With several filaments I’ve used lately, I get a rough surface on the top of my prints that makes me think the printer is depositing too much filament. I took a bit of time today to learn how to calibrate that; and one of the same tutorials gave a nice reference for nozzle temperature calibration, so I did that, too.
These notes are as much for me as for thee, as I expect to run through this again with more filaments in the future.
Yup, went ahead and did it. I’d been holding off because I really want to fix the printer I have and I was afraid that getting a new printer would remove my interest in doing that. But I’m happy to say that my insight into my own psyche after I’d given it more thought turned out to be correct — having a working 3D printer makes me feel more motivated to get my CupCake working, not less.
While shopping and looking at pictures and videos, I had a hard time envisioning exactly what the Prusa’s build capacity was. Some pictures looked like the build platform was huge; some looked like it was scarcely larger than the CupCake’s. I think there’s a lot of wide-angle lensing going on in the world of 3D printing videos. So here’s a shot for you with a reference standard, for your size-interpreting convenience.
I might even write posts about it from time to time.
I just designed and printed a battery holder and I’m shamelessly reusing this image from the blog post about it to illustrate fillets in 3D design:
You might notice that the holder’s mounting bosses have nice roundy fillets that are standard in professional CAD packages and have been a wee bit difficult to achieve in OpenSCAD until fairly recently. The ability to design them now is one of two observations in the last week that have really driven my interest in OpenScad’s 2D subsystem. If you’re not interested in OpenSCAD, you’ll probably want to stop reading now. (Who am I kidding — I’m sure that the two of you still reading are interested in OpenSCAD.)
I’ve assembled a couple of Makeblock mBot robots I picked up a few years back and intend to start programming soon. They come with a 4xAA battery holder, but I’m not a fan of single-use batteries and Makeblock’s LiPo is only $10 on Amazon [no affiliation and not an affiliate link, just a happy customer], so I ordered a couple.
The LiPo batteries came in clear plastic cases with tabs that looked like they should latch into the slots on the robot chassis, but the spacing was off. The robot kit came with hook-and-loop tape to fasten down the battery holder, but yuck. So I designed this holder, which is good enough to use after a single pass of dimensional refinement.
Many thanks to my student employee Kip for printing the battery holder on his Prusa I3 MK2s. The quality is outstanding.
I’ll upload the design to Thingiverse after a bit of code cleanup.
Like many other 3D printer owners, I’ve long dreamed of processing post-consumer plastic into new filament for printing. I’ve now taken a couple of steps in that direction.
Friday evening I left off with the extruder working again. Saturday I focused on the heated build platform.
I’ve always had astoundingly good luck with kapton tape since nophead’s serendipitous discovery, probably because I (still) prefer to print in ABS. When the build platform is warm, my prints stick to it absolutely with no raft or mouse ears and once it has cooled, they release easily. That’s a pretty compelling combination.
So my first step was replacing the scraped-up kapton that I gouged the last time the printer was on. I bought a 4″ roll way back when and I keep a strip of unsticky tucked under the end so I don’t have to peel it up with fingernails and get fingerprints on the stickum.
In the past I’ve always replaced the tape by sticking down the end and using a credit card to “squeegee” it onto the surface, and it can be tough to avoid getting bubbles. Yesterday I unrolled enough tape to cover the platform and when I had it stretched out, it was easy to align the front edge of the tape with the front edge of the platform, at which point I squeegeed it down with my thumb with no bubbles at all. Huh, well, I guess I’ll remember that.
The next step in running the CupCake 3D printer is reinstalling the software and connecting to the machine.
It went surprisingly well, with the only real snag being my misremembering the installation process, leaving me stuck in NotConnectedLand for a while.
I devoted Wednesday, my Independence Day holiday, to getting my CupCake 3D printer running again.
Foreshadowing: It turned out as a pessimist might suspect rather than as an optimist might plan.
After making the filament de-duster five years ago about which I posted recently, I was finally getting consistent, reliable, beautiful 3D prints for the first time ever. For a month.
Then I was trying to print a draft of a pocket holder for a tube of moustache wax and comb and when I came back, I found that something had gone wrong after about 40 minutes of printing. I forget the order in which these occurred, but through the original attempt and two retries it:
The second try, I ran another print of the same model; the third try, I made a tiny dimensional change to the model or Skeinforge settings in case the extruder controller was glitching on some particular G code; but that doesn’t seem to have been the case. I got different bad behaviors and it seemed as though the extruder controller stopped taking instructions and kept doing exactly what it was doing at that moment.
I don’t know whether it’s a firmware bug, a power supply problem, a wiring problem, an extruder board problem, or something I haven’t thought of yet. I have (recently) found reference to a few of the DC extruder motor windings shorting, reducing the coil resistance and increasing the load, to the point that the extruder controller FETs burn out. But these weren’t burned out — they worked again immediately (for another 40 minutes).
And then before I could muster the motivation to troubleshoot it, both my laptop SSD and my workstation motherboard crashed, leaving me no working computer with 3D-printing software installed and no working computer with my CupCake’s calibration settings on it. And then time passed; OSes were upgraded; ReplicatorG versions increased; the barrier to reentry increased substantially; and I simply have not touched it since early 2014.
This shall change.
Another unpublished post dredged out of the distant past — this one apparently complete.
Soon after I got my friend Cort hooked on the Arduino, he said he wished he could easily carry it to the office to play with over lunch, to the tire shop to work on while he waited, etc. I offered him three-ring binders and boxed cases, but that wasn’t quite what he was looking for.
After some discussion, we settled on an empty plastic case from a videocassette. I visited our Media Resources department, had their video director help me scrounge up a suitably large case (Cort says “U-Matic 3/4″ helical scan”), and updated the labeling.
Cort cut out the spindle posts and then stickied down the Arduino, a couple of breadboards, and some other things useful for prototyping and now does all of his development with the AMPduino. Handy for the workbench, the kitchen table, and the tire shop.