Category Archives: Uncategorized

Notes on Marlin – Auto Bed Levelling

Upon enabling the auto bed levelling feature of the Marlin firmware I learned a thing or two through trial and error and wished it had been better documented so I’ll try and let you know what I’ve learned.

Here are links to some useful information that all helped me get setup:

Firmware setup
Hardware setup
PrintrBoard setup

In the Marlin firmware, where you set the left, right, back and front positions for probing, do not set the left and front positions below 10.  I tried 5 (assuming the bigger the test area the better results you would get) and wondered why moving the nozzle back to X0 Y0 after homing resulted in the nozzle crashing both X & Y in to the min endstops.  I quickly noticed that at the start of the probing both the nozzle did not move in either X or Y so they were both then 5mm out when homing after the probing.  I now use 20 for left and front.

I also found that if you just move X & Y to home before probing and your nozzle is quite high in relation to the bed then the bed probe would stop way before it even touched the bed.  I thought I’d fix this by homing the Z before probing but you need to make sure that the probe is within your bed probing co-ordinates (i.e. the middle of the bed, or at least more than you’ve set for left and front).

So here is my start G-Code* that I’ve put in to Slic3r:

G28 X0 Y0 ;home X & Y
G1 X100 Y100 F5000 ;move nozzle to centre of bed
G28 Z0 ;home Z
G29 ;probe bed
G90; set absolute coordinates
G92 E0; reset extruder distance
G1 Z5 F300 ;move nozzle up 5mm for safe homing
G1 X0 Y0 Z0 F5000; move nozzle to home

*If you’re going to use this code then please set your own bed centre and move velocities appropriate to your printer.

If I discover anything more on this topic then I’ll update this post.

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Slic3r v1.0.0 RC1

Slic3r keeps on maturing and getting better with each revision.  Their current release, version 1 release candidate 1 has some great new features.

You can check out the full release notes and download your own copy HERE

A few major changes are:

  • built-in automatic STL repair
  • new support material rewritten from scratch
  • options to avoid starting loops on convex vertices and/or overhangs
  • improved infill patterns and bridge detection

I have already found the STL repair to be very good and saves me a trip round NetFabb and the new infill fills in small holes much better (I always use small gear from Greg’s Wade reloaded Extruder to test whether the infill works or not).

The previous Slic3r (version 0.9.10b) below:

Slic3r Old

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The latest Slic3r (version 1.0.0 RC1) below:

Slic3r New

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I used to get round this by adjusting the Advanced settings but now Slic3r does it all automatically 🙂 JOY!

LCD and Encoder controls (Panelolu) – – – – – – – Part 2, Hardware

This is the hardware section of installing a Panelolu control panel to your PrintrBoard based 3D printer. Please refer to ​part 1, Software post for the updates you need to make to your firmware necessary to prepare your PrintrBoard for the Panelolu.

Again, thanks go to think3dprint3d​ for the following info. More details are available there. Please let me know if you need any further information regarding anything posted here.

The plugs and pins for the LCD and PCB come supplied with the Panelolu kit however for the connections to the PrintrBoard I recommend purchasing two 14 pin connectors similar to connectors found HERE​. I used the 2×7 so I can make further connections in the future. You will also need to buy the pins sold separately.

Notes:

The numbers represent the wire number of the ribbon cable. 1 & 2 were left out for possible connections to Ground and +12Vdc for any future additions to the Panelolu box.

The ‘grey’ 3 is ground and the ‘red’ 4 is +5Vdc. The multiple 3s and 4s must be connected together.

​The ‘yellow’ B and ‘green’ C are the Brightness and Contrast inter-connections between the LCD & PCB.

PrintrBoard Expansion Ports

PrintrBoard Expansion Ports

 

 

These are the headers to where you need to connect to on the PrintrBoard.

 

 

 

 

 

 

PrintrBoard Connections

PrintrBoard Connections

 

 

​      This is a simplified sketch of the connections to the PrintrBoard.

 

 

 

 

 

 

LCD Connections (rear)

LCD Connections (rear)

 

 

These are the connections to the rear of the LCD.  Note the right to left numbering of the pins.

 

 

 

 

Panelolu PCB Connections

Panelolu PCB Connections

Finally, these are the connections to the Panelolu PCB.