SW1 Racquet Swingweight Machine

(22 customer reviews)


The Briffidi SW1 allows you to quickly and accurately measure the swingweight of racquets.


SKU: SW1 Category:


The Briffidi SW1 allows you to quickly and accurately measure the swingweight of tennis, squash, racquetball, and badminton racquets. An available pickleball adapter enables the SW1 to measure paddles. An available twistweight adapter allows high precision (never before available) measurement of twistweight.

Highly Accurate and Precise

The SW1 is spring-driven and oscillates about a vertical axis to measure swingweight independent of mass and balance measurements. The companion apps (available free in the Apple App Store and Google Play) use the gyroscope sensor in your phone to measure with high precision. A retractable rod labeled with two individualized calibration values is included. While the SW1 costs much less, accuracy is as good or better than other swingweight machines.

Easy to Use

After initial setup, place your phone into the holder on either side of the SW1 cradle, rotate the front of the cradle to the left, tap the Measure button, and release. The swingweight measurement will display in seconds. The SW1 is small, requires no external power, is easy to store, and is easy to transport.

You Will Need

  • An iPhone 7 or later – or – a phone running Android 8.1 or later with NFC capability and a physical gyroscope sensor. Android phones with non-standard form factors (flip, folding, etc.) may not fit securely in the SW1.
  • Approximately 4,000 4.5 mm (.177 cal) steel BBs to add weight to the device. In the US, a package of 6,000 BBs is available from many retailers for ~$10 (i.e., Amazon, Walmart). The SW1 is much easier to package for damage-free shipping when unfilled and can be filled easily without tools.

The plastic components of the SW1 are 3D-printed in PETG, which is tough, durable, chemical-resistant, and heat-resistant.

Related Links

User Guide

Video Playlist: Briffidi SW1 Getting Started

Blog Post: Effect of Orientation Error on Racket Swingweight Measurement

Blog Post: Racket Twistweight from Spinweight and Swingweight

Blog Post: Briffidi SW1 Linearity Testing

Blog Post: Effect of Leveling on Briffidi SW1 Measurements

Video: Briffidi SW1 One Gram Accuracy Test


Video: Fix This Anytime You Buy a New Racquet by TennCom (featuring the SW1)

Questions & Answers

Q: BBs are difficult to get in my country. Can I use something else?

A: Yes. The BBs are used as ballast, so something similarly small and dense should work. The BBs required to fill an SW1 have a mass of ~1.4 kg. Sand or common pebbles will not work, as they’re much less dense than steel. A soft mesh diving weight, such as this one from Scuba Choice can be a good source of inexpensive ballast. I purchased the 3 lb. version to test, and it worked well. (Be sure to use handle the lead bits safely.) There was some space left inside the SW1, so the 4 lb. option would be even better.

Q: What happens if Briffidi ceases to exist?

A: The SW1 will still work. The app will continue to function; it does not contact a backend server. If the SW1 will no longer be supported, I will publish the app source code and the hardware design.

Q: How accurate is the calibration object?

A: I estimate that the marked calibration values are accurate to within ±0.6 kg·cm². The values are determined by swingweight measurement after calibration with a pair of reference rods. The length and mass of the reference rods are measured as part of each calibration.

Q: How often should I recalibrate the SW1?

A: If you move the SW1 to a new location, you should re-level and recalibrate it. I have marked the spot where I use mine, so I can place it back in the same spot and avoid re-leveling. You should recalibrate if the temperature changes significantly. For a typical racket, the measured swingweight increases by ~0.09 kg·cm² per °F (~0.16 kg·cm² per °C). Otherwise, it’s not necessary to re-calibrate except occasionally to verify that nothing has changed. When measuring racquets, I typically only take a quick measurement of the extended calibration rod to make sure it’s close.

Q: I broke something, can I get replacement parts?

A: Yes. I haven’t had to replace much, so I don’t have published spare parts. Please send a message to support@briffidi.com, and I will work with you to get your SW1 back in service.

Additional information

Weight 1.6 lbs
Dimensions 10 × 9 × 8 in

22 reviews for SW1 Racquet Swingweight Machine

  1. Jim H (verified owner)

    SW1 is a great product for pickleballers. Easy to use. Seems accurate. YouTube instructions made it easy to get going. I was hesitant as it seemed like a lot of money but I’m really glad I bought the SW1 and the twist weight adaptor. Thank you Brian!!

    • Brian Fitzpatrick

      Thanks for the review, Jim!

  2. Ben (verified owner)

    Hi Brian,

    I’ve now had a month of using the Briffidi SW1 with TW adapter and the BP1. I just wanted to reach out and say thank you very much for the outstanding customer service, communication and smooth experience from pre-purchase correspondence right through to delivery in the UK. The items were packed meticulously in robust packaging. No surprise given the nature of the person, evident from the concept and design of the SW1 and BP1.

    The quality of construction of the SW1 and BP1 are top notch, and beautiful pieces of industrial design. The accompanying software is easy to use and all required data is presented with clarity and efficiency. It is most impressive how the SW1 measures swingweight and twistweight (with adapter) with exceptional accuracy and precision. It’s a marvel just how small a footprint the SW1 has! And the fact that it uses a mobile phone for the electronics means that the device is purely mechanical and easily moved/transported.

    As the saying goes, “It is a beautiful thing when a career and a passion come together”! Congratulations for your outstanding work in the concept and design of the SW1 and the accompanying ingenious twistweight adapter. It is truly a gift to the gearheads in the tennis community!

    Thank you very much once again and I wish you every success.

    With kindest regards,

  3. adamdong (verified owner)

    For a homebrew device, one might question the accuracy of the results. However my results from the Briffidi SW1 matched (in finer detail as well) to several RDC machines that I had access to. Admittedly the calibration setup isn’t the easiest to remember (thank goodness for the instructions to refer to), however once calibrated, you’re good to go!

    The Briffidi SW1 fits my Iphone 11 Pro Max + case with no issue for reference).

  4. Brooks Banks (verified owner)

    I have actually owned the SW1 since Oct 2021, and have used it a couple hundred times (maybe more) since then to measure all of my various racquets (22 total on the shelf right now) of various makes and models I have accumulated over the years. Many I still like (or want to like) so I’ll throw another string in and measure and/or maybe try fiddling with weight/balance/swingweight/etc to see if I can “like it more”.
    This machine has helped tremendously with honing in on what specs work best for me (and what work best under different conditions, like what works best when it’s really cold vs really hot, etc). Now that it also supports Android (not available for the first year+ that I owned the device, so I had to steal my partners old Iphone 8 by buying her a new Iphone 13), I love it even more.
    Easily worth twice the price for all the value I’ve gotten out of it.

  5. David Evans (verified owner)

    This is an incredible value for an easy and accurate Swing Weight (SW) & Twist Weight (TW) measurement device.

    I am so thankful that this was developed and is available at such a low price because it is a game changer for me to be able to match my rackets up quickly and easily to the specifications that I want.

    Calibrated in just a few minutes using the instructions on the Free iPhone App, and got the SW and TW (Using Optional TW Adapter) of 2 rackets in about 5 minutes flat. This all went really smooth considering it was my first time using the device.

    I have always wanted a quick, easy, and accurate way to do these measurements, but the price of the devices on the market have always been a huge barrier for me. The SW1 device along with the Twist Weight adapter at this price is the perfect solution for me.

    Thank You!!!

    • Brian Fitzpatrick

      Thanks for the review, David

  6. romlurosario (verified owner)

    Best tennis purchase since getting back into tennis in 2017. I have quite a collection of wilson 90 sq inch “federer” ncodes, k-factors, blx 90’s and RF97’s. I measured 15 or so (I did say ‘quite a collection’) and found my favorites were 338 SW and those I struggled with were lower 330-ish or 343 SW and higher. Added weight to 4 of the lighter ones to match one of my favorites at 338 and enjoyed all 4 as much as my favorite hitting this morning! Very grateful to Brian’s invention and making it available! Thanks so much! I have already ordered the TW adapter this afternoon.

    • Brian Fitzpatrick

      Great to hear! Thanks, Romulus

  7. mate.musa (verified owner)

    The device is really well made, I would never say that it was made on a 3D printer. The instructions are very clearly written, in the beginning I had a little trouble with the calibration (my fault because I changed the order of weights for calibration). When I realized where I messed up, I did the calibration in less than two minutes. I was impressed by the precision, especially when you get into groups of measurements that are to two decimal places. There is nothing to say about a patent, the man is a genius. This is a device that will always work reliably. Hats off to the floor master.

    • Brian Fitzpatrick

      Thanks for the review, Mate

  8. Stefan Wagen (verified owner)

    Great product, brilliant design, top-notch quality.
    Easy to set up, level and calibrate, as shown with the Youtube videos.
    Even though the parts are 3D-printed, they look and feel very robust and fitting, no gaps or imprecisions spotted. Yes, there is no glossy color and printed logo of a big Tennis company, but the machine is compact and the measurements are highly accurate for a fraction of the price compared to other options.
    Using it with Pixel 5, works like a charm.

    • Brian Fitzpatrick

      Thanks for the review, Stefan

  9. From the Web

    Jonathan at perfect-tennis.com wrote: (link to full review)
    The Briffidi SW1 is a game changer for measuring the swingweight of a tennis racket. It does exactly what it advertises and feels well made.

  10. Kevin Le (verified owner)

    Does a job for a fraction of the price.

    For hardcore tennis enthusiasts this is a must have in addition to a balance board. Finding my swingweight actually helped improve my game as it made me realize I play much better with a lower swingweight so I can match all future racquets to that level.

  11. B. Ko

    Agree with all the reviews. I took a leap of faith, not just because of positive reviews, but after reading all the materials Brian has posted. I could easily see that he is not really in this for the money. He is just another tennis nerd, like us, who happens to be a brilliant engineer with a touch of OCD. From the instructions to the product itself, you can see that he is a guy who pays a great amount of attention to details. The device itself is really well made, and I was amazed at how precise it was. Unfortunately, I can’t speak for the accuracy as I do not have a gold standard, but the precision (if you are like me, who is also a bit OCD, and has to follow all the steps) is remarkable. Highly, highly recommended.

  12. Roy Peterka (verified owner)

    I was curious about this thing, and have often wondered about swing weight of my different racquets. Calculating SW without a machine is nearly impossible to do in a reproducible manner. I ordered a couple of weeks ago, and have had a chance to use it. Setup was easy after I actually read the instructions. The machine is solid and well made. I can understand why it is $250. I am glad I took a leap of faith and bought one. One thing that is important in calculating SW is making sure that the face of the racquet is oriented vertically. Any deviation from vertical increases SW (at least on this machine).

  13. Max Treharne (verified owner)

    This is a really great little device – I am seriously impressed. Really consistent results and so much easier than trying to calculate swingweight manually as I was before.

    It made it all the way to the UK in a week too.

  14. Fred Lam

    This setup have been for my small shop “circle-of-friends” type application. The entire setup is super easy to manage and it’s nice to be able to store away. Measurements are super consistent, taking all the guess work out. I highly recommend for anyone from DIY beginners to tennis nuts who looks to tinker.

  15. Thomas (verified owner)

    I wanted to customize my tennis racquet and wanted to measure swing weight. I was intimidated by the SW1 at first, thinking this wouldn’t require a lot of math to get accurate results, but that is not the case. This device is set up in a foolproof way. It works like a charm. Very pleased.

    • Brian Fitzpatrick

      I just noticed that I can reply to a review. Thanks for the review, Thomas.

  16. From the Talk Tennis Forum

    Kozzy wrote: (link to source)
    I’ve been trying, with extremely limited success, to match/customize my own racquets for years. I know see the #1 problem was that my SW calculations were absolute garbage. I’m sure they don’t have to be, but I clearly sucked at it. Thanks largely to the SW1 (and the TWU customize tool), for the first time ever, my changes actually hit the mark! I was aiming for 328 SW on two different racquets, and I got it! Holy cow. So easy. I’m sure that a real racquet pro would not be impressed, but they pretty much feel the same to me, and I don’t think I can tell the difference. Did it again with another set of frames as well, and got equally good results, in less than an hour! So amazing to have a simple, easy way to measure the swingweight that works every time, even for a clod like me.

  17. From the Talk Tennis Forum

    mad dog1 wrote: (link to source)
    It’s very well thought out, designed and engineered. Highly recommend.

  18. From the Talk Tennis Forum

    PrinceYonex wrote: (link to source)
    Just wanted to jump in here to say that @bfroxen has offered amazing customer service. The moment he saw that I was getting higher-than-expected swingweights, he reached out to me and started to troubleshoot the issue. In short order he figured out what the issue was and immediately offered to send a new calibration rod (incidentally, there was nothing wrong with the build of the original one, just a single measurement typo that was throwing off the calibration process).
    For those who are interested in purchasing the sw1 but a little uncertain about it because this isn’t coming from a big brand, I can reassure you that build quality and customer care are excellent here. There’s an advantage when you are dealing directly with the guy who built the instrument and the app, not with a company rep.

  19. From the Talk Tennis Forum

    tim-ay wrote: (link to source)
    i really am impressed with this machine. that we are even talking about TW is incredible. and to think SW is almost too easy, lol. insane.

    just a great product – hats off to bfroxen

  20. From the Talk Tennis Forum

    Power Player wrote: (link to source)
    Yeah, its really well cut. Like everything fits together like a glove. Its that 3d printed plastic but you can tell he put a lot of thought into it. For example the top lid of the casing for the bbs fits in so well that its almost like one seamless piece when put back together.
    The phone holder is also really cool. Accomodates a case or no case with no issue.
    It was clearly designed by an engineer who knows what hes doing.

  21. Irvin Fuchs

    I’ve had very consistent results measuring SW and TW with the SW1 machine. I’ve found because of its light weight and portability it can move around from time to time. But as long and I calibrate the machine each time it is moved I can get excellent repeatable results.

  22. Tim K (verified owner)

    I’ve had excellent experience with the Briffidi SW1. I’m a recreational player who likes to have matched racquets in my bag and also likes to play around with different set ups from time to time. I got sick of bothering my local shop to use their Dunlop SW machine and using the various phone apps to estimate swing weight. I’ve gotten very accurate results that compare to much more expensive machines. Set up/calibration was very easy using the youtube video as a guide. I highly recommend the Briffidi SW1.

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