My shaper is great for a lot of stuff but finishing cuts and internal slotting have been difficult because the clapper is small and light.
At last I added the single tapped hole I needed to copy the spring Artful Bodger restored to his Logan to make the clapper reseat more reliably. But first I used the hole to lock the clapper by screwing down a square nut milled with a step to make up the difference in height from the clapper box.
This probably shortens tool life but it made cutting keyways in bores easy and chatter free—the slot and cutter here are 1/8” wide.
Here are my slotting tool holders-the short one replaces the tool post and the long one fits my simplified copy of Art Volz’ multiple angle holder.