Introduction

Welcome to the RockTimer documentation. RockTimer is Curlvation's precision stone timing system designed for competitive and recreational curling alike. By accurately timing a stone's travel from the hog line, RockTimer provides skip, vice, and sweepers the data they need to make informed decisions in real time — before the stone crosses the far hog line.

This document is intended for players, coaches, and ice technicians who will be setting up, operating, or maintaining RockTimer units at their curling club or arena.

Product Overview

RockTimer measures the time a curling stone takes to travel a defined distance down the sheet. This elapsed time — commonly called the "split time" — is a reliable indicator of stone velocity, which directly predicts where the stone will come to rest and whether sweeping can meaningfully alter its path.

How Timing Translates to Decisions

Every ice surface has a characteristic speed, typically expressed in seconds for a stone to travel from hog line to hog line. RockTimer captures the split time and compares it to a calibrated reference, giving your team an immediate assessment:

The result is displayed immediately on the RockTimer unit (and optionally on a companion app), giving sweepers the window they need to act before it's too late.

Who Is RockTimer For?

• Competitive teams who want data-backed sweeping decisions to eliminate guesswork
• League and club players looking to improve their delivery consistency over time
• Coaches tracking delivery speed trends across practice sessions
• New curlers learning the connection between delivery weight and stone placement

What's in the Box

Each RockTimer unit ships with everything needed to get up and running on your ice sheet.

Quick Start Guide

Get RockTimer operational in under five minutes.

1. Charge the unit. Before first use, fully charge RockTimer via the included USB-C cable. A full charge takes approximately 90 minutes. The status LED will turn solid green when complete.

2. Mount the unit. Attach RockTimer to the side board at the near hog line position using the included mounting bracket. See Mounting & Placement for exact positioning guidance.

3. Power on. Press and hold the power button for 2 seconds. The display will briefly show the firmware version, then enter standby mode with the LED pulsing blue.

4. Calibrate for ice conditions. Using the calibration mode, input the known speed of your ice sheet (if available from your ice technician). This sets the reference time RockTimer uses for sweeping recommendations. See Calibration for details. (Coming soon)

5. Start timing. RockTimer will automatically detect stone delivery and begin timing when a stone crosses the trigger threshold. No manual start is needed during normal operation.

6. Read the result. The elapsed time and sweep recommendation will appear on the display within 1–2 seconds of stone detection. Sweep calls are color-coded by the LED indicator.

Hardware Overview

RockTimer is a compact, standalone device built to withstand the cold, humid environment of a curling facility. The unit features a built-in sensor array, an e-ink display for high-contrast readout under rink lighting, and a multi-color status LED visible from across the sheet.

Key Components

• Detection Sensor — Detects stone passage at the trigger point without physical contact
• High-Contrast Display — Shows elapsed time and recommendations, readable in all rink lighting conditions
• Status LED — Large RGB LED for at-a-glance sweep call visibility
• Power Button — Single multifunction button for power, calibration mode entry, and display reset
• USB-C Port — Charging and firmware update interface
• Internal Battery — Provides a full day of play (approximately 8 hours) on a single charge

Specifications

LED Indicators

The RockTimer status LED communicates device state and sweep recommendations at a glance. LED states are designed to be visible from the far end of the sheet under typical arena lighting.

Mounting & Placement

Correct placement of RockTimer is critical for accurate detection. The unit must be positioned so its sensor has a clear line of detection across the width of the sheet at the designated trigger point.

Recommended Position

• Mount on the side board at the near hog line, centered vertically on the board
• Sensor face should be oriented toward the centerline of the sheet
• Ensure no ice debris, snow spray, or equipment obstructs the detection path
• The mounting bracket allows ±15° of horizontal adjustment for alignment

Bracket Installation

1. Clean the side board surface at the mounting location with a dry cloth to remove ice residue.

2. Attach the mounting bracket to the board using the provided method for your facility's board type. (Board clip or adhesive pad — included in kit.)

3. Slide the RockTimer unit into the bracket until it clicks into the locked position.

4. Use the alignment adjustment to aim the sensor across the sheet. Verify detection by passing a stone (or similar object) slowly through the detection plane — the LED should flash white briefly.

Timing Basics

Understanding what RockTimer measures helps your team use the data effectively. The core measurement is a split time: the number of seconds a stone takes to travel from the detection point (hog line) to a secondary reference marker.

Split Time Reference

Ice speed is typically described in curling as the number of seconds from hog-to-hog. A "20-second ice" means a stone thrown with typical weight takes 20 seconds to travel from near hog to far hog. Your RockTimer is calibrated to your ice's target speed so that readings above or below the target translate directly into sweep recommendations.

These thresholds are configurable via the companion app and calibration mode to match your team's preferences and your ice conditions.

Reading Results

After each delivery, RockTimer's display shows the timing result and the LED transitions to the appropriate sweep call color. Results remain on screen until the next stone is detected or the display is manually reset.

Display Layout

The display shows three pieces of information after each delivery:

• Elapsed Time — The raw split time in seconds and tenths (e.g., 20.4s)
• Delta — How far the reading deviates from the calibrated target (e.g., +0.4 or −1.2)
• Recommendation — A plain-language call: SWEEP, HARD, EASE, or OK

Sweeping Decision Guide

RockTimer is a decision-support tool — the skip retains final authority on sweeping calls. This guide helps teams understand how to integrate RockTimer data into standard sweeping communication.

Communication Protocol

We recommend establishing a simple call protocol your team agrees on before the game:

1. Timer reader (vice or designated player) calls out the RockTimer result immediately after the LED changes: e.g., "Hard!" or "Off!" using the LED color as shorthand.

2. Sweepers react to the call as they would any verbal sweep call — RockTimer's output replaces or supplements the skip's initial read.

3. Skip confirms or overrides based on line (curl) considerations. RockTimer informs on weight, not line — the skip still reads break and calls for sweeping adjustments as needed.

What RockTimer Does Not Replace

• The skip's read of curl and line — RockTimer measures weight only
• Sweeper judgment on brush technique and pressure
• Ice knowledge and experience — know your sheet's quirks