How to modify a rotary pencil sharpener to sharpen off-center leads?

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In summary, when using rotary pencil sharpeners, it is common to end up with a pencil point that has a long sliver of wood along one side. This is likely due to the pencil lead being off-center in the pencil. Turning the pencil while sharpening may not fix the issue. To modify an electric pencil sharpener to avoid this problem, it may be helpful to use a guide sleeve to keep the pencil centered and parallel. Another potential solution is to shave off a sliver of wood on the side where the lead is farthest from the outside, but this may only be a temporary fix. More research is needed to determine the exact cause of the off-center lead and find a long-term solution.
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Stephen Tashi
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Suggest ways to modify a rotary electric pencil sharpener so it sharpens pencils whose leads are off center without leaving a sliver of wood along the lead.
When inexpensive pencils are sharpened in rotary pencil sharpeners, the result is often a pencil point that has a long sliver of wood running along one side of it. I think this is due to the pencil lead being off center in the pencil. Turning the pencil while sharpening it usually doesn't fix the problem. (I don't understand why.)

How could I modify an electric pencil sharpener so it would not leave the sliver of wood along the point? I wouldn't mind having to turn the pencil as I sharpened it, if that was required.
 
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  • #2
Once the cone is established by the initial sharpening the subsequent sharpening is self centering. Turning the pencil during the first time in may help. The pencil lead/wood assembly is done by machine and is centered pretty well.
The sharpener is usually set for multiple sizes of pencil and has a large bore with a smaller hole matching the pencil covering the front. This can act as a lever transferring any side load into misalignment with the cutters.
A guide sleeve keeping the pencil centered and parallel should eliminate the problem. This also limits how short the pencils can get.
 
  • #3
Stephen Tashi said:
I think this is due to the pencil lead being off center in the pencil.
Before a solution can be found, I think you'd have to determine if this is indeed the cause.

If it is, and the lead is actually off-centre, I suggest trying this:

Take a knife and cut a sliver or two off the side where the lead is farthest from the outside.
When you insert the pencil, it should slip into the cone off-centre, so the rotation axis of the cutters will (ideally) line up with the off-centre lead:

1571412614626.png


This will only help initially. As Torbert points out, the next time you sharpen it, the body of the pencil will self-centre, and you'll be back to the same problem. Unless, I suppose, you repeat the sliver shaving each time.
 

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FAQ: How to modify a rotary pencil sharpener to sharpen off-center leads?

How can I modify a rotary pencil sharpener to sharpen off-center leads?

One way to modify a rotary pencil sharpener is to adjust the blade angle. By loosening the screws that hold the blade in place, you can adjust the angle so that it aligns with the off-center lead. This will allow the blade to sharpen the lead evenly.

Can I use any type of rotary pencil sharpener for this modification?

Yes, most rotary pencil sharpeners can be modified to sharpen off-center leads. However, it's important to choose a sharpener with a sturdy blade that can be adjusted easily.

Will this modification damage my pencil sharpener?

If done correctly, this modification should not damage your pencil sharpener. However, it's always a good idea to test it on a spare pencil first before using it on your favorite pencil.

How do I know if the modification was successful?

You will know the modification was successful if the off-center lead is sharpened evenly and does not break while sharpening. You may also notice a difference in the sound or feel of the sharpening process.

Is this modification reversible?

Yes, this modification is reversible. Simply adjust the blade angle back to its original position and tighten the screws. Your rotary pencil sharpener should now be back to its original state.

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