b'Engineer Innovation | Geek HubIt was now time to validate my design. I filled it with water and tested it over the kitchen sink, and voilait worked! After all the years of performing CFD simulations, I shouldnt be surprised by this. But that thrill never seems to go away. But I wanted some concrete data though, with numbers. I set up a mock test rig using a translucent plastic box and a rudimentary camera stand using kitchen utensils. I filled it with water up to the initial starting point in my simulation and tested itTime to drain (simulation) = 16 seconds. Time to drain (test) = 25 seconds (approx.).That was quite a big deviation, and not what I was expecting. There definitely were enough problems with my test the pudding is in the eating. Why notsetup (a simulation engineer blaming manufacture this cup and test it out?the testing methods, that sounds Validation and verification is thefamiliar). For example, the least count of cornerstone of any design process.my measuring cup was 25 ml, while the total amount of water I added to initiate With the advent of 3D printing, alsosiphoning was 13.6 ml, so I was eye-known as additive manufacturing, itballing quite a few of my measurements. has become very easy even for non- But thats when I found a second issue engineers to create all sorts of objects there was a slow leak in myfrom household projects tocomponent. In this video a secondary automotive parts. This is the path Istream of water in addition to the chose to go down. I approached a localprimary stream flowing down the stem. 3D printing shop in Ann Arbor, and this is where I ran into my first issuetheThe cup was made from a standard 3D printing operation that fit within my3D-printing material called as PLA, budget was based on a process knownwhich happens to be hygroscopic. Every as Fused Deposition Modeling (FDM).time I filled the cup with water, it The nozzle that extruded the plasticabsorbed more and more of it, making material had a diameter of 0.4 mm. Theit even more leaky. The print shop had thicknesses of the walls in my geometryapplied a water proofing aerosol, but it was close to that value. I needed to bewasnt applied along the inside wall of at above twice of that limit i.e. 0.8 mm.the pipe through which the water drains out. Evidently, my trial runs over the Since my geometry was entirely builtkitchen sink had proved costly. Most of using 3D-CAD in Simcenter STAR-CCM+,the advice I found online pointed it was very easy to modify my CADtowards re-printing the product with parameters and regenerate the CAD.some modified printer settings. Just to be safe, I re-ran the simulationAlternatively, I could try using a 2-partagain just a matter of two additionalepoxy called XTC-3D to coat the outside mouse clicks. The results didnt changeof the cupthis was the cheaper by much, as expected. I then providedoption, so thats what I did. The process the modified CAD to the print shop. Itis simple and well documented. It gave took them approximately 14 hours tothe outside surface a hard, glossy coat generate it. The printing process waswhich would hopefully contain the followed by fifteen minutes of post- water.processingshaving off the support structure and coating the part with aTime to drain (test) = 21 seconds water-proofing aerosol.(approx.).64'