By Mark Bashor, Manufacturing Engineer – AE, GoEngineer
The Scenario: A month or so ago while perusing my LinkedIn news feed, I stumbled across a comment that inspired me to write this article.
Long story short, one commenter chastised the author of the original post for using a commercial grade additive manufacturing system (3D Printer) to produce an easily obtained object from a local store (or Amazon).
The seemingly arrogant commenter tried to make the point that if you can buy the item you need off-the-shelf or from a website like Amazon you should always do that as it will be cheaper when compared to the total cost of 3D printing it on a commercial grade system.
In my experience, this is not always true. I think each unique “print vs. buy” situation should be evaluated independently since the general rule doesn’t always hold up to reality.
The Situation
I was up against a tight deadline to produce a sample Polycarbonate hydroforming tool for a customer looking to decide on purchasing a Fortus 450mc.
To minimize run time on the tool and maximize the chances for the ROI analysis to come back favorably, I used an approach highlighted in a recent blog post on printing shelled out versions of bulky parts and then backfilling the empty shell with a comparatively inexpensive structural epoxy.
After burning through most of our breakroom’s supply of plastic eating utensils by snapping them in an attempt to emulsify the mud-like epoxy components, I realized that I needed to get myself a mixer that was better suited to execute the task at hand.
The troubling part is that I was up against the wire and needed to get that epoxy mixed and poured soon to make my rapidly closing shipping window—the end of the day!
To make things worse, I was about to host a web meeting and didn’t have time to spend an hour making a trip to the local hardware store to find something that would work.
The Solution
Suddenly, it dawned on me that the idle Fortus 450mc system, just an arm’s reach away from me at the office, could be the perfect solution to my predicament.
In about as much time as it took me to walk back to my computer and launch SOLIDWORKS, I had modeled up a simple mixer (now on GrabCAD) using only three CAD features.
In the less than 10 minutes that followed, I managed to process and queue the file for building two copies of the mixer, make myself a cup of coffee, and get the job kicked off at the machine.
I resumed work-as-usual, and as my anticipated web meeting entered its final stages, I could hear the unmistakable tones from our print lab as the build tray lowered and the door lock solenoid was released.
My two stirrers were already done!
The total print time was 1 hr 7 min and came at a total material cost of less than $11.
Just a couple minutes after I opened the printer, the stirrers had been removed from the build sheets and loaded to my battery powered drill—ready for use!
They ended up working perfectly for the job, and I was still able to get the epoxy poured and set in time to box them up before the outgoing packages were picked up for the day.
Final conclusion
As this scenario illustrates, choosing to design and print stirrers was much better than the alternative of driving over to the local hardware store to find something that would work. When you factor in the lost time of travel and circumventing the whole process of trying to expense a petty expenditure for a simple need, printing this tool on our readily available commercial additive manufacturing system (in this case, a Stratasys Fortus 450mc) was an easy win over the off-the-shelf alternative.
GoEngineer
www.goengineer.com
