Layout drawings in Imperial units are provided in the steps; layout drawings in Metric units included in step 7.
Step 1: What do you need?
You will need a precise measuring rule, a good framing square, a drafting triangle and a sharp pencil. A magnifying glass will be a big help also.
Step 2: Make the MDF rectangle
Now that you have everything positioned, carefully lift the MDF, apply a line of glue on top the hardwood strip, and replace the MDF, making sure it is still square. Weight the MDF above the hardwood strip and wait for the glue to dry.
After the glue dries, trim off the excess on the left of the saw blade. You will now have the basics of an 18" wide x 16" sled.