Monthly Archives: April 2016

You’ve Got Fail!

TLDR; I released suspect geometry into the wild. Also 3dprinting.fail is now a thing.

failed citadel

Despite rumors to the contrary, it’s not all mimosas and backrubs here at Zheng Labs. There are times, thankfully few and far between of late, when we fail to make the proper sacrifices to the 3D printing gods and models go kablooie on the print bed.

To wit: these Eyrie caps that bought the farm before they could reach their full potential.

eyrie cap

The bottom surface of the Eyrie cap is a thin circle and occasionally won’t adhere to the build platform. Double woe if one gets ambitious and prints multiple models at a time; one failed print can catch on the extruder nozzle and get dragged into its doppleganger, causing a calamitous cascade of failure.

The printer, being blind, deaf, and completely lacking in agency besides, has no idea that this failure is happening and if left to its own devices will merrily continue extruding hot plastic into thin air.

Fail.

A quick primer on 3D printing for those of us who don’t live and breathe this stuff. One can break the process down into three basic steps, about which one could proceed to write volumes of details.

Step 1: Creation! By some mystic means, a 3D model is created. My weapon of choice in this arena is Autodesk Maya because I use it in my day job, but there are scores if not hundreds of software packages that will export a 3D printable model. Amazingly, even Minecraft can do it with the right mods. Tell your nine-year-old niece.

Step 2: Slicing! Before it can be printed a model must be divided up into a vertical series of horizontal layers. If you’ve accidentally introduced wonky geometry in Step 1 the slicing process will create toolpaths that kinda work, but might result in a less-than-optimal print in the real world. More on this and a mea culpa in a bit.

Step 3: Printing! A tireless bot with a melted plastic-filled hot glue gun draws successive layers on top of each other. The plastic cools and before you can say Bob’s your uncle you’ve got a brand new Dice Citadel. Usually it works, and sometimes this happens:

The reasons for print failure are legion, but I’m guilty of letting an avoidable one slip through my quality-control network with the Classic Citadel. Back to slicing and the aforementioned mea culpa:

Here at the lab our preferred slicing software is Cura. Cura has been churning out perfectly usable G-code for months and I’ve printed dozens of citadels with nary a problem. But here’s the rub, mein grübenses: not everyone out there uses Cura.

Printing problems started cropping up once the Citadel was released into the wild. Users of slicers Simplify3D and slic3r were shocked to find that their printed citadels, walls too thin to withstand an assault even by Marshmallow Mangonels, were crumbling to the touch– see the photo at the top of the post.

Mea maxima culpa, I really should have run the models through several slicers before releasing them. Parallels may easily be drawn between the current state of 3D slicing and the early Web when different browsers would render the same HTML in completely different ways. 1996 was a great year for flannel, but damned if I enjoy the return to crossing one’s fingers and hoping that WYS is truly WYG.

Wizzywig. Now there’s a term I’ve not heard in a long, long time.

But! Thanks to the heroic and dogged troubleshooting efforts of Strongholds backers Chris Yohe and Nate Johnson, the problem’s been fixed as far as I can tell. I’ve uploaded a new Citadel to Pinshape and alles gut. Print, my friends. Print LIKE THE WIND!

Other backers have been busy printing Eyries and plinths a-plenty. If you’ve got a print you’d like to show off to our little tribe of medievalists, send it my way.

backer prints

Unexpected creative output: There’s plenty of downtime to be filled while the printer is producing Citadels and Eyries for physical rewards backers, we’ve been thinking about failure a lot lately, and here at Zheng Labs we’re certainly not ones to let a good domain name go unclaimed.

So I went and registered 3dprinting.fail, polished up my JavaScript-stealing chops, and made a nice slideshow of some of the spectacular messes my printers have created over the years. Tell your friends. Tell your mom. Tell your mom’s friends at the next euchre tournament.

beast fails

(That model’s a Beast Token and you can grab your own at The Forge.)

So! That about covers it for this week. Back to printing backer rewards and obsessing over the Next Thing. Here’s another wee teaser for that project, which I’m hoping to release within a month or so:

wee

Who loves ya, baby?

Lao Zheng out.

Travelers, Part 2

eyrie

“Zaogao.”

Jamming a wheel– again– on a mud-slicked rock, Da Xiong muttered under his breath and wiped his brow with a dirty sleeve. Out here, with no one but his dozing master to hear him, he could speak just a bit and break the facade he’d carefully sustained since before escaping the capital five years ago.

Progress along the muddy ground was excruciatingly slow even for a man of his size and strength, made even more so by the weight of the cart he half-pulled, half dragged through the puddles and stones.

Master Qie, as was his wont in the late afternoon, napped on his cushion undisturbed by the bumpy and intermittent travel. Qie had insisted– INSISTED! with a flourish of a silken sleeve, that Xiong load the cart with cheap wines at the last stop. For trade, he said.

Trade, indeed. Not that even the waiguogou would drink this swill. Or properly pave a road, for that matter.

Back home even this minor road would have been carefully laid with precision-cut flagstones. Xiong noted where cutting a swale on the left would immeasurably improve drainage, and over there one could very easily re-grade and straighten the path with an eight-crew and two days’ labor, and just a few li back they’d passed a fine, defensible junction where, if they’d had any sense at all, the locals would have sited a cistern and a toll collector.

Pfft. Barbarians. The only saving grace of plodding through this godsforsaken land was that Master Qie was now very, very far from the Imperial Censor and his torturers.

Ahead of them the tower waited, piercing the canopy and reaching three times again as high as the tallest tree. There were temples taller than this at home, but not many, and none made entirely of stone. A staircase spiraled to the top of tower, narrow and irregular and steep. They’d have to leave the cart and lug the wine up on Xiong’s back.

The glass orb at the top glowed dimly, brighter than the sun in the overcast sky. Xiong estimated the amount of sand, coal, and workers one would need to engineer a glass sphere the size of a house and concluded that either it was clever fakery or the waiguogou possessed a secret foundry bigger than the Emperor’s stables.

Or, most likely given the Eyrie’s inhabitants, it was magic.

Wizards. These people knew the importance of learning and careful study, even if they wouldn’t deign to apply their erudition to engineering a passable turnpike.

Tomorrow, the travelers would meet these mages and make a record of their Eyrie in Master Qie’s ever-thickening journal. Page by page the catalogue of strange places and people grew, but Xiong doubted anyone in the capital would ever read it. He still held hope, but daily became more and more convinced he and his master would never return from this land of fleas to silk sheets and polished rice and love left behind.

Da Xiong sighed and trundled forward. Perhaps, sweet Tianyu, he mused. Perhaps I will hold you again.

eyrie closeup

You can purchase the Eyrie at Pinshape. Read the first installment of this series here.

Printing with NinjaFlex on a Type A Machines 2014 Series1

TLDR: print slow and hot with NinjaFlex. It ain’t rocket science, but does require a little attention to details if you’re used to PLA or ABS. If you’re using Cura you can download my Type A Machines 2014 Series 1 profile here.

Our most recent Kickstarter was a smashing success! We were 119% funded with 140 backers. Watch this space for a comparison/post-mortem describing the differences in funding among the several Kickstarters we’ve launched, successful and not so much. I learned a great deal with Strongholds and I’m eager to apply the new knowledge and analytics to the next crowdfunding effort.

Here at Zheng Labs we’re ramping up to start the print-a-thon for backer reward fulfillment, but we have a little side project to get out of the way first. Scoundrels that we are, we’re using the slow trickle of backer survey returns as an excuse to not engage with the following print ticket:

print ticket

That’s-a-lotta-printing, my friends. We’ll get started this evening, I promise.

The Easter Bunny was kind enough to drop off a roll of NinjaFlex last week, so before the printer gets ocupado producing Citadels and Eyries for the forseeable future we thought we’d give flexible filament a try.

Loading NinjaFlex into an extruder can be like shooting pool with a rope. I found that my venerable Replicator1 sucked the NinjaFlex right in without issues, but the faster G2 extruder on the Series 1 caused the NinjaFlex to bind up, thusly:

extruder

The trick is not to use OctoPrint’s Extrude button to pull the filament into the extruder– it pulls the filament in too fast, the filament backs up inside the nozzle and then starts folding upon itself and turning into silly string.

Instead, just heat up to 240°, push the lever on the side of the extruder, and manually push the filament in until you feel it hit the bottom of the nozzle. Make sure you’ve got good thermal conductivity between your hot end and nozzle too; a liberal application of thermal paste will be quite helpful.

Thermal paste fixes so many 3D printing problems.

Print settings: I’m at 240°, printing at 20mm/sec with .2 layer height. Retraction at 50mm/sec with a distance of 2mm.

Rex turned out nicely, printed on glass with Elmers’ glue stick. Then I mushed him under some PT weights.

rex crushed

(You can of course download Rex from The Forge.)

In other gnus: there will be a lot of human downtime while I’m printing all those Citadels and Eyries, so I’ve started modeling work on the Next Thing. Here’s a peek.

boot

#staytuned. This project’s going to be buckets o’ fun.