Sunday, 24 March 2013

Pretty in Pink

I seem to have sorted my over-heating issues from a few weeks ago, and have been steadily designing/printing various bits for around the house.  Most of these are too bespoke to bother putting on thingiverse, fortunately, they were all pretty fast to model and print:

  • Spice rack for the kitchen - aluminium channel with printed under-cabinet hangers
  • Brackets to hold fluorescent under-cabinet lights
  • Large washers for holding an Ikea cabinet (lost the originals)
  • A "laser" gun toy that straps to my sons forearm - his design
  • A clip for holding a blackout blind closed
  • A replacement holder for a magnifying glass
  • Sword hilt for my son (the original one got trashed)
  • Flexible bracelet for my daughter
My biggest project to date has in fact been the awesome Giant lego Darth Vader model from thingiverse, in pink:

This is also my first commission, got another to do in black when the filament arrives next week - great fun!

The foamboard heated chamber is working well, but I tend to leave the top flap open to stop it getting too warm.  I've also finished playing with my custom start/end gcode for slic3r:

Start G-Code
M104 S0
M140 S80
M190 S80
M104 S210
M109 S210

End G-Code
M108 S50.0
M113 S0.0
M104 S0
M140 S0
M190 S0
G4 P200000

Which is making for very reliable prints.  I am still getting the odd part warping up at the corners and don't feel confident printing full plates, but then I also need to get some pure acetate to clean the glass, so that's probably a contributing factor.

I've also been somewhat paranoid about leaving the printer unattended, so installed an LED light strip and a webcam.  I then run a livestream feed during prints, which I can monitor on pretty much any device (ipad, blackberry, iphone, etc) - surreal moment this afternoon when I found myself watching a print on my wife's android phone whilst at a softplay with my kids!

I have a more complex project almost complete - a DSLR follow focus unit - which I'll post about when it's been properly tested.

Sunday, 3 March 2013

Mendel90 - Heated Build Chamber from Foamboard

I've been steady printing small parts for the last few weeks, but since changing to a new reel of filament (Crystal Clear 3mm from faberdashery), I've been struggling to get reliable print settings.  This has been very frustrating, as the reel of Village Green that nophead supplied in the Mendel90 kit was very reliable.

In case anyone is interested - my settings are currently:

  • Hot end: 200C first layer, 180C thereafter
  • Bed: 90C first layer, 80C thereafter
  • Everything else at Slic3r defaults (everything I tweak seems to make it worse)

One particularly frustrating problem has been large prints curling up at the corners, or failing to stick to the heated bed.  Ambient temperatures in my office have been pretty cold lately, which won't help.  So...  it seemed a good idea to build an enclosure around the Mendel90 to keep it cosy.

I had some spare foamboard which seemed like an ideal material to build the enclosure from.  I also added a 2mm glass sheet to the front (a piece of picture frame glass, approx £3) which can be slid in/out vertically by lifting the flap along the front edge.  I've only been running with it for a few hours, but it's certainly allowed me to print some larger parts that weren't possible before.  Will find a thermometer soon and check the temperature it reaching, but at a guess, I'd say it's in the 30-40 degree range.

Filament is fed through a long slit in top, the slit is covered in thin craft foam to keep the heat in and trap dust.  The foamcore is joined to itself with hotglue and to the Mendel90 with white duct tape.

I'm fairly pleased with how it turned out - it was quick to build, very cheap and appears to do the job - it doesn't even look that bad.

Alongside building an enclosure, I also put together a quick filament spool:

It's similar to many already on Thingiverse, but uses cheap aluminium tube and very lightweight parts - 6mm tube for the arms, 12mm tube for the axle (no bearings). On Thingiverse -

PS - while writing this I've been playing with the custom start GCode in Slic3r, and now appear to have a clogged hotend - just stopped a print as no plastic was coming out to discover it appears to be leaking out above the nozzle - crap :(

Here's the startup GCode that killed it...  derived from nophead's oozefree start

M190 S90
G4 P120000
M109 S200