gifFace Strut Tetragon Spline Mitre

This strut has greater surface area on the mitre and is reinforced with a spline joint.

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The following screenshot shows the arrangement from the sphere interior; thus the strut shown above is flipped, and vertices A and B are uppermost. One strut has been hidden to show the increased mitre area. The spline option is off in this example. All strut faces are guaranteed coplanar.

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The strut width has been deliberatelty increased to show the geometry.

Again, you may use the ‘Hub Normal Cylinder’ intersect option with this strut type. When turned ON, both vertices A and B are moved to the cylinder circumference: this gives a neat uniform appearance to the mitres; using the minimum cylinder radius you can get away with will give maximum room for the spline joint – or another other type of fixing, (e.g., a circular steel ring bracket or star bracket).

The correct value for the hub cylinder radius depends on the width of the strut and the subdivision frequency of the sphere. Higher frequencies with narrower struts can use a smaller radius (down to 1 millimeter). If you set the radius too small, the mitre planes will fail to intersect with the cylinder; in this instance strut generation will halt and you will receive a warning message. Set the radius to a higher value and regenerate the struts. Extortionate differences between Width and Depth will also cause errors. Similarly, the depth for struts built on the inside of a sphere has a cut-off limit, and this depends on the frequency and width. After experimenting with this feature, you will soon guage the optimum radius for any given frequency.

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