Design Tips

More often than not, guess work takes centerstage in mold making and material casting projects. Sadly, most mold experts seldom guess right. This is because estimating the amount of material required to complete a project can be tasking. Consequently, having too little material can disrupt the progress of the project in totality. Having too much can lead to unwanted leftover and waste which is both frustrating and costly. In order to help with estimations, we take a look at a simple method of estimating material volumes (silicone, gypsum, resin) required to complete a project. Keep in mind that there are many variables to consider including but not limited to the variations in dimensions, undercuts, complexity of the model, complex geometries and drafts. Due to these factors, these figures will not be exact but they will be pretty close. Here’s what to do before starting your next urethane casting project: 1. Calculating Resin Coverage Area There is no fixed formula for estimating both area and material volumes in urethane casting. This is because the area and volume is subject to the shape of the mold to be produced. Often, squares, rectangles, triangles and cylinders are used. An example is given below: How much epoxy resin is required for a table measuring 5m by 12m? 2.Calculating the volume of material required We shall put our focus for rectangular and cylindrical or tube-shaped containers and estimate how to calculate the volume for a project. Irrespective of the shape, to estimate the volume of the material required, you will need to calculate the volume of the casting container and the volume of the shape/pattern to be created. The differences in these two volumes represent the volume of material required. For Rectangular parts, we shall consider the length, width and height of the container as shown below: The volume of the rectangle is given as Volume (V) = Length * width * height Let us try to estimate the volume of material needed to make a mold for a 100in3 object using a rectangular mold box that measures 10 by 6 by 4in. To proceed, we shall first calculate the volume of the mold box: Volume (v) of mold box = 10” * 6” * 4” = 240in3 Next, we subtract the volume of the object to be made (100m3) from the volume of the mold box: Volume of material required = volume of mold box – volume of desired part Volume of material required = 240in3 – 100in3 Volume of material required = 140in3** ** The 140in3 is the volume of the material required to make a 100in3 object. To put this figure in gallon, simply divide this number by 231 Volume of material required in gallon = 140/231 = 0.606 gallons of material. For cylindrical parts, we shall consider the radius and height of the cylinder used to mold the material. This volume will help to benchmark the possible amount of silicone or resin required to make your own mold. For tube-shaped/cylindrical mold containers, there is a radius and height to be considered. The volume of material to be used = Vo...