ART
BEAUTY & WELLNESS
CRAFT
CULTURE & HISTORY
ENTERTAINMENT
ENVIRONMENT
FOOD & DRINKS
REVERSE ENGINEERING
SCIENCES
SPORTS
TECHNOLOGY
WEARABLES
Sprocket for 1/2-Inch Chain, Cut by Hand from Steel Plate
A sprocket is a toothed wheel that drives a roller chain. Bicycle chain has a 1/2 inch (12.7 mm) pitch, the distance between pin centres (Wikipedia, Bicycle chain), so the teeth are spaced one pitch apart round a pitch circle whose size follows from the number of teeth. This one is cut by hand from steel plate: a hole at each pitch point for the roller, then the teeth sawn and filed between them. Method and sizes are ours.
The picture: our drawing.
Intermediate
1 day
Instructions
1
1
Lay out the pitch circle
Lay out the pitch circle
Work out the pitch-circle diameter for your number of teeth in the notebook (18 teeth: 73.1 mm). On 3 mm mild steel plate, scribe that circle and the outside circle a few millimetres larger, and step round the pitch circle with the dividers set to 12.7 mm, adjusting until the last step closes exactly. Punch each point.
Materials for this step:
Mild Steel Plate1 pieceTools needed:
Dividers
Scriber
Center Punch
Cross Peen Hammer
Digital Caliper 6-Inch2
2
Drill the roller seats
Drill the roller seats
Measure a roller on your chain and drill a hole of that size at every punched point; these become the bottoms of the tooth spaces. Drill the centre for the hub.
Tools needed:
Drill Press
Drill Bit SetDigital Caliper 6-Inch
Safety Glasses3
3
Cut out the teeth
Cut out the teeth
Saw round the outside circle, then saw in from the rim to each hole along two lines that open outward, and file the tooth flanks and tips smooth and rounded so the rollers can enter and leave.
Tools needed:
Hacksaw
Bench Vise
File Set4
4
Try the chain
Try the chain
Wrap the chain round half the sprocket: every roller should drop into a space without riding up. Ease any tight tooth with the file.
Tools needed:
Roller ChainFile Set5
5
Pitch circle
Pitch circle
Loading Jupyter Notebook...
Materials
1- 1 piecePlaceholder
Tools Required
12- Placeholder
- Placeholder
- Placeholder
- Placeholder
- Placeholder
- Placeholder
- Placeholder
- Placeholder
- Placeholder
- Placeholder
- Placeholder
- Placeholder
This blueprint makes
Related Blueprints
These blueprints share knowledge with this one — techniques, materials, or principles that connect them in the learning graph.
CC0 Public Domain
This blueprint is released under CC0. You are free to copy, modify, distribute, and use this work for any purpose, without asking permission.
Support the Maker by purchasing products through their Blueprint where they earn a Maker Commission set by Vendors, or create a new iteration of this Blueprint and include it as a connection in your own Blueprint to share revenue.