Twisty Tube -- Variations
``Synergy with Thomas Dorf Neilson''

Back to Twisty Tube Plan

The following is the result of a discussion with Thomas Dorf Nielsen <tdn@vrcn.dk> in early December, 2000. We were discussion the 7 white to 2 red colour cycle I used in my own twist tube. Thomas himself was figuring out the colours and construction methods to use in his own twist tube.

Also included is the method I use to figure out the which piece needs which colour, and the numbers of those pieces.

If anyone on the net makes one of these variations, or something completely different, please let us know. Better still send a photo (or a URL to a photo)!

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Colour Cycles

Colouring the twist tube is much more complex than a ``Queue Melon'' or caterpillar tube, as instead of the pieces forming a straight rectangular grid, you instead have a slanted grid forming one continuous spiral.

An easy way to think and to check just how many pieces you need is to draw up a slanted grid a bit like the ASCII art below. Remember as a tube the top edge would join the bottom edge. Ignore the side bulge for this purpose. Include the pieces #1 to #8 at each end so you can figure the colour for each piece (which is what I did).

The 7 to 2 ratio was chosen as that adds to a nine piece colour cycle on the tube which has 8 pieces going around. IE the colour spirals around the completed tube. 2 reds were chosen so the colours would overlap at the joins. EG: ASCII art time: `.' white `*' red..

.../......./......./......./......./... ../......./......./......./......./**** ./......./......./......./*******/***** /......./......./*******/*******/...... ......./*******/*******/......./....... ******/*******/......./......./......./ *****/......./......./......./......./. ..../......./......./......./......./..

Now if I chose a colour cycle one less that the number of pieces around the tube. Say 5 white, 2 red, then the spiral will be in the opposite direction and the red colour would seem to travel upwind as the tube spins. You will also need more red pieces as you would need to cycle more times to get the same length of tube.

However 5 of one colour and 4 of another colour will produce that same spiral as the 7 white and 2 red, just a thicker strip so they are nearly the same width.

Just alternating colours in this design will result in a straight stripes down the length of the tube. That is one colour will match to the same colour in the next spiral loop of the tube (8th piece further down.

If you want a chequer board pattern in you tube, you will need to adjust all the pieces so that an odd number of pieces is required to go around the tube. Also with a odd number of pieces (say 7 instead of 8) you can make a spiral consisting of equal amounts of 2 colours.

NOTE: with the original 8 piece tube plan, you can make a spiral from equal amounts of 3 colours (9 colour cycle on a 8 piece cycle tube).

Two colours per piece

Idea! Another way to make the colour spiral "follow" the bulge would be to simply make all the #9 pieces out of *two* pieces, for instance one half red and other half white. Get the idea? A fair bit more work and a lot more mundane than a real "double-bulge" spiral, but still...

The join should also slant in it to so the colour doesn't get the `jaggies' when 2 #9 pieces join together. NOTE the join would then spiral around on the top of the bugle.

Making the #9 pieces from 3 colours has even more possibilities, and even more work. IE: the red stripe is only on the top of the bulge, not at the ends.

Double Bulge Twist Tube

Thinking about this you could figure out a twist tube with a double spiral bulge down its length! With this scheme you could then assign one colour to each bulge, which will match the colour to the surface pattern of the tube itself, making it look more natural looking.

Thinking about it that way I see that you would need to start two bulges from the front of the tube. EG: for a 8 piece around tube...

***/.../***/.../***/.../***/.../** **/.../***/.../***/.../***/.../*** */.../***/.../***/.../***/.../***/ /.../***/.../***/.../***/.../***/. .../***/.../***/.../***/.../***/.. ../***/.../***/.../***/.../***/... ./***/.../***/.../***/.../***/.../ /***/.../***/.../***/.../***/.../*

That means the cord length needs to be 4 times that of the length of the slant and not 8 times (the widths determines the diameter of the tube) Also only 4 of the starting and stopping pieces are needed. The bulge widths will of course need to be scaled to match the new length.

If the colours were red and white you would essentially end up with a rotating `barber pole'.

From the above discussion, Thomas Dorf Nielsen developed a Double Twisty Tube

-- Anthony Thyssen and Thomas Dorf Nielson.

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Created: 11 December 2000
Updated: 12 December 2000
Author: Anthony Thyssen, <anthony@cit.gu.edu.au> and Thomas Dorf Nielson <tdn@vrcn.dk>