Calibrating my 3D Printer: Overhangs and Supports

Good Morning from my Robotics Lab! This is Shadow_8472 and today I am continuing to work with my 3D printer. I’m covering a lot of ground this week, so let’s get started!

.Gcode Flavor

I left off last week wondering what was with my printer cooling its head when I had already preheated it through firmware. I reached out to various help channels until I randomly speculated that my printer was speaking a slightly different dialect than what PrusaSlic3r was feeding it. A helpful user suggested I switch my .gcode flavor to Marlin (listed as Marlin (legacy) in Slic3r).

I compared outputs from the two flavors after slicing the same object. The two files were similar, but legacy machines like mine –it would seem– do best with some additional information before any custom .gcode a user might want.

In retrospect, I probably should have learned to make my own temperature tower. Running .gcode meant for a larger printer can cause any one from a number of problems. At the same time, I’m glad I printed the tower with raw .gcode or else I might have easily given up.

Calibration Park

Armed with an optimal or near-optimal printing temperature, I set about printing a calibration multi-test [1]. I came back part way through the print and found that a PVC pipe I use to extend the filament holder had fallen off and both the X and Y had been gotten way off (I’m just glad it wasn’t on a more serious print). Additionally, the base was warped something awful. The test was still stuck to the printbed, but it was almost trivial to remove. I figured my bed was too low, which it was, but it took me until I noticed my heated bed turning off after the first layer that I had a setting wrong in Slic3r.

I was able to save my second serious attempt at the test by manually adjusting the temperature from my printer’s touchscreen. It turned out pretty well after that. The scratch in the middle of the bed was obvious, and a lot of the fine details in the lettering describing each test were lost. Otherwise, everything appeared to do OK at the very least. The overhang test was technically still together at the 80 degree inclination, but artifacts were beginning to show up by around 45 degrees. Most importantly: the large artifacts I had when unknowingly printing with wet filament were fixed.

Planning a Complex Print

To date, the most complex print I’ve successfully probably pulled off would have to be my Blinkie Pie case, where I modified a PacMan ghost case so a camera could see out one eye. Aside from a little impossible bridging that quickly evened itself out, that wasn’t a difficult print. But the world of 3D printing is much more diverse than variations on simple shapes.

I decided to try printing a model of unicorn Twilight Sparkle — both for her (percieved) relative simple geometry compared to her friends and so I wouldn’t have to risk her potentially breakable wings as seen across most of the show. I found a model on Thingverse after looking at several different places that wouldn’t let me download without creating an account — free or otherwise [2].

I went back and forth with it between Slic3r and Blender a time or two to refine Twilight’s model. While skimming through the planned layers, I noticed she had a sizable oral cavity. Her tongue and teeth were simple enough to delete, but it took a bit more patience to remove the rest of her mouth and stitch it back together. Somewhere in there I got rid of her eye lashes, which were also separate meshes from her main model as I was sure they would be hardly there to begin with and likely would be damaged while removing support material.

Speaking of support material, I knew from the beginning that I wasn’t getting away without a bunch of it. Twilight’s mane has a number of spots that hang down from layers printed later – let alone her tail as it arches up, backwards, and not quite to the ground. I messed with the automatic settings until I had what looked like a minimal amount of support, but after seeing the results of the overhang test, I put the settings back up. I also ordered up a raft three layers thick to cover up the scratch in the middle of my build plate.

Another concern I had was what Twilight’s center of mass was going to look like. At one point, Slic3r had her tail slotted for mostly solid infill with her head at 15% honeycomb infill. While I was able to find a solution involving analyzing the sliced figure with a Blender plugin, I ended up scaling Twilight up to about four inches as opposed to about three/three and a half – big enough so her tail was also rendered as a shell with infill, but small enough that her legs were solid.

A closer inspection of some supports gave me the distinct impression that Slic3r was being silly. The most complicated part of Twilight’s geometry is her mane, and there were more than a few tiny “overhangs” I figured would be fine being bridged instead of supported. I found some support blocker cubes I could move and scale, but it was clunky and there’s a better system for painting on supports I’ll be looking into next week. I wasn’t the happiest with the results I had, but I printed it anyway.

Cleanup and Repair

Between six and seven hours later, I had a pony standing on my build plate rendered in my recovered red filament. Cleanup started quickly as I cut away large sections where I knew there wasn’t anything, but as I got closer in, needle nose pliers and cutters were getting to be a little too awkward. My father arranged for a poker fashioned from some construction grade tie wire often used for holding re-bar in place while pouring concrete structures. Even then, it was a bit thick to fit in all the needed places. My mother offered a sewing straight pin which was versatile, but bowed more easily.

I quickly became jealous of dual+ head printers that can possibly use a soluble filament for easy support removal. It was a major morale boost when I was finally able to free Twilight’s face. Other tough spots included the arch of her tail, The tight spots between her legs and up across her belly, several tight spots in her mane, and the raft stuck to her hooves. I am very glad I scaled her up as much as I did.

There were a few moments when I wasn’t as careful as I should have been. I broke Twilight’s right back leg below her hock (the ankle-like joint most of the way up her leg) about half way through, and snapped her mane a few times in a couple places. Sections across her belly had to be cut away.

Despite the missing leg, there remains a piece just behind Twilight’s front legs. I had a feeling from the beginning that the supports between her forehead and bangs wouldn’t be coming out and they haven’t. At this point, I’d need to melt a handle to the remaining support material and carefully yank. The toughest holdout is physically trapped between her neck and the bit of her mane hanging to the side. I’ve already chipped the tip of her mane there trying to get it out.

I had already decided that I’d be reslicing and reprinting – I just haven’t yet. However, it doesn’t feel right to leave this Twilight without at least reattaching her leg and doing what we can with her mane. My father and I worked on the remaining bits of raft with a razor stuck to her hooves and used some superglue. The first repair on her mane didn’t go the best, so we’re using some painter’s tape to hold it in place. The leg was more promising, so at least she can stand while she waits. Maybe I’ll come back to her when I have more skill, but for now, this model has served as a learning experience so my next print should go better.

Side Project

I accidentally closed my main FireFox window. Normally that’s annoying, but since there was an update cued, I managed to destroy it completely in my attempts to recover it. I checked around online and learned a little about how Firefox stores saved sessions and I found a backup from not quite two weeks ago. It’s not perfect, but I’ll take 96% restoration over nothing!

Takeaway

3D printing is an art form, even if you’re printing other people’s .stl files. There are many factors to adjust to keep your printer in top condition. Slicing programs require knowledge about your printer’s tolerances to use effectively. Even if it prints correctly, you may want to sand, prime, and paint it.

Final Question

Have you ever set aside a work-in-progress for when you’re better equipped to finish it?

Works Cited

[1] majda 107, “*MINI* All In One 3D printer test,” Thingverse.com, Feb. 25, 2018. [Online]. Available: https://www.thingiverse.com/thing:2806295. [Accessed Jan. 3, 2022].

[2] dragonator, “Mane 6 models MLP:FIM,” Thingverse.com, April 09, 2012. [Online]. https://www.thingiverse.com/thing:21076. [Accessed Jan. 3, 2022].

[2*] David, “Mane 6 models MLP:FIM – Fixed,” Thingverse.com, June 19, 2012. [Online]. Available: https://www.thingiverse.com/thing:25282. [Accessed Jan. 3, 2022].

* The second [2] hosts the same models but “fixed” variants. I don’t know for sure which version I used, but I’m slightly more sure than not that I used the 21076 models.

Calibrating My 3D Printer: Temperature Tower

Good Morning from my Robotics Lab! This is Shadow_8472, and today I am recalibrating my 3D printer after leaving things to rot for a year or so. Let’s get started!

Printer Alignment

The first step in getting my printer operational again was to start from the beginning: alignment. My father got out the bubble level and I folded some large papers to get the plethora of degrees of freedom all lined up.

Tuning continued with the built-in, poorly communicated bed leveling tool. The printhead traveled to each corner and I slipped a calibration sheet under it and adjusted the corners such that it could slide, but not freely. When the right Z-axis was found to be misaligned, my father reached in and turned it a bit. I was sure it would have been frozen, but we were able to level the horizontal bar.

Temperature Tower

One well-used calibration test is the temperature tower. Regular printers use ink/toner (which original manufacturers go to great lengths to regulate) and paper (which is so standardized, it’s rare to see messed up). 3D printer filament is at least as varied and presents itself as universally interchangeable as long as it fits and the printer can melt it. As a result of differences between specific models –and even specific printers/printing environments– filament and printer manufacturers can only make broad guesses as to what the best setting will be for your specific printer.

That is where the temperature tower comes in. Instead of printing the same test shape over and over again on different jobs, they can be stacked one on top of the next and an instruction to change printhead temperature for each “floor” can be inserted.

From what I’ve gathered, temperature towers are normally assembled manually in a slicer for the exact printer, but I decided to try one straight from gcode (that went hot to cold; I didn’t want the filament freezing on the bottom and making a mess trying to print atop thin air). I didn’t first make sure the printer would be able to understand it; I didn’t make sure it would fit within my printer’s volume. I just loaded it up and hit print. Surprisingly, it worked. I had adjusted my bed a bit high and the first layer was smooshed (making it very difficult to remove), but I’m officially printing again.

I used my red filament and the tower that came out demonstrated its ability to bridge, overhang, and produce fine points. Each floor is numbered after the temperature it was printed at. The whole range was fairly good, but there was less stringing higher up, where the printhead was cooler. All other tests performed well at most temperatures.

Side Project

This month’s effort to reward award goes to getting my father printing on Debian. I sat down with him to get it working and we installed the CUPS universal printer driver and it worked with no additional fiddling.

Takeaway

Printer calibration is an important step to understand and use when needed – 2D or 3D. 3D printing is a much younger technology with a literal extra dimension for things to go wrong; it requires a greater degree of technical mindedness to keep in working order to the point where you at least need to be or know a hobbyist to have continued access to this amazing consumer level technology.

Final Question

I had more planned in terms of printer calibration, but it looks like that will need to wait for next week as I figure out the thought process for PrusaSlicer. It looks like they have some sort of preheat function in the .gcode header, but in practice, I already preheat my bed and hot end before selecting a file to print. In my workflow, this programming blurb ends up telling things to cool. Any ideas where the setting is to control it?

Baking Old Filament May Reduce Water Content

Good Morning from my Robotics Lab! This is Shadow_8472 and today, I am getting back into 3D printing, but I doubt it’s going to be pretty. Let’s get started!

Inspection of Equipment and Materials

My 3D printer is in used condition. The print bed is scratched and one of the two Z-axis rods got bent at around the same time. My filaments are old and brittle. I can’t even use the slicer it came with anymore because it’s both outdated and made exclusively for Windows. I’d rather just start over with a standard one designed to be user-serviceable. But that’s not an option at the moment.

I should learn about what I already have and work from there. There’s not much I can do about the scratch unless the original replacement pad shows up or unless I’m willing to fill it in/cover it up somehow. As much as I’d like to replace the Z-axis rod, a suitable replacement proved elusive for reasons discussed above; besides, the tweak doesn’t look that bad – the top of the rod only moves back and forth a little when the print print head is moving vertically and is down low. Alternate slicers exist. Long story short, I may as well give this printer one last chance before giving up on it completely.

Filament Reclamation

I have two PLA filaments I’m considering today: my original, red one and an opaque white one I got later and hardly ever used. Red used to just work. White felt different from its day 1 and never printed nicely. After a couple years of absorbing moisture from the air, they’re both as stiff as spaghetti. I even bent one piece of White until its middle piece snapped out from between the ends.

Besides causing stiffening, absorbed water evaporates when exposed to heat, causing problems such as the ones I experienced last time I tried printing. Water from within the filament forms steam, and it’s the steam that causes mysterious jams that seemingly go away come time for diagnostics.

A number of places have listed methods for drying out filament: bake it. Just be aware of the material’s glass transition phase where it goes from resembling a wire to resembling a more squishy rubber. The whole spool will fuse and you’re reclamation efforts will be for none. For PLA, that transition is somewhere around 140 degrees Fahrenheit.

To be safe, I elected to aim for 100-120 degrees F. My stove at home doesn’t hold its temperature that low. We put a bowel of water in overnight with a rising loaf of bread and it tested way cooler than needed. We tried our old toaster oven and tested at 125 F – close, but as I only had one shot to fix what I have, I didn’t want to risk it.

Specialized devices exist to dry out filaments. I was able to approximate one by modifying a food dehydrator operating at 125 F. My final design involved a rheostat from my father’s soldering iron to adjust the otherwise fixed temperature, some Duplos (a Lego-like block aimed at younger ages we’ve had laying around since I was little) to hold up the lid, and a tall, plastic film from my mother’s cake supplies to extend the tray. Without a thermostat, I monitored the temperature myself with a digital cooking thermometer we got for my sister’s bread making.

Both Red and White were dried overnight. White still felt stiff, so I left it in for several hours more. The temperature was difficult to keep constant. I left the contraption in a small room, and the room warms up and I have to turn the power down. If I had known how to easily, I would have built a thermostat capable of operating in those ranges. In retrospect, it would have been better to just leave it in the toaster oven on warm and not worry about it.

Side Project

I was able to get Vaultwarden running by forwarding the incoming traffic to the container’s port 80 instead of 443. However, this is still sub-optimal. I have my ability to manage passwords between devices back, and that feels sooo good after months of downtime, but I’ve been strongly encouraged to use a reverse proxy. This week, I looked into NGINX, and I believe that will be a focus some time in the coming weeks.

Takeaway

The path to my improvised filament dehydrator was a little longer than going right there. My early approach was At first, I figured I’d want to build something with a couple appliance bulbs like what the oven uses. The food dehydrator I eventually used as a base only has an on-off switch, so to lower its steady state temperature, I used some short Duplo stilts to raise a lower level to let ambient air in. I kept them for my production run, though if I have to run it again in the future, I’ll leave the sides closed and turn the power down lower on the rheostat.

Final Question

What would you tell someone who is ready to know more about 3D printing than: use slicer, level bed, load filament, press start?

3D Printing Against the Pandemic

Good morning from my Robotics Lab! This is Shadow_8472, and today, I am joining the fight to the best of my ability using my 3D printer. Let’s get started!

The CCP Corona Virus has been spreading around the world for months now. Medical supplies have run short, and hoarders reduce availability further. Across the world, people on the front lines are turning to improvised equipment to mitigate the chances of transmission. And when the CDC says that even a bandanna over the face can help, you know it’s serious.

As part of the effort, companies have been bolstering the medical field with products they can adjust their assembly lines to produce. But even with the increased production rate, the demand still greatly exceeds the supply, and will continue to do so as long as an abnormally spike of people are being treated.

Enter: everyday people. With a major percentage of the population stuck at home, people have been seeking out places where they can join the fight. The Folding@Home project has mustered over an exaflop of computing power from donated CPU and GPU time. Seamstresses, such as my mother, have been sewing masks, and 3D printer communities are printing parts that hospitals need.

Good intentions are nice and all, but amateur craftsmen need to realize that quality is an important factor. That is where online communities come in. My mother connected with a local group who is making masks for hospitals. Even though she is giving her masks directly to family, friends, and church members instead of the group, she has learned to make a mask that should be almost as good as the gold standard N-95 masks.

And that brings it up to now, where I just joined a similar group where I can learn what works and what doesn’t work. For me, I need to get my print quality back up, as I discovered when I went to print a number of bias tape folders for the above-mentioned group.

I can’t just use the slicer I had going before because of my recent transition to Debian on that computer, and vanilla Cura doesn’t come with all the settings pre-tuned for my model.

After I finish tuning my printer in, I’d like to look into building face shield parts to compliment my mother’s work, but I’ll see what is needed most when I get there. I’ve already run half an experiment involving layer height and printing temperature. A group should be able to help me calibrate my machine faster.

Final Question: What can you do to help in this fight?

Linux Deep Dive Part 4: 3D Printer Workflow Online

Good Morning from my Robotics Lab! This is Shadow_8472, and today, I am printing myself a bookmark as a “Hello Again, World” project. Let’s get started!

I have a Monoprice Maker Select Plus 3D printer. It’s a rebrand of a product made by Wanhao. For those keeping score, I am running Debian 10 (Buster) on my laptop, and I’m migrating different tasks over to Linux that I can.

My problem: My printer shipped with a version of the Cura slicer specifically tailored to work with it — on Windows. By default, the version of Cura I found on the Debian 10 repositories does not come packaged with presets for my printer or its original branding. Furthermore, the software has had several more years of development since the kiddie pool fork of the software I was used to playing with.

Since last week, I’ve realized that as far as someone at my skill level is concerned, all the specializations are are just a few numbers a sufficiently resourceful individual, such as myself, can look up, punch in, and fine tune as necessary. With the right numbers, I can see where a printer can safely print multiple small jobs on the same bed without waiting on the head to move to each one every layer.

A slicer is only any good if I’m going to print something, so I modeled up a bookmark in Blender. That interface is a new sight for my eyes to behold. I eeked out something for a first prototype using my fragmented knowledge from when I last put printing away.

Over in Cura, I used a slider to set 100% infill; I don’t want this thing breaking on me. I told it to go with structural support and saved it to my SD card. I really like this version of Cura over the dinosaur animal cracker I used to work with.

I went through about half a thing of canned air on my printer and leveled it with an assortment of junk mail and a bubble level. Fortunately I didn’t need to reapply grease. I did have to reassemble my MacGyvered filament holder atop the printer. Somehow, I found the same piece of PVC pipe from before in another part of the house, but I used a rag instead of a strip of cardboard to secure it.

When material started getting laid down, I noticed another old problem. Filament wasn’t quite sticking at the very beginning of extrusion. As the printer continued laying down material around where my bookmark was soon to take shape, I recognized it as a brim. The malformed plastic was relatively isolated, and the print continued without further incident.

Lacking my proper spatula, I peeled the fresh bookmark off the buildplate by the deformity from the beginning, but I quickly learned how easily freshly printed plastic can deform. It twisted and left a minor, permanent warp if one were to look closely enough. Next time, I will let it cool.

The brim was a lot harder to get everything. Between the prototype being too thick for a hardback and me not liking the pointy bits I designed into the sides, I took the design back to Blender, where I had to refresh my memory again on proper modeling methodologies and that’s were I stand now.

Final Question: How frequent do you come across a 3D printer operator using Linux?

Linux Deep Dive Part 3: Stability

Good Morning from my Robotics Lab! This is Shadow_8472, and today, I am just going over the stuff I did this week. Spoiler alert: it’s more of a mix and mash. Let’s get started.

My idea while writing last week’s post was it. I believe my laptop wasn’t booting reliably because GRUB was configured incorrectly. The BIOS went fine and selected the external drive to load from (or the GRUB disk). The bootloader, GRUB, loaded correctly, gave me the option of operating systems to boot, but when it went to load Debian, some of the time the drives respond out of order: when GRUB went to the drive presently known as sda, the internal, Windows drive, and expected to load Debian, it panicked and dropped into BusyBox.

I diagnosed the problem by looking directly at the grub configuration files and sorted out any instances of “sda.” There were a few. After fielding some questions about the suspect config lines, I regenerated the config file after reverting the only change I had previously made without regenerating. When it was done, I scanned for the parts where “sda” had previously shown up, and there was the correct UUID I was looking for.

I wish I had found someone identifying this problem. Ironically, I came within inches of mysteriously solving this issue none the wiser when I tried regenerating the GRUB files to give the drives a full minute to load instead of five seconds. I can see where I might have spent just as long trying to reproduce the bug an failing. I wouldn’t have it any other way than how it happened. I can live with this.

With stability issues out of the way, I have other things to move over. Remember when I used to do 3D printing? Well, I want to make a bookmark, and I want to do it from Linux. I popped my SD card into my laptop, and found the copy of the Cura slicer that originally came with my printer — it’s a .exe file. Linux doesn’t do .exe files.

Side note: I’ve been using aptitude instead of apt-get. They both do the same job, but aptitude tries to put a nicer face on it, like not changing half its name for searching instead of installing.

After teaching myself how to search the apt repository like I did back on MicroCore, I used aptitude search cura and installed the package pertaining to g-code generation. I looked in my program menu and found “Ultimaker Cura.” OK, I suppose this is the generic. I already knew the version I was on before was a fork of some other parent program. Lacking another explanation, Ulitmaker Cura seems to be it.

The first time I opened this newer version of Cura, I was bombarded with a prompt to add my printer. I didn’t see my printer, so I ended up picking a wrong one and continuing from there. And that is where I’m stuck.

I poked around in the menus and did some research, and found the latest version of Cura is on at least version 4.0, but the on in the Debian repositories is 3.3.1. I am starting to get the feeling that this is what they meant when Debian software is chosen for proven stability. I may go around the repository on this one.

Diagnostic procedures involved a bunch of research and plugging in with a USB B connector. I hooked my printer up and told Linux to list my USB devices. I isolated an entry called “QinHeng Electronics HL-340 USB-Serial adapter.” I’m not exactly sure what is going on here, but it looks like my printer is electronically connected to something inside that then talks to the computer outside. Oh, and the menu still works off just USB power.

I am open to using other slicers. The main goal is to demonstrate a workflow, and I don’t have that right now. I also tried Slic3r Prusa and it had even fewer options, but it had a list of questions for configuring other printers.

Looking around, there is a lot more to the world of slicers than the narrow sliver I was looking at before. The IIIP branded Cura is great for someone who is just wants to 3D print or doesn’t want to move away, but there is a whole world to explore out there with different optimizations and features to play with — all locked away behind a learning curve that starts with getting my printer back online.

There are plenty of 3D printing videos out there. Every one I clicked on while trying to get things working on Linux was using Windows. Maybe there was one, but I don’t know. I’m going to have to tackle OS/slicer and slicer/printer issues separately from now on.

Unrelated: I have been getting a lot of use out of my Steam controller. It turns out to be very useful as a mouse on my Widows machine when I want to sit back without a hard surface in easy reach.

Final Question: What was one challenge you faced that left you feeling good for going through it?

Blinkie Pie Case Repair: Stage 0, Part 2

Good Morning from My Robotics Lab! This is Shadow_8472, and today, I have another less-than-full speed progress ahead story. Let’s get Started!

The story so far: I crushed my Blinkie Pie case while it was in my backpack. The damage isn’t terrible, it’s just inconvenient enough it needs to be addressed. One long tab is 99% broken off, and part of the top is peeling away from the rest.

I researched a bit more with my father. It looks like some super glues work well for this kind of thing while the cheaper kinds usually don’t. Another tip was to use baking soda or some other kind of powder to use it as a filler material.

The experimental stage went surprisingly well. I have an aborted print and its original raft I can test glue techniques on. We tried the baking soda method, but the bottle was starting to thicken up. It didn’t mix well with the baking soda and didn’t hold. I went into the workshop and made a bead of some high quality stuff with a fine application tip, and did two test pieces; both were without baking soda, one pressing down the whole time — the other only pressed down after, and both turned out strong.

I went to repair the original in the same way and discovered that super glue can be disagreeable.

I tried multiple times, but the bond wouldn’t hold. I’d think that parts broken from each other would naturally be the perfect surface for each other, but my test failed. The plan now is to try using acetone to remove the residue. After that, I’ll want to test out a number of procedures on my dwindling test supplies.

One drastic method would involve heating the base material with a soldering gun or something and melting some new filament in there. I’ve heard there is such a thing as a 3D printer pen that –while cool and useful– will probably turn out to be something niche.

Another real possibility is to try the baking soda again with a thinner super glue. I’ll need to make sure it actually soaks in this time.

Sanding the parts’ faces and applying super glue to the resultant faces is another option. I’d be nervous of it not being perfect, but if I was really after that, I’d just reprint the whole thing.

Whatever the case, the crack in the case head will be more challenging to approach with how tight it is. I’ve given up the notion that I can get away without a paint touch up, but I’ll still hold out a modest bit of hope.

Final Question: random edition: pronunciation: dAta or da-ta?

Planning a Semi-Sealed Night Light Part 7

Good morning from my Robotics Lab! This is Shadow_8472, and today, I am inching forward to a stop on my current long-term project. Let’s get started!

I finally added a hole for the lamp base in my model. The pegs for the screws still aren’t in there, but I have made accommodation for their addition. I started with an cylinder object and scaled to the correct sizes. I positioned it in the optimal spot to get a visual proof of concept, but I eventually remodeled it to have a better number of vertices. My model is still on a 4 way symmetry, so I needed it to be divisible by 4; and the screw posts need to be on a symmetry of 3, so it needs to be divisible by 3 as well. I already had 40 points to merge, so it needed to be at least 40. Therefore: I gave it 48 points around the approximated circle and made some loop cuts accordingly.

I made a plan to start prototyping, but I noticed something. Sometime during the week, I arranged my Blender window to cover both my screens and set up my small screen to display different wire frame views of my project. I noticed on one of these views that something I did caused some of the loop cuts used for keeping edges sharp even with the subdivision modifier to go slightly out of alignment, and a face normal appeared facing inward along such an edge. I think it was a rounding error or something. Annoyed, I told Blender to remove doubles and I resharpened the edges.

Another incident while modeling happened in the way I added the hole in the bottom of my “house.” Before, it was a simple grid. I just scaled it down, then stretched the corresponding edges to meet the corresponding point on the model cylinder-cone. (I think I may have modeled that a little incorrectly as well, scaling the Z axis alone when I should have just scaled along the edges themselves. Good thing I kept the progress in an old layer.) I ended up with a squished grid and ugly quad geometry… and eventually some unacceptable triangles. By the time I noticed, it was too late in terms of actions to undo my remove doubles command, so I ended up removing bits of the squished grid and replacing it with some much simpler geometry.

I approved my own mesh for prototyping and pulled in a new cylinder and applied a Boolean modifier so I’d only print the ring for a test fit. (Another stay thought: the power cord would have also had issues with the ring I was making.) After catching myself from accidentally sending the .stl file directly to the printer, I went to the slicer and had to go around a few times to figure out the scale. I ended up making a unit cube and figuring the correct scale is about 5BU (Blender Units) to 1 cm, and I am working on a centimeter scale.

Finally, I got the test print to the printer, and I had the drippy white filament again. It didn’t start extruding again, and the raft started separating on the first set of passes when it was supposed to stick to the (absent part of the) outline. It curled on me. I reduced the extrusion temperature by ten degrees and tried again, only to have stuff curl on me on the next, tighter layer.

At this point, I’m thinking I will need to put this project on hold until I can properly fix my printer. It’s not working as intended, and I don’t know what to do with it.

Final Question: What in the world is going on with my printer not starting extrusion right away for the initial outline?

Planning a Semi-Sealed Night Light Part 6

Good Morning from my Robotics Lab! This is Shadow_8472, and today, I am once again picking up the night light project. It’s been a rough week progress wise, so there isn’t much progress. Let’s get started!

The next task is modeling up the print and executing it. It took me a while, but I finally broke off the first piece: actually modeling the lamp base. The lamp I took apart is a sphere with a flattened base. I used a flattened cylinder and scaled up the proportions to the size of the base. The greater radius and height were spot on accurate on the metric system, so when it came to the curved edge of the smaller circle, I rounded to the closest millimeter.

The next challenge is refining the base model and integrating it into my house structure. The base has three screw holes I intend to use to fasten it to the cover as it prints. At some point, I’ll need to model the screw holes in. I’m just glad I managed to get it in at all. However, realized that stock Blender is not the right tool for the job.

Before my next printing project, or sooner if I really need it before then, I will want to find a plugin for Blender that adds some missing CAD functionality. Already, I have been missing the ability to measure between two points of a model, and I had to scale the models using a known size and modifier factors instead of just making something x cm tall. I will say Blender did treat me nicely when I pulled it across my second screen and set it up with multiple angles of my work. It felt good to finally have a visual of how big the base/lamp will be relative to one another.

The next major chunk of work should be modeling up pins I can attach the lamp base. I’ll likely need to underestimate a little and won’t get as tight as a fit as I did with the Pi camera because I won’t have the luxury of sanding. On the other hand, a little cleanup isn’t out of the question.

Final Question: Do you know of any good CAD plugins for Blender?

3D Printer Online Again

Good Morning from my Robotics Lab! This is Shadow_8472, and today, I am bringing a good report about my 3D printer. Let’s get started!

The problem so far: My 3D printer has had some issues with filament running through the extruder tip when it shouldn’t. The plastic semi-remembers its curl from the spool, so it curls around and touches another hot spot on the extruder tip. In addition: This would drag along the initial couple inches of extrusion, keeping the printer from laying the important first outline when making the raft. I even observed stuff peeling off the printbed a couple times.

While I was at investigating printer problems, I got some cleaning filament and played around with using it for something other than a print; some had come with the printer, and I took it for normal material. I followed a tutorial to clean the printer, and got most of the stuff in the printhead out.

I was never able to get the printer to start extruding right away, but by raising the print bed, the troubled corner stuck without the outline. I still had a print I wanted where I would have a hollow cube, but the support structure would account for more than half the weight. The solution: print one side and two edges twice and glue the halves to each other. I think it took on the order of eight hours, and within four hours of coming off the print bed, one of the prongs had easily snapped. I don’t plan on fixing it, nor do I plan on replacing it at this time. The design was flawed; it was only half a centimeter thick, and I think it needs a full centimeter.

Either way, with this distraction out of the way, the printer is a bit cleaner and working correctly again. I can now return to my bigger project. The next step is with Blender.

Final Question: Unrelated: I started a Spigot Minecraft server this week for family and a few friends. What are some plugins you have had fun with in the past that would work for multiplayer cooperative on a small server?