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The Trebuchet TowersThe trebuchet towers are made from 5.5mm foamboard. This material is polystyrene foam sandwiched between two layers of thin coated cardboard. They are cut out of one piece. The angled joins are made by cutting v shaped grooves that do not go through the front layer of cardboard. This provides a continuous surface on the outside. Cutting each face individually and then gluing them together is not as good as this leaves a foam surface at the edge of the board which must be filled prior to painting. Internal horizontal pieces define the shape. The lower ones reinforce the tower and the uppermost one acts as the roof on which the trebuchet will sit. The towers shown at right were glued onto the wall of the upper module and the extension module at the same time. Once the glue was dry, cuts were carefully made horizontally where the two modules join to allow the modules to be separated. Doing it this way means that the upper and lower parts of the towers line up perfectly when the two modules are in position. What Is The Difference Between A Trebuchet and a Catapult?Historically a catapult uses the elasticity of a highly twisted rope. A shaft is placed along the centre of the rope. The throwing arm is attached at right angles to the middle of the shaft. The rope is twisted around and around tightly. When released, it rapidly unwinds, rotating the shaft and flinging the missile on the end of the throwing arm. A trebuchet is a counterweight powered artillery piece. A huge counterweight at one end of a pivoted arm drops under gravity, throwing a missile (such as a lump of rock or iron) into the air. A sling arrangement is often used on the end of the arm as well to provide additional acceleration for the missile. A substantial frame is required to support the huge counterweight and throwing arm. It can throw heavier missiles than any other mechanical artillery, but the largest torsion powered catapult can beat it for range and velocity. For example, one of the largest catapults could throw a 23kg (50lb) rock about 365m (400yds). A large trebuchet using a 15m (50ft) long throwing arm and a 9 tonne (20,000 lb) counterweight could throw a 140kg (300lb) rock about 270m (300yds). From The Complete Encyclopedia of Weapons by Galley Press. ISBN 0 86136 773 1. Wall ButtressesThe decoration at the top of many of the walls consists of a series of raised stepped stonework connected by raised horizontal sections of stonework. These were made from corrugated cardboard. For the stepped sections of the stonework a cardboard template was used. Using templates saves drawing up the same thing each time. If used carefully you can cut round them with a knife to cut out the pattern. In real constructions, buttresses are used to help strengthen walls while also being decorative. The vertical buttresses were made from foamboard. These are cut at an angle as buttresses project more from the bottom than at the top Moulding The DetailTo add the fancy details at the top of Wall 1 was going to be easier by moulding. I decided to do this in polymer clay. This is like a plasticine which hardens when cooked in the oven for a short time at low temperature. Common brand names are Modelene, Fimo and Sculpey. It is available in a variety of colours from art and craft shops. First I drew an outline of what I wanted in AutoCAD then printed it out full size on paper to use as a cutting template. This made it more accurate than drawing by hand because of the elliptical shapes. A chunk of polymer clay was rolled out into a sheet about 5mm thick with the aid of a small toy rolling pin. The drawing was then placed over it and cut around the shape through the paper. Details such as the lines between the stones were carefully pressed into the surface with a modelling knife. Make the detail slightly deeper and wider than you want to end up with, as some detail is lost in making a mould and then the pieces The master was then cooked in the oven. Instructions are on the packets of polymer clay, but for example Modelene is cooked at 130'C for only 10 minutes (although I usually give it nearly 15 minutes) whereas Fimo (soft) recommends the same temperature for 30 minutes. Allow the master to cool down. To make the mould the master was then coated with a light dusting of talcum powder so that it does not stick to the sheet. It was then pressed into another rolled out sheet of polymer clay. Do not press the master fully into the sheet. If you make the mould too deep then it is difficult to remove pieces from the mould without distorting the soft clay. Carefully separate the master from the mould and cook the mould in the oven. Allow the mould to cool down. To make the pieces, roll out a sheet of polymer clay to the desired thickness. Coat the sheet with a thin layer of talcum powder. Turn the mould face downward and evenly press the mould onto the sheet. Only press the mould partway through the thickness of the sheet or you will have trouble separating the mould and sheet. Carefully separate the mould from the sheet and check that the detail has been transferred. If not, then place the mould in the exact same position over the sheet and press just a little harder. Trim the outline and cutouts such as doorways and windows through the thickness of the sheet. Excess pieces can be kneaded back together and used for the next piece. Place this piece on your baking tray and use the mould to make some more pieces. When the tray is full, place the tray in the oven and cook the pieces for the recommended time. Always wait until the oven is up to the required temperature before cooking and timing the polymer clay.
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Above. Two trebuchet towers under construction on the upper module on wall 4 of Minas Tirith (the white foamboard). |
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Above. Wall buttresses and raised stonework at the top of the walls. For the stepped sections of stonework a cardboard template was used (you can see the orange template laying on the green cutting mat). |
Above. Casting the first stone building. Three pieces were made for this - a front and two sides. The latter are mirror images of each other. A drawing in AutoCAD was done to help with the accuracy, but note the slight warping which can be seen in the line of indents. This occurs from stretching if not careful enough when separating the cast piece from the mould prior to cooking. The pieces have been glued using a hot melt glue gun onto an underlying frame of carboard. PVA is slower, but could be used if allowed to dry overnight |
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Above. The master is made using a hobby knife to cut the shape and scribe the details. It is then cooked in the oven |
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Above. The mould is made by pressing the master into a rolled out sheet of polyester clay. The master is first coated with a thin layer of talcum powder so it does not stick. The mould is then cooked in the oven. |
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Above. The pieces are then cast by pressing the mould onto a sheet of polymer clay. After cooking in the oven, the pieces are glued onto the walls with a hot melt glue gun. By gluing the pieces on while still hot from the oven allows them to curve to the wall shape before they cool and fully harden within 5 to 10 minutes. The foamboard wall behind is then cut to the same shape. |
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Lord of the Rings
Making Minas Tirith
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