Rapid Prototyping (3D Printing)
Today I want to tell you about technology that is mind blowing.
Perhaps I am showing my age here but to me this is awesome. I know this is not something most of us will use on a daily basis, but perhaps one day you would like to manufacture a new idea and then you might need this.
A couple of weeks ago we had a 4×4 gathering in Cape Town. One of the guys there had this strange gear thing/gadget on his keyring and I asked him about it.
He told me that it is his business to PRINT these models in 3D?
At first I though he was joking, how can you PRINT in 3D?
So Joe explained to me what it is he is doing for a living.
Joe du Buy used to own his own factory which manufactured plastic goods by means of plastic injection moulding.
These sound like big words but all the plastic goods you use on a daily basis are manufactured this way. They design a mould which is the shape of the plastic thing you are manufacturing. The plastic is injected into the mould and spat out on the other side, when cold.
The problem with this method is that these moulds are extremely expensive to manufacture and it takes a long time to have it done.
So if you want to manufacture a new cool case for sunglasses you would have it designed in CAD. Then you would have to get somebody to build you a mould. The mould will cost you about R100,000 or more to build and take nothing less than 6 weeks. So even before you have a prototype you are R100,000 and 6 weeks down the road.
Now you get your prototype and you realise that it is 1 mm too narrow for the latest XYZ sunglasses which came into the market just after they started building your mould.
So you ask the toolmaker to adjust the mould. No problem; if you are lucky and the adjustment is small it can be as little as R30,000 and 2 weeks later you get your next prototype. If you have to change a lot they will have to make a new mould. So you are back at R100k and six weeks.
It does not take a genius to realise that this is a lengthy and expensive way of doing thing. But believe it or not this is the way it has been done for the past 40 years.
Now, let’s look at Joe’s easy and in-expensive way:
You also have your product designed in CAD as a 3D model. But now you email it to Joe and ask him to “print” you a prototype. As long as it is smaller than 250x250x200 mm Joe will most probably have your prototype delivered to
you within a week (instead of 6 weeks). The price is not easy to determine as it will depend on the size of the project, bit for instance the sunglasses case we used as an example above will most probably cost you only R6,000 to print.
You can now test your prototype and see if every fits as planned. Only when you are 100% satisfied with it you will send your CAD design to the tool maker to have your mould built. This time he will only have to build one mould.
Obviously you cannot compare the two methods as far as cost and time is concerned, Joe’s methods is by far the best way to go.
How is it done?
3D Printing
This is the amazing part. Joe uses a 3D Printing Machine. This machine is like a huge printer. It uses an Acrylic Polymer (plastic) instead of ink. It really prints the 3D model. It starts from the bottom and then print very thin layers. The layers are about 0.016mm thick. It prints the one layer on top of the other and gradually builds up the model.
If there are moving parts in your model, like gears or a hinge, it will print a soluble gel in the area where movement must take place. After printing is complete Joe just washes out the gel and the parts can move. Thus you can build a moving model without having to assemble it afterwards – like the lid of your sunglasses case.
There are not many companies in South Africa who offer this kind of service and who knows what they are doing. Because Joe has so much expereince in injection moulding I bet that he is the best man for the job.
So, the next time you have a brilliant idea, do not let the cost of your prototype get you under. You can do it the affordable way.
I added some more examples below. Also have a look at Joe’s web site at http://www.liquid-edge.com/
Buckle
Wrench
Ventilator
interesting blog..i like your articles
If you’re interested in following the news on 3D Printing and digital fabrication, you might consider reading our blog at Fabbaloo or http://fabbaloo.com