Precise depths, carriage stop spacing and space alignment are sometimes overlooked in key machine operations. Duplicates keys will fail if the cutter is misaligned. Cutter guides can be set too far out or behind the cutter, resulting in keys that are too thin or too deep. The depth of a key cut can also be affected by the carriage stop position. Key spacing may pose an issue only after the gauge assembly has been replaced. In that case, the key gauge should be calibrated with the key machine or problems will continue.
Check the depth of cut settings. Set two matching key blanks flat into each jaw of the vise and then lift up the carriage. Move each key against the cutter in its corresponding vise.
Turn the pulley slowly by hand, make one full rotation, and then lift the pulley up again, leaving it at its highest point. Look at right key first to see if it is slightly touching the key blank. If does not, go to the next step.
Turn the binding screw slowly and loosen it just a little bit. Turn the screw to the left slowly to decrease cut depth; turn it to the right slowly to increase cut depth. Tighten the binding screw and repeat the previous step if both keys do not touch the key blanks.
Check the carriage stop nut and bolt. Remove all keys in the vise jaws, lift the carriage up and turn the cutter by hand. Loosen the nut and bolt, if needed, to ensure that the cutter does not touch the vise jaw and that .008 inches of space is between the vise jaw and the cutter.
Check the space alignment if a key gauge assembly was replaced. Set up a key blank and pattern key and then line both keys up to the cutter and cutter guide. File the correct finger of the gauge to enable contact with the shoulders of both keys.
Invest a small 1-inch size paint brush to clean your key machine's vise jaws after each key filing.
Slightly dampen a soft cloth with cleaning oil and wipe off the shafts at least weekly to help maintain it.
Unplug your key machine from its power source before you apply these steps.
Nina Nixon has more than 30 years of professional writing experience. She enjoys writing about business and technology. Her articles have appeared on Chron, eHow Business & Personal Finance, Techwalla, and other digital content publishing websites.