Guess What. I Designed Another Knife. - Lemmy.World
cross-posted from: https://lemmy.world/post/9936120
[https://lemmy.world/post/9936120] > That’s right, I’ve been at it again. > >
(And if you want to fast forward through all the foreplay and get right to the
action you can download the models package here.
[https://drive.google.com/file/d/1TB8YDRJ0Zv_2tbedTH_wX5evKn41yJbC/view?usp=drive_link]
Merry Christmas, ya filthy animals.) > >
[https://lemmy.world/pictrs/image/273f8881-7401-4bf1-8c17-5d1c40018410.jpeg] > >
Here’s a slightly more practical printable than the last one,
[https://lemmy.world/post/9035683] which I’m calling the Sparrow. > > This knife
has the same design goals as before: Fully printable, with no external hardware
except the Stanley utility knife blade, no supports, and mechanically as close
to a real functional mechanism as is possible. > >
[https://lemmy.world/pictrs/image/d8db6403-4e8c-4f40-8fb9-1a7b7b39b8ee.jpeg] > >
[https://lemmy.world/pictrs/image/11321e29-ecb7-416c-b913-bc546fefc603.jpeg] > >
So it’s a real working lockback folder. It locks up pretty good, too. Getting
that working was one of those things that sounded really simple conceptually but
actually turned out to be a pain in the ass to achieve. The mechanism owes a bit
of credit to the Secret Of Show Business, via the wooden Spyderco kit
[https://lemmy.world/post/8651859] we looked at a while back. > > Oh, and making
it in orange gives the the opportunity to do one of them there themed gear
flat-lays that are so popular with the influencers nowadays. > >
[https://lemmy.world/pictrs/image/ebc83000-7ea3-440c-b5f1-2413dea3f9eb.jpeg] > >
The Sparrow is a pretty pocketable EDC size at about 3-5/8" long when closed.
It’s noticeably shorter than my CQC-6K, but it’s longer than a Gerber EAB
[https://lemmy.world/post/8853606] because I can’t cheat and use smaller
diameter steel screws. A noticeable portion of its length at the tail end is
just to accommodate the printed screw, which I can’t make much thinner if I’d
like it to continue to, you know, work. > >
[https://lemmy.world/pictrs/image/92967319-f501-4d67-acd3-c67177ac4aeb.jpeg] > >
Of course, it has a reversible pocket clip available as well. > >
[https://lemmy.world/pictrs/image/250a9e26-b534-427f-9bd5-3c67f71aaa2a.jpeg] > >
Sure, it’s not as much fun to fiddle around with as a balisong knife. But I find
the simple folding design a lot more practical for daily use. (I’ve been beating
the shit out of my prototype, as is tradition, for a whole week at work before
considering it “done.”) Plus it’s much less likely to draw the ire of the local
constabulary if you happen to live in one of those countries with an unfortunate
deficiency of bald eagles. > > ▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓ > >
Preemptive Burning Questions That Would Otherwise Inevitably Appear In The
Comments > > Q: Why are all the screws and pins separate parts? Don’t you know
you could simplify the design by making it all one solid lump? > > Of course I
know that. However, let’s say you manage to break one of those titchy little 2mm
pins. Would you rather re-print the entire monolithic handle liner assembly, or
one 0.3 gram pin? > > Q: But also making the handle scales separate was still
totally pointless, right? > > Sure, except this allows me to make a variety of
scale styles available, including zooty skeletonized ones you can print in a
complimentary color for two-tone aesthetics: > >
[https://lemmy.world/pictrs/image/9a3000a8-5d4d-4ac6-ab21-eca059f9331e.jpeg] > >
The possibilities practically suggest themselves. > > Q: This is going to break
instantly and you’ll slice your fingers off. Printing something like this is so
unsafe! I know this because I have done no math or testing whatsoever, but am an
armchair expert! > > Well, I clamped my prototype knife in my vise and yanked on
it against its opening axis with a dial scale until it broke.
[https://i.imgur.com/DIkb5af.gifv] You know, for science. > > The major markings
on that scale are 5 pound increments, by the way. It gave a noticeable warning
creak at 37 pounds, and finally broke with the dial indicating 39 pounds. It was
only made out of ordinary PLA. As you can see, I actually had to adjust my grip
and I was bracing my foot against the bottom of my workbench to be able to put
enough oomph into it to break it. If you torque your box cutter at nearly 40
pounds in day-to-day use I suggest you’re probably using it wrong. Provided you
don’t try to use this knife as a crowbar or a piton I really don’t think you’ll
have anything to worry about. > > Q: What’s with the dumb bird on everything? >
> He’s a penguin. Don’t be dissing my penguin, man. > >
▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓ > > .STL Files Download: Here.
[https://drive.google.com/file/d/1TB8YDRJ0Zv_2tbedTH_wX5evKn41yJbC/view?usp=drive_link]
> > As before, the above is provided as-is and with no guarantees, and you are
free to make your own or give printed knives away to friends or family or what
have you, but prints of my models are not to be sold and not to be uploaded or
reposted to any model repository or anywhere else outside of the Lemmy-sphere. >
> ▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓ > > Assembly Instructions and like a
million pictures As Follows: > > People with no interest in printing or
assembling one of these can stop reading now. I promise I’ll go back to my usual
program of loquacious show-and-tell/point-and-laugh over various whackmobile
novelty knives in my subsequent posts. > > Anyway, you will need to print this
small mountain of components. > >
[https://lemmy.world/pictrs/image/b5eec95a-68a8-4a46-a1ea-eb105c100f15.jpeg] > >
The complete bill of materials is as follows: > > - 1x Blade Holder > - 1x Top
Liner, 1x Bottom Liner > - 1x Lock Bar > - 1x Spring Block > - 2x Female Screws
> - 2x Male Screws > - 2x 2mm Pins > - 1x 4mm Pin > - 1x Top Scale, 1x Bottom
Scale of your choice > - If you want to use the clip, you need 1x Pocket Clip,
and replace 1x of the short female screws with the longer one included, labeled
“for pocket clip.” > > Several components are quite close fits, and various pins
and screws need to fit through their respective holes. If your printer produces
parts with a lot of elephant’s foot on the bottom you’ll probably have to trim
the inside edges of the holes with a utility knife blade, which is something I
should hope you’ll have to hand when embarking on this project… > > Start with
the bottom liner. You can identify it as the one with the chamfered holes for
the pins, which you’ll notice have flared heads. > >
[https://lemmy.world/pictrs/image/0d0d32b8-94b4-43b9-82ce-50594fcca838.jpeg] > >
Stick the 2mm pins and the 4mm pin through. They’ll sit flush with the underside
of the liner. If they don’t, you have some trimming to do. Then sandwich your
bottom handle scale underneath that. The scale will keep the pins from falling
out. > >
[https://lemmy.world/pictrs/image/cf6b950c-af0c-487d-b17f-7706500e3982.jpeg] > >
Then identify your screws. There are two screw lengths, and if you’re going to
use the pocket clip you’ll put the shorter one through the front where the blade
goes on, and the longer one through the tail where the clip will go. If you’re
not going to use the clip, just employ two short screws instead, one on either
end. > >
[https://lemmy.world/pictrs/image/f2919bd1-20e4-4eee-99a6-eb6cd185175e.jpeg] > >
Either way, stick the female screws up through the entire sandwich. > >
[https://lemmy.world/pictrs/image/a3a9ef20-6693-48e0-b48d-6028b3efc354.jpeg] > >
Drop the blade holder on the front screw. > >
[https://lemmy.world/pictrs/image/51e6df90-74d9-4428-98c6-b5da8acfb844.jpeg] > >
Then put the lock bar through the middle pin. Play with it a bit and make sure
it drops cleanly into the notch on the blade holder. If anything is going to
require tuning or sanding it’ll be the interface between the lock bar and its
notch there. It should also pivot freely on its pin. If it’s a really tight
draggy fit this will annoy you, and this’ll make the lockup unreliable as well.
> > [https://lemmy.world/pictrs/image/557609e3-5c84-45f1-8078-e4c455258332.jpeg]
> > The spring block goes on next, and obviously the holes on it are for your
last remaining pin plus the screw at the tail end of the knife. The prong on it
goes below the end of the lock bar, i.e. on the inside. When you press the hump
on the lock bar it should spring up and down satisfactorily. > >
[https://lemmy.world/pictrs/image/5353fd62-f610-44ef-ba69-086600cb8b8f.jpeg] > >
Then the top liner goes on. All three pins should rest home in the holes in it.
> > [https://lemmy.world/pictrs/image/ea3f4006-fcd6-4daf-9fa6-5d2201369acd.jpeg]
> > Then the top scale and its (male) screw. You can drive the screws with a
penny if you’re too perverse to use a screwdriver. > >
[https://lemmy.world/pictrs/image/2ca32517-e51a-4e75-9381-3e0f798ce2a6.jpeg] > >
If you’re going to use the pocket clip, decide which side you want it on (of
course it’s reversible; I’m not an animal) and stick it through the slot on the
tail end of the knife. > >
[https://lemmy.world/pictrs/image/58d6e410-8b9f-46aa-9523-3cbe0231003b.jpeg] > >
For strength, I recommend putting the female side of the tail screw through the
clip, then through the rest of the assembly, and then put the male screw on the
side that’s not holding the clip. Depending on which side you chose to put the
clip on you may have to take it out and stick it through from the other side. >
> FYI, if you don’t use the pocket clip there is a hole in its mounting slot you
can use to tie a lanyard through instead, if you’re into that sort of thing. > >
[https://lemmy.world/pictrs/image/80542216-12d7-4362-8a15-89f576a31002.jpeg] > >
The blade slides in from the front and rides in a track that holds it on both
the sharp edge and the blunt spine. Press the blade locking pin flexture down to
get the pins to clear. > >
[https://lemmy.world/pictrs/image/fd17c544-3aee-4f86-9be3-40b36a7566d1.jpeg] > >
The pins ought to click into the two notches on your blade quite nicely. If you
noticed that this is the same blade holding mechanism is very similar to the one
on my last knife, that’s because you’re right and it’s exactly the same. > >
[https://lemmy.world/pictrs/image/501061a9-29c3-4372-a451-70375daed229.jpeg] > >
Fin.
