For this assignment, we were challenged to choose a wooden mechanism and convert the given plans into dimensionally accurate and proportionate 2D vector drawing using Adobe Illustrator.

I chose the Lever and Ratchet Machine from Building Wooden Machines by Alan and Gill Bridgewater. This machine doesn’t really do much. As you turn the drive wheel, it drives the crank arm which turns the toothed wheel and the control arm prevents the ratchet wheel from rotating back. Even though it is not the most dramatic mechanism, its parts do have a good variety of geometry and it is very pretty!

The mechanism is composed of 7 main parts: drive wheel stanchion, toothed wheel stanchion, long crank drive rod, short crank rod, control arm, drive wheel, and the toothed wheel. It also has a tooth to fit into the toothed gear and 2 little plates that go on either end of the control arm (all 3 of which are not shown in the plan below).

I started by making part a (the drive wheel stanchion) and I had a lot of trouble that pretty much continued through the whole process. It really stemmed from the fact that I didn’t know how to use Illustrator at all and I had been spoiled by other drawing programs in the past that made dimensioning and adding relations very easy. I kept muddling through and made both the short and long crank arm as well as the control arm and at that point I was having a lot of trouble with the arc and circle tools built into Illustrator. I honestly think they should add in the ability to make 3 point arcs because it would make life a lot easier (unless it already exists and I don’t know how to use it which, to be honest, is pretty probable). But luckily, by this point I was kind of starting to understand how illustrator works and I decided to tackle the more complex shapes: the toothed gear and the toothed wheel stanchion. For both of them I used the rotate tool and they each took WAY less time to make than the crank arms, so that was nice. Then I finished up by making the drive wheel and reading through the procedure and finding that I also needed to make a tooth to fit into the toothed gear and 2 plates for the control arm which were all really easy to make.

I then put all of the drawings onto a single page and made all of my dowel holes consistent. I don’t think the authors mention specifically the dowel sizes they use, but you can estimate based on the given schematic. I made all of the holes (except the tooth hole and the short crank arm holes that correspond to the tooth hole) 1/4 inch in diameter and I made the tooth hole and the short crank arm holes that correspond to the tooth hole each 1/8 an inch in diameter.

You can see the final ai file here: rachet-dim

And the final pdf here: rachet-dim

Overall, I would say this project really taught me I need more practice with Illustrator before I will feel confident in it, because I know it is a very powerful tool, but at this point I’m not experienced enough with it to use that power.