The freelance economy and 3D printers have converged to dramatically lower the time and cost associated with creating a new prototype. Recently, I was shocked at just how effective this combination has become.
My company, Elvaria, manufactures soft-serve ice cream and frozen yogurt machines. We frequently refine and improve the components of our machines based on customer feedback and our product roadmap. A number of the components that we use are custom manufactured based on our specifications.
The Traditional Process of Prototyping
- Create a CAD drawing of the new part using in-house engineering or bring in a contract engineer.
- Send the CAD drawing out to one or more rapid prototyping companies for a quote.
- Select a vendor and wait for the part.
- Test the part. Make refinements to the design and CAD drawing.
- Repeat until the design is optimized.
- Send the final drawings and specifications out for manufacture.
This usually took a few months.
A New Approach
A few weeks ago we decided to try the “new economy” approach to redesigning an agitator for one of our machines. The agitator is a magnetic mixing blade that spins in the hoppers of our ice cream machines, keeping the liquid product well mixed and preventing product separation. It’s driven by a motor located underneath the hopper and spins by magnetic force. Think of a large version of the spinning magnetic mixer you used in chemistry class.
I started with a set of calipers, a ruler, a mechanical pencil, and a page of engineering paper and made the following sketch:
We have a few engineers in my company that could have drawn this part in CAD. It probably would have taken a few hours and multiple revisions. We are all busy, so I decided to try Elance and hire a freelancer who might be able do it faster and cheaper.
I created a job called “3D CAD Model of Agitator (Impeller) in SolidWorks”. I posted a short description of the job, selected the appropriate skill set tags, and uploaded this sketch. I received two proposals within minutes, one a rather standard looking hourly proposal, and another from a young mechanical engineer in Serbia with solid reviews who said he could do the drawing in one hour for $100. Sold!
After sending me some preliminary drawings and asking a few questions like, “Would you prefer a rounded end to the spindle or a flat end?” Rade delivered on his proposal.
This is what his final STL drawings looked like:
I specified the STL file format in the Elance job description. This is a file format used in rapid manufacturing and computer-aided manufacturing to describe surface geometry. I copied the STL files that Rade sent me to a USB thumb drive and popped them into our Makerbot Replicator 3D printer. I hit print and left the office for the evening.
Technically, it took hours for our fifth-generation Makerbot to print. But when you have a 3D printer in your office like we do, you find that it’s best to schedule a job during the off-hours. Then, when you come into the office the next morning, it’s ready for review without any loss of time.
When I arrived the next morning, I picked up a perfect print of the agitator assembly. I popped in the magnets and put it into a test machine. Success on the first shot! The agitator works flawlessly. You can see a picture of the finished prototype below:
After validating our prototype in a running machine for a few days, we are ready to send the same drawings to a manufacturer and begin producing the part.
This is just one small example of how we as makers can leverage freelancers and 3D print technology to dramatically lower the time required to design, test, and refine a prototype. You no longer need to be a CAD specialist or hire a CAD employee. A few careful measurements, a quick sketch, and a freelancer work wonderfully. You don’t even need to make the investment in a 3D printer. You could easily take your files to your local makerspace or even Staples to print your part.
Now get out there and make something great!