noneYettookmyUN, Thank you for the expansive comment/explanation. I am sorry I haven't replied sooner. You made some very interesting and valid points. I forgot to take into account inertia. Ductility is also a property I overlooked when considering Aluminum as a lawn mower blade. My lawn mower has two 10 inch blades so I reasoned that a smaller diameter allowed for a extra margin of safety in a new material. Smaller things are much stronger than big things generally.
steamworks1960, Your comment is most appreciated. I am somewhat familiar with anodizing from the aircraft world. However, I've never herd of hard coat anodizing. Interesting. Cost is always a limiting factor in manufacturing no doubt. If cost wasn't an issue, could small lawnmower blades be fabricated to allow battery powered mowers to perform better? Perhaps even more exotic materials like carbon fiber/kevlar, carbon boron etc could help. Or a laminated blade with all of these would perform best. I just want more performance. In every other motorized device out there, reduced mass combined with equal strength produces higher performance.
Thanks nophead. You have given me something to consider.
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That's a good point. I only wanted to do this because aluminum is so much lighter than steal. In theory, the aluminum blades(2) would require much less energy from the motors to turn. Thus, the blades might spin faster and/or the batteries would last longer per charge.
DougM2, I do think blade failure is a possibility. However, if great care is taken to balance the blades and there are no stress risers, the blade should hold up the the inertia of being spun.
ac-dc, you make a solid argument. It accrued to me to add a steal leading edge to the blades to aid in cutting. The steal blades would need to be thin and have holes to allow them to be mounted and replaced when they wear down. I still think there might be some performace gains from a lighter mower blade. Perhaps a composite of aluminum, kevlar, carbon fiber, and steal would create the ideal light weight but strong blade.
Yes, aluminum is softer than steal, but it is more ridged and much lighter. If the blade could be made with interchangeable steal inserts on the leading edges, there could be a benefit to having a set of blades that have much less mass to reduce the stress on the electric motors. This could create more efficiency or power.
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