To bastardise the old adage: it’s not what you 3D print, but what you do with it that counts. Take, for example, the process by which one newcomer to 3D printing turned a workshop at Durban’s The MakerSpace into a potential new line of products for her business.
“We mainly supply the shoe and fashion industry, making buckles and trims,” Daniela Guerrera explains, “While we have a lot of existing products in our prototype library, often a client will want something new, or something with their brand on it (for example a buckle with the company brand along the bridge). Currently we have the logo lasered from perspex, and attach that onto an existing buckle. However 3D printing opens a lot more doors in terms of design and prototype development.”
Guerrera started off 3D printing an owl model from Thingiverse. It was printed in ABS plastic – provided by The MakerSpace as part of a class on printing – and in order to get a decent quality to the print, she used low layer heights (0.1mm – typically most people start at three times that) and slow print speeds.
Then she gave her model a bath in acetone vapour, which smooths rough edges from ABS prints and gives them a more polished look. Note – don’t do this at home, unless you know the risks involved.
Guerra then turned the plastic model into a silicone mould using a technique called “spin casting” to create a mould for metalwork.
“In order to create an impression into the mould, the prototype is placed in the uncured silicone (which has a putty-like consistency) and then vulcanised (heated to approximately 150 degrees),” says Guerrera, “This cures and hardens the silicone. The prototype can then be removed, leaving an impression of it in the silicone. This mould is then spuncast – placed into a machine which spins it very quickly, while molten zinc is poured inside it. The zinc cools, and then can be demoulded. Once we have all the cast products, we submit them to various other processes, such as tumbling or grinding (to remove rough edges), assembly (to paint or add additional components) or electroplating (which plates chemicals on to the zinc to give it different finishes).”
“[Guerrera] took the ABS owl through her process which uses vulcanized silicone moulding to create a mould from the prototype and form the part out of the molten zinc that is later introduced to the mould,” says The MakerSpace founder Steve Gray, “The owl print didn’t fall apart during the curing of silicone which applies pressure to the mold at approximately 150 degrees C as it hardens around the prototype.
And the results aren’t bad at all – check out the gallery below.
All images supplied by Daniela Guerrera. You can see more of here work at Euro Industrials.