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Chain sprocket

Cut a sprocket that the chain sits in rather than climbs over.

1

Pick the chain you have. Its pitch and roller size decide everything else.

2

The roller seats sit on the pitch circle, which is what stops the chain riding up.

3

Add a little seat clearance so the chain drops in rather than being pressed in.

Every setting

5

What each number in the dialog means, and where it starts.

Chain

The chain it has to run.

One of: 04C / #25 (6.35 mm), 06C / #35 (9.525 mm), 41 (12.7 mm), 08A / #40 (12.7 mm), 10A / #50 (15.875 mm), 12A / #60 (19.05 mm), 05B (8 mm), 06B (9.525 mm), 08B (12.7 mm)
Teeth

Fewer than about 12 makes the chain run rough.

Starts at 16 · 8 to 120
Seat clearance

Added to each roller seat so the chain drops in.

Starts at 0.1 · 0 to 1
Bore

Centre hole. Zero leaves it solid.

Starts at 8 · 0 to 200
Smoothness

Points around each roller seat.

Starts at 10 · 4 to 40

What it is

Draws a chain sprocket for a standard chain size, with the roller seats on the pitch circle so the chain sits rather than climbs.

Near this one

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