Draw Belt

Right-click the Layers table on the Chute Faces tabsheet and choose Draw Belt... to build a troughed conveyor belt run parametrically, instead of adding faces and vertices by hand. This is the quickest way to add a top belt, bottom belt, or any other troughed conveyor surface to a project.

the Layers table's right-click context menu showing Draw Belt... — The Draw Belt Input Form

Dimensions

The small letters beside the input boxes match the dimensions on this drawing.

Draw Belt dimension drawing: cross-sections for 3, 4 and 5-roll idlers, a side view of the transition and straight run, and a plan view of the plan view angle — Draw Belt dimensions

Letter	Input	What it measures
a	Centre Roll Length	The flat centre pan (3 and 5-roll). For 4-roll, the length of each of the two centre rolls.
b	Wing Roll Length	The wing roll next to the centre pan (3 and 5-roll; not used by 4-roll).
c	Trough Angle	That roll's angle up from horizontal (for 4-roll, the centre rolls' angle).
d	Outer Wing Roll Length	The outer wing roll (5-roll), or the wing roll (4-roll). Not used by 3-roll.
e	Outer Trough Angle	That outer roll's angle up from horizontal.
f	No of Transition Idlers	How many idlers the trough takes to develop from flat at the pulley to its full angle.
g	Transition Idler Spacing	The distance between transition idlers. The transition is f × g long, and level.
h	Straight Length L1	The fully troughed run beyond the transition, measured along the belt.
i	Transition Offset	How far the pulley top P sits above the troughed run. The run is drawn level this far below P, and the transition climbs up to P – see Elevated pulley transition.
j	Plan View Angle	The direction of belt travel in plan, counter-clockwise from +X.
P	X, Y, Z	The pulley top: the transition's flat end at the pulley, on the belt's centre line, at the belt's top surface. The same point Draw Discharge Head Box is placed by.

Idler Spacing has no letter. It is accepted for completeness but does not yet change the drawn belt – the straight run is drawn as one long panel per surface rather than one per idler set.

Cross-section

Choose the number of idler rolls (3, 4, or 5) and enter the roll lengths and trough angles for each tier. Belt width is derived automatically from the roll lengths you enter, independent of trough angle:

3-roll – a flat centre pan plus one wing tier on each side.
4-roll – no flat pan at all: two centre rolls meeting on the belt's own centreline, plus one wing tier on each side.
5-roll – a flat centre pan plus two wing tiers (inner and outer) on each side.

Transition zone

Enter the number of transition idlers and their spacing to build a short wedge near the pulley end where each wing's trough angle ramps up gradually from flat to its fully-developed angle, followed by one long straight run at the Straight Length L1 you enter.

Elevated pulley transition

As the belt goes from fully troughed to flat over the pulley, its edges are stretched more than its centre. To reduce that edge tension it is common practice to raise the pulley above the line of the troughing idlers' centre rolls – an elevated pulley transition, which CEMA calls a "half trough transition" and for which it recommends raising the pulley by half the trough depth.

Transition Offset (i) is that height. Draw Belt keeps the pulley top P where you place it, draws the troughed run level, the offset below P, and climbs the transition's centre line straight up from there to P while the wings flatten. It is suggested at half the trough depth and follows the roll lengths and trough angles until you type your own value. Enter 0 for a transition that stays level with the run. With no transition idlers there is nothing to climb along, and the offset is ignored.

Inclined conveyors. Draw Belt always draws the run level. For a conveyor that approaches the pulley up or down a slope, draw it level and then use Rotate Layer about the pulley to set its incline. (Draw Belt's earlier Approach Angle input, which inclined only the straight run, has been replaced by Transition Offset.)

Non-planar faces avoided automatically. Because a transition idler's wing angle is still ramping between one idler step and the next, its outer edge does not stay in the same plane as its inner (hinge) edge. Draw Belt builds each transition step as two triangular faces rather than a single 4-point quad, so every generated face is guaranteed planar – see Triangulate Face if you ever need to do the same split by hand on an existing face.

Placement and naming

Enter the belt's origin (X, Y, Z) and a plan rotation angle to position and orient the whole run in world space. Every generated face is placed into a new Layer named after the belt (e.g. "TopBelt"), with each face given a distinct, role-based name (e.g. "Wing Left 1", "Trans Wing Right 3") rather than sharing one generic name – useful when picking a specific face out afterward in the Faces table.

Faces are named using the belt-conveyor convention for Left/Right: as viewed facing the direction of material travel, not a raw world Y coordinate.

a drawn belt shown in the 3D view — A drawn Top belt shown in the 3D view

You can add as many belts as required. The images below show how to add a receiving belt located 7m below the top belt and at a 90 degree angle to the top belt. Note the location of the belt is X 1.25, Y 4.0 and Z -7.0. Therefore an offset of 1.25m in X direction and 4.0m in Y direction and 7.0m below the top belt and the Plan View Angle is 90 degrees. Both of the these belts were add as level belts but it is easy to add the belt and then rotate it about (say) the Y axis to get is inclined or declined.

a drawn bottom belt input form — A receiving belt input form example

The above input results in the image below.