2.2.1 – Excessive wear on bushes.
This was the first major hurdles I had to overcome which was to find the right materials, not only for the hub and blades, but especially the pivot bush. I tried many materials, hard lubricated nylons, phosphor bronze, various steels including stainless steel shown middle right. As you can see the damaged caused to the nylon and bronze bush after only one tank of petrol, the stainless steel after three tanks of petrol and the hardened steel bush after ten tanks of petrol.
Very high loads placed on the bush. After doing the calculations I found that a stationary blade placed a load of 43 grams on the bush, but placed a load of 1.3 tonnes on the bush when a brush cutter is running at maximum revs. This is like hanging a small car on the end of a blade and swing it back and forth 250 odd time a second without any lubrication. After trying many options, I found that no lubrication would stay in place as the high “G” forces would spin out all lubricants.
After beginning to think I could not find any material to do the job, I finally found that a hardened steel bush, which was hard enough to handle the loads, but not quite as hard as the flail-blade so it would wear slightly less than the pivot hole in the blade. If the bush was harder than the blade, I found that the harder bush under the extreme loads would rub away the blade pivot hole by rolling up little beads of metal in the pivot hole which you can just see in the photo on the right.
Finding the right grade of steel, finally meant that the bush would last the life of the blade, which made the whole idea of a flail blade possible.
2.2.2 – Blade Flexing and Cutting Into Hub.
2.2.3 – Flail Blade Impacting and Deforming Nut Guard.
2.2.4 – Wedged Grass Causing Vibration Issues.
2.2.5 – Bolt fails causing loss of blade.
2.2.6 – Flail-Blades Destroying one another.
2.2.7 – Flail-Blade Breaks Off Causing Injury.
2.2.8 – Multi Tooth Flail-Blade Difficult to Sharpen.
2.2.9 – Bush Washer Wearing Through Bolt.
2.2.10 – Grass and Vines Tangle Around Gearhead Stalling Brush Cutter
2.2.11 – Customers Blades break and testing to try and replicate failure
2.2.12 – Threaded Bush and Bolt Crushing
2.2.13 – Failure of Bottom Hub
2.2.14 – Failure of Model-16 Bottom Hub and Anti-Fouling Blades.
Feedback is very important, especially when the feedback is not so good. It is the feedback where there has been issues or failures that have driven me to solve these problems and continue to improve the product. Commercial operators have been my biggest source of feedback, they are the ones that use a brushcutter all day, everyday and the ones that benefit the most from a better product. I always keep thinking that this new model will be as good as it gets, but I now know that there will always be improvements, the more people that use this blade the more the feedback, the better the product will become. So after you have used your blade for a while, please share your thoughts.
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