Sunday, January 4, 2015


Reflecting the Past


 Since the beginning of my printing journey I've made few mistakes; choosing cheaper, lower grade,
PLA supplier and constantly wandering in a sea of different ideas without choosing any goal. After the pile of unfinished projects accumulated into size of inevitable irritation I got a grip on myself.

I decided to tweak the mendel as some of the parts had started to show wearing and in the process I also dug into settings of marlin firmware.

After I had printed new set of gears for the extruder the emerging presence of blobs and underextrusion vanished. The main problem, insufficient quality of ABS prints, which caused me to tweak the mendel also brought up one of the defects of supply industry of home 3D printing in practice. As I tried to insert new spool of ABS I realized that my spool holder was not universal enough which causes problems as there is no filament spool standard.  On a quest of finding new spool holder and some time spent in 3D model repositories I realized there were not simple spool holders with linear approach to the problem. I designed my own.

While rising the maximum bed temperature, preheat temperatures and lowering acceleration of Z-axes I stumbled on quantity called jerk. When testing the effect of change in the quantity I had to make a conclusion that the term jerk used in Marlin-firmware doesn't equate the jerk in physics. Also known as jolt surge and lurch, jerk represents the rate of change in acceleration. While changing the value of the firmware's I observed the speeds of different axes and realized that it had something to do with the minimum speed of axis from which the printer is allowed to change the direction. Lowering jerk left me with much more silent prints and  little if existing impact on corners. Also some of the resonance I had experienced due the wobbly structure of the printer dropped by order of magnitude.

And the darkness has not overcome it


When the curtains of the darkness closed and the light got low in Finland, allthough I don't live in Helsinki the residents experienced only 13 hours of sunshine in November,  I found myself pondering. I dove into the relationship of light and human health. During my research I ascertained relation between blue light and the quality of sleep; started using program called F.lux and also became aware of the insufficient illumination of my room.

I had this fluorescent clamp-on desk task lamp since my childhood. A buzzing sound produced by the power supply started to irritate me a while ago but the provocation came from light color temperature of the fluorescent. I decided to upgrade the lamp from 3500K to 6500K; simultaneously replacing the power supply and experimenting with the power LEDs for the first time.

I ordered bunch of 10W power LEDs from ebay; 0.6€/each. The power supply for this application was already present from old laptop and eventually powers two LEDs in series with 20V. The current is limited to 0.25A with 1Ω power resistor and the red button switch is reused from the old lamp. I based shape of the lamp around a heat sink and the button. In the end the shape sculpted itself. The heat sink is from old server the model number I can't recall.

After printing both sides I sanded and smoothed them with acetone vapor. The smoothing was based on the acetone vapor bath method. Before smoothing the bottom I attached a light diffuser, made from 85mm x 55mm acrylic sheet, with ABS-glue; a mixture of acetone and ABS. The support structure was used as the ABS in the ABS-glue; that's some recycling for you. Before attachment the sheet was slightly curved with heat gun. Temperature of the heat gun should be maintained relatively low as poly(methyl methacrylate) can be shaped at low temperature as 100 °C. After wiring and attaching the heat sink to top both sides were glued with the ABS-glue. Seams were softly sanded and whole thing was bathed once again. Before assembly the heat sink reached 43 °C and still touchable as finished. In general I was pleased to the result even if the natural ABS didn't behave as I supposed with the bath; it became rather transparent than just shiny white. Also optical properties of the natural ABS took me aback as I didn't plan for such a illumination of the whole structure.

The beauty of the snowflake lies in the pattern at every scale


Pocketful of new experience and ideas after the lamp and especially working with the ABS I awoke to the growing presence of the approaching holidays. In need of something unique I had to return to the roots, nature, the almighty system of endless creation and generation of glaring beauty and structure from the chaos. For while I explored the science behind biomimicry, the algorithms involved with fractals and after all the pure beauty of snowflakes.
All the influences submerged in my mind I started to play with the Circular Sketch Pattern -tool of the Solidworks and generated pattern using circles. Afterwards I added insert holes for the pin and cropped the frame of the hairpin from the pattern. Being familiar with the limits of my printer I decided to use PLA and curve the hairpin using boiling water and wine bottle to form the shape. As the natural ABS was the only filament I had besides blue PLA I decided to print the inner flower from it and assemble the structure. Softly removing all strings and acetone vapor bathing the hairpin left me with only the inner flower shining as acetone doesn't smooth PLA. During the bath the ABS also glued itself to the PLA forming rigid structure.

There is no need to always reinvent things if the design has proven worthy. For the holidays I wanted to give people something to change their perspective, educate or amaze them. 

                                                               Happy New Year!