Hi James, thanks for a very informative site. I have struggled for years to find any info on this subject.

I have read all the pages and want to embark on building my own sharpener for dog clipper blades.

The one detail I'm hazy on is the wheel taper.
1. when you mention a 0.011 taper, does that mean 0.011 inches taper per inch of wheel radius?

2. Does taper simply mean that the top surface of the wheel falls away by 0.011 inches for each 1 inch we move out from the center to the periphery of the wheel? To put it differently, should the wheel look like a stereotypical UFO when viewed from the side?

Thanks again
James Routledge
Haenertsburg
South Africa

Hi James,

Everything you said about the wheel taper is correct! Please feel free to ask any questions you may have while you are building your new clipper machine I am happy to help as much as I can.

James
Ace Sharpening & Co

Thanks Mate, I appreciate your help!

so looking at the profile of the wheel from center to outside edge it should be a very slight radius and not a straight line? so for a 12" disk .011 x 6" will basically give you the radius? are you casting your own blanks to then machine?

The cut is a straight line from the center to the outside, there is no radius in the cut the straighter the line is the better. Look at it this way, take a funnel and turn it upside down with the point of the spout in the up position. Wrap the funnel in sandpaper, then spin the funnel, then take a piece of wood and put it up against the side of the spinning funnel. the sandpaper will cut a hollow grind into the side of the wood.

That is exactly how the clipper wheel cuts a hollow in a clipper blade except the taper on the clipper wheel is so small compared to a funnel that it is harder to see exactly how it cuts a hollow, but that is exactly how it does it. Both the funnel and the clipper wheel tapers are perfectly straight lines from the center to the outer edges.

I forgot to answer, but yes I am having my own clipper wheels sand cast at a local foundry, they are then hardened, and then I machine them on my lathe to make the finished clipper wheel.

These wheels are made from the hardest aluminum I have ever used so they should not wear out for a very long time. (The harder a clipper wheel is the longer it will last.) These wheels have a Rockwell hardness rating of 80 on the B scale. That is harder than most high end stainless steel scissors that usually come in at 55 to 60 in Rockwell hardness.

Ok that makes sense to me. It hollow grinds because the taper actually goes in a circle rather than flat on a board in a straight line. I wonder what they're adding to the aluminum to make it so hard? Maybe zamak? I've actually been researching the homemade gingery style lathe books which teaches you to make your own foundry to cast the parts needed to build the lathe

They do use a certain type of aluminum to get it that hard, but when the wheels are cast they are not that hard when they come out of the mold only about 40 on the Rockwell scale. To get them that hard they have to be sent to another place that hardens them to 80 on the Rockwell scale.