This is a printable mold for making traffic cones for RC cars out of ogoo. These are great for marking a course for RC cars. The example molds in the photos are 80mm at the base and 30mm tall and we use them for racing with an 1/18 scale RC car.
Ogoo is a silicone caulk based DIY molding material. It is cheap and easy to use, see: http://www.instructables.com/id/How-To-Make-Your-Own-Sugru-Substitute/ Read the safety hints on the cartridge and make sure you understand the required precautions when working with silicone caulk.
The scad file is supplied and is fully parametric, you can make all kinds of shapes. A few examples are supplied as stls.
I did not make the interior hollow because that would just make the molding process more complicated as it would require a (printed) mold core. After all, ogoo is really cheap, with the example molds I could make 3 cones out of a single cartouche for just under 2 EUR. Besides, the filled cones are quite heavy, which is good (in comparision to bought cheap plastic cones which fly around if there it's a little bit windy or if they are touched by a cornering RC car).
Credit: The scad uses the write.scad library by Harlan Martin (http://www.thingiverse.com/thing:16193) for the writing on top. Thank you very much for this easy to use library.
The scad file is fully parametric and the write.scad (see credits) library is in the project dir as well.
Adjust the parems according to your needs. For starters, you might want to adjust base and top diameters, height, writing and number of corners (params P10, P11, P12, P23 and P13, respectively).
If the param show_positive is set, both the mold and the molded object are rendered. For printing the mold, set the param to false, so only the mold is rendered.
Additionally, you can set the mold thickness(es) (P30, P31). I made mine quite thin, so it printed faster and with less filament usage.
Finally, the fn number can be set. The examples are hexagonal. For round pylones, set them higher (P13).
The mold needs to be printed upside down, so flip it in your host software.
I printed mine with 2 perimeters, 15% infill and single top and bottom solid layers, which was sufficient.
After printing, mix an appropriate amount of oogoo. Ogoo is mixed from silicone caulk (the stuff from the home improvement store used for sealing seams in the kitchen or bathroom) with starch added. The starch accelerates the setting of the silicone caulk from days to just minutes (see http://www.instructables.com/id/How-To-Make-Your-Own-Sugru-Substitute/ for background information). When silicone caulk sets, it evaporates acetic acid. When it sets faster because starch has been added, it gives off the acetic acid within a shorter timeframe. Use at your own risk. Start with small amounts to get a feeling for the processes. Be careful and understand what you are doing.
I have used an about 2/3 filled plastic cup of silicone caulk and about 2 table spoons of starch for fast setting . BEFORE adding the starch, you can color the oogoo using oil paints to your liking.
I have used the cheapest transparent silicone caulk I could find, which was just under 3 EUR per cartridge. A single cartridge lasted for about 3 of the example molds.
Quickly press the oogoo into the mold, a used popsicle stick works well. You need to work fast, because the oogoo sets within 10-15 minutes. After filling the mold with oogoo, scrape of excess oogoo from the top of the mold. Use a finger dipped in dishwashing soap for smoothing the surface.
Wait til the oogoo has set (for me, 30 minutes were enough). Using the popsicle stick, carefully remove the object from the mold. If necessary, clean up the edges with a pair of scissors.
The molded pylones are quite heavy, which is a feature, IMHO.