Tuesday, December 2, 2008

Homemade Gavin trigger wheel modification


Ok so this month I purchased a Gavin scooter. Finally now all of us have one of these great pieces of kit and I can't wait to get it in the water.

Whilst giving it a thorough strip-down clean to familiarize myself with its workings I noticed that the trigger wire had an annoying tendency to jump off the wheel stopping the trigger from working. It did this with the least provocation and after disassembling the handle a dozen or so times to fix this problem I figured I had do something about this before taking the scooter into the water.

The problem is clearly in the design of the original wheel which does not have sufficient groove depth to hold the trigger wire in place if slack is applied to the wire eg. when the magnet is rotated independently of the trigger.

A quick internet search showed that I was not alone with this problem and turned up John Preston's (jpreston1845) fantastic Derelin replacement wheels.

Ultimately, I'm sure I buy one of these great replacements but it occurred to me that I could easily modify the original wheel as a quick fix to get the scooter in the water.

My DIY Version

After measuring the available space within the handle I cut two 35mm diameter discs from the back of a CD case and drilled out their centers. Next I shaved the little retaining loop off the original wheel with a sharp knife. After sanding down the surfaces I applied a small amount of Araldite® 2-part adhesive to the outsides of the original wheel and attached the new disks.





















Once the glue had set I fitted the new larger wheel back into the handle and Bingo! Now no matter how much slack I put into the trigger wire it cannot jump off the wheel.