Gyrokey introduction: https://www.youtube.com/watch?v=lutnfhRlRjc

The Gyrokey is a 3D-printed screwdriver handle that can spin like a top, but still offers a great grip for applying a good amount of torque. I created it for sports hydrofoils, but it's great for many other applications as well. The Gyrokey Classic holds one screwdriver bit. The Gyrokey Double-Decker features a reversable design that allows you to switch between two different head types. If you need more than one screwdriver for your hydrofoil, this is the tool for you!

I invented the Gyrokey in 2021 when I decided I wanted a great tool for assembling a hydrofoil for the wingfoiling sport. I had to do 12 screws each time I went sailing and came out, so it started to feel tedious after a few sessions.

The L-shaped Torx tool that came with the foil was also starting to rust a bit even though the salt content of the water I sail in is relatively low. From my windsurfing background, I know that tools generally don't last very long in a marine environment unless they are made for it.

Breaking a couple of prototypes that tried to hold the screwdriver bit in PLA plastic confirmed that I needed a stronger grip on the bits. This gave me the idea of holding the hexagonal toolbit from three sides using stainless steel screws. This proved to work quite well, although I must admit that I still broke some prototypes. PLA plastic has its limits, so if you put a huge amount of torque on the handle, it can crack. Hydrofoil screws are often quite tight to open, so my testing environment has been demanding. Keep a spare tool with you just in case you break or lose your Gyrokey.

The holes for the screws have been sized so that an M6 machine screw can self-thread strongly. Note that making the threads for the first time can result in so much friction that the PLA plastic melts completely around the screw, so I recommend applying a little bit of lubrication (PTFE grease works well) on the screw and going slowly. Thread the holes first, then loosen the screw a bit before you insert the screwdriver bit.

I use six M6 grub screws of 12 mm length for the Gyrokey Double-Decker. Longer M6 screws will also work in a pinch and a quarter inch imperial thread screw may also work (I haven't tried it yet and you may need a thread tap).

There are two variations of the Gyrokey Double-Decker: the older version has the screws out of alignment with the handle spokes. Given that the main failure mode that I saw while prototyping was that the handle would crack along the screw hole, I thickened that area quite a bit, but also made a version where the screws go in through the spokes. The "V2" is thus a little bit harder to assemble (you need a long Allen key or much longer screws for half the screws), but it should be even stronger than the base version.

Note that the hex hole for the screwdriver bit is also designed to be quite tight, so a bit of PTFE grease and a hammer or vice grip may help. If it still feels too tight, put the screwdriver bit in a freezer and warm up the Gyrokey in hot tap water (not boiling).

Tip: you can use a screwdriver shaft extender, if you want to make a Gyrokey with easily replaceable screwdriver bits or a longer shaft.

I really care about this product and my customers, so if you have feedback, don't hesitate to contact me and I will do my best to figure out a solution. If I come up with improvements to the design, the updated parts will be available on this same page (you only pay once).