While this is an old thread and topic, figured I add to it (together) with a photo.
First, I love stock feeders. I think they're a "must have" in a shop if you own a shaper.
Have 4 Maggi Steff 1-HP, 3-PH, feeders in the shop now; (3) 3 wheel paired with 3 different shapers and (1) 4 wheel on one of two the table saws. We did try "sharing" a feeder with a shaper and a table saw. Made a mobile base for it to roll up to and secure to Shaper or TS. While it worked, it was a PITA and ended up buying another feeder.
So wanted the capability of pulling through full 3/4" Ply or MDF sheets to Rip, but with the stock feeder arm only measuring about 28" total, there's not enough to make it possible. Then do they offer a 1000mm overall replacement support arm, but that still wouldn't be ideal ... especially given the cost.
So came up with a Plan "B". Let's add 24" TO the stock 28" arm and push the support base out as far as possible. Wa-La... it works.
Made up a somewhat hefty base to anchor the feeder base to. It's made from 6" tubular steel with a 1/4" steel base plate anchored to the concrete floor. There's also a diagonal arm and mounting plate to help with the cantilevered weight. The factory feeder base is securely bolted into a threaded steel top plate. The factory support arm received a 24" extension by turning a solid steel slug for the interior of both original and added tube, then plug welded, then perimeter welded and ground down. The I.D.'s of the two materials were not the same. What we added way more precise and true than the factory support arm. The end result ... it works well. The new (about 52" OAL arm) allows for over 36" of cutting right of the saw blade. The experiment/task has been a huge help. One PS if wondered/asked. Opted not to make a mount from the ceiling down given the ceilings are over 14-foot high. Wasn't practical, nor desired.CYMERA_20171031_091558.jpg