Bolt-Nut - Tensegrity - 3D Printed

Bolt and nut - held by wrenches - connected by a thin thread, keep a fixed distance to each other and give the whole object a stable structure. It is a fascinating experience when, after the 3D printing and the assembly of the individual parts, this tension is suddenly created when setting up the object: TENSEGRITY!

It's always a bit magical how the physical conditions create this tension that makes this object a unit - a perfect unit. At first sight a bit confusing ... you have to look twice to understand the principle.

Printing parts:

• BoltNutTensegrity_bottom.stl
• BoltNutTensegrity_top.stl
• BoltNutTensegrity_wrench.stl (2x)
• BoltNutTensegrity_bolt.stl
• BoltNutTensegrity_nut.stl

Print Settings

• Printer brand: Prusa
• Printer: I3 MK3S
• Rafts: Doesn't Matter
• Supports: No
• Resolution: 0.2
• Infill: 25%
• Filament brand: Prusa; ICE; Geeetech
• Filament color: Galaxy Black;Romantic Red;Silky Slver
• Filament material: PLA

After printing all parts ...

Remark: As all parts are designed to fit very precisely, it may happen that you have to rework one or the other part a bit with sandpaper and/or cutter due to different dimensional accuracy of the printers and the different behavior of the filaments.

• Nylon thread Ø 0.35 mm
• Cutter knife
• Scissors
• Small screwdriver
• Sandpapier
• Superglue
• Patience!

After printing all parts, start by connecting the screw and nut with a thread (I used a Ø 0.35 mm nylon string. Thread or dental floss might also do the job). The distance between screw and nut should be about 25mm.

Then insert the wrench parts into the existing recess of the top and bottom part.

NOTE: To ensure a good fit, the fitting accuracy is very tight. It may be necessary to correct the fit with a cutter knife or sandpaper. Then apply superglue. For a correct alignment you should use a stop angle!

Cut three approx. 35cm long nylon threads, make a multiple knot at one end of each thread and insert them into the holes of the top part (as the holes are very narrow with Ø 1mm, it can happen that they are partially closed by filament parts during printing. In such a case you should try to push them free with a needle).

To test once push the nut into the wrench. Bolt and nut can only be inserted from one side!

You can decide later whether the screw or the nut should be on top.

You can also hold the base part over it and insert the bolt ... so you can get an impression of what it will look like.

Now take the part prepared in Step 3 (wrench with bottom). Place it - as shown in the photo - to the wrench with top part.

Then push bolt and nut into both wrench parts.

Advice:

To facilitate further work and and to make it easier to align the nylon threads, you should fix the bolt and nut and with scotch tape. This prevents them from constantly slipping out of the wrenches during work.

Now that is the most complicated step! Aligning the lower and upper part by inserting and fixing the nylon threads. You really need some patience!

Now feed the threads through the holes in the socket. The distance between top and bottom hexagon should be about 130 mm. It depends of course on the length of the thread and the distance between the bolt and the nut.

The small notches are for fixing the nylon threads.

If the notches are not clean, try to open them carefully with a cutter knife. To press down the threads into the slots, you should use a small screwdriver. Do the same with the other 2 strings. Now insert the connected bolt-nut construction and turn the object upside down. Start with the adjustment. At first just clamp the strings. Then when the strings are slightly tightened, socket and top are aligned horizontally and the force of attraction is sufficient to ensure a stable stand, then you can secure the strings.

Hurray! You did it! … the Bolt-Nut structure is floating!

Please note that if the tension is too high this can soon lead to the printed parts bending!