Sunday, 11 September 2016

Learning the long way.

The world of 3D printing is daunting. The one prominent piece of advice I hear is “Be prepared for a learning curve”. The main statement is “You will have prints fail”

Even experts in 3D printing spend hours tweaking slicer settings, fixing meshes, checking fill settings, fixing heat settings, calibrating beds and other things I am sure I have not even encountered yet.

This post was initially going to be a quick run through of the concepts and workflow of 3D printing. Then I realised that I was hardly an expert and people might take it as advice. Know this. I know NOTHING. What I can do, however, is outline what I have done and how I have learnt.

My first port of call was the main hub for models www.thingiverse.com. This is pretty much the defacto resource for premade models. All are free to print but re-engineering and even use for resale are covered by CC licences. This means that creators have the right, for example, to say redesign this as long as you credit me and use the same terms. You cannot sell it.

The site then lead me onto a fantastic resource for design called TinkerCad by Autodesk. It is a hugely intuitive and simple builder but able to resolve complex designs which you can then print.

holder

After a bit of practice I was able to churn this one out. A six coaster and holder design. As I have the design talents of a six thumbed silverback gorilla I am rightly rather pleased with it.

Of course designing is still just an early stage. I now need to take this model and prepare it to be printed. The design consists of 2 .STL files one that is the coaster and one for the holder. A 3D printer cannot print this.

So the next step is to use a “Slicer” program to literally slice the image into a series of cross sections (imagine one of those 3D cardboard models) and create the instruction files to pass to a 3d printer. This is essentially a text file known as .gcode. This code instructs the printer head where to move and when to squirt plastic. How hot to do it, how quick to do it, what to heat the bed to and many other things.

Even then you have problems incipient. What about those overhangs on the holder and on the coaster faces. You cannot print onto thin air. So more thought goes into supports to hold these. What if the print comes off 3 hours into the build (did I mention it is slow) that's 3 hours wasted and all that plastic. Even it it works the surface wont be perfect. You will have sanding and finishing to do until you finally have a monochrome block of plastic that is truly from your own head.

Then you show it to someone and they say “oh, is that it”. So despite the massive time sink, cost, and overall over expectations I am bound to encounter I am still keen to print this and hold it in my grubby six thumbed hands.

Maybe one day I can show you too.

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