Category Archives: printrbot

Printing With Steel on the Printrbot Simple

printrbot

One of the most popular pages on this blog is Calibrating the Printrbot Simple. To be honest I haven’t been using my Simple much lately, what with the hullabaloo surrounding my Barbie-Compatible 3D printed armor Kickstarter. Just don’t have the time.

My mental juice can’t be occupied by all Kickstarter, all the time, so I took a few hours to mess around with Mr. Simple, and I decided to try an experiment that’s long been tugging at my frontal lobes. Can I print something recognizable, in metal, using my Printrbot simple and some clever engineering?

There are hobbyist metal printers on the way. I saw Vader Systems’ prototype at Maker Faire NYC, and can’t wait to get one of these bad boys into the basement at Zheng Labs.

But! Enough wishful thinking. Let’s get down to brass tacks.

I’m using baling wire for this project. You can get this stuff at any hardware store. Just make sure it’s not galvanized, because that can give off some nasty zinc fumes when it’s heated up. Also, I highly advise wearing protective gear.

wire

warning Attempt this project at your own risk! There is an excellent chance that you’ll completely junk your Printrbot, or at least melt the plastic collar at the top of the extruder nozzle. Have a fire extinguisher handy, just in case. Goggles, gloves, the whole nine yards. Be smarter than I was: under no circumstances should you down three mimosas before trying this, no matter how much fun you were having at brunch.

As a precaution, you’ll also want to cover the print bed in fire-retardant tape, unless you’re willing to deal with a flaming Printrbot.

I’m planning on doing this repeatedly, so I replaced the Printrbot Simple’s print bed with a piece of asbestos tile instead. Yay for Open Source!

I just redid the kids’ room with asbestos tile and had some left over. It’s cheap and durable and I can’t believe people just throw this stuff away. Watch this space for a blog post about turning old asbestos tile into cutting boards; I’ll be putting them on Etsy once I’ve cut a dozen of them or so.

Temperature is everything here and you’ll have to move quickly once you start, so be sure to have your gCode pre-generated. Don’t waste time slicing the model before you print.

Preheat the extruder as high as you can get it. I managed to get mine up to 275°C by disabling the firmware safeties and working under heat lamps in the basement. (Printrbot firmware hacking is a topic for another day.)

Even 275°C is way too low for melting steel, so you’ve got to help the Simple across the finish line by heating your baling wire up with a propane torch. Depending on the alloy of your wire that means somewhere around 1400°C, which should be within the range of a hardware store torch.

tip

Start the print and gently feed the hot wire into the Simple’s extruder. I epoxied a steel washer onto the collar of the extruder nozzle to protect it from the hot wire. Don’t lick the glowy part!

The print was a miserable failure, just your typical tangle of filament touched by His Noodly Appendage, ramen. This is what happens when you leave steel prints unattended:

print failure

The second time through I stayed with the print, keeping the propane flame focused on the wire as extruder pulled it in.

feed

With just a little filing and polishing the nose ring looks way better than I expected it to. Not bad for a printer kit that retails for $300, even if I did have to babysit the print the entire time.

yurenjiekuaile

Permit me a brief foray into my other hobby, studying Mandarin Chinese. It’s a remarkably concise language, so cramming the entire One Ring poem (to find them, bind them, yadda yadda yadda) onto the side of the ring is easy peasy lemon squeezy.

You can compress the whole poem into five characters, 愚人节快乐. Way fewer than required in the Black Speech of Mordor.

Flagrant stagecraft alert: I printed the ring and nose separately and welded them together afterwards; I haven’t tried printing anything with support yet.

You can download the STL files for the nose ring in the Baubles section of The Forge, or if you’re impatient or don’t have a 3D printer just grab one from Shapeways.

Pro tip: I found that copying my gCode into OpenOffice, coloring it pure red (#FF0000), and then re-pasting it back into Repetier-Host helped me get the extruder nozzle up to 282°C the second time around.

What a difference a year makes.

I’ve been printing with my Replicator1 for just about a year and a half now. Here’s what my Penny Catapult prints looked like when I started out. (This print’s a veteran of many Seej battles.)

And here’s what my prints look like after countless hours of learning and frustration and failure and learning.

That cross-grain seam in the catapult’s side arm is probably caused by two pieces of blue painters’ tape butting up against one another. I do all my PLA printing on painters’ tape whether I’m using my Rep1 or Printrbot Simple.

One major difference between these two prints is that the top is ABS and the bottom is PLA– after a year of working with both I’d have to say I definitely prefer PLA. It smells better and heats up more quickly, which saves precious minutes of printer warming when repeatedly iterating through a design.

You can get a mirror-finish base with ABS, but apart from that I can’t see a reason to bother with it. Most of my stuff doesn’t wind up in high-stress situations so the added strength isn’t much of a draw for me.

Marshmallow Mangonel on the Printrbot Simple


downloadWhen I designed the Penny Catapult to fit on a Replicator1, assuming that printers were only going to get bigger. But the new crop of smaller, inexpensive printers coming down the pike requires a Seej engine that can be printed on a smaller build platform.

Enter the Marshmallow Mangonel. It’ll still throw a penny, but includes a second throwing arm designed for non-coin projectiles; marshmallows, gumballs, magnets, whatever you’ve got lying around that needs to be parabolized. You can find the Mangonel and its bigger brethren in the Seej Engines category in The Forge.

If this is your first exposure to Seej, head over to s33j.net and grab yourself a starter set. Get printing and then get your tabletop wargaming on.

Using Slic3r with the Printrbot Simple and Repetier-Host

Seej Bloxen Flag, Basic

I’ll be using a basic Seej bloxen for my slicing demo. It’s more exciting than a test cube and potentially useful should a vigorous Seej match break out at your makerspace. You can never have enough bloxen sitting around. Grab the model here if you want to follow along.

Open the Object Placement tab and click on Add STL File. Navigate to the bloxen model and Slic3r drops it into your build area. The bloxen should be centered, but if it isn’t, you can fiddle with the translation and rotation values, or just hit Center Object. When you’re done it should look like this:

Added Bloxen

Click the Slicer tab (not the Slice with Slic3r button) and then click the Configure button. We have a few settings to adjust.

This is the point in the tutorial where normally I’d walk you through changing a half dozen parameters. Teach a man to fish, Lao Tzu says, and he’ll eat for a lifetime. Screw Lao Tzu. You want your fish now. You can learn to fish in an hour after your belly’s full.

So I’ve zipped up the settings that have been working for me and put them up for download. You can just swap out whatever default settings showed up with Slic3r with the contents of this archive right here.

On OSX, Slic3r stores its settings in three subdirectories within

~YourUserName/Library/Application Support/Slic3r/

You can copy the archive contents into that directory and you should be good to go.

I have no idea where these settings will be saved in Windows. If you’re on Linux, you’ve already written a shell script to slice models using spare cycles from your video card and can stop reading now.

warningWARNING: The usual warnings about destroying your printer by using the code I’ve provided apply. Use these settings at your own risk. You might think about backing up your old settings in a safe place, just in case.

Once you’ve got the settings installed, click the Slice With Slic3r button. You should have a pile of G-Code in your G-Code panel. I’ve been consistently deleting/commenting out a couple of lines from my code and have gotten good results by really babysitting the first layer of my prints.

Delete this Code

If you comment out the code by putting a semicolon in front of it, the printer won’t use it but it’ll still be there for reference porpoises:

;G28 ; home all axes
;G1 Z5 F5000 ; lift nozzle

This assumes that I’ve manually homed my printer by moving the print bed all the way to the right and the extruder arm as far forward as it will go. The hot end should be over the bottom left of the print bed.

If you’ve manually homed the printer, make sure you hit the Set Home button the the Print panel before you print.

I watch the extrusion carefully on the first layer and adjust the Z-axis manually (physically turning the leadscrew with my fancy new Z-Axis Knob) to make sure I get a good adhesion on the painters’ tape. Once I’m satisfied that the first layer is OK I’ll go wash dishes or something while the printer burbles away.
First Layer

Let’s assume everything turned out more or less OK for you and you’ve got a mostly-perfect bloxen sitting on your print bed. Now would be an appropriate time to learn to fish.

Layers and Perimeters

Layer height: I’ve been getting OK results with .35 mm. This is fairly coarse for a machine that claims .1mm resolution on the spec sheet, but for something as plain-jane as a bloxen it’s probably OK. If you get a .35mm layer bloxen to work, try a higher resolution on a more complicated model. This Magic: The Gathering Beast Token is a great detail test.

Infill

I leave this density at .25 when printing with PLA unless the object’s going to undergo physical stress. If I go much lower I find that the top layer of PLA tends to sag too much for my tastes.

Skirt and Brim

I’ve set my skirt layer height to 0 layers, which effectively turns it off. If you’re not 100% confident in the levelness of your bed, using a skirt can give you a few seconds to nudge your Z-axis before the main body of the print begins. A brim will apparently help your print stick, but I haven’t had to use one yet. Hot PLA and a level platform goes a long way towards sticking to painters’ tape.

Support Material

I try hard to design models that print without support, so I’m not a good source for information on this setting. Keep it off unless you’re printing something that needs it. I keep the raft layers set to 0 as well; no sense in printing more than we have to if things are sticking to the platform anyways.

Filament Settings

Even though your Simple ships with 1.75mm filament, somewhere in a Printrbot setup guide I recall reading that you should set this to 1.70mm. Sure, whatevs.

I’m printing with PLA at 200° for the first layer and 190° for subsequent layers. Go much hotter than 210° and the PLA that printrbot shipped with the Simple starts getting liquid. This seems to work for loading the hot end, but I wouldn’t want to try and print with liquefied PLA.

Printer Settings

I’ve set my Simple to have a 100x100mm build platform, since most of what I’m trying to print is tiny and I usually end up manually homing the printer anyway.

Clearing a Jammed Filament

printrbot calibration fails

In the beginning, One does not know that which One does not know. The Dark Art of 3D printing is shrouded in a miasma of confusion and rage and smug forum posts, and One despairs.

With time, kobolds and goblins and glitches and bugs fall beneath one’s blade as vermin are wont to do, and One’s place at the tavern edges ever closer towards the dim corner where the new Ones timidly approach to receive their quests.

And when One’s troubleshooting reflexes are honed vorpal-sharp, One is a scythe to trouble, or a rapier, or a headsman’s axe, and no issue endures the coming of dusk.


As troubleshooting goes, this is an easy one, but the trick to it is recognizing when it’s happening. This happens on my Replicator, too, it’s just a thing with FDM printing.

The Symptom: The extruder motor pulls the filament in for a few centimeters, and then stops. You can’t feel the motion of the filament between your fingers any more. The extruder motor continues to chug to no effect.

The Problem: A small piece of filament has snapped off inside the extruder, past the drive gear’s ability to move it further. This filament scrap is blocking the new filament from entering the hot end.

The Solution: Remove the hot end from the extruder assembly by backing out the screws that hold it in. Place the hot end on a non-flammable surface and heat it up to 200°C or so. Remove the offending filament with pliers. Let the hot end cool down and then replace it.

Pro tip: an animal-print workspace brings the boys to the yard. Gridded workspaces are sooooooo 2012.

Planting a Flag, Redux

Seej Battle Flag, Basic

About a year ago I designed the Seej Battle Flag, Basic to be printed on my Replicator1. A user on the Printrbot forums was having trouble getting it to print, so I decided to see if I could get it to work myself. Good news! It can be printed on a Simple without any voodoo involved.

It helps if one doesn’t try to print the model all at once, so I’ve broken it into three parts and updated the entries in The Forge and on Thingiverse accordingly.

I find leveling the Simple’s bed along the Y-axis to be a little difficult, especially as the weight of the extruder arm at maximum extension pulls it down in Z. I understand there’s a fix for this, I just haven’t had the chance to apply it yet.

I’ve aligned the parts of the battle flag along the X-axis, which should make them a little bit easier to print individually.

If you’ve never heard of Seej before, check out the rules and give it a go. It’s an Open-Source tabletop wargame based around 3d printing. Have at thee!

Printrbot Z-Axis Knob, Refined

I find myself adjusting the height of the Z-Axis on my Printrbot Simple with every print, sometimes during the print itself. Handling the leadscrew directly can get a little uncomfortable, so having a knob attached to the top of the axis helps a great deal.

Printrbot Z-Axis Knob

downloadThis knob is based off Bill Owens’ Printrbot Simple Z-Axis Knob which is in turn based on jridley’s Parametric hex head screw or nut knob. Circle of LIIIIIIIIFE

This version has some rounded edges for comfort because I’m a delicate desert flower that only blooms once a year and I must preserve my girly hands for stroking my Shih Tzu.

Did you hear about the new zoo that opened in Chicago? It’s only got one animal: a dog. It’s a Shih Tzu.

This knob also has some transitional elements between the two major volumes, and a graceful inverted flare on the shaft. These are completely unnecessary aesthetic changes to the perfectly-usable model made by Bill Owens, but since complexity is free in 3D printing, why not.

Here’s a perfect demonstration of how the Creative Commons license fosters creativity. First, in need of a knob, jridley throws together a parametric design and shares it on Thingiverse. Now anyone can adjust a few numbers and get a printable knob.

Standing on the shoulders of that giant, Owens refined the basic design until he got a knob he could use in his particular situation. He puts it up on Thingiverse where dozens of Printrbot Simple owners download and start using it.

I don’t know much about OpenSCAD, the software jridley used to design the original knob. But I can take the output into software I’m familiar with and edit the geometry to fit my needs.

All legal, all free, no ethical quandaries or patent fights. All we have to do is give each other credit where credit is due.

I found Owens’ knob to be a little loose given the crop of nuts grown in my part of the world, so this model might be a little tighter or looser for you.

You will need a pair of 5/16″ nuts to use this knob properly. Put one nut on your z-axis leadscrew, attach the knob, and then tighten the second nut.

The model is also available in The Forge along with assorted other baubles.