Temperature

I stared printing with some different PLA filament today, and the print quality was terrible. The materials was not flowing well, jamming in the head causing thinning and breaking of the walls. At first I through that there was moisture in the filament as it was making a crackling sound when printing. However, increasing the temperature in attempt to drive out any water made the situation worst. After experimenting with a range of temperatures, reducing the temperature to 200° solved the problem. 

Although you would think increasing the temperature would make the plastic less viscous and therefore flow better, in some cases increasing the temperature can cause the plastic to start to depolymerise, causing it to thicken and jam the Print Head.

Further Calibration

I have printed a extremely detailed and complex test piece to highlight the weaknesses of my 3-D printer so I can improve the precision and quality of its prints. 

The model included a range of slopes at angles between 20° and 45°, cones, domes zigzag shapes and precise holes. My printer performed very well on all the tests except for moving between the pointed object where it left strands of material. This is due to  it insufficient retraction of the filament to empty the nozzle, so as the Print Head moves over a empty space is dribble plastic. I will now experiment with different levels of retraction to find an optimal value to minimise oozing from the nozzle when its travelling between print areas. 

I will work on the settings and setup of the printer to improve the overall quality, and then reprint this test.

Z Axis Stepper Motor Clutch Tool

When starting a new print, it is often required to manually alter the Z axis level to achieve very good adhesion achieved by rotating the clutch on the stepper motor. The clutch is very stiff, and difficult to move as there is little to grip onto.  I have additional difficulty due to Arthtitis in my wrists, therefore I decided to produce a tool to make the process easier. 

This really demonstrates the power of 3-D printing for rapid prototyping as the design and manufacture of the tool was completed in around one and a half hours. I quickly designed the shape using Google Sketchup software, generated the tool paths using Cura software and printed it using PLA material. 

Using the Tool to rotate the Z Axis clutch

I included a X shaped centre to reduce the quantity
of material required and the print duration.