You can easily make 2D orthographic CAD drawings in SketchUp. CAD drawings typically do not have perspective camera angles so we first need to switch the camera angle to parallel projection. Go to Camera in the menu at the top and select Parallel Projection. From here we can select the Front standard view. If you have the Views toolbar activated you can select the Front view icon. If not, go to Camera on the menu at the top, Standard Views, and select Front. This front view will be the bottom left image of our 2D orthographic drawing.
If you’re working with a single component you can duplicate it once to the right and once above the original. If you are working with several components I suggest combining all of your components into a single large component before copying.
The component that you copied to the right will represent the right view. To make the right side of the component visible you need to rotate the component. This can easily be done by using the Move tool (keyboard shortcut M). First, adjust the camera angle so that you can see the top of the component. Select the component. Activate the Move tool and hover the mouse over the top face of your component. This will bring up four red cross hairs near the edges. If you select one of these you will be rotating the component along its center axis. Rotate it 90 degrees so that the right side is now facing the front. Now that it is in the correct orientation you can select the Front view again.
You need to do the same thing to the component copied to the top. This time the top face of the component needs to be rotated down to face the front. You can use the move tool just like before but from the side of the component. Press the Front view button again to return to the front view.
From here you can add dimensions as necessary.