Folding Geodesic Dome

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Folding Geodesic Dome

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Folding Geodesic Domeby yourpalsparky on February 26, 2012 Table of Contents Folding Geodesic Dome . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Intro: Folding Geodesic Dome . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Step 1: Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Step 2: Tools and Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Step 3: Templates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Step 4: Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . File Downloads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Step 5: Cut Out 105 Pieces Using the Cutlist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Step 6: Fabricate Segments: Tape Hinges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 2 3 4 5 6 6 7 8

Step 7: Vents and Door . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Step 8: Deployment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Step 9: Field Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Related Instructables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

http://www.instructables.com/id/Folding-Geodesic-Dome/

Author:yourpalsparkyBob

Intro: Folding Geodesic DomeGeodesic domes are light, strong structures with huge interior space that is very pleasant and inviting. Unfortunately they tend to take many man-hours to erect. I needed a dome that was strong and windproof enough for the desert yet could be easily put up by one or two people in short order. Hence the Folding Geodesic Dome, also known as the Democracy Dome! It takes 105 triangles to make the particular dome shape I wanted (called a 3V), which could be time-burner to assemble. The Folding Geodesic Dome simplifies things with tape hinges that pre-connect many of the triangles into 16 segments, each of which unfolds from a small stack and connects to its neighbors via tabs and clips. The more hinges used the less time spent connecting triangles in the field. The dome goes up with 2 people in 2 hours or less. Takedown time is 30 minutes. There are great Instructables for light domes made from coroplast or cardboard which negate the need for a support frame. This dome was made with an eye for economy, using 20 surplus 4x8 4mm coroplast political campain signs found on Craigslist for $100. The panels can be made from any stiff material (cardboard, coroplast, thin plywood, plexiglass) that is rigid enough to resist bowing. This project was made possible by the resources at desertdomes.com including their dome calculator, dome formulas and the dome diagram that I use in this Instructable. (If you build a dome, please donate to desertdomes.com as I did.) This dome is a light-duty backyard dome, done as a proof-of-concept; it isntt waterproof. My next version will utilize a combination of thin plywood for the hexagons and coroplast for the pentagons to let light in. This project is ideal for a ShopBot CNC mill, as cutting triangles from stronger materials would be made much more efficient and accurate. Please click VOTE above to enter this Instructable in the Instructables ShopBot CNC Contest and help me build Version 2!

http://www.instructables.com/id/Folding-Geodesic-Dome/

Step 1: DesignA 3V geodesic or polyhedral dome is made of hexagons and pentagons, which means you will need 2 basic triangle shapes, called BAA and BCC. Start your project with a visit to desertdomes.com , where you will find dome diagrams, dome formulas and an invaluable dome calculator. This Instructable is for a dome with a 7 radius; this is a 5/8 3V dome meaning taller vs flatter, over 8 tall in the middle. The dome likes a flat surface to sit on making it ideal for the open desert playa, not so suitable for uneven terrain. (Note: the prototype pictured here has a radius of 7.2 but wasted more material from a 4x8 sheet. My next dome and this Instructable use the dimensions for an 84 radius - 7') The dome is composed of 3 basic folding segments: a pentagon (5 triangles), a hexagon (6 triangles) and a hexagon plus 3 (9 triangles for the base row ). Each segment unfolds and is clipped into a convex shape with binder clips or a clamp made from pvc pipe. To calculate the dimensions of the 2 triangles (BAA and BCC), use the desertdomes.com dome calculator and enter the dome radius in inches to get get the lengths of the A, B and C triangle sides. For the radius of 84 (7 feet) we get A= 29.284 (roughly 29 1/8) B= 33.898 (roughly 33 7/8) C= 34.642 (roughly 34 5/8) Height of BAA = 23.881 (roughly 23 7/8) Height of BCC= 30.213 (roughly 30 1/4) .5xB = 16.949 (roughly 16 15/16, for the midpoint of the B edge) For the 3V, there are 30 BAA triangles (to make 6 pentagons) and 75 BCC triangles (to make 10 hexagons and 5 semi-hexagons). 1 wide tabs are placed along B edges to connect segments together, and on some of the C and A sections too. The triangles along the base of the dome have 4 tabs with holes for the anchor stakes. Edges that dont have tabs will have tape hinges that connect to their neighbors. Ive mapped out where the tabs need to be for every triangle needed in the dome, adding up to 12 different shapes youll cut - download the pdf Cutlist for shapes and quantities.

Image Notes 1. Shows where segments clip together once unfolded. 2. A variation of this segment allows for a step-in door.

Image Notes 1. The 3 basic segments laid out but not clipped into their convex shapes.

http://www.instructables.com/id/Folding-Geodesic-Dome/

Step 2: Tools and MaterialsTools: - metal yardstick or metal straightedge. - carpenters square - carpet knife and some extra blades - dextrous gloves with tough palms- coroplast can give a mega-papercut - ladder or stool for erecting - hammer for stakes - spring clamps for easier deployment - (staple gun for wood slats) - (saw to cut pvc tubes) Materials - 15 - 20x coroplast sheets 4x8, 4mm (use stiffer panels for stronger structure) - strong duct tape (use gaffers tape for stronger structure) - 200x 1 binder clips (use 1-foot long x 1.5 pvc pipe tubes with a slit for stronger clamps) - 20x 1 long round tent stakes (minus the plastic dealy) - 20x washers to fit the stakes (bigger the better) - 5x 6 long round garden poles - 5x 8 long round garden poles - 10x rubber tips that fit the poles - bag of thin bamboo garden sticks 6 long for vents - spray tack adhesive - (15x 4x24 thin wood slats for stronger base, hole in center, glue to affix) - (light schedule 1-1/4 pvc pipe to make tube-style clamps)

Image Notes 1. 8' tall metal garden poles, add rubber tips (not shown) 2. 6' square wood garden stakes with rubber tips added 3. Thin bamboo garden sticks

Image Notes 1. Add rubber tips to 6' and 8' poles

Image Notes 1. 10" Camping stakes from which i removed a green plastic rope anchor.

http://www.instructables.com/id/Folding-Geodesic-Dome/

Step 3: TemplatesYoull make 2 templates for the two types of triangle, BCC and BAA. Making the template is complicated to describe, so use the pictures for a better understanding. The base dimension (B) is 33 7/8 for both triangles. For BAA, mark points for the base corners of the B edge at 33 7/8 apart, and mark the midpoint of the two. The estimated apex of the triangle is a point 13 7/8 above the midpoint of B. The apex needs to be 28 1/8 from each base corner; and the project needs both edges to be exactly the same length for it to assemble well. Youll likely have to adjust the estimated apex until you find the sweet spot. Draw your A edges from apex to base corners and cut out your template with a straight edge. Repeat this for the BCC triangle with the appropriate dimensions. Optionally you can include tabs along the template edges as shown. From the 2 templates you will draw 12 different shapes as shown on the pictures and listed in the cutlist. The shapes vary by which ed