I made a trip to the hardware store after deciding that I need to make my attachment system adjustable. I have a couple different laptops that may be used on the new mount and who knows what will be next.
Here is the hardware that I used:
Two 1/4" threaded hooks, two 1/4"x7" turnbuckles , two 3"x1/2" dia springs , 6" of 1/4" rubber vacuum line tubing, 16" of 3/4" convoluted tubing, 1/2" and 1/4" heat shrink tubing.
Remove and discard the right hand threaded eyelet from the turnbuckle.
Straighten the threaded hook to 90°. Then using a measurement of your installed laptop bend an additional 90° to create a hook to hold your laptop.
Slip a piece of shrink tubing to cover the shaft of the threaded hook to isolate it from the hole in the table top.
Slide a piece of the rubber tubing over the hook to insulate it from damaging the laptop. Hairspray works as a lubricant for installation and dries to hold it in place. I capped the end with an appropriately sized vacuum line cap.
Thread the left hand threaded eyelet all the way into the turnbuckle. Push a piece of shrink tubing over the body of the turn buckle and shrink it in place. Cut away excess from the end where the threaded rod from the hook will be attached. Insert the rod of the hook through the hole in the top and thread a nut on the rod. Now thread the turn buckle on the rod. Attach the spring to the eyelet and the hole on the other side of the top. Loosen the turn buckle as needed for spring tension.
Cover the spring and eyelet to insulate them.
It will be a while before I test them out, but I am happy with how it turned out. Time to complete less than 2 hours including the gathering of supplies. Cost was less than $10.
This is a 15" laptop and the one that usually travels with me.
Here is a 17" widescreen onboard.
You could add the same hooks to the back side of the top too if needed. Four of these would really secure a laptop. I am not sure if that will be needed. Right now my cupholders take priority.