Custom fitted carbon fiber cuffs

I have always loved the look of the thick chunky steel cuffs. They just invoke a sense of permanence and unyielding. I was absolutely desperate for a pair but I just couldn’t afford the price tag for a decent set, but never fear… DIY to the rescue!!!

The first step towards making these was to figure out the right shape for my wrist. I wanted them to be snug but not too tight. I didn’t want them flopping about all the time as I knew that would annoy me. To figure out the right shape I cut out various ovals in a bit of paper and held it on my wrist. It was a lot of trial and error but helped me nail down the cuff size. Once I was happy and had my paper template I glued it onto some chunks of carbon. I cut out the internal or ‘wrist’ side first. every now and again holding the half onto my wrist to check the fit and grinding away as necessary. I had to ensure that both the halves of the cuff wrapped further around my wrist than needed so I had space to create the hinge/lock mechanism. once the internal shape fitted my wrist it was easy to copy the shape onto the outer surface and grind it away to give me the cuff shape. In the photo below you can see I’ve just reached this stage and have marked out positions for the hinge/lock

I knew I couldn’t do anything too technical with a hinge mechanism without the cuffs losing strength so I figured the best/easiest way to secure them closed would be to simply use a bolt. I did a cut out in both halves of the cuffs so they slotted together and then drilled down through both of them at the same time. In the photo below you can see me checking they close correctly using some metal pins

In order to be able to use the cuffs as a restraint, I needed a way to attach a D-ring to them. again I chose the simplest solution and glued a threaded insert into the carbon. I had a friend machine me a beautifully threaded insert then I completely failed to try to make a D-ring for it. You can see that I really struggled to get the shape correct. Next time I will definitely put some more effort into this part. I did, however, weld the D-ring closed once it was in the insert to give it strength.

 

In the photo below you can see the final cuff. I wished I could have counterbored the bolt so it was hidden but the cuffs ended up just a tiny bit too thin. But I do kind of like the industrial look it brings. I may try and find some grub screws one day

The advantage to the D-ring being removable is that other things can be screwed into place. you could thread the ends of a metal bar and voila, you have a rigid spreader bar.

I do hope to come back and try this project again one day and create a better system for the cuffs. A hidden hinge would be the first improvement. I would love to find a discreet yet strong locking mechanism too. A set of accessories for the threaded holes would be a fantastic addition as well to make this a nice little set.

 

January 21, 2017