MoI + 3D Printer

My son purchased a used Robo R1+ 3D printer. They sell for $700 - $800 new, but his was $500 and only used twice. I guess some folks give up easily and sell their new toy after they realize 3D printers take some effort to set up correctly.

I sent him a STL file created in MoI just to see how it all works. My simple design is a coolant hose clamp for my desktop CNC milling machine.

Earlier I machined a swing arm from aluminum to allow positioning the coolant at the precise height needed for the miniature cutter. Prior to that I was using loc-line to deliver the coolant, but found it too bulky for my small application. My original coolant clamp was machined from aluminum, but I decided I wanted the tube to tilt rather than be in a horizontal position. Rather than machine a new clamp, I decided to try a 3D printed part made from PLA thermoplastic.

I haven’t been following 3D printer technology closely, so I when my son brought the finished parts over I was expecting a rough surface finish that resembled a vinyl LP record. I really expected I would need to sand the parts to make them look and work well. Instead I was surprised how precise the dimensions and surface finish turned out.

The parts are just 0.130” thick. The groove through the center holds a 1/8” diameter tube taken from a ballpoint pen. No sanding required. I just drilled a mounting hole using the aluminum arm as a guide.

In the photo you can see dark diamond shapes. That is an internal honeycomb structure produced by the printer’s software to reduce the material needed to make a solid. I tested to see if it was watertight – sure enough the parts float in water.

MoI produced perfect STL files that worked the very first time. Now that I have a good idea what this printer can do, my next projects will get progressively more complex.

Ed Ferguson