How to choose parts and design shafts for a chain drive system

[thijs (Thijs Brilleman)]

Based on contributions by JuliusBotger.

Chain drives are a compact, strong and easy way to transfer rotational force, move parts of a machine, or pull products. This covers choosing compatible chain drive parts, building a matching shaft in Autodesk Inventor’s shaft generator, and working safely around a running chain.

What you need

• A supplier of standardized chain drive parts (this guide uses kettingtechniek.nl, a Dutch supplier, as an example)
• Autodesk Inventor, for designing a shaft
• Guarding material for the finished drive (sheet metal or similar)

Steps

1. Choose compatible chain drive parts

All the parts in a chain drive system must share the same size/standard — there are many incompatible sizes and norms to choose from.

1. Pick a chain size from your supplier’s datasheets, and note its product code (e.g. 06B-1).

   

2. Choose a sprocket with a keyway that matches your chain’s product code. To connect it to a motor, use a shaft with a keyway of the same size, so a key can be fitted between them and stop the sprocket rotating on the shaft.

   
   
   
   

3. If the chain needs to drive a second shaft, use another keyed sprocket there too. If you only need to tension the chain — or use it to pull something, or as a saw — use a freely-rotating idler gear instead, ideally one with a pre-fitted bearing, mounted so it can be moved to tension the chain and then locked in place.

   

Make sure every part you buy — chain, sprockets, idlers — shares the same product code, so the parts actually fit together.

2. Build a matching shaft with Inventor’s shaft generator

Rather than modeling a shaft by hand, use Inventor’s built-in shaft generator.

1. Work out your shaft’s dimensions first. Example: a shaft with a 15 mm diameter section that’s 134 mm long, and an 18 mm diameter section that’s 70 mm long.

2. Open your assembly and find the Shaft button under Design.

   

3. In the dialog, double-click the existing cylindrical section to set its dimensions, then click Add cylinder to add and dimension the second section.

   

4. Add keyway grooves: on the dropdown for the section that needs a groove, choose Keyway groove. Double-click the groove in the tree to choose the key type, and set its x position. Example: one groove for a 5 mm key on the long section, and two grooves for 6 mm keys on the shorter section.

   

5. Add any end features (chamfers, etc.) via the button in the section tree.

   

6. Click OK and place the shaft in your assembly.

   

Using the shaft generator also keeps features like keyway grooves, clip grooves and chamfers to standard dimensions.

3. Work safely around a chain drive

Chains are extremely strong, and dangerous when driven by a powerful motor — the teeth of the sprockets can destroy almost anything caught between them.

• Every chain-driven machine should have an emergency stop within reach, which overrides every other command. Press it whenever you work on the chain, and only release it once you’re sure nothing is near the mechanism.

  

• Identify the pinch points where the chain meets a sprocket — these are the areas where a hand can get caught if it slips.

  

• Fit hand guards — solid pieces of material that fully shield the pinch points, so a hand cannot reach the chain or sprocket teeth.

  

Keep these safety measures your first priority, and use common sense around any moving chain.

Related

• How to calculate motor power, RPM and torque for a conveyor belt — sizing the motor that drives the chain

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Rewritten and consolidated (Sept 2026) from the original student how-to’s: How to work with chain drive systems.