My daughter’s science project this year was an interesting one. She had seen a photo of a scooter with two front wheels.
She wondered whether she could make an ice skate with two blades. Would it offer better grip in corners than a single-blade skate? There was only one way to find out…
There already are twin-blade ice skates, but they have limitations (kind of like training wheels on a bike): the blades don’t pivot, so the skater cannot lean into turns. My daughter wanted to make a twin-blade skate that can lean into turns. “Can we do it?” she asked. That is not such a far-fetched question in a household where metalworking and prototyping are a part of everyday life…
In her project proposal, she listed under resources “fully equipped machine shop” and “welding equipment”, as well as “9 centerpull brake pivots” and “metal bars”. Not to forget an extra ice skate and an extra pair of ice skate blades.
We talked about how to keep the blades parallel, and decided that on the rear, only a single link was needed to keep the blades spaced correctly, since the two links on the front already kept them parallel.
And then we headed to Hahn’s machine shop. She got to work with files, and watched how angle grinders and milling machines work. She donned a dark mask as Hahn welded the pivots onto the blades.
As so often with these projects, they take longer than planned, and the work is too hard or too dangerous for children, so parents tend to do a lot of it. But in the end, she was glad to have a working twin-blade leaning ice skate.
She developed the protocol of testing it all by herself, with no adult input at all. She found that the twin-blade skate does feel more stable when skating one-legged (probably due to the friction in the pivots), but it’s harder to come out of turns and get the skate upright again (probably for the same reason). The main issue is weight – the extra blades make the skate very heavy. It was an interesting exercise for all involved, but like many prototypes, it’s probably going to remain a one-off.
Acknowledgments: Thank you to Hahn Rossman for the use of his machine shop for making the skate.