Or search: fork, grip, spoon, spork, cutter, handgrip
3 Syllables: SUU
bloodthirsty, custody, drudgery, gluttony, luckily, lustily, luxuries, luxury, nunnery, shrubbery, stubbornly, submarine, subtly, summary, Tuscany, utterly
3 Syllables: USU
discovery, recovery
4 Syllables: USUU
microscopy, unluckily
5 Syllables: UUSUU
introductory
6 Syllables: UUUSUU
involuntarily

Found 22 words across 5 groupings. Skipped 1 excess word of a similar stem.