DIY UV Curing Chamber Pt. 4

Progress has been made! I left off last time having printed a few components to test tolerances and fitment. Everything fit well enough to move forward with printing a small test frame that held the motor, bearing, and turntable in the correct alignment. I did this by splitting the CAD model to isolate just the main spindle/bearing mount and the motor mount with a web of material joining the two. Because most of the main body is only 1.5mm thick, I added some thickness to the test frame to add rigidity and speed up print time. This proved to be a fairly important design feature down the line, but I didn’t know it at the time. More on this later.

Notice the turntable/pulley assembly’s skewed angle.

After finally “pressing” in the bearing (I kept the fit pretty loose since I wanted to be able to remove the bearing easily) I discovered the first issue. A single bearing acting as a fulcrum, combined with loose fitments between the various components didn’t provide adequate support against tension in the drive belt. The result was that the rotating platform ended up tilting an excessive amount.

So to remedy the fulcrum effect of the single bearing, I added another one along the main axle. I ended up having to add about 8mm to the overall thickness of the turntable, but that was a minor sacrifice. The overall appearance of the device wasn’t affected too severely. I printed another test frame and this time everything looked solid!

At this point I was ready to print the main body in all its glory. The print came out beautifully, and as an added bonus, I finally got my support structure settings dialed in on this print. The support broke away super easily and cleanly. But sadly, all was not well. Remember that extra material I had added to make the test frame easier to print? Well it turns out the main body was super flimsy without that extra material. I probably should have anticipated this, seeing as I have some pretty large, flat areas in the design that are only 1.5mm thick. Additionally, my bridging settings aren’t especially good, so the first couple of layers on the underside have pretty poor adhesion. So back to the drawing board to add some reinforcement.

I had considered adding some manner of cool ribbed structure to the underside of the main body, but that would have been excessive and increased print time unnecessarily. Instead I just added a thick chunk of material bridging the motor mount and the main spindle mount. Not the most graceful design, but it won’t ever really be seen anyway and it makes printing and post-processing faster and easier.

At last! Having finished troubleshooting the issues and printing the main body, this project is finally looking like something. I assembled everything and now I’m ready to start in with the electronics!