Tag Archives: filament

Clearing a Filament Jam on a Type A Series 1

single bolt

Neighbors take out the trash at 3AM, gregarious dogs hump your leg, and 3D printers jam. These are unfortunate but unavoidable facts of life.

I’ve invested in nighttime earplugs and my leg’s been celibate lately, but the other day the first ever maintenance issue with my shiny new Series 1 cropped up. Filament jam. Booooo.

The support section of the Type A Machines website is unfortunately silent on the subject of clearing a clogged nozzle. Scouring forum threads is seldom productive for me, so I grabbed a hex wrench and dove right in on the off chance that I might learn something without breaking something expensive.

The first thing I’ll do is check for obvious problems. Is there a blob of plastic blocking the nozzle? No. We’re good. Just to be on the safe side I’ll insert a pin into the nozzle’s opening and wiggle it around a little.

What about the hobbed gear? There is some powdered filament on there that can reduce the gear’s ability to grab the filament and push it into the extruder. I keep a small, stiff paintbrush around the 3D printers for just such an eventuality. Type A has made the gear very accessible, so it’s easy to clean. Ten points to Ravenclaw.

cruft

Neither of these easy fixes got me up and running again, so the next step is to take the extruder apart and see what’s jamming things up inside.

The extruder comes apart with a few turns of a single hex bolt in the middle of the extruder; ten more points to Ravenclaw for keeping things straightforward.

extruder open

Things are so simple here that any blockage should be obvious. The gray schmutz is probably thermal paste but definitely not melted plastic, and it’s not messing with the printer’s feed tube anyways.

This indicates that the clog is further down in the needle assembly. There’s really only one way to handle this short of replacing the needle and that’s to manually force whatever’s stuck in there through.

The extruder, unaware that it’s been vivisected, will happily heat up as normal with a few clicks from Octoprint. Set the target temperature to 300° and then use a long piece of thick wire to push the molten goop through the nozzle.

You’ll want a pair of pliers to hold that extruder block while you do this. A prehensile tail will be handy if you’d like to photograph the process and put it on your blog.

(My tail’s just a crusty little degenerate twin so no photos for you.)

unforeseen problem Big old warning: if you push too hard, you can accidentally force the needle through the extruder block when you do this. Turns out the needles are designed to be removed, but I didn’t know this when I began the process.

So, gentle pressure it is, with the extruder block held in a pair of pliers. You’ll get some zit-popping levels of satisfaction when the hot plastic plug finally bursts free through the nozzle.

Just to make sure there’s a free flow of filament, keep the needle at 300° and use a second pair of pliers to push a length of narrow gauge wire all the way through the needle and then work it back and forth. You’d be surprised what kind of crud you can floss out of one of these.

floss

Reassemble the extruder (one hex bolt. ONE!) and you’re back in business.

back in business

Plunger Fail

Lately there’s been a proliferation of 3d printing failure blog posts percolating around the twitterverse. I’ve got plenty of these on the blog already, so I’m dropping another one in the spirit of mutual commiseration.

Plunger Fail

I’ve been printing dozens of bloxen in preparation for Maker Faire NYC lately, and finally managed to wear out one of my delrin plungers. I had two or three days of intermittently failing prints before I figured out the problem.

I printed a new one, but printing a replacement plunger while using a faulty plunger leads to interesting results.

Ultimately I held my filament in place manually while the replacement plunger printed. It’s a quick print, about five minutes, so it was a good time to put a little dent in my Netflix queue.

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.