Read this if you are totally new to 3D printing


Please remember, I am new to this, I have built myself a printer from scratch and printed a few good parts, by far an expert, but my printer is working and I am very pleased with the outcome.

The info here is only meant to make anyone who have no idea about 3D printing maybe get a better understanding of how it is all tied together. This is not the exact science, just my way of trying to explain what goes on. There are many much better and detailed articles on the reprap site but this is my bit for the road.

For those of you who are starting out for the first time it can be a bit daunting to figure out the whole process that is involved with this printing business. It was for me anyway. Correct me if I am wrong but this is the process in a nutshell:

You need a printer obviously or you need to know someone who has got one and are willing to let you print your files.
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FIRMWARE:

When you see the word firmware we are talking about a file which contains the code that is uploaded to the hardware (controller such as the Arduino Mega 2560). The firmware is like an interpreter which translates what the host software (such as Pronterface) wants the printer to do. It translates it so that the hardware knows what to do when you tell it to move 1mm left. The firmware controls the pins on your board. In my instance I have an Arduino with the ramps board. The Arduino is the computer or controller and the firmware I use is called Sprinter. There are several other firmware that can be used. The firmware can be edited. This is very important as the various printers are different in many ways. To calibrate your printer you need to edit the firmware and upload it to the controller (Arduino). You also need to use the host software to talk to your printer, to move your axis. If the printer moves 8mm to the left when you tell it to move 10mm then there is only one way to correct this. You guessed it, in the firmware. There are values that you can increase or decrease to achieve the wanted results. You can change the maximum speed of the motors while printing, while homing, the end-stops at max or min positions, the type of thermistor you have etc, etc. When you have got it right you don’t need to adjust the firmware any more (normally). The firmware for the Arduino is edited in a software that you can download from the Arduino site. I use version 0023 at the moment. Don’t use version 1.0 as it currently does not work with sprinter (well, I can’t get it to work.) The firmware “stays inside” your hardware permanently until you update it again. If you turn off the power it will still be there when you power it back on. 🙂

HOST SOFTWARE:

Ok, firmware is all good and you have calibrated your printer. To talk to your printer you need a host software such as pronterface. I quite like it. The host software has a similar role as the firmware editor except that it does not upload the firmware to the Arduino, but the file that you would like to print. This file is a GCODE file. But where do you get this file from? Well, you can download other people’s files of items that they have designed or you can be more creative and make your own designs. To make your own designs you use a 3D application such as 123D from Autodesk. There are lots of other applications you can use as well.  After you have made your design, could be as simple as a 10x10x5mm cube, you save it or export it as an STL file.

CREATING GCODE FILE:

Now that you have a file you would like to print, you can do what I do (and many many others do) use a program called slic3r. Slic3r creates GCODE out of the STL file. In slic3r you set values such as the layer hight, nozzle size, filament size, lift (the nozzle lifts above your print as it moves between positions) and lots of other things. Slic3r works very well and the gcode file that you just created is the one that you now will load into the host software, such as pronterface.

 

CAN I PRINT THIS?

Can you print anything, any shape etc?

No, you can’t!

Remember that the printer is placing plastic on top of another layer of plastic. It can’t build anything in thin air. The plastic would just fall to the ground (or whatever is below the nozzle). My rule when designing a part is T means trouble and Y means yes. That means that a T will not print! The top bit of the T will fall down, but the Y is ok as the printer can print climbs at about 45 degrees. But there are ways to get around this, at least some times. What if you place the T upside down….Yes, then it can be done. When making parts, it is important to understand this as it is a waste of time spending hours designing and then you can’t print it. There is also another way of getting around this problem, it is called support material. I am going to stop here as I am no expert on this, as a matter of fact, I know nothing about using support material yet, and my T and Y rule has to work for now.

 

Help! MY PART IS FACING THE WRONG WAY UP!

Okay, that happened to me on my first design. It was placed side ways in pronterface after I had converted the STL file into GCODE. Help!! And help I found, in a software package called Netfabb. Again this is free (the basic version). You simply open up the STL file in Netfabb, select the icon from the menu which is called “Align to bottom plane”, then double click on the side on your design you want to face down. Select the Part menu and export or save as STL file. Absolutely brilliant.

Sometimes you will find that a file may be broken in one way or another and that it needs to be repaired. Netfabb will do that job as well.

 

Hot End Size:

When you see hot end sizes 1.75mm or 3mm it means the filament size. A 3mm hot end can take 3mm filament (plastic feed, plastic that you print with). This is the actual diameter of the filament before it enters the hot end. This is the size you buy from your supplier. Some hot ends use 1.75mm filament and others use 3mm filament. 3mm filament is easier to handle. 1.75 becomes more like a fishing real…..easier to get a birds nest than with 3mm 🙂 . Rember, you can not use 3mm filament for a 1.75mm hot-end or 1.75mm filament for a 3mm hot-end. They must match.

Nozzle size:

This is the actual opening of the nozzle where the melted plastic comes out. 0.5mm is quite normal but 0.35 and even 0.25 are becoming more standard as they give you better resolution. The smaller the hole the finer the plastic comes out and you can make more detailed prints. With a smaller hole the printer needs more time to print as well. It is like painting a wall. Use a large brush and the job is quick, smaller brush and you may need a lunch break before it is finished off.

This is just a very basic explanation of the printing process, something I found a bit daunting to figure out at first. I hope I have not confused anyone by my explanations.

Look Here!

and

Look Here Too! 🙂

Regards

Jan

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