In a previous project, I 3D printed a fidget spinner. It was in the shape of the Adafruit logo and designed using forms in Autodesk Fusion 360. I had originally 3D printed it vertically to achieve a smooth surface finish (though, it requires support material & rafts). A few folks in the community asked, “Why not 3D print it flat on the bed?”. Hadn’t actually tried, I quickly thought of using the concentric external infill pattern feature in Simplify3D. 3D printed flat, leaves lots of build lines and appears a lot like a machined part.
This led me to try CNC machining the part on the Othermill Pro. Since I already refined the part for 3D printing flat on a bed, it’s also “CNC” ready. I had a cheap piece of pine stock laying around, so I thought I’d use that for testing. Next, I had to come up with the tooling strategies in Fusion 360. I was able to resolve the part using just two processes. 1x 2D Face, produces a quick operation for preparing the thickness of the material. 1x 3D Adaptive clearing, makes a series of cuts with variable depths to produce the part by removing quantities of material. I only used one tool for the job: a 1/8″ flat end mill. This took approximately 2hrs to machine (same amount of time 3D printing) with a cutting feed rate of 800mm/min. I did a light sanding just to remove all of the burrs. It could be smoothed a lot more and could even be stained.
I think it was a good first test of machining a 3D object. I’ve only made a handful of parts so it was good practice. If I were to machine it again, I’d adjust the center pocket so it has a tighter hold on the 608 bearing. I had forgotten it was designed for 3D printing, so it’s a bit more open. If I were to guess, I’d need to offset the inner diameter by 0.1mm. I’d most likely run a test cut using scrape material first (which I have plenty of). I’d also use dense wood like or walnut or hard maple for the final part.
Join us every Wednesday night at 8pm ET for Ask an Engineer!
Maker Business — Presentation: Ten Year Futures – Benedict Evans
Wearables — Simulate tattoos
Electronics — Servo Pulses
Biohacking — Nutrigenomics – Personalized Vitamin Supplements Based on DNA
No comments yet.
Sorry, the comment form is closed at this time.