Reference Section > Shape Library > Other Shapes

The Pointed Comb is a rectangular bar with a row of equal teeth standing up from its top edge. Each tooth is a trapezoid that narrows from its base to a flat tip, or a pointed triangle when the tip has no flat. The teeth are evenly spaced, with a plain shoulder at each end of the bar. It is used for toothed strips, serrated edges, locating combs and similar parts that need a regular row of tapered teeth.

It appears in the shapes library under Other Shapes. Square Comb is a separate shape with no Tooth Flat property.

Insert point and orientation

The insert point (0,0) is the top left corner of the bar, at the outer end of the left shoulder. The bar runs to the right along X and hangs below the insert point, from Y = 0 down to Y = -Height. The teeth stand up from the top edge (Y = 0) to Y = Tooth Height.

Along the top edge, from left to right, the shape is: Left Shoulder, then the teeth with one Gap between each pair of neighbouring teeth, then Right Shoulder. The overall length of the bar is:

Left Shoulder + (Num. of teeth x Tooth Width) + ((Num. of teeth - 1) x Gap) + Right Shoulder

With the default values that is 50 + 150 + 50 + 25 = 275 mm. Each tooth is Tooth Width wide at its base and Tooth Flat wide at its tip, with the tip centred over the base.

The outline is a single closed profile. It starts on the top edge at the base of the first tooth, runs left along the left shoulder, down the left end, along the bottom, up the right end, back along the right shoulder and then over the teeth from right to left, finishing where it started.

Properties

Property	Description	Default
Height	Depth of the bar in Y, from the top edge (the base of the teeth) to the bottom edge. The teeth are not included. Length unit, 0 or more.	50 mm (2")
Num. of teeth	Number of teeth along the top edge. Whole number, 0 or more. 0 gives a plain rectangle (see Notes).	3
Tooth Height	Height of each tooth above the top edge of the bar, measured square to the bar. Length unit. Negative values are allowed: the teeth then point down into the bar and become tapered notches.	75 mm (3")
Tooth Width	Width of each tooth at its base, along the top edge of the bar. Length unit, 0 or more. 0 removes the teeth and leaves the top edge straight.	50 mm (2")
Tooth Flat	Width of the flat at the tip of each tooth, centred over the base. Length unit, 0 or more. 0 gives pointed (triangular) teeth. Equal to Tooth Width gives square teeth.	25 mm (1")
Gap	Straight length of top edge between the bases of two neighbouring teeth. Length unit, 0 or more. 0 makes the teeth touch at their bases.	25 mm (1")
Left Shoulder	Length of plain top edge from the left end of the bar (the insert point) to the base of the first tooth. Length unit, 0 or more.	50 mm (2")
Right Shoulder	Length of plain top edge from the base of the last tooth to the right end of the bar. Length unit, 0 or more.	25 mm (1")

Defaults are shown for metric units, with the imperial default in brackets. All teeth are the same size and evenly spaced; they cannot be set individually.

The dimensions drawn on the shape are Height, Left Shoulder, Right Shoulder, Gap (between the first two teeth), Tooth Flat and Tooth Width (on the first tooth) and Tooth Height (on the last tooth).

Notes

The shape does not check its values against each other. Lengths and Num. of teeth are entered as 0 or more, and the property page enforces that minimum. Tooth Height is the only property that accepts negative values. If the build raises an error, the shape catches it and the property page shows the red warning "Warning: Cannot build shape from these parameters". The code does not enforce the limits below, so keep to them:

•With a negative Tooth Height, keep its size less than Height. If the notches reach the bottom edge the outline crosses itself and is not a valid part.

•Tooth Flat may be larger than Tooth Width, which gives teeth that are wider at the tip than at the base (dovetail form). Keep Tooth Flat less than Tooth Width + Gap, or the tips of neighbouring teeth overlap and the outline crosses itself.

•Num. of teeth = 0 gives a plain rectangle, Left Shoulder + Right Shoulder long and Height deep. This rectangle is built above the insert point (Y = 0 to Y = Height), not below it as the toothed bar is, so the part moves when the tooth count is changed to or from 0. The tooth dimensions are still drawn.

•Height = 0 gives no bar, only the row of teeth closed along a single line; this is not a valid part.

Every 2D shape also has the Transform properties (Base X, Base Y, Rotation, Scale, Mirroring X) and the Polar Array properties, listed after the shape's own properties on the property page.