- Under development, this is a fork of the Hrbl shield for integrated motors from the Fabricatable Machines project
- To help, go to the issues and find out what needs to be done or raise new issues
- A fabricatable replacement controller card for the Shopbot PRSalpha
- It has a Arduino Nano running GRBL which does the motion planning.
- It can be fed with gcode over USB using Octoprint or Universal Gcode sender
- Pluggable connections that combine all connections needed per axis in one connector per motor (Needs work!)
- Full optoisolation separates the computer-arduino circuit from all signal and power wires.
- Z axis milling bit probe connection with external pull-up
- Spindle on/off and speed control (Needs work!)
- External power loss detection, keeps the controller in ABORT mode when there is no power to the motors.
- The 2 sided card can be CNC milled with a Ø0.4 mm milling bit
- Laser cuttable solder mask and silkscreen
The HRLB card that was made for Hedy
These need to be reconfigured to match the connections on the shobot
Shopbot driver pins
- Question: How does the shopbot controller connect to the limit switches?
HRBL for integrated motor drivers is currently in use in:
- Hedy v1 A CNC milling machine made to mill circuit boards like this one.
- Humphrey v3 A large size CNC milling machine built as a kit by Makerspace in Brumundal.
- Download this repo and go into the Hrbl_for_shopbot/grbl_spindle_enable_no_alarm_on_boot folder on your computer
- Open the grblUpload.ino file in the grblUpload subfolder.
- Connect the Arduino Nano, select the correct COM port and upload.
- The config is set for spindle enable, pwm and disabled (homeing warning) alarm on boot.
- Dowload UGS or another gcode sender
- Connect and cofigure the homeing direction, max speed, acceleration and steps per mm. Make a backup of these settings in a txt file and upload them here.
- Problems? See the Official GRBL instructions
- Arduino UNO
- Stepper motors with DIR and STEP pulse control interface
- 8 pole cable with 0.5mm2 wires
- Power supply and cables
- Control computer or raspberry pi
- Limit switches
- VFD (spindle driver) communication translator (Needs work!)
- Careful with which layer you mirror when you mill it!
- 8mm/s @18000rpm with a Ø0.4mm 2 flute china endmill worked! (did most with 4.5mm/s)
- Attach with double sided skotch tape (Jernia-brand worked well)
- Mill and drill from the side where you will solder the most thorugh hole components first
- Drilled Ø1mm holes were too tight for the contacts, mill them to at least Ø1.2mm next time.
- Don't make the alignment holes for flipping the card too tight.
- HRBL-shield is potentially great to combine with Hertz - axis monitoring board. Optimized for ihss57 integrated closed loop stepper motors.
- Create a version with a onboard 328p microprocessor to be able to skip the arduino uno altogether, remember to breakout programming pins for the MCU
- Consider replacing the 16 single channel SFH6206-3T optocouplers with 4 channel 4TLP291-4(GB) for reduced part count and cheaper BOM.
- (From issue 20 consider if we should change the 5V voltage regulator.
- Establish a maximum current that we can draw through the card to the motors without overheating the traces (or ribbon cable).
Laser foil for solder mask and silkscreen