IndyMill

About

Somewhere in 2022 I decided I wanted a CNC machine. I decided to build an IndyMill.

Project website: https://indystry.cc/indymill/

Ordering

TBD

Building

TBD

Setting up GRBL

Installing GRBL

🛑	Dies might be a bad idea, since GRBL has been abandoned since 2019…

1. Install Arduino IDE 1.x (not 2.x!)
2. Setup board type
3. Setup serial/USB-connection (you might want to add your user to group dialout to allow accessing /dev/ttyUSB0…)
4. Download as .zip: https://github.com/gnea/grbl
5. Extract zip
6. Open Arduino IDE

Sketch → Library Import as .ZIP → select grbl-master/grbl

File → Examples → grbl → grblUpload

Testing Connection

1. Download CNCjs-AppImage: https://cnc.js.org/
2. Launch it, set Connection parameters (device / speed)
3. Enter something like this:

• Get current settings with

$$

CNCjs 1.10.3 [Grbl]
Connected to /dev/ttyUSB0 with a baud rate of 115200
Grbl 1.1h ['$' for help]
client> $$
$0=10 (Step pulse time, microseconds)
$1=25 (Step idle delay, milliseconds)
$2=0 (Step pulse invert, mask)
$3=0 (Step direction invert, mask)
$4=0 (Invert step enable pin, boolean)
$5=0 (Invert limit pins, boolean)
$6=0 (Invert probe pin, boolean)
$10=1 (Status report options, mask)
$11=0.010 (Junction deviation, millimeters)
$12=0.002 (Arc tolerance, millimeters)
$13=0 (Report in inches, boolean)
$20=0 (Soft limits enable, boolean)
$21=0 (Hard limits enable, boolean)
$22=0 (Homing cycle enable, boolean)
$23=0 (Homing direction invert, mask)
$24=25.000 (Homing locate feed rate, mm/min)
$25=500.000 (Homing search seek rate, mm/min)
$26=250 (Homing switch debounce delay, milliseconds)
$27=1.000 (Homing switch pull-off distance, millimeters)
$30=1000 (Maximum spindle speed, RPM)
$31=0 (Minimum spindle speed, RPM)
$32=0 (Laser-mode enable, boolean)
$100=250.000 (X-axis travel resolution, step/mm)
$101=250.000 (Y-axis travel resolution, step/mm)
$102=250.000 (Z-axis travel resolution, step/mm)
$110=500.000 (X-axis maximum rate, mm/min)
$111=500.000 (Y-axis maximum rate, mm/min)
$112=500.000 (Z-axis maximum rate, mm/min)
$120=10.000 (X-axis acceleration, mm/sec^2)
$121=10.000 (Y-axis acceleration, mm/sec^2)
$122=10.000 (Z-axis acceleration, mm/sec^2)
$130=200.000 (X-axis maximum travel, millimeters)
$131=200.000 (Y-axis maximum travel, millimeters)
$132=200.000 (Z-axis maximum travel, millimeters)
ok

GRBL-Settings

Setting step width

• Change settings as described in Nikodem's manual for stepwidth:

$1=255
ok
$100=640
ok
$101=640
ok
$102=400
ok
$110=1000
ok
$111=1000
ok
$112=1000
ok
$120=80
ok
$121=80
ok
$122=80
ok

I changed above to meet my (micro)-stepping-setup (DIP #2 of my TB6600, micro-step 8, Pulse/Rev 1600) and ball-screws.

$100=320
$101=320
$102=800

Hint: Make sure you reset the machine after changing values, my GRBL acted strangely when not.

Setting directions

• Set directions:
  • Inverting Z-axis:

    $3=4

Enabling Limit-Switches

• See also:
  • https://www.youtube.com/watch?v=LZri0vlNrRs&list=PLktKi_COpyPRd8JZfjhskWSvsFN3Cb1v8&index=9
  • https://github.com/gnea/grbl/wiki/Set-up-the-Homing-Cycle
  • https://github.com/gnea/grbl/wiki/Wiring-Limit-Switches
• Do:
  • MAYBE NOT: Enable hard limits: $21=1
  • Enable homing cycle: $22=1
  • Set top left home location: $23=1 (see above links for more values)

Testing

Try this:

$H

Z-Axis-Probe

• See also:
  • https://www.youtube.com/watch?v=l9o6ZUjb3k0
• Do:
  • TBD

Work with CAD- and CAM-Software

Converting STL to solids in FreeCAD

See also: https://forum.freecad.org/viewtopic.php?t=14136

1. Open the STL file
2. Select object

Part → Create shape from mesh

1. Select new object

Part → Converte to solid

Create GCODE with JSCut.org

💡	If you're creating your own SVG, make sure the pockets are "objects", meaning "areas", not paths.

• Create SVG
• Launch https://jscut.org/
• Open SVG
• Set units correctly (in my case mm)
• Set speeds and diameters, material strength and so on...
• Select object
• Generate operation
• Preview
• Download
• Hope for the best :)

Create GCODE with FreeCAD

See also

• https://www.youtube.com/watch?v=XRNnWAUoXrk
• https://wiki.freecad.org/Path_Job

Do:

• Launch FreeCAD
• Make sure you have already created proper solids (see above)!
• Make sure units are ok:

Preferences → General → Unit System → Metric small parts & CNC

• Create Job:
  
  

  1. Select solid 2. Choose Path-Workbench 3. Create Job
• Choose solid:
  
• Set

Output to grbl

• Create tools as needed:

Path → Toolbit Library Editor

• Remove default tool
• Choose Tool, set # to 1
• Set H/V speed
• TBD TBD TBD

Lessons Learned

• Origin is in front-left corner, increasing up (Z), right (X) and back (Y)
• Double-Check all settings before first use (most importantly step width, end switches)
• Don't think it's as easy as 3D-Printing!
• You have to make decisions while creating the GCODE:
  • Which pockets should be done first?
  • Which pockets should be done last?
  • Will any operation make your part move or break?

Footer

• Links
  • TBD
• Footnotes: