Monday, 7 November 2011

Twelve days of thingiverse - Thing-A-Day - Part 1

As a break from printing machine parts and structural objects I decided to print something off my thingiverse list every day for 12 days.
They got harder to print/slice and more complex each day - On the last day I designed my own thing, see part 2 for that.
And of course, I learned a few new techniques and tricks along the way, I'll share with you here - 



Sing along with me - On the first print of Thing-A-Day my RepRap gave to me...


Mr Alligator and a Fractal Tree :)



Alligator by mraiser

Fractal Tree 2 by tc_fea


On the second print of Thing-A-Day my RepRap gave to me...


A Turtle and a 'Dove' tail joint.

Triangular Dovetail Joint by VeryWetPaint


OK, that's enough of that song... It's not Christmas just yet. Below are on my 'all-time want to print at some-point' list, which is growing every day...


My general goal was to try a few things that have been on my list for a while and also some things that no one else seemed to have tried to print, or at least prints with little evidence of success.


So an easy start - 
A nice Pink Gekko by guru was first up -
This showed up a few minor fill issues so I tweaked settings in Skeinforge and firmware and moved on to -


solid gold Honey pot - basic receptacles by MakeALot. the Idea here was to test my calibration and speed of a hollow object as I had plans to test more hollow things shortly.
this was 100% infill just using multiple shells, it produces a nice heavy pot.


The next object was slightly obscure, but I wanted to print it simply because of the first comment made by Raster on the thingiverse page here 
It's the Awesome Cow by JonMonaghan


From the cow I wanted to try something that looked difficult and as per the cow I wondered if it could be sliced in half to print more easily - 
And it could - Behold the mighty Stegosaurus!  by Hurtzmyhead
My sliced Version can be found here


This shows how the low polygon count in the STL model translates to the printed object.

From printing the Stegosaurus he led me to chop off the head of a very fine Venetian Lion Here  as another test in printing something that people only printed with support.
He is hollow and was also 70% filled with Hama beads. 
This is a derivative work of the full Venetian Lion by tbuser.

At some point around here I started filling my other hollow objects with things, 
He has a shiny gold underside.


The Banana Slug (High Res) by scanlime is a fine example of a nice model and a perfect thing to print hollow.


My version is 2 x the size and is filled with Hama beads to give him a nice rattle.


And a version of the great Yoda lite model by faberdasher
This has less robe and more of the detailed face.


I also filled them with various objects and experimented with temperature for a number of reasons.


One test was for my Failed print Blog and the other was to actually see if I could create different effects with PLA and temperature, the answer is Yes as you can see in the photo. With more opaque PLA you can also get some nice matt effects with higher temperature.


Brain Slug by 7777773 was next
Top Tip Here - 
My version is hollow again and was a test of colour filament mixing but I also realised at this point that active gentle cooling of the extruded PLA was essential for a good looking organic (or hollow) prints, so I setup a small cooling fan to blow across the build area after the first layer had been put down, this gives much better results as you can see with some of the other items below, I now always use this fan to blow across PLA whenever I'm printing with it. I have yet to find a situation where it has not improved print quality.

I wanted to print something that could be hollow and also needed to be sliced, so my nest subject was the most excellent model of Roal The Bratty Dragon Prototype by SplotchyInk


My version is bigger and has three sections you can print in different colours to make him look more vibrant.

As an experiment one side was printed with 0% infill and this side shown above was just 5% infill - I had some minor holes using 0%, you can't avoid this on some objects when done hollow, so a low % of infill usually rectifies the issue.
The tummy also needed some infill to stop sagging and collapse of the outer perimeter while building, still a few issues with this print, but a slightly higher infill will resolve this (Extra shells don't always help).


This shows what usually happens to objects like this when you try to print them hollow or with low % of infill
A smaller layer slice height can help, but some infill is almost essential for parts like this. Remember a severe  'overhang' is the same problem if it's going into an object or out of an object.

And a short video of some of the objects, view it Here in Hi-Def directly on Youtube, or below


That's part 1, look out for Part 2 shortly, it'll have some interesting prints, objects and effects.

Thanks for looking, and do try an external fan, you'll be impressed how much better it can make objects print. 

Rich.