Pinion Gear BYO Upgrade 15 tooth 14.5°PA 10 pitch

Upgrade to DragonLAIR Without Replacing Your Rack

The BYO Upgrade Pinion Gear lets Backyard Observatories customers upgrade to DragonLAIR automation while keeping their existing rack system in place. We've modified a proven industrial gear to fit our 600W motor and mesh with standard BYO racks-so you get reliable automation without tearing out infrastructure that's already working.

Why This Gear?

If you built your observatory with a Backyard Observatories kit, you've got a rack system already installed and functioning. Upgrading to DragonLAIR automation shouldn't mean ripping that out and starting over with new rack-that's unnecessary cost, time, and hassle.

The problem: our standard drive gear uses Module 4 pitch, which doesn't mesh with BYO's 10 diametral pitch / 14.5° pressure angle rack. Different tooth profiles, different standards. You can't just swap motors and expect things to work.

We solved this by sourcing the Martin S1015-an industrial spur gear designed for commercial power transmission applications-and modifying it for observatory use. We drill a 5/16" hole through the hub and provide a bolt and nut for secure mounting to our 600W motor shaft. The gear's 3/4" bore fits the motor perfectly, and the tooth profile meshes correctly with BYO rack.

This is a convenience part. You could research gear specifications, hunt down a compatible gear, and figure out how to mount it yourself. Or you can order this, know it works, and spend your time imaging instead.

Key Benefits

Drop-In Compatibility with BYO Systems

The 10 diametral pitch and 14.5° pressure angle match BYO rack specifications. Your existing rack stays in place-you're only replacing the motor and adding DragonLAIR control. That's a weekend project instead of a major renovation.

Fits Our 600W Motor Directly

The 3/4" bore matches the output shaft on our 600W Roll-Off Roof Motor. The 5/16" mounting hole aligns with the existing hole in the motor shaft. Slide it on, insert the bolt, tighten the nut, and you're done.

Martin Industrial Quality

The Martin S1015 is a commercial-grade spur gear used in construction equipment, conveyors, and manufacturing systems-applications where reliability isn't optional. High carbon steel construction handles torque and wear. Moving your observatory roof a few times a night is light duty compared to what this gear was designed for.

Simple, Secure Mounting

The bolt-through-shaft mounting is straightforward and solid. The bolt passes through the drilled hub and the motor shaft's existing hole, secured with a nut. No press-fit pins, no special tools, no hoping things stay aligned.

What's Included

• BYO Upgrade Pinion Gear (modified Martin S1015 with 5/16" hole drilled through hub)
• 5/16" bolt and nut for shaft mounting

Technical Specifications

Integration/Compatibility

The BYO Upgrade Pinion Gear works with:

• DDA 600W Roll-Off Roof Motor - Direct fit to the 3/4" output shaft
• BYO (Backyard Observatories) rack systems - Primary use case; confirmed mesh with standard BYO rack
• Other 10 DP / 14.5° PA racks - Should work with any rack matching these specifications

For a complete DragonLAIR upgrade, you'll also need our 600W motor, motor mounting bracket, and DragonLAIR controller. Your existing BYO rack stays in place.

Installation/Setup Reality Check

Installing the gear itself takes 5 minutes or less. The full BYO-to-DragonLAIR upgrade-replacing the motor, installing the mounting bracket, wiring the controller-is more involved, but this part of the job is simple.

Time required: 5 minutes (gear installation only)

Tools needed: Wrench or socket for the 5/16" bolt and nut

Skill level: Beginner-if you can tighten a bolt, you can install this gear

Process: Slide the gear onto the motor's 3/4" shaft, align the hole in the hub with the hole in the motor shaft, insert the bolt, and tighten the nut. That's it.

What You Need to Provide

From Dark Dragons Astronomy (sold separately):

• 600W Roll-Off Roof Motor - The motor this gear is designed to fit
• Motor Mounting Bracket - Secure mounting for the motor
• DragonLAIR Controller - For automated roof control (or use a reversing relay for manual operation)

Already in place:

• BYO rack system - Your existing Backyard Observatories rack

Tools:

• Wrench or socket for the 5/16" bolt and nut

Real-World Performance

The Martin S1015 is a proven industrial component-the same gear is used in construction equipment, conveyor systems, and manufacturing applications where failure isn't an option. Martin has been manufacturing power transmission components for decades, and their spur gears are a standard choice for commercial applications.

We've modified the gear for observatory use with the drilled mounting hole and confirmed compatibility with both our 600W motor and BYO rack systems. The result is a drop-in solution that lets BYO owners upgrade to DragonLAIR automation without replacing their existing rack infrastructure.

Keep Your Rack. Upgrade Your Control.

You built your BYO observatory. The rack is installed, it works, and you don't want to tear it out. The BYO Upgrade Pinion Gear lets you upgrade to DragonLAIR automation-network control, weather safety, battery backup-while keeping the mechanical infrastructure you've already invested in.

We've done the research, sourced a compatible industrial gear, and modified it for our motor. Order it, install it, and get back to imaging.

Need help? Join our Discord community for installation guides, troubleshooting, and direct support.