Part 3 – Step 18. Fine Tuning the Printer Dimension Accuracy

The Big-60 3D printer uses stepper motors to move in all directions. Part of the firmware's configuration are the "steps per mm" settings that are based on a calculation of the steppers accuracy, the gears, and pulley attached to them. These settings define the amount of rotations needed to achieve 1 mm of movement.

The correct configuration for Big-60 is defined as:

  • 200 steps for X axis.
  • 100 steps for Y axis.
  • 2000 steps for Z axis.
  • 418.5 for the extruder motor. 

To fine tune your machine, measure the axis accuracy by printing a large bar on one of the axes (i.e. a 500 mm long bar on X axis). Measure the length of the print and use the equation on the right:

Example:

Say the result of the print is 502 mm instead of the planned 500:
200/(502 x 500) = 199.203 -> 199.203 is your new X-axis steps per mm.

 

We will use the M92 command to set the steps-per-unit for one or more axes
directly from the terminal console (Pronterface command line):

Command structure:
M92 [E<steps>] [T<index>] [X<steps>] [Y<steps>] [Z<steps>]

Following the example above, your command line would look like this:

M92 X199.203

Use the M500 command to save your new settings to the EEPROM.

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Part 3 – Step 17. Converting to 3 mm Filament

Advantages of 1.75 mm

·       More variety of materials as the 1.75 mm is the market standard.

·       Faster melting as 1.75 mm offers a better surface-to-core ratio.

·       More flexible and therefore easier for the print head to pull it during printing.

Advantages of 3 mm Filament (2.85 mm)

Degrades slower in very humid environments as it gets less moisture inside compared to 1.75mm.

The Titan extruder is universal and allows for both the 3 mm and the 1.75 mm.

The E3D hot-end needs a few different parts, please find the links to the E3D online shop below: https://e3d-online.com/v6-heat-break-3mm https://e3d-online.com/v6-heatsink-3mm-direct   (main) https://e3d-online.com/v6-heatsink-3mm-bowden https://e3d-online.com/volcano-brass-nozzles https://e3d-online.com/bowden-tubing-100mm-3mm-filament  (you will need 1.5 or 3 meters) https://e3d-online.com/bowden-adaptor-3mm-filament Pay attention on the E3D website for the right choice of nozzles and other items

https://e3d-online.com/bowden-adaptor-3mm-filament

Pay attention on the E3D website for the right choice of nozzles and other items.

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Part 3 – Step 16. Troubleshooting

Pauses During Print

If you notice short pauses while printing from the touch screen, it might be noise that affect the quality of the signal transmitted over the ribbon cable.

1. Ensure that this problem is caused by noise on the ribbon cable by printing from a computer connected by a USB cable. If there are pauses by printing from computer as well. Please contact support.

2. If your computer can print with no pauses, please try cover the ribbon cable with the provided metal sleeve and install the Ferrite Magnet on the ribbon cable as close as possible to the entry of the electronic box.

3. Try routing the ribbon cable outside the machine.

4. Try the shorter ribbon cable supplied in the original touch screen plastic bag. If this works, you might a have a faulty ribbon cable. Please contact support.


Horizontal Lines in Small Print

During the print time, the print bed temperature oscillates around 1-1.5°C. Due to the high coefficient of thermal expansion of aluminum, the plate bows (bends) just enough to create noticeable lines in small prints. In large prints, the oscillating temperature effect is hidden and almost invisible.

1. Try reducing the bed temperature during the print (or shut it down completely) after a few mm of printing. Printing with a cold bed is not recommended while using PEI sheets. If you are planning on printing a lot of small objects that require a smooth surface finish, you might consider using blue painter tape or printing stickers such as PrintinZ or Buildtek.

2. Try releasing the two frontal screws holding the bed down to the 2020 profile. This will allow the bed plate to expand horizontally and reduce bowing upwards during heating cycles

One of the Z Ball Screws Does Not Rotating

1. Make sure that the motor wires plugs are correctly in. Disconnect and reconnect them. Sometimes one of the pins inside the motor connector is bent.

2. Make sure that the pulley on the motor is connected tightly to the shaft.

3. Make sure that the Z motor wires are firmly attached to the driver socket in the controller board.

4. Cross check the wires. Disconnect the other two motors and connect one of these wires to the motor that is not rotating to see if there is a faulty connection.

5. Release the belt that attaches the motor to the screw and try to rotate the screw manually.

6. Replace the Z driver with one of the spare drivers.

 

Under Extrusion

Under extrusion happens when the hot-end is not extruding enough plastic-- this could be either a consistent or inconsistent phenomenon.

 

Consistent Under Extrusion

Fragile prints and/or perimeters that not touching each other are signs of a consistent under extrusion.

Please check the following options:

1. Increase the printing temperature -- in some cases, a semi-clogged nozzle may provide higher flow rate at higher temperatures. Go up to 230°C  with PLA to check if this helps. If so, replace the nozzle.
- A clogged nozzle may be due to dust on the filament. Use a dust filter at all times. Insert the filament through a small piece of foam to remove any particles of dust on it.
- Do not leave the hot-end at a high temperature during non-use. Whenever you are not printing, shut down the hot-end heater. Keeping it hot will degrade the filament inside the nozzle, carbonizing it inside the nozzle.

2. Check the diameter of your filament-- it might be thinner than 1.75 mm. If so, configure the slicer software to the right filament diameter.

3. Try increasing the extrusion multiplier parameter in your slicing software. Try adding 5% (1.05 in the settings) and test the effect.
Slic3r - Filament Settings (Third tab)

Simplified3D - Extruder Settings (first tab)

Inconsistent Under Extrusion

This will appear as cracks and noticeable weak layers in your prints. Usually, these type of problems are hardware related. Please check the following:

 

1. Extruder related

- Loose drive gear

- Loose heat block: please check if the heat block is firmly attached to the heat sink

- Check the tension on the extruder's lever spring

 

2. Hot-end related

- Possibly a loose particle inside the nozzle, you can clean the nozzle or, in extreme cases, replace it.

- Replace the short PTFE inside the hot-end. Make sure is not too short.

- Check the hot-end fan. Is it working smoothly? Is it covering the lower fin of the heat sink?

- Temperature stability: run the print via Pronterface and check if your temperature is stable. If not, please contact support.

- Leaks: check for plastic build up on top of the nozzle, above or below the heat block. If you see leaks, disassemble the hot-end, clean it and put it back together again.

Correct Z-Offset for Different Materials

We have to find the right Z-offset for printing as we want our first layer to adhere well to the bed.

Different settings can affect how prints will stick to the bed. Different filaments (PLA, PETG, etc.) and different methods of preventing sticking (PEI sheet, hairspray, blue painter tape, etc.) will require different Z-offset settings. For example, when printing PETG filament, we would want a higher offset than PLA as it adheres much stronger to PEI bed and will be very difficult to pull off-- it might even destroy the PEI.

If the hot-end is too high, the filament can be easily pulled off the bed with a touch of a finger. This will result in prints that do not stick well to bed and fail. If the nozzle is too low, the filament will not be able to exit the nozzle freely. This will result in "overcooking" the filament and soon your nozzle will not provide nice and clean prints or, worse, it will become clogged and need replacing.

Updating Z-Offset in Slicing Software:

After setting the Z-offset in the printer firmware, ideally we would set the Z-offset in the slicer to zero. However, if we want to change the offset for a specific print, we can include it in the slicer options. The new Z-offset will be the combination of the values from the firmware and from the slicer.

Slic3r: Under "Printer settings" - "General" Tab

Simplified3D: Profile settings -> G-Code Settings.

If the value is fixed, it is recommended to set it in the firmware for future use.

Slic3r Z offset settings

Simplified Z offset settings:

BabyStepping: BabyStepping is a real-time control of the printing height via the LCD menu. This feature will help you to fine tune the Z-position of the bed while printing the first layer. This feature is activated during printing by double tapping the LCD knob (or pressing and holding it). Turning the knob counter clock wise (-) will move the print head closer to the bed, while turning it clockwise (+) will move the print head further away from the bed. The intervals are very small. If you change the Z height by more than 1mm you should consider changing the printer’s Z-offset or UBL mesh. Note: The BabyStepping menu can be reached even after the first layer height but it not advised to use that after the first layer.    
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Part 3 – Step 15. Updating the Modix Big-60 Firmware

From time to time, you will have to update the Modix Big-60 firmware (either for new features or for changing configurations in order to meet your exact needs).

Download XLOADER:  http://xloader.russemotto.com/ and extract the folder to a location of your choosing.

We currently have two preconfigured versions, one for the default inductive sensor and another for the BL Touch Sensor.  Download the latest version of the firmware from our support section. make sure you are downloading the 'HEX' file. 

http://www.modix3d.com/support/

Marlin is a powerful open source firmware for 3D printers with a very active community that experiments with and improves the firmware frequently. We will send updates once we think they are necessary and stable.

  • Open XLoader and set the fields as shown in the picture
  • Extract the '.hex' file and load it using the '...' button.

 

  • In the COM port field, note the port names.
  • Connect the electronics box to your computer via the USB cable.
  • Choose the new port that was added to the field.

 

  • Press the ‘Upload’ button.
  • The upload is finished when this message appears:
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Part 3 – Step 14. Secondary Print Head Fine Calibration

We do not recommend using the secondary hot-end without getting experience with the main hot-end. Mount the second hot-end as high as possible or skip installing it until later.
Release the four M4 screws. Two full turns for each screw should be enough.

In order to calibrate the height of the nozzle, turn the thumb screw. Watch the nozzle carefully and see if the direction you are turning makes the nozzle go UP or DOWN.

When installing the secondary print head, it is important that both nozzles are not the same exact height. Otherwise, the lower hot-end will scratch the bed and may even destroy the printed part.

When finished with the calibration, tighten the four screws. The thumb screw is hollow, so we will feed the PTFE tube through the screw to the hot-end.

Rough Height Adjustment

Use two thin pieces of paper to adjust the height.
Lower the primary hot-end to a level that you can feel friction when you pull the paper (clean the hot-end carefully before running this procedure). The 2nd hot-end should have less friction than the primary.

Horizontal Offset Adjustment

Use the 3D printed calibration model available in this link:
https://www.thingiverse.com/thing:124450
Follow the instructions on either Simplified 3D or Slicer for dual extrusion.
The secondary hot-end offset starting parameters should be by default: Y = -39 mm. It is possible that you will have to adjust X offset as well.

Once you print, you will notice small gaps that can be corrected by using the right offset settings for your setup.

Final Fine Tuning Height Calibration

Examine the multicolor printed parts carefully from the bottom and top. Look for any signs of an uneven finish at the bottom or scratches on the top (usually the color that is printed by the higher nozzle is scratched by the lower hot-end). Adjust the height of secondary hot-end and try again if necessary.

Uneven bottom

Even bottom

The current dual print head configuration is better suited for printing soluble support material (i.e. PVA), but you can increase the finish quality of dual color printing by using techniques such as Ooze Shield.

More information:
https://www.simplify3d.com/support/articles/printing-with-multiple-extruders/

http://manual.slic3r.org/expert-mode/multiple-extruders

Slic3r Quick Dual Extrusion Start Up Guide

Under the "Printer Settings" - "General" Tab you can define how many extruders are available-- change to 2.

Once you click on the second extruder you can find the offset settings to define the position of the second extruder relative to the main one.

Under "Print Settings" - "Multiple Extruders" you can find options to define the second extruder as the "Support Material". This will allow you to use PVA as internal support that later can be dissolved in water.

If your model needs to be printed with two materials (ie: a flexible and a rigid one), you have to create two 3D models for each part, load the first one, double click on it, and then choose "load part".
Once you have two parts in this screen, you can assign one extruder for each part.

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Part 3 – Step 13. Running Your First Print

Note: It is best to run some tests with every new filament until you get your desired outcome.

Recommended settings to start with:
Wall Perimeters - 3 is a good starting point

Infill - 40% for strong part, 20% for a solid model

Bottom layers - start with 3

Top layers - 3 is a good starting point, if your model has a lot of top curves, increase to 4 or 5

First layer temperature - keep at 230°C for PLA to get a good first layer
Printing temperature - keep around 210-220°C for PLA, depends on the filament provider

Speed - start with 60mm/s and increase for draft up to 100 mm/s, can be as slow as 50 for a detailed print

Extrusion multiplier - lower to 0.9 for models that have moving parts or need high accuracy,
make it 1.15 for thin wall parts that need some extra strength

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Part 3 – Step 12. Fine Tuning UBL Mesh

To fine tune the mesh to get a better result, we have created a tool to help you calibrate the mesh. The tool is a web-based app that can be found here:
http://www.modix3d.com/large-3d-printer-calibration/

Attention: The tool works only with Pronterface.

To see the mesh and where we need to fine tune it, we recommend downloading the following G-Code(extract it from the zip file):  http://www.modix3d.com/_downloads/3d-models/bed-level.zip

save it to the SD card and print it using PLA.

After printing the pattern and observing it, we can now understand which sections of the mesh we need to edit

Too Low
Too High
Perfect

Follow these steps in order to fine tune the mesh:

  • Load the mesh you would like to edit s the mesh slot, Usually 0)
  • Print the UBL mesh to the screen (G29 T)
  • Copy the mesh as shown on the image 
  • Open Notepad and paste the mesh. Add square parenthesis to the first point and remove any other squared parenthesis as followed:
  • Go to the web-based tool and press Upload.
  • Paste the UBL mesh in the textbox and press CLICK TO PROCESS.
  • Now the tool should look like the image
  • Change the Step size to a value that is suitable to you.
  • To change only one point, press the ‘+’ or ‘- ‘buttons next to the point or just modify the point manually.
  • To increase the gap between the nozzle and the bed, use the ‘+’ button.
  • To decrease the gap between the nozzle and the bed, use the ‘-’ button.
  • For changing multiple points, press to the side of the point you would like to change and press the ‘+’ or ‘-’ next to the Modify selected.
  • To deselect a point, click on the side again or press the CLEAR SELECTION
  • Press the EXPORT button and save the G-Code file.
  • Open Pronterface and load the G-Code file we just saved and then click the Print
  • View the UBL mesh and make sure it is correct (G29 T)
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Part 3 – Step 9. Printing Settings for Slicing Software

There are several slicer programs out there, but for the purpose of this manual, we are using Slic3r. Download Slic3r software from http://slic3r.org/ Under Menu → File → Preferences, you should switch to 'Advanced Mode' and restart the software.  
Go to Printer settings. Under the 'General' tab, click on 'Set' for bed shape. Configure it the size of the printer bed (600X600 mm for the Big60). The true size of the bed is 610X610 mm­, however, it is advised to test your printer's capabilities for safety.   Basic Troubleshooting: Sometimes a timing belt slack on X or Y will prevent the print head from reaching the end of the rail. If you cannot reach to the end X axis, check for belt slack. If you cannot reach to the end of the Y axis, make sure you have 29 units of the drag chain (you can always take one from the longer unit serving the cables on from Y motor to the electronic box).

Add the following to 'Start G-Code':

 

G28 X Y  ; Home X & Y

G1 X300 Y300 F5000  ; Go to Center

G28 Z  ; Home Z

G1 Z5 F5000 ; lift nozzle

G29 L0; load ubl mesh

G29 A; activate ubl

 

Add the following to 'End G-Code':

M104 S0 ; turn off temperature

G28 X0  ; home X axis

M84     ; disable motors

Go to the 'Extruder 1' tab and set the Nozzle diameter to 0.4 (default).
To learn more about Slic3r's settings: http://manual.slic3r.org/
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Part 3 – Step 11. UBL configuration

 Attention: This section assumes that you have followed the previous section of the Z-Offset configuration.

Unified Bed Leveling (UBL) is an advanced bed leveling that allows you to run a more accurate and longer probing session (100 points on the bed), storing it in the controller memory for later use. This will allow you to save time before each print as well as give you the ability to manually adjust the mesh for the best results.

  • Connect the printer to Pronterface.
  • Home all axes (G28)
  • Heat the nozzle to 200°C and the bed to 60°C.
  • Remove the filament from the extruder and make sure the nozzle is clean. Disconnect all PTFE tubes from the printer. During this process the print head will move to random positions.
  • Go to the center of the bed (G1 X300 Y300 F5000)
  • Home Z axis (G28 Z)
  • Go to a printing height and make sure the height is correct (G1 Z0)
  • If the height is not correct, please set the Z offset again using our guide.
  • Home all axes (G28)
  • Start the probing sequence (G29 P1). This sequence will take a couple of You will know that the probing is finished when the print head returns home.
  • Repeat until all mesh points are filled in (G29 P3 T). Nothing will move—this part is entirely mathematical.
  • You will now see the Z compensation values. Make sure there is no radical difference between the edges of the bed. If so, manually adjust the bed and repeat steps for the Z-offset and UBL sections.
  • Save the UBL mesh points on slot # (G29 S#) # means the number of the slot where the mesh was saved (choose 0 for the first time)
  • Set the Fade height correction at 10 (G29 F10)
  • Activate UBL (G29 A)
  • Save to the EEPROM (M500)
  • In the slicing software add the following to 'Start G-Code':
    • G29 L0 is loading the mesh that you have saved in slot zero.
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Part 3 – Step 8. Heat Tightening the Nozzle

For proper sealing, you must tighten your nozzle at a high temperature.
Remove the silicon cover from the heat block. Preheat the hot-end to 250°C. Once it reaches that temperature and stabilizes, increase the hot-end temperature to 260°C (instructions below).   Press on the LCD button and select ‘Control’-->’Temperature-->’Nozzle 1’ -->rotate the button clockwise until you reach to 250°C -->press the button to confirm. Make sure that the target temperature (last picture) is now 250°C. Repeat these steps to reach 260°C. Note: You can do this section with ‘Pronterface’ or any host program as well.

Instructions on tightening the nozzle from the E3D documentation:

"You want to aim for 3 N∙m of torque on the hot nozzle - this is about as much pressure as you can apply with one finger on a small spanner. The nozzle does not need to be torque down incredibly tightly to form a good seal, when at lower temperatures the aluminum will contract and hold the Nozzle and Heat-Break together.

Attention! Do not over-tighten as you might break the nozzle. You do not need to turn the spanner, just to apply some force on it to keep it tight.

To cool off the nozzle, return to the ‘Nozzle 1’ menu and decrease the value to 0.
If you have a 2nd hot-end already installed, repeat these steps for ‘Nozzle 2’.
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