6daa3114be
This reuses the same (external) tooth profile from pygear but swap some parameters to make the resulting gear internal. This prototype is mostly a copy of the external involute gear. Eventually we should refactor this to share more code but this has to be coordinated with the megagrant endevour. Otherwise merging becomes a nightmere. Note that in contrast to the involute rack I choose to base the "thickness" on the pitch diameter, not the root diameter. This has the benefit of keeping the outside diameter stable when e.g. adjusting the clearance. And setting the outside diameter directly could result in an invalid shape when chaning the numnber of teeth. The default head value of "-0.4" is choosen to match the invernal gear profile from the PartDewign WB.
A Gear module for FreeCAD
Requirements
FreeCAD > v0.16
python > 3 (for python2 use branch py2)
Supported gear-types
Cylindric Involute
- Shifting
- Helical
- Double Helical
- Undercut
Involute Rack
Cylindric Cycloid
- Helical
- Double Helical
Spherical Involute Bevel-Gear
- Spiral
Crown-Gear
Worm-Gear
Timing-Gear
Lantern-Gear
Installation
Addon Manager
Starting from v0.17 it's possible to use the built-in FreeCAD Addon Manager
located in the Tools > Addon Manager dropdown menu.
pip
pip install https://github.com/looooo/FCGear/archive/master.tar.gz
Important note: Most systems have multiple versions of python installed. Make sure the pip you're using is used by FreeCAD as well.
Usage
Create a gear manually
- Open freecad
- Switch to the gear workbench
- Create new document
- Create a gear (click on a gear symbol in the toolbar)
- Change the gear parameters
Scripted gears
Use the power of python to automate your gear modeling:
import FreeCAD as App
import freecad.gears.commands
gear = freecad.gears.commands.CreateInvoluteGear.create()
gear.teeth = 20
gear.beta = 20
gear.height = 10
gear.double_helix = True
App.ActiveDocument.recompute()
Gui.SendMsgToActiveView("ViewFit")
References
- Elements of Metric Gear Technology (PDF)
FreeCAD Forum threads
These are forum threads where FreeCAD Gears has been discussed. If you want to give Feedback or report a bug please use the below threads. Please make sure that the report hasn't been reported already by browsing this repositories issue queue.
- "CONTINUED: involute gear generator preview !" (thread)
- "Bevel gear - module/script/tutorial" (thread)
- "Gears in FreeCAD: FC Gear" (thread)
- "FC Gears: Feedback thread" (thread)
License
GNU General Public License v3.0