Handknobs For Faster Changeover with John Henry
My goal in changeover reduction is elimination of all tool usage. There may be a few exceptions, particularly when required for safety. With a bit of ingenuity, though, most, if not all tools can be eliminated.
One obvious aid is handknobs and handlevers. Handknobs are available in a wide variety of sizes and styles but are all characterized by being symmetrical around the thread. Handlevers are asymmetrical. Many handlevers have ratcheted handles for ease of positioning.
TIP: Spend the extra money and buy handlevers with stainless steel ratchets. Plastic, brass and aluminum may be cheaper but will strip.
I make a rule of using handknobs when complete removal is required. Handlevers should be used when only loosening is required. This is partly for ergonomics but also for also as a memory aide to prevent removal of fasteners that do not need removal.
When Handknobs need to be fully removed, take a tip from NASCAR and relieve the last 1/4 to 3/8″ of the threads. This prevents cross threading when replacing.
Several styles of quick acting knobs and levers are commercially available. These can be useful but do not provide the same mechanical security as regular, fully threaded, fasteners. they should be used with caution and only on non-trivial applications such as adjusting guides rails.
Knobs and levers should only be used on those fasteners that are touched during routine changeovers. they should not be used elsewhere. This serves as a memory aide. If a tool is required, it is not to be adjusted.
Knobs and levers are so simple and common that we take them for granted. We shouldn’t.