zip tie downs presents how to use a geodesic dome calculator part 5 panels and coverings every geodesic dome is made up of triangles these triangles can be covered with plywood or polycarbonate for solid dome panels or with ripstop polyester or canvas for a fitted cover when you cut your plywood panels you will need the exact measurements for each triangle so that the edges will fit around the dome this is a zip tie down with plywood panels used for an art exhibit in Berlin Germany cutting polycarbonate reflecting mylar or a fitted plastic sheeting will require the exact dimensions of each triangle these beautiful domes are manufactured by Gavin McArthur of dome Gro domes in Masterton New Zealand when we made a fitted ripstop polyester cover for our dome we realized that while most dome calculators could tell us the length of the edges of each triangle they could not tell us how tall our triangles would be we needed to know the height or altitude of each triangle to know how wide our fabric had to be the altitude is the height of the triangle from the base to the top a triangle with an altitude of 5 feet cannot be cut in a single piece from a 4 foot wide sheet of any material regardless if it is plywood polycarbonate polyester or canvas in this example the triangle edges are only 4 feet 7 and 1/4 which gives the triangle an altitude just slightly less than 4 feet which could be cut from a 4 foot wide sheet a material so while the edges of the triangle can be greater than the width of the material the altitude of the triangle cannot be greater than the width of material and still be cut in a single piece so let's talk about triangles geodesic dumb triangles come in three types there are equilateral triangles where all three sides of the same length isosceles triangles where only two sides of the same length and scalene triangles where all three sides are different lengths an equilateral triangle only has one altitude as all sides are equal and the altitude is the same on every side for anna sossel each triangle with two sides having the same length we can measure the altitude down the middle of the triangle but if you turn an isosceles triangle over and use another side as the base with the altitude be different the answer is yes and for a scalene triangle where all three sides are different lengths if used each side as the base of the triangles would the altitudes be different the answer is again yes you will have three different altitudes and the geodesic dome calculator should help you find the altitudes of every triangle in the dome so that you can correctly cut your material to cover your dome so let's find the altitude of a triangle on the dome calculator go to WWE x comm hover your cursor over the dome calculators in the navigation bar and then click on the for frequency dunk a later scroll down there are six different strut lengths for the four frequency dome let's make the blue strut five feet long click calculate this makes a 30 foot diameter dome that is 15 feet tall let's see if we can build this dome to use 4 foot wide dome covering material click on the dome panels and covering link the first part of the dome panel section shows all the different types of triangles needed to build the four frequency dome there are two isosceles triangles a B a and C BC with 30 triangles each 60 C D F scaling triangles 30 deg isosceles triangles and 10 EEE equilateral triangles for a total of 160 triangles this will not be an easy dome to cover with panels scroll down the 30 ABA triangles have an altitude of 3 feet two inches yet if you turn it on its side the triangle has an altitude of over 3 feet 8 inches so how the panel is oriented can make a big difference when cutting the material scroll down the 30 C BC panels have almost no difference in altitude based on orientation and there are both less than 4 feet and altitude the reason is the B and C struts are almost the same length one is four feet six and a half inches long and the other is four feet six and three-eighths inches so this is almost an equilateral triangle the CDF scalene triangles have three different orientations each with its own altitude if we use the D strut as the base this brings the altitude of the triangle to less than four feet altitude and so it could be cut from four feet material but the de D triangles have an altitude greater than four feet regardless of orientation and the blue EEE triangle has the greatest altitude of four feet four inches and cannot be cut from four foot wide material and all of our calculators the blue struts are always the longest let's see if we can get this triangle with an altitude of less than four feet scroll back to the top of this section click on the down calculator link enter 4.6 and the blue e strut field click calculate this makes a 28 foot diameter dome that is 14 feet tall scroll up and click on the down panels and coverings link scroll down to the de dee triangles this triangle is now less than four feet in altitude for either orientation and the 10 EEE triangles have an altitude of 3 feet 11 and 3/4 inches which is slightly less than 4 feet so that this dome can now be covered with 4 foot wide material now there is a much better way to do this scroll up and notice that there are 5 different types of triangles for the 4 frequency go these triangles are complicated and this makes the for frequency and higher frequency domes very hard to cover click the construction diagram link see how complex the pattern of triangle placement is and notice the scaling CFD triangles if you were to sew a covering with these triangles and got just one of these triangles reversed the dome covering would not fit when we decide to make a dumb covering we knew we did not want to make our first covering for this dome as it is just too easy to make a mistake with a 4 frequency dome let's choose another dome scroll up and click the dome calculator link and know the navigation bar go to the three frequency five eight stone click on the down panels and coverings link notice that there are only two isosceles triangles that need to be covered for the three frequency dome as compared to five different triangles for the four frequency dome there are just thirty CBC triangles and 75 ABA triangles for a hundred and five total triangles to cover the zone click the construction diagram notice that the 30 CBC triangles are grouped together into red Pentagon's and that the 75 ABA triangles are grouped together into blue hexagons by choosing the three frequency dome this made sewing our cover together much easier all we had to do was to cut just two triangle shapes and then assemble them into red Pentagon's and blue hexagons then attach these together into a dome covering scroll up and click on the dome calculator link the three frequency down we covered use the super-sick trench hubs which has a center ring that adds three and a half inches to every strut length this center ring will affect the size of the triangles to be covered so for this project we fit the radio button to the super six-inch hubs which adds the center ring distance to the calculation we purchased the role of ripstop polyester fabric that was five feet wide and our dome had already been made with five foot long blue stripes would we be able to cover this dome with the five foot wide fabric let's put five in the blue strut field and click calculate this produces a 25 foot wide dog that is 15 feet tall in the center click on the down panels and coverings the dimensions of the CBC triangles are only 3 feet 7 and 3/4 inches and altitude and so can easily be cut from 5 foot wide materials while the bee strut length is 4 feet 10 and 5/8 inches the addition of the three and a half inch center ring makes a bee edge this triangle an actual length of five feet two and 1/8 inches and the seed strut is four feet to one eight inches but with the addition of the three-and-a-half inch center ring this makes a triangle edge four feet five and five eighths inches the ABA triangles have an altitude of four feet seven and three-eighths inches which will fit our five foot wide ripstop polyester roll and the edges of this triangle including the center ring will be 5 feet 3 in 1/2 inches and 5 feet 2 and 1/8 inches to make our coverings we took these dimensions and added one inch to every dimension so that we could overlap the fabric when sew together we made a paper template for each triangle and then cut the fabric according to the template each hexagonal and pentagonal section was secured to the dome using velcro straps thanks for watching please give us a thumbs up and subscribe to our Channel