This past week, I made a few test prints of my critical component, the cam which actuates the needle and allows it to ascend and descend within the tattoo tube, and the results were mixed. I prefer not to use the ITLL’s 3D printers, as I feel the constant use of the printers from many curious students has led to significant wear and tear and potential problems when it comes to producing quality prints. Instead, I have purchased my own spool of filament, and a very kind friend has allowed me to have unlimited access to the 3D printers inside his home. Here, I will be able to make as many test prints as I would like, as to toy with the many possibilities of settings which exist within the Slic3r software, and to hone in on producing a part which is up to my standards of quality.
The first few prints of the cam were of mixed success: on a couple occasions, the printer would under-extrude, meaning there would be less molten filament being exported from the nozzle’s end, and the result is what my friend and I have taken to calling a “ghost part”: a part which looks completely solid, but falls apart in your hands when you pick it up. On other occasions, the part would print with incorrect dimensions, or the resolution of the part would be so low that it was nearly impossible to discern certain aspects of the part from others.
After much trial and error, I was able to get a couple prototypes of the cam with which I was pleased about. I proceeded to test the rigidity of the part as a hole, and of the peg which would be taking much of the stress during operation. The part as a whole had fairly proficient rigidity, but the peg would fail after not much force at all. On top of this, I have now started to consider friction forces between plastic and metal, and am now unsure of how much of an issue slippage will be when I finally do produce a functioning prototype. I fear that I may have to redesign the cam, or worse (in terms of time), take the design to the machine shop, and mill the cam out of 6061 aluminum and tap the side to include a set screw to mitigate any possible slippage.
These, and many other concerns and issues, will surface as the project progresses, I’m quite sure.