We are discussing the making of the clock for Nadi, Vinadi and Prana. In the first part, we spoke about the gear ratio calculations. Let us design gears in Freecad.
We can use spreadsheet workbench to create spreadsheets within FreeCAD. This will help in keeping all variables in place. These variables can be referred to in all the parts we are going to design. This is good for consistency as well as future changes if any to a particular variable like thickness of the gear or axle diameter,etc
All gears will be of module 1.5 for this project. Thickness of each gear will be 4mm. For compound gears smaller gear will be 6 mm thick. This leaves a gap of 2 mm height wise when gears are meshed. Let’s leave Other parameters like pressure angle as default.
3mm SS rod will act as an axle. Adding 0.4 mm to this value is good enough for holes in the gear to rotate around the rod.
To ensure that gear rotates without wobbling let us add some height without the teeth.
Right now our clock will be driven by Motor so let us provision for its location as well.
Let us create aliases by clicking here so that we refer to these values during creation of parts.
We will create our first compound gear. Open the Part design workbench, create a part and body.
Let's name it G_30_10. Compound gear with 30 and 10 teeth. This convention we will follow in the project. G for gear
Only two values need to be changed module and number of teeth - 1.5 and 30
Same for the second gear 1.5 and 10
Let us add a hole for the axle and provide some height.
We will have to move the sketch by 10 mm in the z direction.
Our base gear is ready.
Let us introduce some holes in between to make it lighter.
We will use a polar pattern to create six holes from this one hole.
Finally, let us add filet to the axleHole. That way it will not be holding the axle when 3D printed.
Our first gear is ready to print.
We will create remaining compound gears similar to this one, except the number of teeth will be different.
With compound gears in place, let us take up gears which will drive Nadi/Vinadi hands or pointers.
This gear will be used by a green pointer. We will use aluminum pipe with 6mm Id and 8mm OD for the same. This pipe will act as an axle for the next axle gear which will drive the Vinadi pointer.
This gear will be used for Shining or viandi Pointers. We will keep its ID as 8.4 so that it can rotate freely with an axle of OD 8mm. Its OD will be 13 mm.
Last axle gear will host the Nadi pointer. Its ID will be 13.5 mm just 0.5 more than the OD of the earlier one and the ID will be 17 mm.
Last gear we will create for the motor with 20 teeth.
Here we have 8 gears of different types.
Now its time to design housing for these gears so that we can perfectly mesh these gears together.
That will be covered in the next video.
Thank you.