Measuring Slider Knobs
Measuring control knobs is critical to ensure that replacement knobs will fit your equipment. Below is a description of the critical factors to consider and how they are measured.
Width / Length
Width
The width is measured from one side of the body to the other at it's widest point, including any protruding position indicator markings. This dimension is perpendicular to the slider movement direction.
Length
The length is measured from the top to the bottom, at the widest part of the body. This dimension is in the same orientation as the slider movement direction.
Shaft
Minimum Shaft Depth
The minimum shaft depth is the minimum amount that the shaft must be inserted into the body of the knob, in order to make suitable contact with the shaft fixing.
Maximum Shaft Depth
The maximum shaft depth is the maximum amount that the shaft can be inserted into the body of the knob. This is measured from the lowest part of the base of the knob to the bottom of the hole.
Height & Clearance
Height
The height of the knob is measured from the lowest part to the highest including any position indicators.
Clearance
The clearance is the space between the bottom of the knob and the equipment it is mounted to. While this is not a direct specification of the knob it is important to consider this dimension when selecting a control knob.
An appropiate level of clearence between the base of the knob and the surface of the equipment is nessessary to ensure smooth control and to prevent damage.