There it is- the new guard. I haven’t put it onto a chair yet, but I have a good feeling about it. I think I got things fairly straight. A jig to hold everything during tack welding would have made things go together easier. It also would have been nice of I had been able to mill the edges of the inside edge of where the horizontal tubes come together at 90 degrees. I had to grind off the interfering edges, and any imprecision created a gap that I had to bridge with filler. It’ll be strong enough, I think, but would have been easier with a nice tight fit all around.
It weighs 10.8 pounds, about two pounds more than the World Cup guard. I don’t have access to a CAD system that will calculate rotational inertia for me (and I don’t feel like doing it by hand for), but I suspect that the new design isn’t quite as good in that respect. Regardless, this is about $80 worth of steel, compared to $300 for the cheapest commercially available guard. It also has a much more square tip, allowing the player to hit the ball with a spot closer to the end of the guard where the speed is highest.
I’ve been working on a design for the team that will be somewhat light weight, and not as expensive, time consuming, or fragile as the one I made for Kendra.
Aircraft Spruce sells some 1″ diameter tube for $2.80 per foot, compared to $3.50 per foot for the smaller diameter tubing I used before, and I get to use less of it. I also don’t use any of the square tubing that costs $10.75 per foot.
More important than the cost of the tubes, the old design had a lot of semi-precise milling required, and had almost 50 welded joints. This design has simpler tube preparation and less than half the welds. Access to the joints is better, so it’s a little easier to get the torch into all the required angles. The tubes are much stronger than the 1/2″ tubes, so I don’t expect this guard to get dented in from any normal hit.
The guard weighs about half a pound to a pound more than the one I designed for Kendra, and a lot less than the guard I posted on September 24th. It remains to be seen if it gives a good hit on the ball, but I’m optimistic.
Do you remember the story of my friend who accidentally at dog food on the bike tour? I went to the store today and found a can of Alpo- it really is hard to see where it says it’s dog food! Check it out: