About air cavities, holes, and grooves
What the factories have said about large open cavities on the face of their clipper wheels:
“These holes get packed with grit when you charge your clipper wheel and then allow you to get more blades sharpened per charge.”
At first, that sounds plausible especially if you just take their word for it and go on, which is exactly what many people did, and then did not think much about it anymore believing it was true. After all, that is what the factories said. Right? Well, not so fast. How about we give it a little thought before we just take their word for it and move on? As I have said before, The blade factories don’t always tell you the truth. So, what really happens? If you pack these holes with grit, then spin the wheel at say 1750 rpm the cutter will cause a venturi effect and some of the grit will be pulled out of the holes every time the holes pass under the cutter (from the back side) This grit will then be air born.
What happens next is not what we want. Instead of the grit settling back down onto the wheel, and then riding on the face of the wheel to go back under the cutter? Instead, it stays airborne and ends up blowing in your face, and filling up the rest of your work area, because at 1750 rpm there is wind, and this wind will not allow what the factories have said will happen which is why I call it a myth. (because it is) What the factories are trying to do is make lemonade out of a lemon. They saw the big holes and knew people would question them. So, to fix that problem they explained them away. (In a good way) but, the problem is, that people can figure these things out if they want to.
Drilling holes in your wheel
The next myth is drilling holes in your wheel. What? Yes, people have actually done this! They think that what the factories have said is true so by drilling holes in their wheel, they believe they are mimicking what the factories have said. It is true, they get pretty much the same results. Grit in their face, and work area, less surface area to support rolling grit, so it takes a longer time to sharpen a cutter.
Grooves in your wheel
So, if you can believe it, grooves are even worse than holes. Yes, they hold grit, until the wheel spins up to speed, (and none of it goes onto the tip tops of the grooves.) The reason grooves are so bad is that grooves eliminate over half of the sharpening area of your wheel. you won’t have much of any rolling grit on the tip tops of the grooves. They are very narrow, to say the least, and rolling grit will not last very long there so you end up sharpening with the little grit that has gotten embedded into the tops of the grooves. This means the hard metal of the cutter will be in contact with the relatively soft aluminum of the clipper wheel causing drag and prematurely ruining your clipper wheel.
So, what is the best surface you can get?
I am glad you asked! The very best surface is a taper that is true flat on the center line of the wheel. Think of a funnel that is turned upside down. The funnel has a taper and the tapered sides are true flat. The same is true of a clipper wheel just not as pronounced as a funnel, but the same type of taper that a clipper wheel has. Ok, so what does a flat taper on a smooth clipper wheel with no holes or groves in it do? It gives you the full surface of the clipper wheel to sharpen blades on. You get the maximum amount of rolling grit possible, so your wheel has the most protection than any other type of clipper wheel. (Again rolling grit is the only thing that stands between the hard cutter, and the soft aluminum wheel) This means your clipper wheel will last longer and you will also get the maximum amount of blades per charge that you can ever get. More rolling grit sharpens faster, so less time on the wheel will give you more blade sets per charge. At Ace Sharpening we only make new, and resurfaced clipper wheels using a true flat taper for the very best results possible.