ZETA’s Imbus pegs should be thought of as ‘lock-down’ pegs. They are not intended for fine tuning, but rather for ‘holding’ the pitch level of the string over a long period of time.
Fine tuning to exact pitch should be accomplished by the fine-tuners at the tailpiece. Fine-tuners should only be turned down a few turns at most, and when more ‘tuning up to correct pitch’ is necessary . . . the fine-tuners should be backed off and the ‘lock-down’ Imbus pegs then used as described below.
Proper use of the Imbus peg starts with clock-wise turning (de-tuning) and simultaneous lifting (un-seating) of the peg. With the peg free from a tight friction fit in the peghead (and the string below pitch) . . . then and only then is the string brought up to pitch (turning counter-clockwise) without any friction in the peg. [NOTE: The Imbus peg should not be ‘squeaking’ during any of its turning. If it is, then too much friction is present (ie peg is locked). Release the friction by lifting up on the peg while de-tuning.] Once at pitch the peg is then seated firmly and securely in the peg-hole. Then the fine-tuner is used to bring string to final pitch, which should take less than a full turn of the fine-tuner.
In general . . . damage to Imbus pegs comes from trying to tune up a locked peg. Not following the above procedure can damage the Imbus peg which may eventually require a replacement peg.