Going into this project I had a little bit of experience with 3D printing but not a ton. Considering how critical it is for engineering (and engineering design especially), getting more practice was long overdue.
To start, I selected my the design I would print. I didn’t have any specific ideas for an impossible project going in, but I ended up settling on this Ball in a Cube design:
First, I decided to use FDM to print just one model to see if it would work. I kept all the parameters as recommended and let it go. When I returned to the OEDK the next day, it came came out great, leading me to assume that printing the other copies would be just as straightforward (more on that later).
Then, I went on to print out of SLA. This process was surprisingly simple. I uploaded the design into PreForm, scaled it, and let it print. I then washed it and cured it, leaving me with these two models:
Then came time to print out the remaining models from FDM. For some reason, this ended up being incredibly problematic and time consuming. I printed 4 models at a time, giving me back ups in case something happened.
The first problem I ran into was the prints not getting past the first layer, which I was able to fix by slowing down the speed for the initial layer.
Then, I had a print that got about half way through when the printer just shook, causing a ball to roll off the print bed, ultimately ruining the print.
I had a few prints where, despite cleaning and gluing the print bed, the design would just slip after a few layers:
After this, I slowed down the speed for all layers. This was working out pretty well, up until the last 10 minutes of a print when yet again one of the balls rolled off the bed. I kept the print going, hoping the three other models wouldn’t be affected. At the literal last minute of the print, all three of the balls broke loose from their minor supports and started rolling around within their cubes, causing the nozzle to hit the wrong part of the ball. The resulting prints looked like this:
While I was content with calling it a day at that point, I decided to give it one more go.
Following the advice of another student in the OEDK, I added a ton of extra supports, mainly raft supports to keep the bottom together, and let that print. It took about twice as long as the others, but considering it was the only successful print, I’d say it was worth it.
Price breakdown (for successful prints only):
Labor: 7 hours x $12/hour = $84
FDM: 9g per model x 5 models x $25/1 kg = $1.125
SLA: 14g per model x 2 models x $155/1 liter = ~$3.94
Total cost : $89.07
