…code, cg, electronics, 3d printing…

I recently got OctoPrint working on my C-Bot.  It’s been pretty nice to remote-login and check my prints (and an emergency shutdown once during a jam).  One of the last remaining issues has been the quality of the timelapse video.

I’m using a Raspberry Pi camera module, and based on where I’ve mounted it (front top cross-member of the bot), plus the size of my build platform (12″ square), it prefers to focus on the rear of the platform, rather than the middle.  The effect is that anything from the middle to the front comes out blurry.

I’d read on the forums that you can use a pair of +2 reading glasses to pull that focal-distance closer, so I trekked to Walgreens today and picked up three pairs for $10 (It was 3 for the price of one):  I got these values to test: +1.25 (they were out of +1.5), +2, +2.5.

After popping them out of the frames, based on testing, it looks like the +2.5 increased the quality the best:  I was immediately able to see fine detail at the middle and front of the build platform.

But how to mount?  The pi_cam_head_v2.stl file sure wasn’t modeled to support reading glasses.  Hot glue to the rescue (aka, manual 3d printing) :

View is from the right-front corner of the build-platform, with the front leadscrew in-frame.

Making sure to first clean it really well, and center it on the camera itself, I simply ran a bead of hot-glue along the top and bottom edge of the lens, .

The only easy way to tell the difference is to compare the timelapse vid’s I’ve made to date:

• First vid ever, low-res, low quality encoding, out of focus: Eiffel Tower

• Second vid, 720p HD, higher quality encoding, out of focus: Big Christmas Reindeer

• Third vid (shot today), 720p HD, same high quality encoding, in focus:  Small Christmas Reindeer

Only place to go from here is to mess with the encoding more, see if I can bring that quality up, and possibly get a fish-eye\wide-angle lens for it.

I’d found a great model if the Eiffel Tower on Thingiverse:  I’d wanted to print it on my C-Bot for some time (since it seemed like a great way to maximize its build volume), but I knew with all the required retractions, the Bowden extruder would never handle it.  After recently switching to a direct-drive extruder, it seemed approachable again.  And with the recent attacks in Paris, I felt a desire to somehow pay my respects to that beautiful city, and landmark.

It didn’t go entirely smoothly though:  The extruder jammed when it hit first landing… I think all the super small handrails caused possible retraction issues, and the filament notched.  But I was able to reslice/reprint it right at that point, and glue the top on.  You’ll see this failure in the above movie… which was my first time making a timelapse in Octoprint, so the quality is a bit low as I figure out the settings.

The print looks fantastic, especially in the sun or with a light shining on it at night.  Really happy with the results.

Print stats:

• Model height:  20″
• Print time: 69 hours (yes, 69 hours)
• 150 micron layer height
• 6mm E3D-v6 Volcano nozzle
• Sliced in Simplify3D
• Just over a pound of material
• Printed at 60mm/sec
• Makergeeks white PLA, extruded at 230 degrees (per their recommendation)