One of the critical parts in a FFF 3D printer is the extrusion nozzle. It's that part that lays the rubber on the road. The exact flow of plastic is determined by temperature which affects viscosity, filament feed rate which is pressure, filament size which is volume. Put those factors through an orifice of a specific size (which then is a metering device), the exact flow can be calculated. The nozzle is the orifice but it also determines the initial diameter of the extruded plastic.
Just after leaving the nozzle there are a few more additional variables which are separation distance of the end of the nozzle above the deck or previous layer and the rate of travel of the nozzle following the commands from the computer code. There is also a cooling factor along with departure temperature that that determines how much the plastic will flow or be compressed. Then throw in shrinkage (warping) to keep it interesting.
No, I don't have all the magic setting numbers. The operator (print master) has to understand all these flow variables.
The design of the nozzle is fixed, although it is certainly permissible to experiment with designs and hole sizes. A few more variables to add to the mix.
Here I have taken a closer look at the standard 0.40mm print nozzle under the microscope. The hole is far too small for these 70 year old eyes to see anything unassisted. The hole is just as critical as any of the other factors in the printing formula. It needs to be understood as much as the numbers plugged into the setup.
Sometimes I suspect a partially plugged or damaged nozzle hole to be the answer to of a lot of my "what changed now?" troubleshooting investigations. When all else fails, change the nozzle.
You can see in the pictures I have purchased a package of those 0.40mm "nozzle cleaning" drill bits. Let me be clear on this:
I do not believe in cleaning an old plugged or mal-functioning nozzle. Throw the bad one away and install a new clean nozzle. It's cheap.
I bought the micro bits for gauging the hole size in new nozzles and making sure they are perfectly clear, no burrs. Not for cleaning used nozzles. Also for making these pictures of the process. Spare nozzles should be stored carefully in a very clean place.
The short video shows me prodding the bit through the nozzle hole checking size and clear passage. The video and pictures were made through the USB electronic microscope seen in the pictures.
A little project at the request of my spouse. She was admiring my 3D printed holders for my wax carving tools and files. However, the holes were too small for the things she wanted to hold. I was tasked with creating holders with larger holes.
The first one was using three holes with a hole design diameter of 12mm. I “project named” it the TriHolder. A square sided cube wouldn’t be aesthetic so I created some curves on two sides. They widen the base and make it look a bit better.
This print is for my daughter. I made the green Yoda for her twin brother, so I needed to balance my generosity! Ha! Vause is the fancy word for a cheap plastic vase...
It’s another design I gathered from Thingiverse. This one is in the form of an SCAD file. That is a CAD drawing program that has parameters which can be changed or altered to create variations of a design.
This is not an original creation of my own. My adult (45ish) son is a Star Wars fanattic. So I thought I should make him a Yoda to add to his collection.
I picked this one out on Thingiverse for no particular reason. It is call pot à crayons / pen holder starwars Yoda by TiZYX. (https://www.thingiverse.com/thing:2225855) Go get the files if you are interested.
I printed one in orange at about 50% to see what it was like and to save time and materials. It was the color already in my printer. I decided it didn't need all the automatic supports, so I eliminated about half of them on the green Yoda. The chin and ear tips are the most critical support areas.
I have a new 3D print original project. My wife has a makeup box setting on the very long built in sink counter in our bathroom. It is located between the two sinks built into the counter top. All one piece.
Splash water will sometimes accumulate around this box. It is made from pressed wood and has absorbed some of this water and bulged out a bit on the bottom edge. She asked me if I could make something to raise the box off the surface so the water on the counter top could not get to it.