0.6-mm Nozzle for Faster Printing

September 7th, 2021 by Keith Neufeld

I recently brought home a trio of Ender 3 Pro printers needing a little love … that’s a story for another day. But this weekend I put a 0.6-mm nozzle on one of them for doing faster draft prints. Let’s see about some PrusaSlicer settings to take advantage of that.

Draft of a wall holder for a chef’s knife:

  • 9h12m for Prusa MK3S, 0.20-mm layers
  • 11h13m for Ender 3 Pro, 0.20-mm layers
  • 4h22m for Ender 3 Pro with the 0.6-mm nozzle

4h22m print on Ender 3 Pro with 0.6-mm nozzle

Okey dokey, what do we need to do to configure to use a 0.6-mm nozzle?

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The Lawn Under the Lawn

August 22nd, 2021 by Keith Neufeld

“Yak shaving,” well-known among a certain class of nerds, refers to artificial dependencies that you insert before your ultimate objective, distracting you and derailing you from getting the job done. My favorite sample yak shaving is on Seth Goden’s blog from 2005.

Yak shaving would be: I want to use the lab power supply on my workbench, but my CupCake is hooked up to it, and I haven’t finished getting the CupCake’s aging extruder motor to work, so suddenly I’m spending the weekend working on the CupCake, so I can get it fixed and move it out of the way, so I can use the power supply under it to do … whatever it is that I was going to do. (This is a fictional, but relatable, example.)

Some time back, Cort said to me:

Doing technology work is often like going out to mow your lawn, and you think it’s going okay, but partway into it you discover there’s a whole ‘nother lawn under your lawn, and now you have to mow the one underneath before you can mow the one you thought you were there for. And then sometimes you start mowing the lawn under your lawn and you find out there’s another one under that, too.

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Tryna Print Some TPU

August 6th, 2021 by Keith Neufeld

I picked up a couple rolls of Overture TPU and it’s lovely stuff — supple and squishy and I really want to use it — but I just can’t get it to print right.

Block printed in Overture TPU with insufficient extruder tension

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Getting Started with D-duino-Clone ESP8266 and SSD1306 0.96″ OLED Module

August 6th, 2021 by Keith Neufeld

D-duino clone ESP8266 and SSD1306 OLED module

I’ve been interested in the ESP8266 for a long time; and way back in 2017 when I first learned that support had been added to program them with the Arduino IDE, I ordered this totes adorbs little guy, who’s been patiently waiting for me until today. In the process of figuring out how to program it, I learned that it’s a clone of the D-duino.

I find the ESP8266 market space very confusing, with lots of boards and lots of assumptions that you already know what you’re doing. It took me a fair bit of searching and fiddling to get this working. In case you’re in the same boat I was until yesterday and want to try this yourself, here is one currently-available product [no affiliation] that I expect will be identical to mine. You may find others; and/or you may not even need this walkthrough, both of which are perfectly fine.

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CNC Fabric Cutterhead Prototyping: BLDC Motor

April 24th, 2021 by Keith Neufeld

Last fall when I was looking for ways to drive a reciprocating fabric cutter, Ed Nisley suggested that I look at hobby brushless DC motors as possible sources of enough of both speed and torque. Not knowing anything about their care and feeding (and after a significant delay), I did my homework and learned how to lash one together well enough to make it spin.

After which I inevitably put together a completely unusable cutterhead prototype.

reciprocating cutter prototype with BLDC motor and skate bearing

My intent all along was to use the same tattoo gun brass cam as on the tiny motors, but last weekend I couldn’t find a tiny hex key for the set screw to remove it from the previous prototype and affix it to the BLDC motor. It being a very short drive from Missingtherighttoolville to neighboring Badideatown, I printed a plastic cam and new connecting rod to fit a standard skate bearing. Let me tell you, turning on that cutter was like holding a powerful vibrating thing with a razor-sharp blade in your hand.

It didn’t cut the fabric particularly well, either. It had plenty of torque but lacked either sufficient speed or travel to cut unclamped fabric; it just shoved it out of the way. (It cut just fine when the fabric was held in tension, but that’s not the objective.) The eccentric mass of that heavy skate bearing did not motivate me to turn it up faster, particularly when I already had the other cam in mind.

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CNC Fabric Cutterhead Prototyping: More Speed (Less Torque)

April 18th, 2021 by Keith Neufeld

In a previous installment, I used a 900-rpm gearmotor in my reciprocating-blade prototype and it didn’t have the speed needed to cut fabric sitting on a styrofoam spoilboard. The only place I could find to order a higher-speed version was AliExpress, and it took a while to arrive.

reciprocating cutter prototype

Quickly swapped into the same prototype cutterhead, with predictable results: It has a higher no-load speed but bogs down in the cut. This style of gearmotor won’t be my solution.

Achievement Unlocked: First Hobby Brushless DC Motor

April 18th, 2021 by Keith Neufeld

I had not worked with hobby BLDC motors before (I keep saying “hobby” here because my cordless drill and driver have BLDC motors); but as you can see, they’re cute as the dickens. Much cuter than chickens. About walnut-sized, and very cheerful. More cheerful than chickens?

hobby brushless DC motor

YouTuber How To Mechatronics has a stellar video How Brushless Motor and ESC Work and How To Control them using Arduino explaining all the theoretical and operational details of BLDC motors and their electronic speed controllers (ESCs). If you want to know (pretty much) everything about them, go watch! Or for a quick overview, keep reading.

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Blue 3D-Printing Build Surfaces Are Great

January 7th, 2021 by Keith Neufeld

Creality CR-10 Mini 3D printer with print

I am loving this slightly-textured build surface. ABS sticks to it well enough not to peel even without an enclosure, and PLA works great, too. The texture is just enough to make the bottom of a print blend in with the other faces. So far it’s providing so much better results than my Prusa PEI spring steel sheet that I’m on the verge of ordering a clone spring steel sheet and covering it with this.

You can find them on Amazon by searching for “blue 3D printing build surface” (or just “3D printing build surface”) and scrolling through the inevitable irrelevant Amazon results until you find the offerings from Chinese companies named <random letter> <random letter> <random English word>.

And, er, I bought a secondhand Creality CR-10 Mini (300 mm x 220 mm build area) to be able to print something a little longer than my Prusa can do.

MakerBot CupCake’s Triumphant Return, Part 2: Skeinforge Slices; CupCake Prints

October 31st, 2020 by Keith Neufeld

With the CupCake printing successfully again, the next step was slicing so that I could print new things instead of only reprinting G-code that I’d saved in 2012.

As noted before, I hadn’t figured out how to get Skeinforge to run on a current computer, after losing my previous Skeinforge installation to the crashes of both my personal desktop and laptop computers, on which I had all of the data and none of the software or configurations backed up. (I’m wiser now.)

I struggled figuring out how to get Skeinforge running again now, in part because I think the instructions that come with it never got updated as its capabilities did. No, I am not going to copy the STL into the system executable directory every time I want to slice something and then move the resulting G-code back out. It turns out that any version of Skeinforge that I might actually want to run has a file browser and remembers where you browsed the last time you used it; so it’s pretty easy to get along with.

And as to which version I actually want to run, one of the files I did have backed up was my detailed notes on fine-tuning Skeinforge settings for my CupCake, which (naturally) included the fact that I was running Skeinforge 0035. So there we go.

3D printer calibration objects

With slicing working, that just leaves calibration, and I’ve done that now too.

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Replacing a Pollcat Power Supply

October 3rd, 2020 by Keith Neufeld

Replacing a power supply should not be a noteworthy task; but when an exact replacement for the failed power supply isn’t available, one wants to exercise some care and diligence installing a compatible-but-different power supply.

Shamefully long ago (cue Wham’s delightful “Last Christmas” and sing along to ignore the guilt), one of the two redundant Pollcat telephony call-detail-monitoring gateways at work didn’t recover after datacenter electrical maintenance. Last weekend I finally looked at it, confirmed that the power supply was dead, and confirmed that the rest of the unit operated fine when run from bench power.

Pollcat shown with new and broken power supplies

I couldn’t find a reasonable source for the original model of power supply (the right of the two, toward the center of the photo); so after a bit of searching came up with different a 5-VDC 2-A open-frame power supply (the left, on some bubble wrap) that can physically fit into the available space in the enclosure and that can also operate from 100-240 VAC (important for datacenter 208 VAC) for a very affordable $10. We ordered a couple of them and I got it replaced this afternoon. I expected from the beginning to have to make a mounting adapter, but I also had to mind the polarity of both the AC and DC power connectors.

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