I paused the print and just extruded a bunch of filament out into space. This worked. I believe that the issue is that my insulated chamber was working too well; the filament was softening to the point where my extruder bearing just pressed right through the filament and into the drive gear. By stopping every 2-3 hours and extruding the filament into space, I let a little heat out of the chamber and took a little heat off of the drive gear.

    Next I got in an order for some printed parts for a Rostock Mini (check it out on my blog at printedsolid.com). I plated all of the parts together to make the build a little easier and still did the 'check things every 2-3 hrs method'. About 75% through one of the builds, I got a y-axis shift. That is, at a certain height, the whole cross section just shifted forward. I believe that I must have bumped the extruder a little bit in the y-axis during one of my middle of the night filament checks. Since there is no feedback mechanism, it just kept printing away with about 1/4" offset. Ugh.


    2013-03-12 16.26.49.jpg
    Needless to say, I am going to have to change something. I bought a cheap datalogging thermcouple set up so before I do that, I am probably going to see if I can correlate the filament break to a specific air temp. I may look into adding in a vent that exhausts the chamber if temp gets too high.

    @Jeff, I took a hybrid approach to your suggestion. Usually I don't use rafts, but it occured to me that a raft will essentially do what you suggest in a manner that I am comfortable with. So I laid down a good coating of the ABS slurry then printed with a raft. The thinness of the raft makes it easy to peel away from the slurry when I use a Cricut spatula and the parts hold on to the raft well. Once I get this batch of orders built, I am going to try your suggestion of laying down the slurry in a thin pattern.

    I've also started doing some experimenting with acetone vapor polishing that I will be posting on that thread.
     
  11. tesseract

    tesseract Moderator
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    It sounds like this test seemed to work. What was the size of the piece you did not want to have lift. Two clarification/suggestions:
    1. Instead of a thin solid pattern try something like a chessboard with maybe 1/2 -3/4 inch squares or something relative to your print, some thing so only about half of it is slurried down
    2. try thinning the slurry itself down. I believe it ends up being very translucent


    Oh by the way I am jealous that you are able to print can't wait to get my printer lots of ideas but in the meantime I am learning how to draw objects. I have a cool design in my mind that I think the ROBO3D guys will love.
     
  12. tesseract

    tesseract Moderator
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    Please keep us informed as to your acetone vapor experiments as well. I was under the impression it was heated to a vapor in a larger container and only took about 5 minutes. I wonder if yours was too concentrated. What didn't you like about it.
     
  13. Printed Solid

    Printed Solid Volunteer Admin
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    The part was essentially the entire build volume of my rep1 ~6X9X6. I'm guessing I'll probably continue using the rep1 as my go to printer for detail work, but I'm looking forward to the Robo for larger parts with less detail. At the time I ordered, I was thinking I would be mostly working in PLA on the Robo and didn't order the HBP option. Now that I'm geting into vapor polishing and solvent welding big parts together, I may have to change that!
     
  14. Seshan

    Seshan Active Member

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    2 people like this.
  15. kilodoublemike

    kilodoublemike New Member

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    Just curious, why not get pre cut plexi glass from a hardware store. Have a thermostat and heater/fan to maintain an optimal temperature for abs printing (tbd). The case could have hinges for the face for removing molds after they are done and hinges on the top piece to open during pla prints. The enclosure should also be large enough for maximum print sizes on all three axis.
     
  16. Seshan

    Seshan Active Member

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    This is what I am planning, I'd like to start designing something, but I don't have enough details about the printer, so I'm just keeping it in my head for now. You would only have to worry about the Y axis, since the X and Z don't move out side of the printer case. So you can make a case that fits close to the sides of the RoBo and only needs to extend out the front and back.
     
  17. JDM_

    JDM_ New Member

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    This is a good idea. Plexiglas would look great for this. How would you attach or seal it to the RoBo body? Can you sketch it out so we can see if this concept will work?
     
  18. Seshan

    Seshan Active Member

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    I wasn't planning on attaching it to the body, just a box that went over it that fit close to the sides of it. So it can be removed if I didn't need it. But if you wanted to attack something I don't see it being that hard, My original plans where to just attach panels onto the front of the RoBo, but then realized that wouldn't work since the part moves out side of the shape of the RoBo, but attaching to the sides would save on plexi. Maybe I will sketch some things up to give people a better idea.
     
  19. Printed Solid

    Printed Solid Volunteer Admin
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    I was also planning on designing a simple plexiglass enclosure that just sits around the printer. This might be a good opportunity to pool resources rather than each of us going and designing our own. My plan was to just do it when the robo arrives, but if people want to get started on a design now, I'd be glad do help.
    I just met a good contact for lasercutting last night, so if we want to get more fancy than a bunch of simple rectangles hinged/bonded/screwed togeher, I can look into getting it priced out.
    Panels should probably be done in a more common file format like dxf rather than stl.
     
  20. JDM_

    JDM_ New Member

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    To design something now we would need to request a CAD of the exterior shell of RoBo. Especially if we were going to try to match up the angles on each side. Hopefully Team RoBo wouldn't mind releasing this to us.
     

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