The Unbreakable Pencil – Zebra DelGuard – Gadgets Under $10
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The Unbreakable Pencil – Zebra DelGuard – Gadgets Under $10

November 22, 2019


This looks like a perfectly normal mechanical
pencil. But it actually has a lot of interesting engineering
to solve one frustrating thing. Broken lead. Hi I’m David and this is the Zebra Delguard. The unbreakable lead pencil. So let’s look at this pencil in action. During typical operation it works and feels
like any normal mechanical pencil, but if you’re a heavy writer who applies too much
pressure on your lead tip, that’s where the Delguard protective mechanism kicks in
to prevent the lead from breaking. But let’s take a closer look. Pressing down firmly on the lead at an angle
and you’ll see the sleeve tip extends out to protect the lead. Or if you press down vertically on the lead
it will auto retract inside again protecting the lead from breaking. It’s the combination of these two mechanisms
that makes it almost impossible to break the lead no matter how much pressure I put on
it. Opening up the pencil give us a better idea
on how it works. This is the chuck, it’s the part of the
pencil that dispenses and holds the lead in place and makes that clicky noise when you
press on the cap. But what’s special in this case is the suspension
of the chuck. On this pencil the chuck is held in place
by a spring that allows it to move around freely from the rest of the pencil. With enough pressure the spring will compress
and push deeper inside the case. But it also has a lot of flexibility to bend
off axis from the rest of the body when you press on the lead at an angle. The next part to look at is the sleeve or
guard of the lead pencil. And this part is designed to extend out and
shield the lead when you press down on it at an angle. The sleeve is held in place by a spring but
when you pull it out you can see that the sleeve isn’t cylindrical but instead curved
like a spinning top. So when you apply a perpendicular force to
the sleeve, the curved shape causes it to extend out and shield the lead from breaking. This dual spring design makes it almost impossible
to break the lead on your pencil from pressure alone. But it does have some limitation. The DelGuard pencil comes with the warning:
Lead may break when retracting the lead more than 3 times or using a softer lead. And this makes sense because the guard system
is only design to extend out so far. So any part of the lead that extends past
the range of guard just can’t be protected. So that’s the Zebra Delguard mechanical
pencil. A pretty cool feat of engineering to solve
the problem of lead breaking for heavy handed writers. But if you don’t have an issue with breaking
your lead, it feel just like any normal lightweight mechanical pencil. In that case, maybe check out the Uni Kuru
Toga. Another pretty nifty piece of pencil engineering. But hope you guys enjoyed this one. You know what to do. And I’ll see you in the next video.

Only registered users can comment.

  1. just ordered it comes in today extremely excited mostly because I always run out of lead because I break it all the time

  2. Does the sleeve touch the paper and create friction? I like a smooth writing experience with soft lead on paper.

  3. My zebra delguard broke but still works if u know what I mean and sometimes it just shoots the grip out like a gun and people in my class wants to trade me something for it and an annoying kid in my class said he’ll give it to me for $70 bucks lol
    But NO
    Cause the chance of that happening is rare.
    Oh and if u hold the grip and THEN press the button the lead comes out

  4. I have that pencil and the lead kept breaking
    Turns out I had it out to much and used to much pressure

  5. So when this video just came out I said I'll buy it, and 2 years later….
    MOM! can I buy this….
    Mom: Sure
    Me:Holy Sh*t Yes! Only 2 years to get!

  6. I bought this pencil right after I saw your video. It's been two years, I am 100% satisfied with this pencil.

  7. i dont lose pens so i dont have a problem with buying something like this where you only have one of them at a time so im definitely going to get this now

  8. me: puts 6 inch lead inside
    me: puts the whole lead out
    also me: stabs paper perdendicularly
    lead pencil: breaks
    me: i want a refund….

  9. Me while using a mechanical pencil in school: in the text uh crap I just broken the led ok in the text it says crap I ddI it agin I give up throwing the pencil in the garbage and I pull out a pen that later I will break to

  10. The lead will break if you take a bunch of that out so technically this is not a unbreakable pencil you could literally break the lead and break the pencil itself

  11. I got that pencil and used it for 4 months and then the easer was dead. I liked it because it could cut paper and you didn't even mention that part.

  12. Mine was stolen by a classmate never got it back and when I went to the stores to buy it it was out of stock😭

  13. If you push down so hard to be able to break the lead that is your own problem, so change the way you hold the pencil. You might want to only have 1/16 or 2 mm of lead outside the guard. I have a pile of Kohinoors and Rotings as an mechical engineer so I know more than a little about mechanical pencils.

  14. Me: Hey I just got this pencil and it’s supposed to be unbreakable!

    Give pencil to friend

    Friend: Oh yeah? Watch this. Snaps pencil in half

    Me: … I meant the lead

    Friend: Oh…

  15. le cri I want the shaker Tombow mixed with this and then with the Uni-Alpha Shaker. But alas, I'M NO ENGINEER XD

  16. This delguard is so strong that when my friend in school tried to break it with his regular wooden pencil, the delguard broke my friend's ✏️ into pieces XD

  17. I've always found mechanical pencils beautiful to write with, I don't know why. I've had on of thsee for a few weeks and a great $3 piece.

  18. i just dropped it in class today, forgot to pick it up went to the washroom and someone stole it, smh. Found it was my teacher, she put it in her pencil case

  19. I have both the Uni Kuru Toga and Zebra DelGuard, thinking that they are both "unbreakable" pencils… but ONLY the DelGuard manages to prevent my lead from breaking (maximum 2 clicks, not 3!) – and I am indeed using 4B leads.

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