Extruded Controller Shield PCB Design

This weekend I ordered my first set of professionally manufactures circuit boards from Osh Park. I designed the board in Fritzing, so I will upload the layout shortly. It's based on the old RepRap extruded controller, but instead of using an integrated ATmega328, it will use an Arduino Uno R3. The board supports 2 thermocouples, 2 thermistors, and 3 PW.M outputs for controlling heaters.

Here are a couple previews of the board. It is expected to be complete by the end of the month. I should be able to start assembly in early December.

Here's the current Fritzing file for the board:
 Arduino Extruder Controller v1.2

3020 CNC 3D Printer Conversion Part 3: First Prints

 This weekend I finally got my 3020 CNC Router converted to a 3D printer setup. It was actually much easier than I expected! As I previously stated in my post on the MIB heater controller, I am using a conversion kit purchased from MIB instruments.

The kit did not include a mount for the spool of filament, so I grabbed some spare 8020 aluminum extrusion and fabbed one up. Also, the mount they provided to attach the extruder to the Z-axis carriage was not a direct fit because it was designed for a MIB 3020 machine, not the generic one I have. I don't like the way it mounts, especially that holds the extruder with only one bolt. This will have to be improved later. I also need to run the wires for the heater and thermocouple through the cable track. One important addition was a connector on the cable that was previously used to run the spindle. With this connector I can easily swap out the extruder head for the spindle again without running a separate cable. Then I just switch with port I'm attached to on the controller box (A-axis or Spindle).

The heated glass bed they sell is a standard 200mm x 200mm size. Again, the holes did not match up to my generic 3020 bed, so I had to re-drill them.

First and second print results of a 35 tooth gear wheel for a Harbor Freight 7x10 lathe. The original gear from HF is on the left in the first picture. The second picture shows the tops and the third picture shows the bottoms. The difference between the two prints was adjustments in the feed rate of filament and the temperature of the extruder nozzle.

I guess I need a post on my software setup as there is a lot missing as far as explanation for that aspect of this project. I am using LinuxCNC and Slic3r currently.

3020 CNC 3D Printer Conversion Part 2: A-axis Stepper Driver

The next two images you can see the HY stepper controller that I use for the new A-axis that my feeds the filament. This was shoe-horned into my existing controller once I did a little reverse engineering in one of my previous posts. See YooCNC reverse engineering and HY-DIV268N-5A driver. Long story short, there are some extra pins that drive the added motor controller. I will have to design a new enclosure now!

 

I will add some pictures of which pins I am connected to on the YooCNC driver board the next time I have it apart.

TB6600 Stepper Driver - HY-DIV268N-5A

The first place you should go for information on this topic is the CNCzone.com thread on the topic:
TB6600 drive from EBAY
The guys on that forum have put a lot of work in to finding out the problems and issues with the board. I will only share my experiences on this blog. So for a more complete story, see the above link.

 The goal of purchasing this controller was to add an "A" axis to my YooCNC controller for my 3020 based 3D printer. I wanted to make a schematic so I was sure what I was getting into regarding wiring.

 Schematic created by "lonewolf55" on CNCzone.com. Thanks for your work lonewolf55.

 

I've unfortunately done some redundant work since I didn't find the above schematic until a few days ago. Hopefully some will find it useful to have the schematic in Fritzing format. Please download the latest version here:

HY_DIV268N_5A.fzz - (Last Updated May 25th, 2015)

Please let me know if you find any serious errors. It is not a final version, and may be reworked in the near future. Since there are many different versions of this board, some resistor and capacitor values may differ from my Fritzing file.

3020 CNC 3D Printer Conversion Part 1: Heater Controller

For the 3020, 3040, and 6040 series CNC Routers, there is a stand alone heater controller sold by MIB Instruments (based in China). This controller takes care of most of the necessary heating and monitoring needed to convert a CNC router to a 3D printer. The biggest problem I have encountered was that the unit was designed only for those who have an extra axis not currently used by their system. (i.e. A-axis) If you purchased from a cheaper reseller of the 3D routers you most likely do not have a compatible controller, at least without a little modification. These modifications will be discussed in another post. For now we will just discuss the heater controller made by MIB Instruments called the M3D-H2.

Here is a link to their website. They also have an eBay store where they sell all of their equipment.
http://www.mib-tech.com/
3D Printer page:
http://www.mib-tech.com/3d_printer.html

The "kit" is sold/advertised as a complete kit to convert your MIB Instruments 3020 CNC router to a 3D printer. It does not include everything you need, and the 2 components you do need to make a complete kit, are only sold separately on their eBay store.

Heater Controller & Heater Bed: (I paid $282.34, shipping included)
http://www.ebay.com/itm/321111260236

Filament Feed Stepper, Heater, & Thermocouple: (I paid $79)
http://www.ebay.com/itm/330943103747

I also purchase 2 1KG spools of filament. One PLA and one ABS so I can experiment with the different materials.

 

A dot-matrix LCD display is "glued" to the PCB. While this makes for a clean, single board installation, it's not so easy to replace if the back light goes out it you want to make any changes to the design.

 

I first impression was one of disgrace when I saw the hack-sawed heatsink that must've been pulled from a scrap bin. For the two most critical components on the board, the FET's that power the heaters, you would think they could put a little more effort into cooling.

The board is expandable. You could add two more thermocouples as well as 2 more heaters. I may throw together a schematic in the future to help explain this.

The microprocessor that controls everything is a PIC 16F866.

The thermocouple chip is a MAX6675 (U5).

A LM2575T (D3) switching regulator is used for ?

A IRF4905 (D8) ??? is used for?

A ND B1205S-1W DC-DC converter is used to isolate the control circuitry from the power circuitry.

 

The heater controller uses a 250W 24V switching power supply to power everything. Nothing special here.

I may revise this in the future, it's sort of a draft, but I want to get it posted and out there so you all can read it.

YooCNC T62-3AX Reverse Engineering

I have been planning to add limit switches and spindle control ever since I got my 3020 CNC a while ago. Many people have done it, and there are a few pages that show the "idea" of how to do it. It all boils down to a few unused pins on the T62-3AX board. This board I believe is exclusive to the 3020 CNCs (and maybe 3040) as the larger ones use separate motor driver boards and a breakout board.

I previously did a limited post on the T62-3AX board on my blog, but I only showed a limited schematic here:
YOOCNC T62-3AX CNC Controller for 3020T

I feel the first step should be a solid and complete reverse engineering of the existing board to make sure we fully utilize its capabilities. This will also serve as a great reference to those needing to make repairs or wanted to further understand its operation. I will be creating a Fritzing file that will have a PCB layout and schematic of the board. I will upload it as I work on it, so there will be versions that are incomplete or missing components. If you find any faults with it or want to help add, please do and send me the changes so I can upload them here.

Top:

Bottom:

 

General schematic screenshot from Fritzing (download link is below):

 

Please note, some components may be missing or mislabeled.

Current Fritzing file (created in 0.92):
YooCNC_T62_3AX_v04.fzz (Last Updated May 11th, 2015)

What I have learned from drawing up this complete schematic of the CNC driver board:
1) Unused pins, list to come.

2) Unused opto-couplers & header pins, idea for limit switches.

3) Unpopulated positions for DIP switches permit changing of stepper driver presets. Details to come...

4) Generally well designed except for missing A-axis control. My current focus is on adding an A-axis to control the feed stepper for my 3D printer attachment I've purchased.