QB-GRV-30

1. Overview

The Qanba QB-GRV-30 is a 30mm snap-in mechanical arcade pushbutton from Qanba's Gravity series, launched around 2021 as a Chinese challenger to market leaders Sanwa Denshi and Seimitsu. The original Gravity used proprietary Logitech Romer-G switches (non-hot-swap, soldered) before Qanba evolved the line into distinct sub-families: the snap-in KS (Omron linear silent), screw-on LX (Omron grey, linear silent), and adjustable-throw KT variants. The Gravity family is sold standalone as an upgrade or replacement part, and is featured as stock or optional hardware in a growing number of arcade controllers from third-party builders including Fruits Factory, Y Lab, Akecon, and Qanba's own Sapphire leverless controller.

2. User Sentiment

The Gravity line is widely described in the fightstick community as "responsive yet quiet" and "among the most popular buttons in the fightstick world" (The Arcade Stick directory). Users of the KS snap-in variant specifically praise the 0.8mm pre-travel and 2.8mm total travel as delivering "the smoothest button presses I've experienced," and call the snap-in design a "game changer." The silicone inner cap and optional silencer pad are frequently highlighted for reducing noise compared to both standard arcade buttons (~65 dB) and even Sanwa's own silent buttons. The original first-generation Gravity (Romer-G based) received mixed reception and was described by the Saturn Forge community FAQ (2022) as having "debuted with some hype but largely remained overshadowed by the Crown 202" due to its non-MX-compatible, non-hot-swap design. The newer Omron-based KS/LX variants appear to have substantially improved community standing. Multiple YouTube reviews (Oct 2021, Jul 2022, Feb 2024) document direct comparisons with Sanwa OBSF and Seimitsu PS-14.

3. Real-World Applications

The QB-GRV-30 / Gravity line is used primarily in fighting game arcade sticks (fightsticks) and DIY arcade cabinet builds requiring standard 30mm panel holes. The buttons appear as stock components in products from Fruits Factory (DRY+, RAINY+), Y Lab DoubleSalt, Akecon Leaf, DUB PL8, FS-MINI, and Qanba's own Sapphire leverless controller as of 2024–2025. The 30mm snap-in format is compatible with the same panel cutouts used by Sanwa OBSF-30 buttons, making them a direct drop-in upgrade for most Japanese-layout fightsticks. They are also sold in boxed 8-piece and 12-piece sets targeting builders and modders.

4. Technical Specifications

• Button Diameter: 30mm
• Mounting Type: Snap-in (QB-GRV-30 / KS series); Screw-on (LX series)
• Switch (KS/LX variants): Omron linear silent mechanical switch
• Switch (original Gravity): Logitech Romer-G (proprietary, non-MX-compatible, non-hot-swap)
• Pre-travel (KS): 0.8mm
• Total travel (KS): 2.8mm
• Actuation force (KS/LX): 45 cN (approximately 50g)
• Actuation point (LX): 1.5mm
• Total travel (LX): 3.2mm
• Rated cycle life: 70,000,000 actuations
• Noise level (LX): ~45 dB (vs. ~65 dB for standard arcade buttons)
• Panel hole compatibility: 30–32mm diameter
• Panel thickness (LX screw-on): 1–13mm
• Cap: Removable, accepts custom artwork inserts
• Available sizes: 30mm and 24mm (KS/LX)
• LED options: Standard or RGB LED illuminated (select SKUs)

5. Ordering & Compatibility

Retail pricing ranges from approximately $3.68 (Arcade Shock, LX screw-on solid) to $5.95–$7.75 (Paradise Arcade Shop, ASIndo.pro, Focus Attack) per button, with 8-piece and 12-piece boxed sets available. The 30mm snap-in format fits standard 30mm Sanwa-compatible panel cutouts, making it a direct replacement for Sanwa OBSF-30, Seimitsu PS-14, and similar Japanese-spec buttons. The KS snap-in variant is available in 8 translucent color options (Clear Red, White, Blue, Green, Orange, Pink, Violet, Black); the LX screw-on comes in solid and metallic finishes (including Metallic Silver, Gold, Blue, Green, Violet). RGB LED variants require compatible PCB hardware (FB2040 or Gen5X) and a separate RGB harness.

6. Known Issues

The original first-generation Gravity button used Logitech Romer-G switches, which are proprietary and not Cherry MX compatible, limiting aftermarket switch customization and requiring soldering for any switch replacement — a disadvantage vs. hot-swap buttons like GamerFinger. This generation was considered to have underperformed vs. expectations in the community. The later KS and LX variants addressed this with Omron switches and non-proprietary designs, though the KS/LX also use soldered (non-hot-swap) connections according to retailer notes. No significant structural or reliability issues have been reported for the Omron-based Gravity variants.