All competitive brands of desktop or production braille printers has to be maintained on a regular base. The maintaining alway include mechanical adjustment of the pin/anvil position during the forming moment.
Desktop printers uses typically solenoid to create the energy to forming the braille dot. As competitive printers uses the the force from the solenoid (not movement energy) to form the paper it is necessary to adjust the position when the piston hits the paper to when the solenoid gives maximum force. If the solenoid is too close to the anvil the force will not be enough and if it is too far away from the anvil it will also not give enough force. The position of the solenoid/anvil need to be within 0,05 mm precision.
Some older desktop braille printer constructions form the braille dot against a matrix instead of an anvil. The matrix is like a pyramide where the formed dots have a pyramid form. This type of dots will be cut on four sides of the pyramid with a short dot lifecycle and bad readability.
Some very old and sheap braille printers forms forms the dot against a soft rubber or plastic. This solution gives a low braille dot which do not have the correst sphere form. Index Blue Bar from the 80-ties used this technology.