Instructions

ArrowTime Chrono 

Initial setup: 

The first time you download ArrowTime Chrono, you’ll be prompted to approve microphone use, enter your first bow’s name and its brace height and your draw length for that bow. You’ll also be prompted to give a name and length of your first arrows. Whatever your first bow’s draw length is becomes your default draw length for other bows you may shoot.  You can change this default later in settings. Different bows may have different draw lengths and you can set them per bow. 

Brace height:

Brace height is the distance from the string at your nocking point, to the handle where your hand contacts the bow. Usually brace height is measured at the top of the grip or the furthest point your hand touches the bow. Brace height is different for each bow. In ArrowTime Chrono, you can adjust the brace height per bow in “Manage Bows + Arrows”  Compound bows typically have one brace height that is not adjustable, and you can find it in the specs of that bow online. Recurve bows typically have a recommended brace height, but it is up to the archer to check and set the brace height by twisting and untwisting the string to shorten and lengthen it. The longer the string, the shorter the brace height.

A bow + an arrow + a draw weight is a combo. If you do not know your draw weight, skip it. Then your combo will just be your bow + your arrows. If you only have 1 bow and 1 arrow, the choice is easy. These will be shown in the bow and arrow pickers on the home screen, and you can go straight to ‘shoot’ from the home screen.

If you have multiple bows and multiple arrows to choose from, select your combo correctly. The functions of the app are dependent on your chosen combo. The shooting data collected by ArrowTime will be attributed to that combo. You want your shooting data to match up so that your Distance Curve is accurate and useful. 

Shoot screen:

Set the distance to the target distance for this group. Knowing your shooting distance and standing at that distance, with the ball of your lead foot on the shooting line, are critical to the function of ArrowTime Chrono. Using a range finder is a viable approach to knowing your distance from the target. Being at a range with marked distances is another. A third approach is to own a long measuring tape. Measuring tapes for construction are typically only 25’ but are available out to 100’ or 330’ or further. 

Which distance should you prioritize / shoot first?

Many Compound Bow sighting systems advise you to sight in 20 yards first. If your goal is developing a sight tape, 20 yards is an important first distance to shoot in ArrowTime. 

For recurve shooters, 20 yards may not be a viable first distance because your skill level isn’t there yet. Try 15 and 10 yards first.

         ** ArrowTime Chrono has inherent limitations on precision when shooting at short distances. Small variations in where you are standing relative to the shooting line, as well as whether you lean slightly forward or slightly back when shooting, will impact the distance your arrow has to go, and thus the reported speeds. Try to stand the same way when you shoot. Be mindful of leaning forward or back. Be mindful of putting the ball of your foot on the shooting line. Double check the shooting line with a tape measure or range finder. 

The app itself also has variation in how it picks the release (the moment the arrow leaves your bow.) The further back you shoot, the less these small variations matter, because your arrow has more time in flight to make them inconsequential. In practical terms distances less than 20 yards on compound bows and distances less than 10-15 yards on recurve bows may have a wider spread. You should not take the results of any one group to be your definitive speed, but instead accept that speed results, especially at short distances, will be a cluster. The Distance Curve smooths out the variations for you, removing outliers, and making the data understandable!

Shoot a whole group of arrows (often called an ‘end’ in archery) from the same spot. Ends are called “groups” in ArrowTime. A group can be any number of arrows. It may be helpful at the beginning or in certain sessions to shoot the same number of arrows in each group. That way if you look back at your groups and see that they each reported the same number of shots, you’ll know that every shot picked up and the app was functioning properly. But if one of the groups has 4 shots, but the others have 6 shots, you’ll know that one of the groups had 2 missing shots.

ArrowTime Chrono calculates time-to-target and speed using the distance you entered and the shot timing it hears. If you stand closer or farther than the entered distance, the displayed speed will change. If you stand in front of the shooting line, but do not change the distance, your shots will read faster than they are. If you stand behind the shooting line, your shots will read slower than they actually are.

Phone placement: 

Phone height should be at the level of the bow. Phone placement is important to timing but less so than the archer’s distance from the target. There are two options for phone placement: front and side. 

Front means 8-10” forward of your bow when at full draw. This would be helpful if you are using ArrowTime Chrono in addition to a traditional chrono, where you have to shoot over it / through it.

Side is the preferred position for ArrowTime because your phone will not be in your field of vision when you shoot. Side means arm’s length over the shooting line. Arm’s length means you can easily reach out to arm and stop your shooting sessions, or to swipe away a bad shot.

Moving the phone during a group can change the sound timing and make later shots harder to compare with earlier shots.

Before shooting, choose an ambient environment.

The best environment for ArrowTime Chrono would be a quiet environment where only the sounds of your archery are heard. If you are fortunate enough to have an environment like this, choose ‘quiet’ in shoot mode. Quiet mode has no noise cancellation so there is no chance of any of your shots being cancelled. 

For real world conditions, use either Normal or Windy mode as these modes have noise cancellation that will reduce the number of false shots. False shots are shots that register before or after your actual shots are caused by sounds in the environment, not by your shooting.

In Shoot screen before hitting arm you can see what ArrowTime thinks of your ambient environment. Your mic meter moving up and down is the cue that the mic is working. If you see a noisy or very noisy rating, that would be an indication to choose normal or windy, not quiet.

ArrowTime reduces false shots by learning patterns of your shooting, then using those patterns to ignore sounds that do not line up with the likely timing of your archery sounds. Early on, noise rejection relies more on broad estimates. After you’ve recorded some clean groups, ArrowTime can make better and better timing predictions, so in the same conditions the app can usually reject more false shots while still keeping real shots.

Hit Arm before shooting. 

Tapping Arm means the app will begin to listen and register shots. Hitting stop doesn’t end the group, it is more of a pause button that allows you to continue the group if you want to, or hit done if you are done, 

Importance of shots 1 and 2 for in-group noise cancellation. 

The first two shots of any group help ArrowTime learn the likely speeds of arrows in that group. The first two accepted shots are as important to noise cancellation as all of your historical data; they help ArrowTime confirm the timing for this specific group. If a false shot happens in the first 2 shots, you must reject it or swipe it away to avoid the rest of your group being impacted by the wrong read.

Expected speed is a guide for noise cancellation. 

Expected speed, shown next to the distance on the shoot screen, is ArrowTime's best guess for when the impact sounds will arrive. The plus/minus value shows how much uncertainty ArrowTime is allowing around its guess. A high amount of uncertainty is about +- 25% of the expected speed. For a 250fps shot that would mean +- 62fps. The expected speed is only used for noise cancellation. A wider plus/minus next to your expected fps is normal when the distance curve is jittery or when ArrowTime has not yet learned this combo. Expected speed doesn’t affect the speeds. It affects where ArrowTime looks for your shot to arrive. 

Noise cancellation can be increased or decreased.

Next to Normal and Windy you will see a number, that defaults to 5. 
If you are getting lots of false shots, you can increase the amount of noise cancellation by holding down “normal” or “windy” then picking a higher number. The higher the number, the more noise cancellation.

After you shoot, you will notice two small dots for Release and Impact . If they both turn green, you’ll also see a shot with a speed in your shot list. If release is heard but impact is not, you’ll see an empty or red dot for impact. 

If your shots are not registering, try to notice the behavior of the dots, as these will inform how to tweak the settings.

What to do if your shots aren’t registering. 

1. Switch to quiet mode. There’s a chance that noise cancellation is hurting, not helping. You will know this is the case if you switch to Quiet mode and try again. 

2. Increase “Release Gain” in settings.  Your bow may be too quiet to register. You can change the amount of gain. Default gain is 0. Try increasing it 2db at a time until you get better results.

What to do if you’re getting too much trash (false shots). 

1. Increase noise cancellation in Normal or Windy mode by long-holding the button and picking a higher number.

2. Decrease “Release Gain” in settings by 2db at a time until your ArrowTime is more stable. 

Review your group after shooting

When you are “Armed” you will see a red “Stop” button on your shoot screen. This means new real shots can get logged and new false shots can also occur. Hit Stop to pause your shooting and review your shots. If you like the group, you can save it to your distance curve by hitting “Done”. If you do not hit Done, the group will not get saved to your longer-term shooting history. The only reason not to hit Done is if you think your shots were executed incorrectly, you were standing at the wrong distance, or the app got them wrong. If the app got 1 or 2 shots wrong but the rest are fine, you should delete the weird shots and save the good ones, so that your ‘Distance Curve’ gets more and more data. 

From the ‘Done’ screen (Group Review) you can see the stats on your group. Hit ‘back’ to do another group. Shoot more groups at the same distance or different distances, remembering to verify on each group if you are at the correct distance.