Gravity Conveyor Component Selection
Working from the product being conveyed back to the roller, the end cap and the shaft, so an unpowered lane carries its load without breaking bearings.
Gravity lanes fail at the end cap long before the tube gives up, usually because the load per roller and the impact of loading were never calculated.
Step by Step
Define the Load
Problem: Buyers quote total product weight rather than load per roller
How it is handled: Load per roller is calculated from the product bottom type, hard bottoms dividing weight by two and flexible bottoms dividing by the rollers in contact minus one
Apply Loading Impact
Problem: A pallet placed by forklift or crane loads a roller far harder than the static weight suggests
How it is handled: The calculated load is multiplied by an impact coefficient from 1 for no impact up to 3 for loading from the shoulder
Fix Tube and Shaft
Problem: Replacement rollers arrive that do not fit the existing frame
How it is handled: Tube outside diameter, wall thickness and shaft diameter are confirmed first, for example a 30mm tube with 1.5mm or 1.8mm wall and an 8mm shaft
Choose the End Cap
Problem: Plastic and metal housings are treated as interchangeable when they are not
How it is handled: Metal MTR housings are selected where calculated load or impact is higher and plastic or KTR housings where load is lower
Decide the Lane Layout
Problem: A single track lane is specified where the load needs more support
How it is handled: A double track roller conveyor increases supporting rollers and carries 1.5 to 1.8 times the normal weight, normally with a pallet
Gravity Conveyor Component Selection Questions
How do I calculate load per roller?
For a hard bottomed product divide the weight of one product by two. For a flexible bottomed product divide it by the number of rollers actually in contact minus one.
What impact coefficient applies to forklift loading?
Use 1.5 to 2 for a forklift, 1.5 for slow loading by hand, 2 to 3 for a hoist or crane and 3 for loading from a person's shoulder.
When should I use metal end caps instead of plastic?
Where the calculated load per roller or the impact load is higher than a plastic housing is intended to carry.
What dimensions do you need to quote replacement rollers?
Tube outside diameter, tube wall thickness and shaft diameter, plus the roller length and the quantity.
Does a double track conveyor carry more?
Yes, because the number of supporting rollers increases it can carry 1.5 to 1.8 times the normal weight, normally with a pallet.
Work Through Gravity Conveyor Component Selection With Us
Send the figures you already have and the missing ones will be worked out together before a model is chosen.