Support

For common support issues, check below. You may also reference the User Guide here or in the app. If you need additional help, please contact me at support@briffidi.com.

SW1 Common Issues

Most SW1 support questions are due to problems with calibration. I plan to improve the calibration process, but in the meantime, perhaps some of the explanation below will help.

Measurement Group Checks

Three measurement groups: This check verifies that there are at least three measurement groups. The calibration process only considers the three latest measurement groups. The latest groups are displayed at the top of the list of measurement groups on the Measure page.

Counts: 1 and 3 equal and not zero: This check verifies that, of the three measurement groups, the first and the last groups each contain the same number (count) of measurements. For a standard calibration, the first and last measurement groups should contain one measurement of the fully-collapsed rod.

Counts: 2 equal to sum of 1 and 3: This check verifies that, of the three measurement groups, the middle group contains twice as many measurements as each of the other groups. For a standard calibration, the middle group should contain two measurements of the fully-extended rod.

Periods: 1 and 3 are similar: This check verifies that the measurements (the periods of oscillation or the time required for one cycle of oscillation) in the first and third measurement groups are similar. For a standard calibration, these groups should both contain measurements of the fully-collapsed rod, so they should be similar.

Periods: 2 greater than 1 and 3: This check verifies that the measurements (the periods of oscillation or the time required for one cycle of oscillation) in the middle measurement group are greater than the other two. For a standard calibration, this group should contain measurements of the fully-extended rod, so the periods should be greater than those of the fully-collapsed rod. For a calibration rod with removable weight, where calibration object #1 is greater than object #2, the check will be “less than” instead of “greater than”.

Calibration Results

After all measurement groups checks are satisfied, the Calibrate button will be active. When you tap it, the calibration results below the button are updated. The spring constant should be between 215 and 235. The Apparatus MoI should be between 5 and 15, depending on the size of your phone. If the calibration results are outside of these ranges, the likely cause is that the calibration rod was not fully-extended or fully-collapsed during the calibration measurements. When fully collapsed, the rod is 20 cm (8″) long. When fully-extended, the rod is 74 cm (29″) long. There are four internal sections (five sections, including the external section). Make sure that you’ve unlocked and extended all four.

When recalibrating after a “bad” calibration, the measurements of the calibration rod will be off. This is fine. The calibration calculations only consider the periods of oscillation, not the moment of inertia (swingweight) values.

Tare Button

Be aware of the Tare button. If you tap this by mistake, the measurement results will be skewed. The button is filled in when the tare function is active and just an outline when inactive. When the tare button is activated, the preceding measurement is subtracted from all subsequent measurements. The tare function is used with the twistweight and pickleball adapters.

Pickleball Adapter

If you’re using a pickleball adapter, make sure that you calibrate without the adapter. The calibration values are valid for the unadapted, 10 cm, measurement position. After calibration is complete, mount the adapter and tare it out before measuring a paddle.

If you’re using the 5 cm pickleball adapter, and your measurements are lower than expected, make sure that the adapter is installed into the SW1 cradle properly. The tabs on the bottom of the adapter should fit between the front and rear supports of the cradle. The adapter should be unable to slide in the cradle.

Twistweight Adapter Common Issues (original design, before November, 2023)

When oscillating a racket, the handle wobbles, or measurements vary a lot with small adjustments to the centering of the racquet. If the racquet is secure in the TWA, these issues both indicate that the racquet is not centered. Start by lining up the racquet with the center indicator of the TWA centered between the two center main strings, but you may need to tweak it slightly. When centered, the measurement will be at a minimum, and it will increase slightly as you move the racquet in either direction. I see this issue with one of my racquets, and it appears that the drill registration is slightly off. Note the location of the center dot relative to the strings of the top racquet in the photo below.