An end mill -
View attachment 169625

Exactly what I am talking about, except much smaller. And now, reviewing that original post, it seems like the TS wants to motorize an existing sharpener, while I had been visualizing a super-overkill version more like a subminature compound lathe.

 

https://www.amazon.com/Premium-Gear...locphy=9015345&hvtargid=pla-491601432928&th=1 - I think this is a fake

 

Yes, and since the manual cutters rely on the pencil and sharpener rotating relative to each other, I assumed that would be the case for any single blade solution. It would make no sense at all to have the pencil and blade stay stationary relative to each other if there is only one blade.

I can't even imagine what that suggestion would be...

You still don't get it. bill said to replace the flat blade that is on the angle needed with an end mill, he said nothing about the end mill turning while it rotated around the pencil or the pencil rotated around it. Holding the end mill from turning and either rotating it around the pencil or the pencil around it, will only make a groove in the pencil. This is due to the geometry of the end mill. There will only be one point of contact with the pencil. When done as explained, there can only be one point of contact, whether you use the side or the end of the mill cutter.

In a pencil sharpener both the cutter and the pencil 'guide'(don't know what it is called) rotate around the pencil. That isn't what he said. He said to replace the flat blade in the hand sharpener in post #20. So that is what I based my response on. That is how a crank style sharpener works already so why reinvent the wheel?

You haven't been around long enough to understand either MrBill or the thread starter. To know why I am holding them to a higher standard and calling them out. They both post some out there things that don't hold up if really looked at, and this forum deserves better.

 

When I'm out in the shop and want to sharpen my pencil I put it in a battery powered drill and spin it against a rotating sander. I can control the angle and how sharp I want the point. 120 VAC for the sander and 18 DCV for the drill.

 

When I'm out in the shop and want to sharpen my pencil I put it in a battery powered drill and spin it against a rotating sander. I can control the angle and how sharp I want the point. 120 VAC for the sander and 18 DCV for the drill.

That is basically how the sharpen golf pencils and colored pencils at the factory. But instead of an electric drill, it's done with two belts, one on top and one on the bottom spinning the pencil against a sanding belt.

 

it's done with two belts

Yeah, I've seen that on "How It's Made".

 

You haven't been around long enough...

Nothing to say to that. I'll just ignore this thread.

 

You still don't get it. bill said to replace the flat blade that is on the angle needed with an end mill, he said nothing about the end mill turning while it rotated around the pencil or the pencil rotated around it. Holding the end mill from turning and either rotating it around the pencil or the pencil around it, will only make a groove in the pencil. This is due to the geometry of the end mill. There will only be one point of contact with the pencil. When done as explained, there can only be one point of contact, whether you use the side or the end of the mill cutter.

In a pencil sharpener both the cutter and the pencil 'guide'(don't know what it is called) rotate around the pencil. That isn't what he said. He said to replace the flat blade in the hand sharpener in post #20. So that is what I based my response on. That is how a crank style sharpener works already so why reinvent the wheel?

You haven't been around long enough to understand either MrBill or the thread starter. To know why I am holding them to a higher standard and calling them out. They both post some out there things that don't hold up if really looked at, and this forum deserves better.

The arrangement that I was describing works a lot like a "compound" on a lathe, except with the milling bit instead of a cutting tool. So the cuttr path would be a tapered helix. That is how a small high speed cutter bit can cut the required taper on a pencil.
BUT then, going back to the first post, it seems that possibly the TS is wanting to motorize an existing sharpener, which leaves a whole lot less room for creativity. Creating different ways to do things was one of my very strong points during my industrial equipment design career. Those ideas made my employer a lot of money.

 

Those ideas made my employer a lot of money.

And so did mine. But I was hourly not a designer and had to fight to get things done, things that were simpler both to make and to use on the shop floor. The degreed engineers hated it. Usually I had to make one to show them mine was better than their idea.

 

Nothing to say to that. I'll just ignore this thread.

No need to ignore just join in.

 

The arrangement that I was describing works a lot like a "compound" on a lathe, except with the milling bit instead of a cutting tool. So the cuttr path would be a tapered helix. That is how a small high speed cutter bit can cut the required taper on a pencil.

Still don't see what your talking about. Explain?

 

Still don't see what your talking about. Explain?

Sounds like he is describing live tooling??
Max.

 

Sounds like he is describing live tooling??
Max.

Or reinventing and making the simple hand crank sharpener more complex.

 

Was telling my wife about this thread. She said "Why is he trying to invent electric pencil sharpeners? Don't they have them already?"

The reason why the crank pencil sharpener works so well is because the cutter shears across the grains of the wooden pencil. The razor blade doesn't shear it cuts through in a similar process to how they make plywood. They actually take a log and spin it. As it spins a cutter much like the cheap plastic sharpener cuts a thin veneer of the wood and forms the layers that are later oriented in an alternating pattern to build up the sheet of plywood. The cross-laid fibers make plywood much more stable. (boy that's off topic)

I have to wonder as my wife did; why are we building this? Have I lost sight of what the TS wanted to accomplish? is it the power of the commercially available sharpener at issue? Reminds me of my six year old grandson who for some reason has a favorite one word question: "Why?" To which I run out of answers but he always has one more question. "Why?" Gets to a point where I either say "I don't know" or "Ask mommy to bake cookies."

 

The pencil sharpener is interesting.

I have to wonder as my wife did; why are we building this? Have I lost sight of what the TS wanted to accomplish? is it the power of the commercially available sharpener at issue? Reminds me of my six year old grandson who for some reason has a favorite one word question: "Why?" To which I run out of answers but he always has one more question. "Why?" Gets to a point where I either say "I don't know" or "Ask mommy to bake cookies."

Well, I wondered about that also. I suggested the available off the shelf solutions back there somewhere in the beginning. The thread starter seemed to imply he wanted like a six million dollar man version of an electric pencil sharpener, possibly he has oak pencils? Anyway, it does get interesting how many ways we can sharpen the common pencil.

Ron

 

I'm the poster who tried to explain to the TS that GA was impossible. He replied the the post was a joke. Let's assume the pencil sharpener was part of the joke and we are wasting time on it.

 

I'm taking something like this and putting it on a motor to spin around very fast and powerfully.

 

I'm taking something like this and putting it on a motor to spin around very fast and powerfully.

That is the one/method I posted back in #20.
If spinning at high rpm, you may not have sufficient torque if making it pocket size.
Although mine runs about 200rpm.
Max.

 

The razor blade doesn't shear it cuts through in a similar process to how they make plywood.

If that blade isn't shearing also what would your description of it be? Seems to me the what they describe the layer cutting for veneer(what they do for plywood) is called a shear lathe cutter, and the process is called something like, "cambio-shearing".

 

@shortbus: I'm not the expert at woodworking. When I refer to sheering I mean the cutting blade is skewed so as to not face the cut directly. Take a plane for instance: You can push it straight along the wood edge with the blade 90˚ to the cut OR you can skew the blade by turning the plane slightly to one side - say - 70˚ angle. Thus, a shearing action.

The sheering I am referring to in the rotary pencil sharpener has spiral blades that actually cut on some angle whereas the sharpener with the razor blade cuts directly into the pencil. Same is true of the plywood shearing.

Sheer: (noun) A deviation or divergence, as of a ship or plane from its course; swerve.

Shear: Mechanics , Geology . to become fractured along a plane as a result of forces acting parallel to the plane.