Using a TINY 96 GW Motor for Electric Pencil Sharpener

The listing for the motor is wrong; there is no possible way for a motor that size to use gigawatts. A motor weighing more than you do would not need even one gigawatt.

An earlier poster found the true specs. One of the fundamental rules of this hobby is not to get carried away by wrong info and the internet is loaded with wrong data.
 

Tonyr1084

Joined Sep 24, 2015
7,853
16GW! That's 13.2 times stronger than what Doctor Emit Brown used on his Delorian Time Machine. With that kind of power you can sharpen pencils for the next century. Tim Taylor - eat your heart out!
 

Tonyr1084

Joined Sep 24, 2015
7,853
And google already has enough of my info
Google knows more about you than YOU know about you. I guess the good news in all this lack of privacy is that it won't last long. Maybe another 30 years or so. Then all we'll be is fossils for the next sentient species to arise and perform archeology and discover who we (those boneheads) were and how we destroyed ourselves.
 

Thread Starter

-live wire-

Joined Dec 22, 2017
959
The listing for the motor is wrong; there is no possible way for a motor that size to use gigawatts. A motor weighing more than you do would not need even one gigawatt.

An earlier poster found the true specs. One of the fundamental rules of this hobby is not to get carried away by wrong info and the internet is loaded with wrong data.
It was intended as a joke! Obviously it is not 96 GW!
 

MisterBill2

Joined Jan 23, 2018
18,176
The electric one on my desk uses 4 AA cells, it has a 'standard' looking hand style sharpener that is rotated, one advantage is if the batteries are flat I just use it as a normal manual version.;)

View attachment 169529

Max.
With that small fast motor, take a manual one like shown in post #20 and replace the straight blade with a milling bit or a router bit to just remove a very small amount with each pass. If the amount removed was small enough it would avoid breaking the leads while sharpening. AND it would not take much power.
 

shortbus

Joined Sep 30, 2009
10,045
With that small fast motor, take a manual one like shown in post #20 and replace the straight blade with a milling bit or a router bit to just remove a very small amount with each pass. If the amount removed was small enough it would avoid breaking the leads while sharpening. AND it would not take much power.
Can tell that you've never been a machinist, or done machine work.
 

MisterBill2

Joined Jan 23, 2018
18,176
Can tell that you've never been a machinist, or done machine work.
As a matter of fact, I have done a fair amount of machine work. Yes, I am quite aware that it would be tedious to produce the hardware, but I can see already what the design looks like. And all of the machines that I did the mechanical designs for worked on first startup, at least the mechanical portions always did.
Certainly the mechanical system would have a degree of complexity, and the product would never be a consumer item because of the price for the machining time and effort, but it would certainly sharpen pencils quite well.
 

Ya’akov

Joined Jan 27, 2019
9,070
With that small fast motor, take a manual one like shown in post #20 and replace the straight blade with a milling bit or a router bit to just remove a very small amount with each pass. If the amount removed was small enough it would avoid breaking the leads while sharpening. AND it would not take much power.
If the cutter was a fixed one like a traditional sharpener, with a modified cutting surface that minimized contact, and the device handled the pencil feed, it could use feedback from the motor to avoid stalling it and use a much smaller motor.

Something like your idea, inverted—but, I think, mechanically simpler.
 

shortbus

Joined Sep 30, 2009
10,045
Then explain how a round mill cutter spinning around a pencil but not turning itself, like the flat cutter in the manual sharpener, is going to make a angle like the point of a pencil? It will only mak a single groove in the side of the pencil, due to the geometry of the mill cutter. A helix (cutting edge of the mill cutter) that is held static, spinning around a part(pencil) will only cut where there is contact, and that will only be at one point. This will make a groove, not a angular cut.
 

Ya’akov

Joined Jan 27, 2019
9,070
Then explain how a round mill cutter spinning around a pencil but not turning itself, like the flat cutter in the manual sharpener, is going to make a angle like the point of a pencil?
i have to say I assumed one or the other would be rotating since that is an obvious prerequisite.
 

djsfantasi

Joined Apr 11, 2010
9,156
Then explain how a round mill cutter spinning around a pencil but not turning itself, like the flat cutter in the manual sharpener, is going to make a angle like the point of a pencil? It will only mak a single groove in the side of the pencil, due to the geometry of the mill cutter. A helix (cutting edge of the mill cutter) that is held static, spinning around a part(pencil) will only cut where there is contact, and that will only be at one point. This will make a groove, not a angular cut.
First, who said use a round milling cutter? I’d suspect an end milling cutter would be used. Or any cutter whose cutting edges are axial. Then, the cutter axis must be at an angle to the pencil axis.
 

MisterBill2

Joined Jan 23, 2018
18,176
i have to say I assumed one or the other would be rotating since that is an obvious prerequisite.
I did state that it would not be simple! The pencil would be rotated by hand and the cutter would function like an end mill, being at right angles to the angle of the taper. Thus it would indeed only work on a very small segment of the pencil at any time.So as the pencil was rotated the cutter would traverse from one end of the taper to the other end of the tapered section. Thus the whole tapered point would be created after a fairly short time. The added advantage of this approach is that it would produce a nice high-pitched whine as it did the cutting, thus demonstrating that it was far superior to the more common sharpeners that only produce a growl. So the machining process will include both the production of a precision slide almost an inch long as well as a rotating collet to maintain the pencil in alignment, The collet will need to be adjustable so as to firmly support pencils of different diameters. Hopefully you can visualize what I am describing. Picture a small milling head mounted on the compound of a lathe, with the pencil grasped by a 3-jaw chuck, as an overgrown version of the same concept. OK?
 

shortbus

Joined Sep 30, 2009
10,045
Oh, that's going to be much better than rotating a single blade, something that has worked for who knows how long.
Or he could build a laser beam to evaporate the wood. Or do it like they do when they make golf pencils or colored pencils, with a grinding wheel.
 

Ya’akov

Joined Jan 27, 2019
9,070
Did you read his original post?
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...
 
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