Turntable Traction Drive Project

Design Render

This is my design for a Turntable Traction Drive. It's meant to turn a large theatrical turntable covered in sets and actors in a safe reliable way. It can be built for less than $3000 USD.

I was inspired to take on this project by Alan Hendrickson's chain-driven design featured in Technical Designs Solutions for Theatre Volume 2 (Sammler/Harvey 2002). His design shows how a chain drive can rotate a turntable. I was interested in designing an easier-to-integrate "bolt-on" solution.

Feel free to make your own or iterate on this in any way permitted by the license! If you do happen to build one, send me a picture, I'd love to share it!

This project has a website.

Critical Documents

Document Name Description
Safety and Liability Discussion of the drive and safety factors associated with its use.
Design Document Discussion of design and considerations made.
Parts Sourcing Guide Instructions on how to buy the right parts to build your own Turntable Traction Drive.
Assembly Guide Instructions on how to build your own Turntable Traction Drive.
Integration Guide Instructions for Technical Directors on how to integrate this machine into your set desgin.
Operation Guide Instructions for Technical Directors on how to operate this machine.
Bill Of Materials A list of the parts required to build this machine.
Wiring Guide Instructions for wiring up the VFD, Control Pendant, and Emergency-Stop.
Custom Parts Overview A one-page PDF helpful when ordering custom cut steel.
Creative Commons Attribution 4.0 International The license under-which these plans are made available.

Checklists

Document Name Description
Integration Checklist A list of integration requirements for safe scenic integration of the Turntable Traction Drive.
Operations Checklist A "preshow" checklist to verify before each use of the Turntable Traction Drive.

Part Files

Part Description
Chassis Parts 2D CAD drawings of chassis parts to be cut from 1/4" mild steel.
Safety Placard A PDF to be made into a printable label and applied to the top of the chassis.

Media

Turntable Traction Drive Specifications

Traction Drive Feature Detail
Design Units INCHES
Height 9.875"
Width 32.875"
Depth 33"
Chassis Weight ~112 Lbs
Total Weight ~228 Lbs
Number of Parts 63
Minimum Turntable Size 6' Diameter
Maximum Turntable Size Proven on a 23' diameter Turntable with steel and wood scenery.

Powerplant Details

My motor decision was based on what I had lying around. You may easily sub in your own motor, but for simplicity of integration try to pick a motor matching NEMA Frame 145TC. Otherwise you may have to drill new holes in the Base Plate and Motor Gusset.

Powerplant Feature Detail
Model General Electric 2HP TEFC (5KE48WN8167)
Speed 1725 RPM at 60Hz
Layout NEMA Frame 145TC
Gearhead Morse 175Q140LR5
Gearhead Ratio 5:1

Control Details

In order to vary the speed of drive motor we must use a Variable Frequency Drive (VFD). The VFD will be responsible for managing the speed and acceleration of the traction drive.

VFD for 3 Phase Power (208 VAC)

In our environment we have easy and plentiful access to 3phase 208v. For this reason we have selected a 3phase input VFD. If you have access to 3 phase power you can benfit from our integration notes throughout this documentation.

VFD Feature Detail
Model Automation Direct DURA Pulse (GS23-22P0)
Input Power 230V 3-Phase (208 is fine)
Output Power 1.5 KW (2 HP)
Output Range 0 - 600Hz
Safe Torque Off (STO) Yes

VFD for Single Phase (120 VAC)

Our initial testing was performed on a .75 KW 120V VFD. We were able to easily turn the 23' turntable using just a single wall outlet.

VFD Feature Detail
Model Hitachi L-100 (L100-007NFU)
Input Power 120VAC 15A
Output Power 0.75 KW (1 HP)
Output Range 0 - 360Hz
Safe Torque Off (STO) No

We decided to replace this VFD for two reasons: