First Print - How To

[Rick Pollack]

Step 1: Manual Extrusion

Terms:

Hot-end - where the filament is melted (black insulator to the nozzle)

Filament drive - contains the drive pulley and tensioning mechanism. The filament drive grips the plastic filament and forces the plastic through the hot-end (aka extrudes the plastic)

Extruder - combination of hot-end, filament drive and stepper motor

Plastic Filament - the plastic that is fed into your extruder

Test your extruder:

1) Set the temperature in your host software (pronterface, repsnapper, etc)

     - 195C for PLA, 200C for 1.75mm ABS, 215C for 3mm ABS. Your final operating temperature may vary based in filament type, size and color but these temperatures should get you started. You should not need to run your extruder above 220C for standard operation.

2) Set the extrusion speed to 230mm/min for 1.75mm filament or 100mm/sec for 3mm filament

3) Set the extrusion length to 20mm

4) Let the extruder get up to temperature you selected and then press the extrude button. You'll need to press it multiple times.

5) Filament should flow out of the nozzle. It is not unusual for PLA to curl up around the nozzle. Use tweezers to remove filament from the nozzle.

**You should use the printer in a well ventilated area, especially if you are printing with ABS.**

**If you turn on your extruder heater and the extruder is heating but you do not see a reported temperature in your host software, immediately shutdown or unplug the heater and seek assistance. Uncontrolled heating can damage the hot-end.**

If you have trouble getting the filament to extrude and you received the hot-end fully assembled the problem is generally one of the following:

1) Tension: Too little or too much tension on the filament. The extruder has a drive system that bites into the filament to push it through the extruder. Depending on the specific filament you are using the teeth marks may need to go up to half way through the filament. ABS is softer than PLA and may require more grip (deeper teeth marks). On Mosaic the tensioner is a horizontal screw at the top of the filament drive (just below where the filament enters).

2) Temperature: If the temperature is too low, plastic can't be pushed through the extruder or plastic may begin to extrude and then stop. Typically the filament drive pulley will chew and divot into the filament.

3) Speed: the plastic needs to have time to melt before it is extruded. If you run the extruder too quickly the plastic may begin to extrude and then stop. Typically the filament drive pulley will chew and divot into the filament.

4) The insulator is getting too hot. The simple solution to this problem is to mount a CPU style fan (40mm is a good size) and point the fan at the top 1/3rd of the insulator (black plastic). Mosaic already has a cooling fan.

If you assembled the hot-end and the above items do not solve the problem:

1) The heater barrel may not be fully tightened. There should only be a 2-3mm gap (two visible threads on the brass heater barrel).

Feedback welcome.

[Charley Jones]

Nice Rick,

I'd go into a bit more about what stripped filament looks like.  Esp divet can be seen after a few track marks.  This is where the gear teeth continued to chew into the filament rather than pushing it through.  In such a case, gear teeth may be blocked and need cleaning.

Biggest problem we ever had with cupcake 1 was the drive motor.  originally gear driven was famous for dying out. Make a mark on drive bearing or on newer models, use an indicator arrow.  Non rotation is a temperature or motor problem.  Our motor would frequently stall during prints.  Drove us mad. Always have a spare drive motor.

Dataman

[Cristian Petrescu-Prahova]

I'm using pronterface and a Dec 2011 MakerGear Prusa.

> 1) Set the temperature in your host software (pronterface, repsnapper, etc)      - 195C for PLA

The kit came with a roll of green plastic thread, likely this is PLA, but it would be nice to confirm.

> 2) Set the extrusion speed to 230mm/min for 1.75mm filament or 100mm/sec for 3mm filament

This could be Settings/Options/e_feedrate, but it would be nice to confirm.

> 3) Set the extrusion length to 20mm

This could be "Extrude XXmm" on the main interface, but it would be nice to confirm.

> 1) The heater barrel may not be fully tightened. There should only be a 2-3mm gap (two visible threads on the brass heater barrel).

On my kit there is a 5 mm gap. The nozzle hex part appears to be shorter than other people's which could account for the difference. The green plastic thread flows smoothly all the way to the nozzle top.

- The thermistor has a 4066 beta value. In some documentation this is stressed to be important, but I could not find any place in the software where this value is used or should be configured.

- There should be a test step for the thermistor at 50C, to avoid dangerous temperature overflows if there is a mistake in the wiring.

Happy New Year!
Cristian

[Triffid Hunter]

On Sun, Jan 1, 2012 at 1:11 PM, Cristian Petrescu-Prahova
<cris...@gmail.com> wrote:
> - The thermistor has a 4066 beta value. In some documentation this is
> stressed to be important, but I could not find any place in the software
> where this value is used or should be configured.

This value, along with the nominal resistance at 25 celsius and the
value of the pull-up on your electronics (4k7) are used to generate
the conversion table from ADC readings to temperatures. All the
firmwares come with a table already calculated for a 100k 4066b
thermistor and 4k7 pull-up so you don't need to generate it yourself.

This is the table used when you select thermistor type #1 in sprinter.
Other firmwares may have other methods to select the appropriate
table.

tl;dr: this is an important value but if you have a standard
thermistor the work has been done for you already.

[Joshua Wills]

Because you self sourced your parts, the machine-specific sections of
this guide will not be useful, but the Pronterface section should
help: http://makergear.wikidot.com/m2-getting-started .

Also, you will need to download a firmware for your machine - once
again, as you self sourced the parts, you'll need to customize all the
settings for steps/mm for your X, Y and Z axes. For E, you'll need to
use the value 471.5 steps/mm (assuming x16 microstepping), and tweak
from there. Marlin and Sprinter are the two common firmwares used on
Prusa machines, that I know of.