A roller conveyor looks simple in a catalogue photo, but the drawing behind it decides whether cartons flow smoothly or jam at every transfer. This guide walks through the dimensions, layout notes and specification details that make a roller conveyor design work on a real production line.
Start with the load, not the frame
Record the smallest and largest item: footprint, weight, base material and how rigid the base is. A roller conveyor supports the load on a row of separated rollers, so a soft bag, a warped pallet or a very small part will not travel reliably. A working rule used in many layouts is that the smallest item should rest on at least three rollers at any point; if that is not possible, a belt conveyor is usually the better choice.
Also note the required rate in items per hour, whether product has to stop and queue, and the direction of travel at each interface. These details set roller pitch, drive type and whether the line needs separate zones.
Roller diameter, pitch and material
Common roller diameters are 38, 50, 60, 76 and 89 mm. Larger diameters carry heavier loads and roll over small imperfections more easily, while smaller diameters allow a tighter pitch for short cartons. Pitch is normally set so the smallest load spans three rollers, with a little margin for skew.
Galvanised steel suits dry carton handling; stainless steel is used where the line is washed down or exposed to moisture; rubber or PU lagging adds grip on inclines and on smooth plastic totes. Shaft type, bearing rating and end caps belong in the specification too, because they affect both service life and the spare parts you will order later.
Reading and drawing a roller conveyor diagram
A useful plan view shows overall length, effective width between side guides, working height at both ends, support leg positions, drive position and the direction of flow. Curves, merges, transfers and zone boundaries need their own callouts, as do stops, sensors, guards and emergency stop points. An elevation view helps where the line changes height or meets an existing machine.
Mark the power and control connection points on the same drawing. When a roller conveyor system links to a scanner, weigher, sealer or palletiser, the interface height and handover speed matter as much as the conveyor length. A dimensioned sketch from the buyer is normally enough for a manufacturer to return a layout drawing for approval.
Gravity slope and powered drive options
Gravity sections have no motor and rely on a slight fall or on an operator pushing the load. The slope needed depends on carton weight, roller condition and base rigidity, so it should be confirmed with a sample on site rather than taken from a table. Long gravity runs can lose too much height, which is where a powered section is inserted.
Powered rollers are commonly driven by chain, O-ring belts, a line shaft or 24 V motorised rollers. Chain and line shaft drives suit heavier loads; O-ring drives are quiet and simple to service; zoned motorised rollers allow zero-pressure accumulation and precise indexing. State the destination country voltage, frequency and phase so the drive and controls are built to match.
What belongs in a design PDF or specification sheet
Buyers often search for a roller conveyor design PDF. Rather than a generic download, the document that actually prevents mistakes is the specification sheet sent to suppliers: product dimensions and weight range, required throughput, floor plan with obstacles, working heights, incline or turning sections, environment (wet, dusty, food contact, washdown), frame and roller material, drive and control requirements, electrical standard, packing and container loading needs, and the destination port.
Include photographs of the product and the installation area. Ask for a dimensioned general arrangement drawing and a parts list before fabrication, then keep the approved version as the reference for spare rollers and future extensions.
From drawing to a working system
Once the layout is agreed, check leg spacing against floor flatness, allow access to the drive for maintenance, and confirm that side guides do not foul the product at curves. Plan how sections will be packed, labelled and assembled on arrival, especially for export orders shipped knocked down.
JINDA builds roller conveyors to the approved drawing and can supply matching rollers and spare parts against the same dimensions. Send your sketch and product details through the contact page to start a layout review.
