Welcome in my tutorial. I will show you how to 3D print over sized parts on printer with small build platform. In this case we will use Blink dagger item from dota2 from thingiverse by user Subzerofusion these techniques are quite fun and expands your skill around post processing 3D prints.

BOM

Any ABS fillament
Acetone
Skewer
Spray filler
Spray paint white
Spray paint silver
Nail polish
Clear spray lacquer
Sand paper 200 and 600 grade

Step 1: Split .stl to Multiple Parts

Adobe mesh mixer is nice and free tool to prepare your parts in. I use it mainly to slice my .stl files before printing. You will be maybe a bit disappointed first time in mesh mixer, but its quite powerful when you will know how to deal with it. First drag and drop your .stl in to Mesh mixer. Go to Edit -> Slice, select cut type as "slice keep both". Move cutting plane by pooling arrows and turning half circles. Click accept when plane is on correct place. For first look it will seems that nothing happens, do more cutting same way as before on different places. Use select tool, click anywhere to your part and pres "e" on your keyboard. Voala it will select part you cut before. Go to Edit (under select menu) -> separate. Now your part is separated. Separate also other parts this way. Use File -> export to export your part back to .stl, you have to export them one by one selecting it in newly popped Object Browser window. Enlarge your part in slicer you use for your 3D printer and print. You can use really rough and fast print settings we will post process a lot.

Step 2: Glue Parts Using Acetone Technique

We will use ABS acetone slurry to glue parts together. Process of doing your own ABS slurry is described in next step.Good thing is that 3D print can be done in really terrible way and everything can be fixed by ABS slurry. You can make your slurry in different viscosities to be used for filling huge gaps or thin groves. You can use super glue to pre-fix parts together before using of slurry. Different kind of clamps can be used to fix parts together until slurry gets cured. Be prepared that cured slurry loss its mass a bit, so re-layering of slurry can be necessary. Newer put pure acetone directly to your part, acetone will eat it all always dissolve ABS in acetone first.

Step 3: Acetone Technique

Use any kind of glass bowl, ABS slurry can be easily removed from that bowl after complete cure. Use same color of ABS plastic as is used for your prints. Use any excess parts, cut brims, support structures and even cut filament to pellets to be dissolved in acetone. Put 2-4mm of acetone to the bottom of bowl. Use skewer to mix and manipulate with slurry, any kind of painting brush will be destroyed by slurry. Mix your slurry time to time to dissolve all ABS. Huge completely undissolved chunks can be used to fill big holes in your model. Put bowl to the side when most of ABS goes liquid. Best viscosity to start with is when drop of slurry remains on skewer (did not fall down). If you are done and slurry still remains, make few holes and hills by skewer to slurry before it completely dries, it will help to dissolve it next time. Parts connected or covered with slurry are more stronger when slurry completely cure.

Step 4: Filler and Sanding

Use medium spray filler and put one even coat on the part. Let filler to dry and use really hard sand paper like 200 grade to sand your part, do not hesitate to sand really hard. Just be careful to keep your details fine. Respray part with filler and repeat it again and again with softer and softer sand paper. Its good to have thin sanded layer of filler, big chunks of filler can crack during the time after part is finished.

Step 5: Painting

My paint consist two layer of white coat, you can also do base paint on first layer. My white spray paint stick well without problem, even one coat will be fine. More coats makes your part look like bulky, and edges will lost sharpness. Then i put one touch with silver spray paint to the blade of the dagger, be really careful doing this touches. Let all layers to cure according to your spray paint instructions. It will newer harden if you put more layers without curing even increasing bulk effect. Buy yourself nice glittering nail polish to make details, nail polish can do really fantastic effects. Take also you GF or any girl there to don't look stupid buying nail polish if you are a man, at the end she can use all remains :D Again let it dry, nail polishes usually dries quite fast. Put one layer of clear coat on top. I will use more nail polishes from this time, I also catch my self checking for nail polish sales on the store, trust me best paint ever :)