Tuesday, 13 October 2015

Let's get rolling! CAD design of custom embossed rolling pins.

From time to time my close friends and family (and clients, contacts, pretty much anyone) give me great ideas for items that would lend themselves to 3D printing. Being able to design and make stuff is only a part of the process - coming up with real-life uses for my design skills and 3D printing ability are often limited to things that I am interested in. 3D printer upgrades, robotic claws and house-hold objects which I will use myself to name a few.

Recently my brother saw a batch of cookies which had been embossed with a special rolling pin, The design was a skull image which was laser-etched into a plain-old rolling pin. This would leave a sheet of dough behind with the skulls embossed, ready to be cut with a plain-old cookie cutter, baked in a plain-old oven and presto! Cookies with little skulls all over them!

A short discussion followed with some of my female family members who were interested in having custom-made cookie rollers themselves, so I decided to take it on as a bit of a love project.

Using Autodesk Inventor as my software of choice, I initially came up with a basic shape for the roller. It would resemble a traditional rolling pin but to make it easy and cheap to manufacture I decided to use a piece of wooden dowel as the 'handle', that way I just needed to print a cylinder with a hole through it to put the dowel in and some embossing on the outer diameter.

I sat back and admired my work - first time I'd tried embossing a cylindrical surface with a continuous pattern. It turned out pretty good! I showed them and they liked it too. Great!

But while the artist in me (note: there isn't one) was happy, the engineer wasn't. I ran this model through my 3D printers 'slicing' software and found that it would take a whopping 13 hours and about a third of a roll of plastic to print it. They would be quite expensive to make, and if the girls wanted a few designs there would be a few rolls of plastic and many days of printing.

So I developed...


The idea here is that I could print a central hub for them ONCE and then print much thinner 'sleeves' which would slip on over the central hub. The cost for a single design would be a little more than the solid roller, but once they had a second design in mind the cost came down significantly. Each sleeve would only use about one tenth of a roll of plastic. Great!

Add some handles for the ends of the dowel and we had a finished product! Here are the first two designs they requested, love hearts and paw prints.