Spinworthy MK1 Red Blood Cell (RBC) Metal Responsive Model Kit - Detailed Collectible for Anime Fans & Science Enthusiasts - Perfect for Display, Gifts, and STEM Education

The RBC is a collaboration between Spinworthy and MK1 Yoyos for premium modern responsive play.

The idea was to take one Spinworthy’s wooden models called the Bloodcell and turn it into a metal responsive yoyo.

Rather than using an A sized bearing, we decided to use a smaller MR85 bearing that is only 8mm in diameter, the same as the wooden axle in the original wooden Bloodcell. This bearing combined with the same gap width as the original is intended to replicate the ideal play characteristics of fixed axle yoyos with the smoothness and power of metal.

The result is a very reliably responsive yoyo, even with a dry bearing. It was a challenge to design a lightweight hollow-bodied yoyo, but we managed to dial it in at 48g using 7068 aluminium with a diameter of around 55mm. It’s fast, lightweight, powerful and best of all, very reliably responsive. It’s a 0A beast and we hope you’ll love it!