For our third assignment, the 2D drawing, we had to choose a complex mechanism and draw its components using Adobe Illustrator. I chose my machine from the book “Making Mechanical Marvels in Wood” by Raymond Levy.
The mechanism I chose is called Intermittent Drive. It is a simple mechanism that will drive for half a revolution, pause for half a revolution, and then drive another revolution, providing a useful action for display turntables, rotate valves…
How does it work? The drive member and the driven member have their centre offset from one another, so the part diameters are eccentric. A tang projecting from the driver engages a lug on the rotor at the close point of eccentricity, and releases it half a revolution later. This is a picture of all the part assembled together:
My work on Illustrator was divided in 5 parts:
- Drive Ring;
- Rotor and Bearing Journal;
- Back Plate;
- Base Plate;
- Pins (extra).
For all my drawing I decided to make more than one orthographic view, actually 2 or 3. I decided to do it because I think it can be easier to both imagine the object and get all the measurements right!
Ps.: It is important to notice that all the invisible lines are red colored!
- Drive Ring:
The drive ring is composed of 2 parts, the front member and the rear member. Neither of them gave me a lot of trouble while drawing!
The biggest difficulty on this part was the tang slot, so to do it I decided to make lines using the pen tool and then connect the lines with the square and circles using the white arrow and the command Ctrl+J.
2. Rotor and Bearing Journal:
These were by far the most difficult components to draw! To measure both circles I used my amazing skill on Paint and using the scale given I could find out the dimensions…
To draw the rotor I used two concentric circles and using a rectangle and the pen tool i could draw the “ears” (I wish I had saved the process). After that I had to figure out what tool I should use to delete all the necessary lines, so I decided to use the Pathfinder and scissor tool. After getting it all cut I could join everything using the white arrow and the command Ctrl+J.
The problem on the bearing was figuring out what the two big concentric circles meant, because on the colored drawing there is clearly only one big circle. After reading the book I realized it was gap supposed to exist so that everything should fit together and I decided to remove the white space in between and make it bold.
3. Back Plate:
This part also didn’t give me a lot of trouble. To draw the eccentric circle in the right positing I drew lines with the dimensions were the centre would be located and then deleted those.
4. Base Plate:
This part also didn’t give me a lot of trouble, and to draw it I used that same method as the back plate.
5. Pins and etc… (Extra):
So even if we were supposed to only draw the “laser cuttable”parts I decided to draw the pins beeches I think it would help with the Illustrator.
My biggest problem was drawing the drive tang because I didn’t have the size of the right side, and to find it I has to use my skill in trigonometry…
And after that I could draw it using the pathfinder, pen tool, white arrow and command Ctrl+J.
SELF CRITICISM: For me the biggest chalenge was using the program itself. I have never used a drawing tool and after learning Illustrator as the first one I could realize how frustrating the whole process of 2D (or maybe 3D) drawing can be.
After finishing all the drawings I was proud of myself. I didn’t become a master or even good on Illustrator, but now I know that I can basic shapes and designs and if I want to do something more elaborated I can figure it out using the different tools or maybe even “real life”methods.
You can find the Illustrator file here: Intermittent_Drive_Final
I hope you have liked my 2D drawings and I see you next on the fourth assignment: Laser Cutting! (I am excited for it).
