The Tool Desk
Outbyte Driver Updater FREEFix the driver behind crashes, sound loss and screen glitchesFind Drivers →Outbyte PC Repair FREERepair Windows errors before they cause bigger problemsFix Now →iTechGuides is reader-supported. When you buy through links on our site, we may earn an affiliate commission. As an Amazon Associate I earn from qualifying purchases. Learn more
A homebrew two-stage animatronic tentacle uses four cable-driven bending directions: each of its two stages bends along two perpendicular axes. In Sonya Vasquez’s 2016 Hackaday series, a flexible core supports the vertebrae, paired cables steer the stages, and a manual controller manages cable tension. The three posts cover the mechanism, controller, and assembly; the final installment includes fabrication files for readers who want to follow the design.
How does a two-stage tentacle mechanism work?
Each stage bends in two orthogonal directions, giving the two-stage design four bending degrees of freedom overall. Combining those movements produces a range of poses. The design describes the stages as independently controllable in principle, but friction and material behavior affect how they move in practice.
| # | Preview | Product | Price | |
|---|---|---|---|---|
| 1 |
|
Skullkrane Animatronic Repair Kit Pro - Repair Halloween and Christmas Animatronics! | $34.99 | Buy on Amazon |
The mechanism uses paired control cables. Turning a pulley pulls one cable while releasing its complement, bending the tentacle toward the shortened cable. Since a wire rope can pull but cannot push, complementary cables are needed to steer in opposite directions. A conduit constrains the cable route and resists compression; cable pre-tension and fixed terminations help the assembly hold a pose.
Outdated Drivers Are Slowing You Down
One free scan finds every outdated or missing driver and matches the right update for your exact hardware.Free scan · exact hardware matchWindows Errors? Fix Them Before They Spread
Repair common Windows errors and clear accumulated junk for a smoother, more stable PC - no reinstall needed.Free scan · no reinstallVasquez notes two important characteristics of this particular design: friction at the vertebrae keeps the tentacle from forming a perfect arc, and the core does not twist along its length. The no-twist choice suits the puppet-like motion the project targets; it is not a general requirement for every tentacle mechanism.
#1 Best Overall
- x25 8T gears
- x25 9T gears
- x25 10T gears
- x25 pulley gears
- x25 small rubber belts
What parts and materials does the project use?
The Hackaday guide presents these components as selections for its build, not universal specifications or current shopping recommendations. Check the original assembly files for dimensions and compatibility before sourcing parts.
| Part | Role in the mechanism | Build consideration |
|---|---|---|
| Automotive speedometer cable or flexible rotary-tool shaft | Flexible central core | Vasquez describes both as possible core materials. She observes that a larger flexible shaft may suit builds that would twist under their own weight with the cited 0.125-inch speedometer cable; this is a build observation, not a general performance rating. |
| Delrin (acetal) plates and hobby motor hubs | Vertebrae and mounting elements | The article describes adapting a hobby motor hub with an additional Delrin plate. Exact dimensions and material compatibility should be taken from the project files. |
| Flexible wire rope | Control cables | Wire rope carries tension, so paired lines are required for bidirectional bending. |
| Continuous-length extension spring | Flexible cable conduit, particularly for multistage routing | The spring provides a flexible path for cables passing through moving sections. The article names this type of spring and mentions custom spring fabricators for smaller dimensions; confirm size and availability directly with a supplier. |
Core selection depends on the scale and weight of the build as well as the available shaft diameter, bending flexibility, and resistance to twisting. The series does not provide controlled comparative test results, so it does not establish a universally best core. Fabrication choices also depend on the builder’s tools: the project emphasizes repeatable laser-cut and 3D-printed parts, while alternative vertebra materials such as wood may suit different goals and constraints.
What does each post in the series cover?
-
The Bootup Guide to Homebrew Two-Stage Tentacle Mechanisms (September 13, 2016) explains the two-stage mechanism, cable routing, and component choices.
Recommended: Crashes or Glitches? A Free Driver Scan Usually Finds the Culprit →Recommended: Fix Windows Errors and Clear Junk Files in Minutes - Free Scan →Special offer. See more information about Outbyte and uninstall instructions. Please review EULA and Privacy policy. -
Two-Stage Tentacle Mechanisms: The Cable Controller (October 5, 2016) focuses on manual hand controllers and managing cable tension.
-
Two-Stage Tentacle Mechanisms: Final Assembly (October 21, 2016) covers assembly and tuning and lists the supporting design files.
The final post lists a bill of materials, laser-cut vector drawings in pre-offset and original forms, STL models for 3D printing, and original CAD models for the tentacle and controller. Use those files—not a summary—to check dimensions and fit before fabrication. The series reflects a 2016 project; its material choices do not establish present-day stock, prices, or vendor availability.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.How should a builder approach the design?
-
Choose the motion and scale. Decide whether two bending stages and no axial twist fit the intended puppet or prop movement.
Do these 3 things before closing this tab:
1Repair Windows errors before they cause bigger problems2Fix the driver behind crashes, sound loss and screen glitches3Clear out junk files and repair common Windows errorsSpecial offer. See more information about Outbyte and uninstall instructions. Please review EULA and Privacy policy. -
Select a core and vertebra approach. Compare speedometer cable and flexible rotary-tool shafts for the intended size, then choose a fabrication method that matches available tools and the project files.
-
Plan paired cable routes. Each bending direction needs complementary cables, and multistage routing must remain flexible as sections move. Match conduit flexibility and dimensions to the cable path.
-
Build and tune the controller. The second post addresses manual control and cable tension; the final post covers assembly and tuning. Consult those instructions and the original drawings rather than inferring unlisted dimensions.
Vasquez frames the project around commonly available components and repeatable fabrication. She also points readers to a Stan Winston Tutorials lesson on cable mechanism basics, taught by Richard Landon; the 2016 article does not establish whether that lesson is currently available.
Quick wins for a faster PC:
Scan for outdated or missing drivers - takes under a minuteDriver Scan →Clear out junk files and repair common Windows errorsFree Scan →Fix the driver behind crashes, sound loss and screen glitchesFind Drivers →Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
