I've always found screw-pin shackles intensely irritating, the pins are fiddly to turn and awkward to tighten. I don't find a slotted shackle key a lot of help, and usually keep a bull-nose plier in my pocket. Even so it's not ideal.
I was thinking recently that it would be really handy to have a spinner, akin to a nut runner. It would be a similar tool, but with a slot in the end rather than a hex socket. No such thing seems to exist, but then I thought it shouldn't be too hard to make one. So I did - here's how.
I checked the heads of the shackle pins I wanted to use it on, the biggest was nearly 10mm wide, and all were about 2mm thick. So I bought a 10mm nut runner with a deep socket, and some 10mm hex brass bar. I was able to buy a short 5cm piece on eBay for around £2, which was handy.
I put the bar into the nut runner, and cut if off flush. I then took the piece that fitted into the socket and cut a slot into it. I simply used a hacksaw, being brass it's easy to work. I cut the slot corner-to-corner to get maximum width. The thickness I needed was about that of three hacksaw blades, so once I'd started the slot with two parallel cuts, I put three blades into the hacksaw and cut straight down. A depth of 10mm was enough for any of my shackles, which is around half the length of the brass piece.
Having checked that it worked as expected, I simply glued the brass piece into the socket with Sikaflex. I found I had to drill a small hole into the flat end of the bar through to the bottom of the slot, otherwise I couldn't push it fully into the socket with the sealant in place.
Job done, this should be a handy tool come next season! Check out the photos below.