PrintrBot Simple 2013 Troubleshooting

Getting one of these great little 3D printers working correctly can be quite a mission. I think I’ve worked out most of the kinks though, so here are my quick fixes.

Extruder Clogged

The extruder motor is turning the gear correctly and the motor isn’t skipping.. what next? Most likely you have a clog, which can occur from either dusty filament or uneven filament.

  1. Heat up the hotend to 200°C or so.
  2. Remove the extruder from the head. You need to undo the 2 hex screws that hold the top of the extruder in, then wiggle it loose. You should be able to leave the Phillips head screws in place.
  3. Now try and push the filament through, directly into the barrel. Likely it won’t move.
  4. I found that with a thin nail I could push filament through a bit better.
  5. If you still don’t have plastic spaghetti coming out, remove the hot end tip with a spanner and check if you can push the filament through now. It should push through pretty easy, otherwise go back to step 4 and find something to open up the extruder neck.
  6. Get a jet burner and flame the crap out of the tip. Don’t burn yourself or your stuff. You should hopefully see a small glob of black plastic crud drop out.
  7. Put the tip back on the extruder and try push through some filament again. It should come out correctly now.

Now I attach a bulldog clip with a make up remover pad inside it to the filament to clean it before its pushed into the extruder. Cotton wool would probably work, use what you can find around the house.

Y-Axis Sag

You are suffering from Y axis sag if your bed is level but the tip is hitting the bed when it is fully extended on the Y axis, but a bit above the bed when fully retracted. This is generally because the cable ties holding the steel rods have expanded during use, or were never tight enough to begin with.

  1. Grab the printers arm and see if it wiggles. It should.
  2. Tighten all 6 cable ties using a set of pliers. Grab the end of the cable tie while holding the other end and make it REAL tight.
  3. If  you cut off the cable ties real close to the bearings, it might be possible to use some tweezers to grab just a tiny bit of the tail and stretch the plastic out to something you can grab with normal pliars.
  4. Notice that you can’t wiggle the printer’s arm as much as before.

 Wrong Size Prints

You need to calibrate the printer, see for a good guide.

Negative Space Test


The default steps for a Simple 2013 are M92 X84.4 Y84.4 Z2020 E94.5

Dave Matthews Band Perth April 13th 2014

Greyome set that I don’t want to forget:

  • Ants Marching
  • Seven
  • Satellite
  • Don’t Drink the Water
  • Rooftop
  • Squirm
  • Crash
  • Grey St
  • Belly Belly
  • You & Me
  • Dave says ‘quokkas are dumb like chickens’
  • What Would You Say
  • Funny The Way It Is
  • The Space Between
  • So Much To Say
  • Anyone Seen The Bridge
  • Dave says ‘you cant get this shit on the radio’
  • Jimi Thing
  • Sexy Mother
  • Shake Me (encore)

Dozens of drumsticks loosed on the audience at the end.

Can’t wait for the two Byron Bay gigs!

Tracks I would love to see at those gigs:

  • You Might Die Trying
  • Everyday
  • Recently
  • Two Step
  • Louisiana Bayou
  • Crush
  • Seek Up
  • Big Eyed Fish
  • All Along the Watchtower
  • One Sweet World
  • Lie in Our Graves
  • When the World Ends
  • So Damn Lucky
  • Grace is Gone
  • Gaucho
  • Cornbread
  • Mercy
  • Bartender

Dave Matthews band Byron bay April 20th 2014

  • Belly belly
  • Funny the way it is
  • You might die trying
  • Satellite
  • Don’t drink the water
  • Rooftop
  • The space between
  • So much to say
  • Anyone seen the bridge
  • Too much
  • You and me
  • Jimi thing
  • What would you say
  • All along the watchtower
  • Everyday
  • Ants marching
  • Grey st

Setting up Varnish for Drupal on CentOS 6

Varnish has an offical repository so let’s add it to Yum as outlined on

Set Varnish to start on system boot

Setup DAEMON_OPTS in /etc/sysconfig/varnish, something like below. It will be commented out by default:

Edit the default.vcl file. We use the following for Drupal, which Four Kitchens kindly made available.

Now update your web server to serve from port 8080, and restart the server and varnish.

Download and enable the drupal varnish module:

Add something like the following to settings.php:

Hopefully the site is now using Varnish, you can get some good stats using the varnishlog and varnishstat programs that are included with Varnish.

Setting up memcached with Drupal 7 on Centos 6

Firstly get access to RPMForge repositories. Next install memcached:

Check memcache stats:

Configure memcache:

Configuration details for memcache can be found here

Install the PECL memcached extension for PHP

Install the memcache drupal module and configure the website via settings.php

You don’t need to enable the module unless you want a stats UI.

Edit your site’s settings.php, adding something like the following:

Truncate the cache table, clear the cache and check that the cache table stays empty when you load some pages. Check the memcache stats and see that data is going into the cache.

Hopefully it’s working now!


Drupal Memcache module –

Configuring Memcache from the memcache wiki –


Installing RPMForge repositories on CentOS

By default CentOS Yum has a pretty poor selection of packages compared to something like Debian. So it can be a good idea to add RPMForge to get access to more up to date packages.

Now choose the appropriate repository for the CentOs version and architecture:

Install the repo:

You should now have access to a heap more packages via Yum.