MakerBot Industries

Slicing with style

Gian Pablo’s excellent tutorial on how to manually edit Skeinforge profiles on Mac OS X got me thinking that manually editing Skeinforge profiles isn’t exactly intuitive for just about any operating system. ¹  For instance, Windows Vista will store Skeinforge settings in one of two locations.  These profiles are located either in a sub-folder where you have ReplicatorG installed or a sub-folder of your user profile.

1. Location of Skeinforge Settings in ReplicatorG
   • replicatorg-0024\skein_engines\skeinforge-35\skeinforge_application\prefs
2. Location of Skeinforge Settings under User Profile
   • C:\Users\USERNAME\.replicatorg\sf_35_profiles

The settings folder within the ReplicatorG sub-folder should contain a series of sub-folders with the stock profiles:

• SF35-cupcake-ABP
• SF35-cupcake-HBP
• SF35-Thingomatic-ABP
• SF35-Thingomatic-ABP-Stepstruder
• SF35-Thingomatic-ABP-Stepstruder-1.75
• SF35-Thingomatic-HBP
• SF35-Thingomatic-HBP-Stepstruder
• SF35-Thingomatic-HBP-Stepstruder-1.75
• SF35-Thingomatic-non-heated

It seems that when you create a new Skeinforge profile within ReplicatorG the new settings profile will be stored under your User Profile.  The profiles themselves are basically a collection of text documents laid out in the exact order you would see them in when viewing Skeinforge.  Changing the settings manually is merely a matter of opening one of those text documents in a text editor and changing the relevant values.

1. Photo courtesy of pj_vanf [↩]

Infill - half empty or half full?

I had the opportunity to talk to Nick Starno of MakerBot yesterday about something we are both passionate about – getting the best Skeinforge settings to print sweet awesome things.  ((Photo courtesy of micmol))  One of settings we discussed was “infill.” ¹  While this may be review for some, I’m hoping to do a few more posts that will build on this topic. ²

25% infill, 75% infill

It is probably pretty intuitive that an object that is 100% filled with plastic is going to be stronger than an object with 0% filled with plastic.  But, what if you don’t need the strongest part possible?  What if you just need an object that is purely decorative and doesn’t need to be strong at all, an object that just needs to be only just strong enough for a particular application, or an object that will print very quickly?

Generally speaking, a higher infill ratio will lead to a stronger and sturdier object that will use more plastic and time to print.  Whereas, a lower infill ratio will lead to a lighter, less sturdy object that uses less plastic and time to print.  When I don’t need a part that is super-strong, I typically print with about a 20-25% fill ratio.  I find this makes for parts that are very strong and durable while still being quick to print without using a ton of plastic. ³

What infill ratio do you use for strong lightweight quick-printing objects?

1. • Fill -> Infill Solidity (ratio)

   [↩]

2. So hang in there! [↩]
3. However, infill isn’t the only consideration for strong lightweight printed object.  Next time: extra shells! [↩]

Obsolete 40mm Cube Test Object by bre

As some of you may know, I’ve been working on a Skeinforge calibration projected called, “ProfileMaker.”  I released v3.0 last month over at MakerBlock.com. ¹  My goal was a web-based cross-platform easy-to-use Skeinforge setting calculator.²

Calibration by cube is essentially a trial and error process.  Print a cube, examine the results, take some notes, change a setting, and LRR³ until you have a satisfactory result.  There’s nothing wrong this this, but it is time consuming and can be frustrating.  ProfileMaker uses the same math and formulas as Dave’s Profileinator to derive the flowrate (or speed at which plastic comes out of the nozzle) based on the few settings you choose.  There are also some advanced options, for the more adventurous.

When you calculate some new profile settings, ProfileMaker will generate the settings and tell you exactly where to enter them in Skeinforge.  Or, if you wish, it can e-mail a zip file containing those settings as part of a complete profile.  Just unzip into your directory and start slicing!

As always, I’d appreciate feedback!

1. In that time more than 200 people have generated nearly 1000 profiles.  I see this as a good trend.  If people weren’t happy with the profiles they’re getting, they probably wouldn’t come back to generate five profiles on average. [↩]
2. In fact, if this isn’t the easiest Skeinforge calibration system you’ve EVER used, I’ll give you your money back! [↩]
3. Lather, rinse, repeat. [↩]

Improving prints through coating

This is the seventh in a series of posts about ways to get even better print results from your 3D printer.  The prior posts provided information on calibrating hardware, upgrading hardware, calibrating software, maintenance, finishing by abrasion, and finishing with heat.   Your hints, tips, hacks, and suggestions have been really great!  Please keep sending them in!  Today’s post is about a surprisingly little-used technique – coating:

1. Coat.You could choose to coat your object in another material that would obscure any imperfections in the printed object.  These will inevitably lead to a loss of detail, but improve the look of the final object.
   1. Covering a printed object with successive coats of paint. ¹
   2. Dipping your object in liquid plastic grip material.  This is typically used to put a very “grippy” layer on tool handles.
   3. I’ve heard of others who have used ABS glue or other material to essentially paint a coat of plastic onto the surface of a printed object.

Have you used some kind of coating to improve your 3D printed results?  Please share your ideas and tips in the comments section below!

1. Unfortunately, it appears that the user or Flickr removed the pictures from that post.    [↩]

Thingiverse citizen nrp uploaded a Python script that enables a Kinect to track a hand in the air and feed the corresponding Gcode to a 3D printer – a process he calls “gestural 3D printing.”  From the video above you can see how the monitor provides visual feedback for the user while his RepRap in the background mimics the user’s movement.

Gestural 3D Printing by nrp

Really, the best description is the video:youtube.com/watch?v=BRJY927raTo Also on my website:eclecti.cc/computervision/gestural-printing-jumping-the-shark-on-kinect-hacks We’ve seen a seemingly endless array of amazing Kinect hacks over the last few months, from superhero generators to obstacle avoiding quadcopters. However, it was only a matter of time before someone came up with a hack so inane and irrelevant that it would bring shame to the entire hobby. That time is now, and that someone is me. I bring to you, gestural 3D printing! Using the Kinect to track your hand, you can draw one layer at a time, with the printer following your every move. Pushing forward extrudes plastic, while pulling your hand back will start a new layer. Who needs difficult and confusing CAD software when you can just directly draw the object you want to print?

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Another kind of feed rate

I’ve been a MakerBot operator for about 18 months now, and only just now am I really coming to understand Skeinforge’s nomenclature. ¹  Dave Durant did an excellent job of explaining the most important settings and terminology for Skeinforge in his series on configuring Skeinforge.  “Flowrate” is the rate of plastic exiting the extruder’s nozzle.  With a little math and science the flowrate is a function of the extruder motor speed and the volume of filament.  “Feedrate” is the rate of speed of the XY platform.  There are several different methods proposed on Thingiverse for configuring Skeinforge, and most of them involve solving for the proper flowrate or the proper feedrate for a given profile.

When using a MK5 or other DC motor powered extruder, there’s a very narrow range of reasonable flowrate settings.  The MK5 DC motors had a maximum speed of 255 PWM and a functional minimum of around 230-240. ²  Much less below 240 or so and the motor just wouldn’t turn.  The MK6 stepper motor extruder, on the other hand, has a much wider range of speeds – from around about 0.0 to up to about 3.0 RPM or so. ³

What values, then, is a 3D printer operator supposed to modify to get the best profile?

If you’re using a MK5 or DC motor extruder, I would recommend calibrating Skeinforge as you hold the DC motor speed at 255 and the maximum reliable flowrate you are able to obtain.  You’re going to want to adjust the other variables that are easier to control – the feedrate⁴ , the layer thickness⁵ , and thread width⁶ .  Since I like choosing my resolution and there’s not much choice in flowrate, I like to vary the feedrate since it’s easier to control.

If you’re using a MK6 or other stepper extruder the flowrate, feedrate, layer thickness, and thread width are all easily adjustable.  I prefer to choose the layer thickness and thread width, hold the feedrate at a level I know my robot can handle without problems, and vary the flowrate.

Here’s the interesting thing about solving for flowrate: the nozzle size ends up not being super critical.  As long as you’re choosing sane numbers for layer thickness and thread width, the amount of plastic going in will always equal the amount of plastic coming out.  While a 0.5mm nozzle would be capable of up to about 0.36mm thick layers and 0.75mm wide threads⁷ , these numbers might not make sense for a 0.4mm nozzle⁸ but could still work for a 1.0mm nozzle.

What settings do you like to vary when you’re configuring Skeinforge?

1. Photo courtesy of MadBuster75 [↩]
2. My understanding is that a PWM of 255 equates to about 2 RPM [↩]
3. A few disclaimers are in order.  You can set your RPM in the control panel to whatever you want and try to extrude – with no guarrantee it’s actually going to extrude at the mathematically calculated flowrate.  Additionally, the maximum effective RPM will be a function of the nozzle aperture. [↩]
4. XY platform speed [↩]
5. The thickness of each layer as it is laid down.  0.25mm/layer to 0.36mm/layer are reasonable ranges [↩]
6. This is the width of the filament as it comes out of the extruder nozzle. [↩]
7. Since they’re getting squished as they’re laid down [↩]
8. Since it would be tough to squeeze a 0.75mm thick layer out of a 0.4mm filament [↩]

Make Your Own Gears by Dustyn Roberts

I don’t know about you, but I am continually envious of the really excellent designs up on Thingiverse that make use of gears.  Greg Frost, Emmett, and Whosawhatsis have been rocking Thingiverse lately with their incredible designs incorporating gears.  But, what’s a simple blogger with zero gear-knowledge supposed to do?

Well, Chris Connors, teacher and Maker-extraordinaire, recently posted about gears, motors, and attachments thereto over at Make: Online!.  His post referenced a gear tutorial by Dustyn Roberts, author of Making Things Move, all about gears.¹

I learned more about gears in Dustyn’s first paragraph than I did after hours of trying to design my own gears from scratch.

One nice thing about gears is that if you know any two things about them – let’s say outer diameter and number of teeth — you can use some simple equations to find everything else you need to know, including the correct center distance between them. In this project, we’ll design and fabricate spur gears using free software (Inkscape) and an online store (Ponoko.com) that does custom laser cutting at affordable prices out of a variety of materials. If you have access to a laser cutter at a local school or hackerspace, even better! You can also print out the template and fix it to cardboard or wood to cut the gears by hand.

Dustyn’s tutorial style to explaining gear mechanism is very nuts-and-bolts² with lots of pictures, diagrams, and charts. ^3 4

1. Also, both were speakers at Botacon!!! [↩]
2. Pardon the pun [↩]
3. I think I hear some skittering spiders in our future… [↩]
4. Please don’t click that link. [↩]

Simple Hinge by PieterNr1

Apparently, when you properly arrange objects in an STL for printing at once, you can do so in such a way as to eliminate the need for support structures!  Not only is this a clever use of limited build space, but it also conserves plastic while allowing printing of ever more intricate designs.

PieterNr1′s Simple Hinge above is the first object I’ve seen to use this technique.  It appears from the photograph that there is some slight drooping underneath the top two ledges – but I’m guessing this isn’t enough to interfere with proper operation.  Looking at his implementation of this technique, I have to wonder whether it could be used to print some of the various tracks and treads under development on Thingiverse.

Simple Hinge by PieterBos

My attempt of making a hinge. I do not know how strong it is but it works for now at least. It a openscad thingi so you can mod it. It only hinges at 90 deg but that is what i needed ;-)

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Perfect prints come from careful build heights

Once I had my Thing-O-Matic build-height dialed in, I never thought about the starting build height again.  As a Cupcake owner, I used to obsess about getting the build height right for every print job.  I’d start a print job, watch the raft to make sure it was going well, and scrap the print if it didn’t.  A calibrated Thing-O-Matic will automatically home to the specified build height.

Until very recently, I had exactly two profiles I would print with – one for PLA and one for ABS.  Using Dave Durant’s formula, I’ve been able to print with any vertical resolution I feel like.  It was only this weekend that I realized that I can’t use the same starting build height for every profile.  When printing at 0.36mm layers, I have to use a build height 0.3mm higher than the build height when I’m printing at 0.25mm.

After months of intensive research and development, MakerBot Industries is proud to announce a newly realized capacity of the MakerBot Thing-O-Matic 3D Printer- the ability to print listenable vinyl records from the desktop.

“The process of transcribing an audio file into a vinyl record is so simple, anyone can do it.” Said Chief Audio Engineer Isaac Dietz. “Right now, I’m using the Automated Build Platform to rip my entire MP3 collection to individual records!”

“It’s an exciting innovation for MakerBot, as we all grew up listening to vinyl. We all wish that more records were available with the latest hits,” said Audio R&D Associate Marisol Murphy. “I can never get enough Justin Bieber or Rebecca Black until I listened to them on my turntable.”

The process utilizes the MakerBot 96khz AudioNozzle™ technology to print audio waveforms in real time. Using the MakerBot Generation 4 Electronics microstepping capacity, the AudioNozzle™ modulates the amount of plastic deposited to create a high-fidelity waveform. The results often surpass the dynamic range of 24-bit recordings and can contain frequencies up to 57khz — even higher than the Nyquist frequency for 96khz digital recording. You can even record directly to your 3D Printer by attaching a microphone to your computer, and singing into it.

Says Ethan Hartman, Vice President of Audio Operations: “MakerBot’s pioneering spirit has always hearkened back to early inventors like Thomas Edison. We are honored to be able to re-invent the audio record for the personal manufacturing space in the burgeoning 20-teens.”

Pre-orders for the 96khz AudioNozzle™ will be available shortly.

MakerBot 3D Printed Vinyl Records can be downloaded from Thingiverse here.