How to 3D Print IMPOSSIBLY BIG Objects

3D Printing objects that are too big to fit on a 3D printer is easy if you know what you are doing. You will know how to do that by the end of this tutorial. If not I will most definitely would love to hear about it and try to get you back on your feet.

You will need the following for this tutorial.

  • 3D Pen
  • 3D Printed parts split at different points to fit on your printer in cad
  • Filament
  • Sand Paper or Belt Sander
  • Hot Glue

In this tutorial I will show you how to assembly a 3D print that is split into multiple pieces in CAD so it can fit on your printer in smaller individual pieces, assemble it with a hot glue gun, and fix the seam on it with a 3D pen and sand paper. Good luck to you!

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Step 1: CAD (Computer Aided Design)

I found blender worked for me for separating STL files from each other. There are other ways. Here are a few software for separating STL files in half.

  • Blender
  • Cura 15 or higher
  • Slic3r
  • FreeCAD
  • and more...

Step 2: Hot Glue, 3D Pen, Sanding, Oh My!

  1. Firstly you need to hot glue your project together and do it so they are as aligned to the original model as close as possible.
  2. Then you 3D Pen a seam around the edges.
  3. Lastly you sand off that with sand paper or belt sander.

Step 3: Conclusion!

The possibilities are endless what you can do with this. Without painting the print after all this it won't be as pretty. I hope you enjoyed this tutorial as much as enjoyed making this. Thank you for reading it if you read the whole thing. Let me know of any questions or feedback because I am open to them. Enjoy!

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    14 Discussions


    10 months ago

    Just an input on how I join parts printed with PLA together. Rock-solid & fast:
    Pour a thin layer (1mm) of acetone in a glas or metal dish. Flat bottom is a must.
    Then, stand the top part into the acetone for 3-4 seconds. Take it out, don't turn it, let acetone on the part evaporate for 5 seconds. Now press it onto the lower part. It will stick immediately. After around 10min its fully "cured" and holds incredibly strong. I had prints tear in the printed parts and not on the seam...

    I may make a ible for this...

    9 replies

    Reply 10 months ago

    That will only work with abs prints unfortunately and I hate printing in abs which is why I didn’t consider doing that. Good idea though! You should right an instructable on that lol.


    Reply 10 months ago

    Sorry, thats not correct. :)
    abs can be smoothed by acetone vapor --> is HIGHLY reactive with acetone even in vapor-state.
    PLA I only mildly reactive and only softens in direct contact with liquid acetone.
    I already have a vid where I "glue" a lid on a box, both PLA.
    I see if I can do a quick print in the company and glue those under video.
    I tested it with many different chinesium pla and with pla from Innofil (now BASF).

    Edit: See Thomas Sandleders Video on this as well: and test of weld @
    He wasnt able to pry them apart even with a screwdriver...


    Reply 10 months ago

    :) You are welcome
    Thats why i commented this: It is super sturdy, fast, easy, very clean and super convenient... and not a lot of people yet know this amazing trick.
    Spread the word, pay it forward. :)


    Reply 9 months ago

    Great trick!
    1. Do you think that you could 'paint' the acetone on with a brush?
    2. Do you need to apply acetone to both surfaces or just the one?


    Reply 9 months ago

    1.: Yes. But as the acetone evaporates really quickly and the PLA needs multiple seconds to soften up, you may need to more dab it on than brush so a bigger amount of acetone gets deposited than just a few micron think film...
    2.: If you can yes. If both sides are softened, the weld is MUCH better and stronger. But you can get away if you still have liquid acetone on one surface if you fit them together. In that case, i suggest you first just lay it down without pressing. Wait for 3-5 secs before pressing them together. That should be enough time for the acetone to soften up a bit the other side.


    Reply 9 months ago

    Thanks for letting me know. I'll pass it on to the LuBan group, as they build *huge* models out of blocks that fit their 3d printer's volume, and an easy way to bond those blocks well would be *VERY* much appreciated..


    Reply 9 months ago

    May I suggest that you create an Instructable on as many different ways to use this as you can come up with? I'm sure that it would be of *GREAT* interest to the 3d printing community.

    Pernickety Jon

    Question 10 months ago on Step 1

    I know nothing about 3D printing...

    Is the printed material heavy for it's size? For example, like clay or like expanded polystyrene foam?

    Could the tower be printed as a hollow cylinder? (To save on the printing material.)

    Would it be possible to make the printing 'cuts' across structural lines like the top of the brick foundation, or the line at the top of the arched buttresses (or both)? You've given yourself a really hard task to recreate the stonework across the glue-line where the model has been separated.

    Like I said, I know nothing about 3D printing.

    1 answer
    nschreiber0813Pernickety Jon

    Answer 10 months ago

    3D prints are almost always hollow. FDM manufacturing which is the form of 3D printing I used doesn't print solid objects unless you tell it to for a few reasons. Time and conservation of materials. This print in my case is so light weight I believe a 100 grams is probably how much that tower weighs.

    The tower could be a hollow cylinder. There are such things as vase mode to do stuff like that. The only problem with that though is it wouldn't have anything for a roof making the task impossible of doing this tutorial. For more information on vase mode check this out.

    Yes it is possible. I did that prehand for this tutorial to make the object able to be printable. The reason it wasn't printable before was because it was so big. I instead printed it in half along the layer lines to make it easier as somewhat explained in this tutorial.

    No worries you are probably better than most people about 3D printing. Some people will probably never know quite what it is until it become a revolution and they are forced to have one in there own home.

    I hope you found this resourceful. Let me know if it isn't. Thanks for the reply! Always glad to help.