This chain tensioner can be used to address issues with chain hopping, chain slap, and rattles. It can be printed and assembled for less than $6, and offers equivalent perfomance to comercial products sold for $30.
Bill of Materials[edit | edit source]
- Tensioner.scad
- (2) ZipTies
- (1) 8-32 Thread, 1-1/4" Length Machine Screw (eg. McMasterCarr:91792A201)
- (1) 8-32 Thread Locknut (eg. McMasterCarr:91831a009)
Tools needed[edit | edit source]
- MOST Delta RepRap or similar RepRap 3-D printer
- Screwdriver
- Adjustable Wrench or Pliers
Skills and knowledge needed[edit | edit source]
- Ability to use a 3d printer.
- Ability to use a wrench and screwdriver.
Technical Specifications and Assembly Instructions[edit | edit source]
All parts are symetric such that component orientation is not an issue.
Assembly:
- Ziptie the cage to the Bicycle frame just above chain.
- Hold the chain up so it is captured in the cage.
- Bolt the pully in place
- gently crank the pedals by hand and shift throug all gears to ensure nothing is binding
Common Problems and Solutions[edit | edit source]
- If the fit to they bicycle is loose or overly tight the OpenScad variable "pipeDia" can be set to match your bike frame's tubing diameter.
Cost savings[edit | edit source]
- Approximatly $23.50 (78.3%)
- 30g of PLA at approx. $30/kg = $0.90
- Machine Screw, Locknut, and bag of zip ties approx $5.60 at local hardware store
- Equivalent Chain Tesnsioner: Bionicon C.GUIDE approx. $30
- 30 - (5.60 + 0.90) = $23.50