Thanks guys! Joe, I drilled a hole through the riser and rock. I used a 1/4" drill bit 12" long. I rotated the table on my drill press vertical and clamped the riser to it. I centered the bit in the limb and carefully started to drill. I could only drill a few inches because that's all the travel I had with the table so low. I then drilled as far as I could using the hole as a pilot and pushing the riser up with my hands. Then I reclamped the riser other end up on the table. I used a laser line to line the bit up with the hole I just drilled the best I could. To my surprise, the holes lined up the first try!