Hello, I have a bunch of set diameter tubes which need to fit inside another
tube tightly. The numbers needed prevent getting them together and
measuring the diameter so how could i find out what the inner diameter of
the outer pipe should be with x number of inner pipes with diameter of D?
Hope thats clear, Thanks in advance

"izzi4" wrote: (clip) how could i find out what the inner diameter of the
outer pipe should be with x number of inner pipes with diameter of D? (clip)
^^^^^^^^^^^^^^
Hexagons pack tightly to form a honeycomb pattern. Each hexagon can have an
inscribed circle, which will be tangent to all the inscribed circles around
it, so the circles pack with the same density as the hexagons. So, I would
lay out a honeycomb pattern with the correct number of circles/hexagons.
Then find the smallest circle which can fit over the cluster of inscribed
circles. This could be done graphically, or it could be calculated.

7 is the smallest number of largest diameters that can fit inside a
given circle.
3 times the small circle diameter equals the outer circle's diameter.
I s'pose you could do something recursive on this (-:
or follow the hexagon layout suggestion given earlier, 7 / 3 is just a
special case of that.

Back when I was a cable design engineer, at the age of 19, we derived
this information graphically. We drew the theoretical sizes in a 5:1
scale and then scaled the result. We were right nearly as often was we
were wrong so the company always ordered the jackets after the cable
had been laid up. With cables the tigher the lay pattern the biger the
jacket had to be. I don't know about your situation. Leigh at MarMachine

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.