Straight sections are forgiving. Curves are not. A product that runs perfectly on a straight chain plate conveyor can jam at the first curve if the slat width, radius or guide arrangement is wrong. These are the details to settle at the drawing stage.
Key takeaways
- The curve radius should be at least 2.5 times the conveyor width for standard slats.
- Slat width and pitch must allow the chain to articulate without binding.
- Guide rails should guide the product, not clamp it.
- Curves increase chain tension; size the drive for the worst combination of curves and load.
Radius and conveyor width
A curve that is too tight forces the chain to articulate beyond its design angle. The result is high friction, rapid wear and a tendency to jump the sprocket. As a working rule, keep the centreline radius at 2.5–3 times the conveyor width. A 600 mm wide conveyor should have a radius of at least 1,500 mm.
If the layout cannot accommodate that radius, use a transfer instead of a curve: two straight conveyors at an angle, with a powered or gravity transfer between them. A transfer is often cheaper than a custom curve and easier to maintain.
Slat geometry on a curve
Straight slats on a curve create a fan shape: the inside edges touch and the outside edges open. If the slats are too wide, they bind on the inside. If they are too narrow, the gaps on the outside become large enough to trap small products. The slat width should be selected with the curve radius in mind, and the gap between slats should not exceed one-third of the smallest product dimension.
For tight curves, use a tapered slat or a segmented slat. A tapered slat follows the curve with a constant gap. A segmented slat uses small plates that articulate individually. Both cost more than straight slats, but they avoid the jam that stops the line.
| Conveyor width | Minimum radius | Slat type | Typical product |
|---|---|---|---|
| 400 mm | 1,000 mm | Straight, 80 mm pitch | Small components in fixtures |
| 600 mm | 1,500 mm | Straight or tapered | Medium castings, housings |
| 800 mm | 2,000 mm | Tapered | Large parts, pallets |
| 1,000 mm | 2,500 mm | Tapered or segmented | Heavy assemblies |
Guide rails and product orientation
Guide rails keep the product on the conveyor and absorb the side load created by the curve. They should be smooth, adjustable and positioned so that the product is guided rather than squeezed. A rail that is too tight increases friction and can tip a tall product; a rail that is too loose lets the product drift and jam at the curve exit.
For tall or top-heavy products, lower the centre of gravity or add a top guide. A top guide is a rail above the product that prevents tipping without clamping the sides. It is common on curve sections handling tall castings or housings.
Transitions between conveyors
At a transition, the product must cross from one conveyor to the next without catching, tipping or falling. The gap should be no more than one-third of the product length, and the two surfaces should be at the same height within 1 mm. A small height difference is enough to catch a leading edge.
For heavy products, use a transfer plate or a powered transfer roller. For products that must maintain orientation, use a comb transfer or a nose bar. The transfer type should be chosen with the product's leading edge and centre of gravity in mind.
Drive load on curves
Each curve adds friction. The chain is pulled against the guide, and the effective tension increases. A conveyor with two 90° curves can require 30–50% more drive torque than the same length of straight conveyor. Calculate the tension at each section and select the drive for the maximum, not the average.
If the conveyor has multiple curves and a long straight run, consider a split drive. Two smaller drives are often cheaper than one oversized drive and a heavy chain, and they provide redundancy if one section stops.
Frequently asked questions
Can I use a curve on a gravity chain plate conveyor?
Only with a sufficient slope and a product that can tolerate the additional friction. Most gravity chain plate conveyors are straight; curves are usually powered.
How do I stop products from falling off at a curve?
Use a guide rail on the outside of the curve and a lower speed. If the product is tall, add a top guide. Check that the rail is smooth and that the product does not climb the rail.
What is the maximum number of curves on one conveyor?
There is no fixed number, but each curve adds load and wear. More than three or four curves usually justifies a split drive or a different layout.
Send the layout and product drawing to our engineers through the contact page; we will check the curve geometry and the drive load before quoting. The chain plate conveyor section covers straight and curved configurations.
