The Deadbeat Escapement Mechanism
Ғылым және технология
Also known as the Graham Escapement, the deadbeat is a variant of the anchor escapement that eliminates the recoil action, increasing energy transfer efficiency from the driving wheel to the pendulum. It's the time-regulating component of a mechanical clock, and this model will hopefully be developed into a fully functional timepiece with a practical runtime.
Stl files will be released at Printables, Cults3d, and Myminifactory once it is finalized. Follow me on either one of the platforms to receive updates when the files are available!
Printables: www.printables.com/social/497...
Myminifactory: www.myminifactory.com/users/M...
Cults3d: cults3d.com/en/users/Mechanis...
Non printed parts (commonly used in all other designs):
1.5mm Pin (Ali Express) : bit.ly/3g3vxBY
M2 Screw (Ali Express): bit.ly/3STSeqG
Пікірлер: 4 400
Unlike any other model I’ve seen, this includes a double pendulum plus a crank to wind the weights independently, showing you how a clock weight is reset without disturbing the time. Brilliant and simple
@jhsevs
5 ай бұрын
Time is never disturbed ⏳ it’s only there and it’s running out ⌛️
@matthiass._.
5 ай бұрын
It's also shaped like a penis fr
@juliannaszarka6666
4 ай бұрын
@@jhsevs❤❤😂😢😭😭😭😭🤣🤣😴😴😴😴😴😴🤬🤬🤬🤬🤬🤬🤬🤬🤬🤬🤬❤️❤️❤️❤️❤️❤️💘💘💘🕳️🕳️🕳️💯💯😽🎉
@Crykir
3 ай бұрын
Time can never run out, as for now time hasn't even happened.
@danylol772
3 ай бұрын
Those two comments make me feel second hand embarrassment
This is actually the best demonstration I’ve seen on how a mechanical clock works
@Heck_Yeah
Жыл бұрын
yeah
@rensonernest4398
Жыл бұрын
@@Heck_Yeahs
@sameerageeth3912
Жыл бұрын
❤
@qwasbae5854
9 ай бұрын
fancy metronome
@xilongma4794
9 ай бұрын
Remove the l
I like this, the falling weights would provide a more linear force than an unwinding spring
@johnflux1
2 ай бұрын
You meant constant, but either way the force shouldn't matter at all (ideally of course), because the timing is purely dependent upon the length of the pendulum.
This could be a great time tellling tool for competitions, like an hour glass
@MonkeFlip2000
Ай бұрын
Or like a clock????
@Jacob-yg7lz
23 күн бұрын
This is a clock without a face.
@gogodogodo3283
17 күн бұрын
Maybe use a fking hourglass then buddy?)
@randomstranger1188
10 күн бұрын
@gogodogodo3283 Bro, chill. This design would be an extremely unique timer that would look very cool in a competition, and the timeing mechanism is capable of doing more than just one specific time measurement.
"You can only save one... clock's ticking, Batman"
@ryanjeffery292
3 ай бұрын
"Oh yeah?" *rewinds clock without breaking eye contact with villain*
@linkbond08
3 ай бұрын
There's no laws for the Pokemon Batman... DON'T DO IT JOKEEEEEEER!!! I'm gonna do it!!
@Fireheart__
3 ай бұрын
@@linkbond08💀💀
@TheOneCity1
Ай бұрын
900th liek
@Panda_man78071
8 күн бұрын
hey clock king the early 2000s called they hit the second tower
I thought it said “the deadbeat dad escape mechanism” 💀
@reaanncariaga2898
Жыл бұрын
👑👑👑👑👑
@eclatshwartzbaumcybertune2063
Жыл бұрын
My mind went there also lol
@ddawg3974
Жыл бұрын
No you didn't
@ryan-uk6jf
Жыл бұрын
@61k man especially with that username 💀
@zac9933
Жыл бұрын
Just magically adding words to things. I guess our minds go the direction we most subconsciously expect thing to go....
I’d pay this guy to fix my grandfather clock
Simple yet elegant demonstration
I love how it formed a "familiar" shape
@ge118
Жыл бұрын
get yer mind of the gutter! have some cold water🌊🌊🌊🌊🌊🌊🌊🌊🌊
@Sand_the_Lazy_sand
Жыл бұрын
as RCE said, its the strongest shape
@bakedgoldfish45
Жыл бұрын
😏😏😏😏😏
@renownedbandanawearer1345
Жыл бұрын
Why else would it be called the _Deadbeat_ Escapement Mechanism? 😏
@mrkill2020
Жыл бұрын
@@ge118 how about you get some bitches
“Amazing, what does it do?” “I haven’t thought that far ahead”
@francomelisa498
8 ай бұрын
😅
@nicreven
7 ай бұрын
it's a clock! :D
@jeconiahhoffman4892
7 ай бұрын
Actually, this is the basic concept for how grandfather clocks work! They're absolutely amazing and fascinating pieces of mechanical art. If you love that sort of thing, then be prepared to end up in a very expensive hobby very quickly lol
@spyseefan975
6 ай бұрын
It slows down spin from (in this case) gravity driven power, which can be used to turn anything (that it has enough torque to turn) for much longer than just tying weights to it and letting them fall.
@Sebastian-cn8lh
6 ай бұрын
i think is a battery.. energy storage (kinetic energy)
Bro had no idea what kind of shape is that💀
i didn’t see it until looking at the comments. my mind must be healing
@SpheresVA
Жыл бұрын
same
@flooku987
Жыл бұрын
ZE HEALING IS NOT AS GRATIFYING AS ZE HURTING
@hirokinkun186
Жыл бұрын
Yeah, I feel like people are too dirty minded here
@Y0UMYT0Y
Жыл бұрын
@@SpheresVA
@Y0UMYT0Y
Жыл бұрын
@@SpheresVA
Intresting gear shape ya got there 😂
@SantuaryTakke
2 ай бұрын
Its how you tell time you dirty minded little-
@I_eat_drywall95
2 ай бұрын
I AM A MATURE ADULT! I AM A MATURE ADULT! I AM A MATURE ADULT! I AM A MATURE ADULT!
@thestranger1475
2 ай бұрын
@@I_eat_drywall95You’re the opposite of me, I saw that and said: “haha Penis…”
@S0meCrazyIdiot
2 ай бұрын
You’re not, none of us are if we reply to this comment…
@puffboifedora6831
2 ай бұрын
I AM not mature that looks like a dong
This is remarkably cool looking. I want a clock like this mechanism
The ticking is so satisfying😮
Her: Nice clock there Him: yeah its pretty big isnt it?
@Hebelinahebel1
Жыл бұрын
L joke
@spawnpoint111
Жыл бұрын
@@Hebelinahebel1L human
@SmileUponBalls
Жыл бұрын
💀
@Hebelinahebel1
Жыл бұрын
@@spawnpoint111 When i read your reply i got a feeling of anger and i have this suden urge to listen to a drake song. I wanna get rid of it, any tips?
@spawnpoint111
Жыл бұрын
@@Hebelinahebel1 the pacific rim ost Its made by adele
It’s interesting how mechanical clocks share components who serve similar purposes to electronics.
@danielzhang5395
Жыл бұрын
I suppose a clock is a form of analog computer
@Indra_Security
Жыл бұрын
@@danielzhang5395 Maybe. Pseudo analog computer? Probaly.
@Indra_Security
Жыл бұрын
@@user-rk2ht9xq5s Lmfao
@Funfactthisisahandle
Жыл бұрын
0________o
@kylerwin
Жыл бұрын
Yes, mechanical systems are analogous to electrical systems. An LRC circuit diff equation looks a lot like a mass/spring diff eq
So that’s how those old clocks work
Thats mesmerizing to look at and how its put together
I'd love to print this, I found sourcing the steel rods is the hardest part of building your designs. This one seems minimal in its requirements though, and would love to have it as a desk piece.
@nono9370
Жыл бұрын
Pianowire
@WildoTheRubberFist
Жыл бұрын
steel pins from any hardware store. Or find a free 2d printer and take it apart, they are full of useful pins, screws and other doodads.
@mjolnirswrath23
Жыл бұрын
Or just magnets in opposition
@serios555
Жыл бұрын
Use nails, choose diameter and cut or saw to length
@RapTapTap69
Жыл бұрын
Nails for hanging pictures work really well. You can even leave the head on and they are easier to glue to the body
Also just known as a classic clock. My family owns an old coukou clock, it has the exact same mechanism inside, got weights hanging off of it.
@clocklover0110
Жыл бұрын
usually German cuckoo clock uses another mechanism 'recoil escapement'
@georgeblack589
Жыл бұрын
This is nothing like a cuckoo clock. One weight in the cuckoo clock drives the strike train, while the other weight drives the time train (assuming the cuckoo clock isn't musical). This clock uses BOTH weights to drive the time train. It also has a different escapement from what you'll find in a cuckoo clock.
@dinamosflams
Жыл бұрын
there are not that many gears inside this CLOCK huh
@KINGK20092009
Жыл бұрын
Yeah them using technical terms for a basic design just feels like putting on airs
@georgeblack589
Жыл бұрын
@@KINGK20092009 They're hugely different. A deadbeat escapement is much more efficient than a recoil escapement, meaning it'll keep better time and last a lot longer. The fact that this is 3d printed is causing the hundreds of years of brilliant design to go completely unappreciated and misunderstood.
Such a beautiful design
Very very interesting and a great example of a mechanical clock in action 👍
Him: *puts 6 gears* "Sigh time to go to the comments"
@jackgraff420
Жыл бұрын
7 lol
@brettoyanagi9441
Жыл бұрын
@@jackgraff420no there is 6
@jackgraff420
Жыл бұрын
@@brettoyanagi9441 7 lmao
@ramsinte
Жыл бұрын
5 gears. yellow pieces are not gears and the one record to the pendulum is not a gear etheir.
@Virus0_0
Жыл бұрын
@@jackgraff4205, "lmao"
That’s one cognitive behavioral thearpy session alright
@jiralishu
Жыл бұрын
Maybe a different kind of cbt.
@tonkotsuramen8453
Жыл бұрын
the good cbt
@grayscale888
Жыл бұрын
I can give you a better cbt if you know what I mean 😉
@thuyduong8695
Жыл бұрын
@@jiralishu 😊
@Like.a.boss.
Жыл бұрын
definitely, its even smiling at you
This makes great ASMR. So satisfying.
amazing work .............appreciable
So that’s how a grandfather clock works. That’s really cool
@larry8712
Жыл бұрын
created by da vinci btw
@silaskuemmerle2505
Жыл бұрын
@@larry8712 off by about a century, rather, it was invented by Christiaan Huygens.
@larry8712
Жыл бұрын
@@silaskuemmerle2505 Oh no sorry he probably invented the grandfather clock but da vinci made the original, Christiaan just added an extra weight and thats about it
@silaskuemmerle2505
Жыл бұрын
@@larry8712 incorrect, Huygen invented the escapement. Galileo discovered the idea of using a pendulum for timing. Stop attributing every scientific discovery from the renaissance to Leonardo DaVinci.
@larry8712
Жыл бұрын
@@silaskuemmerle2505 but the clock of da vinci already has a swinging pendulum, its just at the top going back and forth on both sides instead of going left to right
This is so unbelievably satisfying. Hats off to you, clock wizard.
@circumferenced
Жыл бұрын
cock wizard*
nice clock bro
The coolest 3d print ever.
"You are a mature adult... You are a mature adult..."
@fxrwxrd6936
Жыл бұрын
💀
@Ricolicous
Жыл бұрын
Science is adulting
@thehoward8736
Жыл бұрын
Es ciencia para adultos
@TylerDurden-id6yp
Жыл бұрын
@@thehoward8736 lo dice porque los engranajes tienen forma de pene. Muchas gente es lo primero que ve.
@renpunye4650
3 ай бұрын
What? I see nothing dirty there
That's a soothing sound hearing that constant "Tick, Tock, Tick Tock"
@AnimilesYT
Жыл бұрын
This is the sound of KZread, not Tiktok :p
@CeilingFanRat
Жыл бұрын
@@AnimilesYT wow i am laughing so hard 😐
@zaeemchogle848
Жыл бұрын
@@AnimilesYT tellm me your dumb without actually telling me your dumb
@batrachianbill9760
Жыл бұрын
@@AnimilesYT good joke
@S-CB-SL-Animations
Жыл бұрын
@@AnimilesYT Not funny + Didn't laugh + Ratio + You fell off + L + This you? >>> 🤡
Deadbeat escapement mechanism, I usually call it leaving to buy milk
My Deadass read it as ‘deadliest escapement mechanism’ 😂 but seriously a wonderful model you made there.
Dudes a redstone professional
@Mr._Bellic
2 ай бұрын
I know right? He made an automatic pickaxe machine!
Me when I get out the shower and I'm bored:
@obama_bin_laden6179
Жыл бұрын
🤨📸📸📸
@85hv68
Жыл бұрын
🤨📸
@rcdaily8754
Жыл бұрын
🤨📸. 😟📸. 😂📸
@cheapawareness8464
Жыл бұрын
I regret nothing 😌
@obama_bin_laden6179
Жыл бұрын
@@cheapawareness8464 alright postal dude
Need this while studying
Looks very cool
Good demonstration of a force driving a mechanism on one side, and a pendulum regulating speed from the other end. The basic principle of all mechanical clocks, regardless of the force feeding it (be it a wound up spring or gravity). Technically, the same also goes for the electrical force and the quartz crystal in battery operated watch.
@comicstaan2407
Жыл бұрын
Thanks 👍 for explaining..
Love the gear placement
Nice clock
The start : YOO WTF FUU- Middle : huh.. Whats this? End : tf is this a grandfather clock?
great video👍😊 thanks from Gilgit-Baltistan👍❤
I remember starting off as a beginner horologist studying this movement.
@gianlucapassarini9064
Жыл бұрын
Need some explanation: how does the pendulum always reach the same width?
That looks so cool😄
This is the actual main reason I want a 3d printer. I’m obsessed with escarpments and watch like mechanisms and I wish I could print bigger versions of them
ALRIGHT DEATBEATS, I think we're at the wrong destination.
@gemeosnosgames
Жыл бұрын
What do you mean?
@LookingGlass69
Жыл бұрын
Your wet blanket talentless oshi is two blocks down.
me putting together my beyblades:
@AzlanTalin
Жыл бұрын
YES
@Official_butter_gaming
Жыл бұрын
Same bro same
@DanishSyawal
9 ай бұрын
Me putting back my bootleg beyblade launcher:
@genericalfishtycoon3853
7 ай бұрын
Beyblades are still a thing? Holy F lol haven't even seen one in like 15 years now.
@DanishSyawal
7 ай бұрын
@@genericalfishtycoon3853 There's like another 5 seasons of beyblade with the same mechanism where the beyblade can be destroyed and also be reassembled and can be combined with another parts from another bey
Looks like a Batman villain trap. “Hurry hurry Batman, the clock is ticking”
This would be my new clock
All of these creations are so awesome that I want to build some of it one day
Ngl I was thinking it looked like something else
@SamuraIshan
Жыл бұрын
What does it look like
@rdblocks5490
Жыл бұрын
@@SamuraIshan ✒is
@rdblocks5490
Жыл бұрын
@@SamuraIshan 🖋is
This kind of stuff is what makes me want a 3d printer
33:39 Johnson pulled off the BYE! Have a great time 😂
The top gear is like the slow passage of cars through alternating traffic lights when I'm trying to get to work!
Love the design and the shape
@Player_Gamer_1234_2
4 ай бұрын
Stop it!, you are literally contributing to connect 18+ content to teenagers and children for them to see and understand
@TheQwuilleran
2 ай бұрын
Do you see the face? . @ @ . ○ . -__-
Help, I can't stop watching this...
My primal urge would make me pull the gold pieces down no mather if it brokes
Now thats efficient engineering
"We all know what we were thinking of. It's just implied that we all know what we were thinking of. The kids don't know, but we do"
@Lucy17171
Жыл бұрын
I’m 7 I know straight away
@YesItsFrozen
Жыл бұрын
@@Lucy17171 that's not an accomplishment-
@Lucy17171
Жыл бұрын
Jk I’m 14 and it kinda is tbh bro
@ed.coelho
Жыл бұрын
I'm 18 yo and I have no idea :P
@ed.coelho
Жыл бұрын
oh nvm I got it
“He’s just starting at me, menacingly”
This will be the next type of timer that jigsaw uses
The Comment be like : 85% PP Part 10% Willy Wonka References 5% Others
@NKVD1944
Жыл бұрын
Actually this whole video is a Saw 5 Reference
@Bagus_1003
Жыл бұрын
@@NKVD1944yeah, but why the colour domain Is purple and gold color?
I love that shade of purple combined with that golden... Reminds me of my childhood... And lots of rythmatism haha!
Bro this is very cool god bless you man❤
She's MIGHT just be the most humble and heartwarming person to exist❤️❤️❤️Sie ist vielleicht die bescheidenste und herzerwärmendste Person, die es gibt❤️❤️❤️
No one, that medieval executioner :
и тут я вспомнила наши старые огромные часы с таким же механизмом)
@miroslavbondarev2604
Жыл бұрын
Это и есть они
Woah. Nice clock.
Now we just need the deadweight escapement mechanism
I refuse to believe that this is just an ordinary grandfather clock
@Burnt_Loaf.
2 ай бұрын
But it is.
@echognomecal6742
2 ай бұрын
Correct. My family has a grandmother clock. To my knowledge, the only difference is height, but there may be others. As far as I'm concerned, I'm calling this a mechanical hourglass...bc it amuses me.
@chri-k
Ай бұрын
@@echognomecal6742Clocks, if they din't use springs, usually only have one weight (although there might be a second one on the same chain as the first one to provide tension)
@TankR
29 күн бұрын
Well its a type of clock movement. Movements are the more accurate name for the clockworks inside a clock or watch. And yes, this is basically what is in a longcase, or grandfather, clock. Weights provide motive potential, and the pendulum regulates the rate at which the escapement yoke walks around the escapement wheel. From there its just simple gear ratios. The ones with the fancy chimes have wheel with notches or pins across it to beat the gongs (technically they're either lengths of metal or tubes tuned to the notes) in the right sequence like a music box, then a wheel with shallow and deep notches where the shallow notches indicate the hour by not letting an arm inside the strike mechanism fully reset until the last gong. The arm falls into the deeper cut of the gear and catches the striker mechanism until the next quarter, half, or hour depending on design or setting.
такие механизмы времени нужно поставить в детских поликлиниках. дети будут увлечены, и забудут о процедурах. может для кого-то из них это будет увлечение всей жизни и они станут великими инженерами и изобретателями
@chinaUA
Жыл бұрын
Ты просто гений
@FoxMacLeod2501
Жыл бұрын
Absolutely! I completely agree. I'm enjoying this fascinating mechanism, as an adult, in 2022. When I was younger, as a child of 5 or 10 years, I would have **loved** this. I would probably have tried to figure out how to build such a mechanism myself, with the very small LEGO I had, cardboard, glue, and wood. Children, at least in America, are not normally presented with a good enough selection of things to elicit that sort of tenacious desire to learn everything about a subject. We put them in front of a very basic, disturbingly lacking education system. In our popular TV a programs and film, almost all fictional child characters merely tolerate a school experience that they would happily discard, if they were able to continue seeing their friends without being at school. We're taught to loathe an education system that doesn't go out of its way to be much more than barely tolerable. We should be investing in our future survival and success, by supplying our little ones with as many opportunities as possible. They should be allowed to experience a wide variety of educational pathways, and encouraged to pursue any constructive avenue that they really *want* to learn about. Life at school can be much more mentally and emotionally balanced and rewarding than it is, currently. Imagine a school day with a few mandatory classes, to teach the basic, foundational necessities. Instead of only lunch and recess to look forward to - or maybe even extra-curricular activities like sports, if you are fortunate enough to have anything even available to you, _and_ you have parents with the time and money needed to make it happen. Now imagine every day, or even just 2, 3, or 4 days per week, where you would be excited to complete the other classes, as part of the work required to get the reward: getting hands-on experience as part of learning more and more, about something you **love** learning about! Additionally, because you chose the subject yourself, you get to enjoy a genuine sense of agency in your future, a feeling of having some bit of control over your life's path, when almost everything else in your world is dictated by adults with complete authority over you. Instead of putting teenagers into the adult world with only half-remembered trivia answers that they weren't paying attention to learning, and without ever teaching them the myriad of important life skills that today's _parents_ only learned later in life, if at all, and only through the hard lessons taught by life experience. We could be doing so much better than we are, in America and in many, many other places, too.
@ded_Pid_Ji
Жыл бұрын
Мда , не перевелись "умы" в России 🤦 В детских поликлиниках ! Да ребенок с ума сойдёт од этого "тык-тык" - напоминает пытку когда пленный с завязанными глазами днями-неделями слушает падение капель воды , чем это может заинтересовать ребенка ? В нормальных странах в больницах детям (и не только) телевизор ставят , а тут , средневековье
@Lenny.262
Жыл бұрын
You people should leave Ukraine alone.
The coolest, most convoluted metronome ever...
Very good idea 🎉
My brain: hehe you know what dat looks like? Me: NOOO
@renniarn3057
Жыл бұрын
Me too
@Cohen-
Жыл бұрын
the gears 👀👀👀
@colenichols
Жыл бұрын
COCK CLOCK
@AlexanderKrivacsSchrder
Жыл бұрын
Is it a... Clock and balls? I'll see myself out.
@Orsonster
Жыл бұрын
@@AlexanderKrivacsSchrder i would be mad but im laughing too hard
Made my own song to the tempo. Thanks for that.
@proton..
11 ай бұрын
nuh uh you didnt
Legend says those weird ornament things are still waiting to touch the ground
I'ma need a full-length video on this.
“He had us in the first half not gonna lie”
Dude, you understand that you may hold the worlds fascination on this reproduction of thus antique tech, just as people back then held such fascination for this tech being new, at the time. Pun most definitely intended. Thanks for sharing..
Imagine hearing this noice when u woke up in the middle of the night.
i can't belive it, this must be the clockmaker's equivalent of drawing a willy.
Incredible work ! In the description you mention that the final construction will hopefully end up having a practical runtime. What is the runtime for the mechanism as shown ?
@mechanistic3d
Жыл бұрын
Thanks! Right now, it’s about 20 minutes (max at 30 if I use a smaller winding spool diameter). This model is just an initial of a proof of concept to figure out some escapement design parameters. the final version will have greater reduction ratio and larger drive weight. I’m hoping to achieve at least a week of runtime, Steve Peterson managed to make one that runs for 32 days in a single winding, I guess 7 days should be feasible 😂.
@frankbank2425
Жыл бұрын
@@mechanistic3d a week of run time would be incredible! Haven't heard off Steve Peterson yet, so I'll definitely look them up as well ! I'm excited to follow your progress! Keep doing what you love!
@mjolnirswrath23
Жыл бұрын
@@mechanistic3d have you thought about using Magnetic vacuum pressure bearings instead of Pins?
@PatrickKQ4HBD
Жыл бұрын
@@mjolnirswrath23 Do you buy those at your local Fusion-R-Us?
@PatrickKQ4HBD
Жыл бұрын
@@mechanistic3d If your pendulum has 1/10th the period, it will run ~10x as long. It could tick once every 10 seconds, or six times a minute.
This would be a sick saw trap if it was scaled up to human size
Wow I really need one
I'm pretty sure that tick-tock sound could be used as a form of torture after a while!
- Который час? - - Без 10-ти - - Без 10-ти чего? - - Не знаю, маленькая стрелка потерялась.-
I can always count on the internet to have a dirtier mind than my dirty mind :/
@rrkik
Жыл бұрын
😂😂😂😭
@melodyhaokip856
Жыл бұрын
@@rrkik
@twitzmixx8374
Жыл бұрын
same I actually didn't thought of that until I read comments xD
@workingonthename6094
Жыл бұрын
What is it can someone help me understand?
@ARandomWolfApproaches
Жыл бұрын
@@workingonthename6094 the gears look inappropriate :|
Mente genial demais que inventou este mecanismo!
Oh that's what makes that clicking noise when I turn the knob on my old-ass laundry machine
It's a new version of DaVinci clock ⏰ Good job 👍🥃
POV you’re looking for that one comment about the shape💀
@zabranrafasandya4812
Жыл бұрын
💀
@Grifjaguar
Жыл бұрын
💀
@ladykrishaabdul6583
Жыл бұрын
Tru💀
@user-uw4fb8bf8p
Жыл бұрын
💀
@Waterbottlez_
Жыл бұрын
Its literally the top comment
The details 👌
Give this to Adonis like a quest item. He’ll need it later.
Every time I see one of your videos I’m thinking, “What the Mechanistic doin?”
Deadass exspecting to see this in a saw movie
Strongest shape. Real Civil Engineer would be proud.
Teacher:everyone pay attention to class (Some random student in the back😂)
That's the escapement that went out for a pack of Marb Reds and never came home. Keeps accurate time and sends a birthday card every four years or so.