Tag Archives: PLA

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

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.

Once More, With Rigor

This is a follow-up to yesterday’s post on printing with PLA, where I claimed that the orientation of the painter’s tape on the build platform is important to the stick-to-it-ive-ness of a PLA print.

But is it? Really?

A comment from CymonsGames (who’s doing some great stuff on Thingiverse, BTW) got me thinking. Is this 3d-printing feng shui, or is this a real effect? Does the grain of the painter’s tape matter? It worked once yesterday.

But anecdotes ain’t data, people. Imma test this.

I’ll try and remove as many variables as possible from the experiment, but since my basement clean room is currently occupied by an eldritch horror I’m stitching together from abattoir scraps, I’ve got my Replicator in the living room and ambient temperature control isn’t really possible. It’ll be somewhere between 64° and 69°F.

I made a special model for this print test: it’s just a 30x30x2mm solid with a raised zheng on it.

And some skeuomorphic rivets. Because, rivets.

Most importantly, this model is thin, so I can run this print a bunch of times quickly.

ReplicatorG Settings:
10% infill
.22 layer height
print 240° on first layer, 210° afterwards
HBP: 35°C

I used fresh tape before every print, all from the same roll. The first three prints were with front-to-back tape, the next three were with side-to-side tape. All tape was the same stuff, 3M Scotch 2090-1A ScotchBlue Painter’s Tape.

Minor tip: Make sure you have tape everywhere that you plan to lay down PLA, especially the homing line from the corner of the build platform to the start of the print. If you miss that little detail, your print head may end up dragging a blob of plastic all over your first surface and mess with the print.

Here are the results:

In summary: these tests don’t show much difference in stickiness with different orientations of painter’s tape.

I even mixed up the orientations just to see if I could mess up the print. No good. Every print looked more or less the same except for a little curling on front-to-back #1.

The information contained in that last post is no longer operative. Put your tape on side-to-side, front-to-back, whatever gets you through the day.

Scientific method. For great justice.

Printing on Painters’ Tape

Here’s a little tip that would have saved me some grief and troubleshooting when printing with PLA on painters’ tape with my MakerBot Replicator 1.

The orientation of the tape matters.

Lay your tape front-to-back on your build platform, not side-to-side.

Look at this photo (of blue PLA on blue painters’ tape, so click to embiggen):

See where the front-to-back tape ends, and the side-to-side tape creates a rats’ nest of tangled PLA filaments?

Now look at the same print, but with front-to-back tape covering the print surface:

Much, much better adhesion. Fun new model coming soon, so watch this space.

Raftless Printing with PLA

I’m no expert at 3D printing, but through a lot of trial and error I’ve discovered a few nuggets of information that I wish I’d known a few months ago.

A few weeks ago I said I was chasing a raftless print. I’ve finally got it, at least with PLA and ABS, printing Seej bloxen.

This comparison isn’t entirely fair, since the bloxen are sourced from different models, but the difference between a hot, rafted print on the left and a cool, raftless print on the right should be pretty clear. Both of these are printed from the same roll of 1.75mm PLA.


Here’s what I’ve learned.

PLA likes a cool build platform, somewhere around 45° C: My MakerBot Replicator ships with a heated build platform, and ABS plastic seems to stick nicely around 115°.

When I first started printing with PLA I just assumed it was more or less like ABS. When prints started shifting off the platform I kept cranking up the temperature on the HBP, eventually resorting to elaborate raft structures with painters’ tape.

It never occurred to me that lowering the HBP platform temperature was the solution.

Changing the build temperature in gCode is easy: just find a line that looks like:

M109 S100 T0 (set HBP temperature)

And change S100 to S45. This assumes that you’re using ReplicatorG to generate your gCode.

There’s one other change that seems to be helping: print a nice, gooey first layer of PLA, and then back off the printing temperature to maintain the model’s integrity through the rest of the print. The gCode for this isn’t much more complicated, but you have to get it in the right place. First, set the extruder temperature at the beginning of the print, close to the top of the gCode:

M104 S240 T0 (set extruder temperature)

Change 240 (or whatever it is in your gCode) to 210.

The last step is to find the point in the gCode where the first layer stops and the second layer begins, and back off the temperature a bit.

In the other two instances there are existing M codes that tell the machine to wait for the extruder or bed to reach the specified temperature before proceeding. You’ll have to put those codes in yourself for this line.

Find the first example of:

M73 P1 (display progress)

and add these lines after the next <layer> tag:

(*custom gCode here*)
M104 S190 T1 (set extruder temperature)
M6 T1 (wait for toolhead, and HBP to reach temperature)
(*end custom gCode*)

That should drop the extruder temperature down to 190° and then resume printing. The delay can be a little unexpected the first time your Replicator just seems to stop printing abruptly, but then your forebrain will kick in and you’ll realize it’s just doing what you told it to do.

The usual warnings about bricking your Replicator or burning down your apartment building apply. Use this code at your own risk, and you should probably own couple of fire extinguishers anyways.