Floating Hexagon - Magnetic Tensegrity - 3D Printed

... a new contribution to the topic "Tensegrity".

The main difference to the other models is that the tension in the middle is not created by a thread but by the attracting force of two magnets. Therefore the top is of course not as loadable but the object all the more interesting for the eye! It's magic!

After all - so I show in my video - the construction can carry light objects. The closer the magnets are to each other, the more weight the plate can carry. Please note that if the magnetic tension is too high - for example, if the magnets are too close together - this can soon lead to the printed parts bending. Note, this object is primarily intended to impress the eye and not necessarily to carry weight!

The magnetic attraction (that alone is surprising at first ... one would expect the opposite to be the case) - besides the four threads connecting hexagon plate and base - builds the tension structure in this object. It's a bit magical how the physical conditions create a 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.

Print files

• FH_top.stl
• FH_midpart.stl (2x)
• FH_base.stl
• FH_magnetholder.stl (2x)

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.

Magnets:

• I used two small 8x3mm neodymium magnets. Unfortunately they are only available in larger quantities, like for example
• https://www.amazon.de/dp/B072FDBHBF/ref=cm_sw_em_r...

Tension strings:

• I took a nylon string Ø 0,35mm
• https://www.amazon.de/dp/B07HLF6SYY/ref=cm_sw_r_cp...

Tools:

• Precision mechanics pliers
• 2 small pieces of plywood 20x20x3,5mm (can also be something else in the thickness of max.7mm)
• rubber band
• small screwdriver
• superglue
• cutter
• sandpaper

Print Supports:

• None. All parts can be printed as oriented in the stl files.

Infill:

• FH_top.stl: 10% (the top should be as light as possible!)
• FH_base.stl: 15%
• other parts: 60%

Such or similar tools are very helpful when adjusting the nylon threads later on.

For the first step you need "FH_top.stl" and the color matching "FH_midpart".stl.

The arrow at the bottom is there to align the middle part correctly. You should place them as shown in the first picture!

To ensure a good fit, the fitting accuracy can be 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!

For the next step you need "FH_base.stl" and the color matching "FH_midpart".stl.

As in the last step, the arrow at the bottom is there to align the middle part correctly. You should place them as shown in the first picture!

To ensure a good fit, the fitting accuracy can be 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!

Take the color matching "FH_magnetholder.stl". Check if it can be attached to the center part without problems. Then put a drop of superglue into the square recess and press it to the middle part.

Do the same with the counterpart!

Put a drop of superglue in the magnet holder. Take a magnet and press it in. It should almost "disappear".

Do the same with the second magnet.

Attention: With the second magnet, you must make sure that it attracts the other magnet before gluing it in!

Now you need 4 (nylon) threads of about 30-40 cm. At the backside of the top plate you see 4 fixing points with little holes. Take one string and make a multiple knot at one end and then pull the thread through one hole of the plate.

Do the same with the other 3 holes. The next step will be the essential one ... create the tension structure!

Now begins the most complicated part of the assembly ... with a little patience you can do it!

To make this a bit easier, I put two small plywood plates of together about 7mm thickness between the two magnets and fixed them with the middle parts with a rubber band ... even this is not quite easy to do! Pay attention to the alignment of the middle parts (see picture 1).

Place the object with the bottom side facing up. Then feed a first thread through a hole in the socket.

At first just clamp the thread. If the notch is not clean, try to open it with a cutter knife.
Do the same with the other 3 threads.

When all 4 threads are provisionally tightened (I use a small pair of precision pliers and a screwdriver to push the thread down in the slit), you can carefully remove the wooden pieces and the rubber band from the center.

The magnets should now have a distance of c. 6-7mm. The bottom and the plate should be horizontally and parallel to each other. If this is not the case, you need to carefully correct the thread tension.
Once this is done, you can finally fix the threads and cut off the overhanging threads. Do not cut too short, so that a later correction remains possible!

The distance between the magnets will be able to be a maximum of 7mm. A larger distance is hardly possible in this overall constellation.

The closer you bring the magnets together, the more loadable the hexagon plate will be. However, a too strong attraction will possibly lead to a bending of the middle parts in the long run.

Well, I hope you don't despair and you can enjoy this physical miracle!