Roll-Off-Roof 1 Meter Gear Rack
Roll-off roof rack for DDA drive systems. Galvanized steel, Module 4 pitch, includes mounting hardware. Measure your roof travel and order that many meters.
The Rack That Moves Your Roof
The Roll-Off Roof 1 Meter Gear Rack is a galvanized steel rack designed to mesh with our Drive Gear and move your observatory roof. It's the same Module 4 rack used in gate opener systems-proven technology repurposed for observatories. Each 1-meter section includes standoffs and mounting hardware. Measure your roof travel, order that many meters, and you've got the track your drive system needs.
Why Buy It From Us?
Let's be direct: this is a commodity part. You could source Module 4 rack from Topens, Amazon, or a gate opener supplier. We offer it for one reason-convenience. When you're building a DDA drive system with our motor, gear, and mounting bracket, you can add the rack to your order and know it's compatible. No researching pitch specifications, no hoping the teeth mesh correctly with our gear.
About 50 of these racks are installed on DDA observatory systems right now. The oldest installations have been running for four years. The galvanized coating holds up to outdoor conditions, the teeth mesh smoothly with our 17-tooth drive gear, and the tall tooth profile makes alignment forgiving during installation. It's steel with holes and teeth. It works.
Key Benefits
Guaranteed Compatibility
This rack is Module 4 pitch-the same standard used by our Drive Gear. No guesswork about whether it will mesh correctly. If you're buying our motor and gear, this rack fits the system.
Galvanized for Outdoor Use
The galvanized steel construction handles the temperature swings, humidity, and exposure that come with an unheated roll-off roof observatory. Gate opener manufacturers designed this for years of outdoor service; your observatory is well within its capabilities.
Tall Teeth for Easier Alignment
The tooth profile on this rack is taller than some alternatives, which makes alignment more forgiving during installation. You don't need perfect precision to get a smooth mesh with the drive gear-the geometry works in your favor.
Simple Mounting with Included Hardware
Each 1-meter section comes with three standoffs and mounting bolts. The standoffs lift the rack off your mounting surface to provide clearance for the drive gear. Mount to wood framing or metal angle iron-both work well.
What's Included
- 1 Meter Gear Rack (galvanized steel, Module 4 pitch, 8mm wide)
- Standoffs (×3)
- Mounting bolts
Technical Specifications
| Specification | Value |
|---|---|
| Length | 1 meter (39.4") |
| Module | 4 (meshes with DDA Drive Gear) |
| Width | 8mm |
| Material | Galvanized steel |
| Mounting | 3 standoffs with bolts included |
| Rack Compatibility | DDA Drive Gear, Topens, other Module 4 gears |
Integration/Compatibility
The Roll-Off Roof 1 Meter Gear Rack works with:
- DDA Drive Gear - Module 4 pitch for proper mesh
- DDA 600W Roll-Off Roof Motor - Complete drive system when paired with gear and bracket
- Topens Gate Opener Systems - Standard Module 4 compatibility
- Other Module 4 Gears - Any gear with matching pitch
For a complete drive system, you'll also need the motor, drive gear, and motor mounting bracket. The rack is the track; the gear is what engages it.
Installation/Setup Reality Check
Installing a full run of rack takes 1-2 hours, including planning, mounting, and meshing with your motor and gear.
Time required: 1-2 hours for a typical 3-4 meter installation
Tools needed: Drill with appropriate bits, socket set or wrenches for mounting bolts
Skill level: Moderate-you should be comfortable with power tools and basic mechanical assembly
Mounting surfaces: We've mounted these successfully to 2×4 wood framing and 1/8" angle iron. Both work well.
Pro tip: When joining multiple rack sections, clamp a spare piece across the joint on the back side to ensure the teeth stay aligned while you secure the mounting bolts. The tall teeth are forgiving, but this trick makes alignment foolproof.
What You Need to Provide
From Dark Dragons Astronomy (sold separately):
- 600W Roll-Off Roof Motor - The motor that drives the system
- Drive Gear - Meshes with the rack to move your roof
- Motor Mounting Bracket - Secure mounting for the motor
You'll also need:
- Drill and appropriate bits for your mounting surface
- Socket set or wrenches for the mounting bolts
- Measurement of your roof travel distance (to determine how many meters of rack you need)
How Much Rack Do You Need?
Measure the distance your roof travels from fully closed to fully open. That's how much rack you need-round up to the nearest meter to ensure full coverage. Most hobbyist observatories need 3-5 meters of rack depending on roof size.
Real-World Performance
About 50 of these racks are installed across DDA observatory systems, with the oldest running for four years. They're handling the job they were designed for: providing a reliable track for the drive gear to engage, cycle after cycle.
The galvanized coating has held up well across installations in various climates. This is proven gate opener technology-designed for outdoor exposure and thousands of cycles per year. An observatory roof that opens and closes a few times per night is light duty by comparison.
Complete Your Drive System
The Roll-Off Roof 1 Meter Gear Rack is the track that makes your drive system work. Pair it with our 600W motor, drive gear, and motor mounting bracket for a complete, tested setup-or use it with compatible Module 4 components you already have.
Could you source this rack elsewhere? Sure. But if you're already buying the rest of your drive system from us, adding the rack means one order, guaranteed compatibility, and no time spent researching specifications.
Measure your roof travel. Order that many meters. Install and go.
Need help? Join our Discord community for installation guides, troubleshooting, and direct support.