Compliant Mechanisms & Mark Rober's Nerf Gun | Real 3D Printed Products

[@slant3d]

Do you guys think Mark Rober's channel will blow up one day?

[@armorhide406]

cheeky lol

[@thebrassgoblin5454]

Yea I do think it will; Also I was in cad playing around with this design. My skills aren't there but you guys may be able to do it. Imagine if the spring mechanism was mirrored in a 360 fashion... I'm not certain if this would lock the mechanism and it would not be functional but it would be incredibly more powerful. You would also be able to change the print orientation which may change the power of the spring... obviously increasing the length of the draw would add power as well. Interested to see what you guys can do with it.

[@suit1337]

nah, that dude is just some underdog playing with squirrels in his backyard and pranking others with glitter ;)

[@Mr_Yod]

Probably, if he starts to experiment with explosives... 🤔 =)

[@AGFrontYT]

Not if this happens: Be warned: the government is trying to put the sellers and buyers of 3D printers through NICS criminal background checks. Your RIGHTS are in danger, be warned.

[@Premier-Media-Group]

Love that Slant3D goes out of their way to highlight smaller YT channels like this!

[@milolc]

lol

[@slant3d]

Yea, Mark has a good thing going. He might make it on the platform

[@danielfernandes2813]

I don't think mark's channel is small

[@NonJohns]

@@danielfernandes2813 no if you compare any two channels mark is definitely smaller

[@user-fj3gt2rj4e]

@@NonJohns yep, hopefully this shoutout will get him to 2k subs!

[@calebweldon8102]

I’m a mechanical engineer and we often avoid compliant mechanisms because they wear down faster and are harder to repair; but in certain cases they let you do stuff you simply can’t do otherwise

[@theaveragepro1749]

I thought one of the main advantages was no wear? As long as its not pushed past the fatigue limit

[@KaloyanDobrev]

Could you respond to @theaveragepro1749?

[@diveforknowledge]

@@theaveragepro1749 Very few modern lightweight materials (that I'm aware of) have fatigue limits. Steel does, aluminum doesn't. I don't believe any polymers have fatigue limits. Would work great if you made everything out of steel and titanium, much harder (material science-wise) materials to machine than Al and polymers.

[@reidboggs4344]

Exactly. With traditional manufacturing if a part breaks, you can remove the part and replace it. With compliant mechanisms, when something breaks (and it will) you need to throw away the whole device and get a new one. It’s inefficiency masquerading as efficiency.

[@corncobjohnsonreal]

ok.

[@Liberty4Ever]

When Joerg from The Slingshot Channel sees this, he'll make a semiautomatic version from wood that uses a magazine of 30 mini crossbow bolts and propels them at 950 feet per second.

[@robbyg3989]

HA HA HA HAAAA!

[@Micharlus]

You mean fully automatic. :P

[@Liberty4Ever]

@@Micharlus - Let's compromise on fully semiautomatic. :-)

[@No_Way_NO_WAY]

Frame of wood and the compliant mechanism made of leaf springs *cough

[@Mr_Yod]

And we'll let him show us it's features!

[@No_Way_NO_WAY]

This thing should be easy to injection mold with some minor changes to the cocking mechanism and trigger group. The narrow lines from the compliant mechanism vs the thicker lines of the frame can be mitigated with additional injection points.

[@MichaelChin1994]

That's what I was thinking too

[@Electheo]

Yeah same, I don’t agree with Slant’s statement at 1:05 that the gun can not be manufactured. Only minor changes need to happen for the part to come out of the injection mold. So, definitely manufacturable.

[@t1e6x12]

@@Electheo It goes against everything slant3d stands for. When something cant be on a 3d printer with a desirable outcome he says "design for the process". When something is more expensive/ difficult on injection molding, its "this X could not be manufactured". He has made his business to compete with injection molding. The last thing he will do is admit even the smallest concession to that process.

[@studiomodoki]

^ This, toolmaker by trade, and there is nothing about this mechanism that couldn't be injection moulded. It's annoying listening to this guy.

[@andrewglick6279]

At 4:44, you suggest making the bottom surface solid and having the compliant mechanism above that--how would you make sure that the compliant mechanism is able to move on top of the solid surface without fusing to it? Support material doesn't seem like it would work there and it also seems too complex to rely on bridging alone.

[@ChuckMcKnight]

I'm very curious about this too. Not really picturing how that could work well.

[@gordonbowe]

Same way we have parts on a raft that separate easily? Design in a 0.05 gap, the plastic below should help significantly with the bridging but it won't fuse like a normal layer would.

[@MichaelPetito]

Printed one of these myself and was a bit disappointed with the tumbling bullet. I'll have to try the dual density approach! Also the "raft" idea doesn't seem like it would work well. Wouldn't it introduce friction as each of the fins flex along that new surface?

[@joelhollingsworth2374]

Probably want to make it so thick that there's space to build the springs unsupported.

[@rossbrown1273]

I’m also not a fan of the raft idea. Large solid cross sections may be geometrically “simple” but the shear material usage and layer time is unattractive. Not to mention when you put that much plastic on the plate you run a much higher risk of thermal warping or peeling (at least on entry level printers). A 30% grid infill is much more stable on a first layer than 100% solid first layer for a large XY footprint part.

[@TimCortesi]

Hey Mike!

[@MAGSHowToVideos]

Yes you should improve it. I would also suggest adding a magazine to the front. You should be able to print a spring inside allowing the gun to still be one piece. The tricky part would be figuring out the best way to load it.

[@cretinousmartyr3522]

Awesome idea! If that's too complicated for 2.0 maybe a 3.0 after the rest is figured out because this already seems like a lot. Also... How did I end up in a 3d printing youtube rabbithole, I just watched a video about a guy who used smart tech with his 3d printers and it wasn't even this guy lol! I'm going to be subscribed to a dozen of y'all by the end of the day

[@slant3d]

Let us know what improvements YOU would make to Mark Rober's Nerf Gun, and if you think we should redesign it in another video. Thanks for watching!

[@McRootbeer]

I definitely would like to see what a slant slinger would look like. As well as improved darts. I'd wonder if you could use triangular or gyroid infill to create the spring features. Though that might add to cost.

[@BWBGarage]

I’d be awesome if you completely redesigned it to be a fully enclosed nerf gun made out of one part. Especially if it had similar power to a traditional nerf gun. That would be epic

[@patricktierney4392]

I would move the handle more underneath the mechanism rather than in line with it to get a little more use out of the size of your plate. Also it would be cool if instead of shooting pellets, it shot a winged gilding projectile.

[@AerialWaviator]

While I understand the goal of Compliant Mechanisms is to minimize part counts, single part products seem more are a novelty. What would be the advantage/disadvantage of having additional material snap into place to create a thicker handle for better grip and product functionality and a more useful lifecycle? Example: a design including a fold-over sections that sandwich and lock to the handle. Example: a design with additional textured handle part(s) that could go on either side, to increase thickness and appearance. (increasing the possibility of using a second color, or material like TPU to make a handle more grippy) Realize this would add requirement for assembly, be it the consumer or as a manufacturing step. What would be some of the non-obvious impacts to mass manufacturability that designers may need to consider when weighing part counts and assembly options of a design?

[@watchm4ker]

While this might be a bit too big of a challenge, something you should at least consider is scaling it to the standard Nerf caliber of .50, probably with half-length darts.

[@Roobotics]

3:37 .. what? adding a ripple just makes them marginally longer and more deflection, so a weaker spring per same thickness. How would that make them behave like they are thicker aside from just.. making them thicker? Maybe if you had a biased curve one direction then the other like a singular 'S' per spring element, but not continuous repeating ripples unless you are creating a tension or compression spring. In Rober's design it's a compound spring element more complex than those, the central shaft even deflects a little, unsure if intentional or not.

[@JohnRuckart66]

Obviously I knew you were kidding, but I literally laughed out loud when you said a small KZbinr

[@nfgwaka1343]

Bro had me questioning his sub count

[@Niohimself]

These are all good improvements... BUT a fully 2D version is interesting too, cause you can make it out of sheet metal using any 2D process (waterjet cutting, laser cutting, etc).

[@slant3d]

But you can't. YOu can to enclose the plunger and the bullet. It would have to be a 2-3 layerer metal part

[@WaffleStaffel]

Rober does have a laser cut wood version on the Thingaverse page, but it's really just a demonstration I guess, as you'd need to glue on extra pieces to hold the bullet in place, like slant3D said.

[@hanelyp1]

@@slant3d sometimes a larger count of simpler parts is the better option.

[@arpytrooper2604]

I like the video a lot but a few things kinda stuck out to me. The biggest is- can't you make a dual density part by simply hollowing out a cylinder up to a certain point and leave the rest completely solid? I don't think that dual density parts made from a single object are anywhere near unique to 3D printing.

[@jonnyhifi]

Seeing you talk through an improved design and indeed designing it would be really interesting. Yes please !

[@Linkehand]

1:23 No, not really every modern waterjet, lasercutter, plasmacutter or even cnc mill could manufacture that without issues

[@slant3d]

Incorrect. Take a close look at the design

[@Linkehand]

@@slant3dI don't know what you could be referring to? I get that you're trying to shill your 3d printing service, but there really is nothing special about that design in terms of manufacturing complexity. Its just a 2-dimensional part with a few holes cut out, every modern cnc machine can achieve this precision. Or are you saying that a 300$ desktop 3D Printer is more accurate than a 20.000$ lasercutter or cnc mill? There even are multiple nerf guns in the mark rober video made with conventional manufacturing techniques, cut out of acrylic sheet, steel and wood.

[@xTerrene]

If we get more engineering KZbinrs making videos like this and so on, products like this can actually become a reality and I love that idea

[@j-tibz8299]

A thicker version I think makes a lot more sense. I would also get rid of the contoured handle, so that it can be scaled up or down without having to drastically affect the ergonomics

[@Yuriel1981]

Just printed this this week, had already come too most of the same conclusions about improving the strength of the launching mechanism. But your ideals for the ammo are very insightful as well. Great work, hope you do an improved version soon!

[@mglenadel]

I would also like to mention that the bullet doesn’t need to be round. A square-section bullet would mean that the “barrel” could be printed as a simple square hole, with its sides either 45-degree to vertical or at 90, with bridging.

[@Nabikko]

Eh

[@ThatOneJalapenoKid]

That might affect aerodynamics though. I'm assuming square projectile wouldn't shoot as well as a round one, but thats just a guess. Might not matter without projectile rotation

[@mikebilodeau1693]

I'd like to see the Improved model. Would you be able to release a file so others could print it if you do?

[@Liberty4Ever]

I know engineers. They love to change things. - Dr. Leonard McCoy Hells yeah I want to see a remix of the Mark Rober's nerf gun!

[@afeefazaman4373]

Me too!

[@Derp3D]

Just printed that out last night, yes I would like to see a redesign always have great ideas

[@chungdha]

Instead of just talking about it, better design it and make an improved one version to show the difference, as now just all talk and not really means what you said really improves it.

[@adityashinn3896]

1:28 it doesn't have to be made with 3D printing, stuff like this can also be made pretty easily with lasercutting

[@seanewing204]

What if, instead of making it thicker, you printed several at a time, connected side-by-side? Whoever removed them from the printer would pop the layers apart, like with plastic model kits. That way, you get your wider base for minimal adjustments.

[@D1j1t]

Please try these improvements I'd love to see whether it worked

[@LILOREB]

I would love to see a time sunk total into a redo along with a cost to print current form vs your future version.

[@DiDaenskePyndt]

I have read about compliant mechanisms a lot over the years, and what i notice as the big problem for making these designs ready for mass production (At least in many instances, i can't speak for all designs.) is that bringing part count down from X parts to specifically 1 part becomes the be all end all goal. Why not think about it from the perspective "How do i make this from the fewest amount of well designed, robust compliant mechanisms, while keeping manufacturability (Is that a word?) in mind at all times. For instance, this design looks like it could be split into three or four parts if i'm not missing something (trigger group, spring and plunger, and a "shell" that could consist of one solid piece, or two, depending on what is the best way to assemble it.

[@nicholashenry200]

Does this still work with resin printers. I feel like you would have more flexibility from a product design standpoint. But it could also make "batches" from a single print

[@kurtacus3581]

I disagree with getting rid of the back stop/cover on the pulling mechanism. I think the main reason for it is so that you cant bumb into on accident and set it off. It would also protect the ring if it were to be dropped. That way the back guard takes the hit instead of the thing that makes the gun work getting hit and possibly breaking.

[@964cuplove]

Look at the mechanism that adjusts the mirrors of JWST -mcoarse and fine adjustment in one construction- looked genius to me !

[@andrewkrahn2629]

It looks like a nicer production version would have: - thicker frame to make the back loop guard redundant and the springs stronger - moving parts piece here would have snap-ready post holes on the plate side and snaps/clips on the top of the print - face-plates, one with snaps/clips, the other with holes for them, and maybe a logo/bullet-clips on the top of the print

[@NaztyNate]

3d printing this is easy for sure, but this is just a flat plate with shapes cut out. Great candidate for water jetting, wire EDM and really wouldn't be hard to CNC machine depending on size.

[@seelyw.4818]

Great Video as always! I think they made the round leap at the back to connect the upper part of the blaster to the handle, so that it doesn't wobble around.

[@The920Workshop]

I know printing as one piece would be ideal. But some of the issues you addressed could be solved by a 3 piece design. one being the dart gun mechanisms, and two outer "shell" pieces that provide the profile. I do think its awesome to print everything in one piece, but three pieces that snap together is significantly less than the initial injection molded counter part. A added bonus is you could use different colors for the center part and the outer shells to provide more visual variations without the need for multicolored printers (granted each printer is already using different colors)

[@yannsalmon2988]

With very little modifications to this design, you could make 98% of this object by laser cutting it or using a CNC, all from one sheet of material. The only downside would be to have to pierce the bullet hole separately and doing a bit of sanding. That’s the thing that puzzles me a lot with how people use those compliant mechanisms. Most of them would be perfect for laser cutting or CNC manufacturing, which would be so much faster and cost effective than 3D printing.

[@NonJohns]

3d printing is just a low commit prototyping medium and admittedly doesn't scale well but if you just need one or two, or need to iterate. S perfect process. the kicker though, is i think the price floor for a cnc machine is a little much

[@hanelyp1]

A 3 piece sandwich covers the barrel channel, and the guide at the back, leaving the center layer as a pure 2D section. 3 pieces that could be made by a laser cutter, injection molding, CNC, etc.

[@kaigraham1287]

I'm guessing a it would make more sense to print the compliant mechanism as a module , as the mechanism is the only thing that needs to be printed in one part and its size is limited to the build plate, an outer frame can be printed in parts

[@iamstickfigure]

Yes. Please do the design. It was interesting to see you talk about it, but I want to see the final product

[@doomersnek3878]

I bring great interest to you designing an improved version of this blaster.

[@macrumpton]

Seems like you could CNC it out of PCB. The stiffness would make it so it needed less springs. It would be pretty fast to make. You might even be able to stack the PCB and cut several at a time.

[@worm628]

Yes! Do want to see you iterate on the design. This stuff is fascinating!

[@AerialWaviator]

Regarding a circle being 'the ideal first layer' (4:20) .. is this thermal related, or just a desire for minimize sub-feature size?

[@slant3d]

Simplicity

[@freedomcaller]

Would be cool to see a fully enclosed on both sides version.

[@FranciscoTChavez]

I'm not so sure about the statement about not being able to get multiple densities from a single material. It's a much easier way to get a dual density from the same material, but not the only way. Lots of materials will expand and contract (changing their density) as they're heated and/cooled. And, steel will sort of lock itself if you cool it down fast enough. Because of this, you can dip part of a yellow hot steel bar into some liquid clay and then quench the entire bar. The part that was in clay will cool more slowly, resulting in a denser, smaller size. After that, you can machine the thing into an even thickness, giving you a single, solid, even material with a non-uniform density.

[@infered5365]

It's got nothing to do with the video, but my cousin bought a stick hockey table and I noticed it had a 3D printed logo on the side. It's nice to see them in the wild!

[@migueldevela2917]

If you make the blaster 'thicker' you'll need a taller bullet? Is that practical?

[@MichaelChin1994]

Just curious, is this design impossible to make with two half molds welded together?

[@Ich8in]

You can Stack them with a interface layer of another material between each, so you can print a ton at once.

[@Zhinoi]

You guys should apply these changes and make a video on it. I think a lot of people would like to see that.

[@jasongooden917]

Whenever I print it the loop at the back can’t be pulled back

[@gravewalkerz7787]

Could you stick two of them together and make it a double barrel with two triggers?

[@technosaurus3805]

Shift the compliant mechanism into the handle and add a slotted area to slide in different barrel types.

[@DobryDrug]

Hi! and why didn't you make your model with all the improvements you're talking about?

[@zues287]

Someone in the FOSSCAD community has already turned this into a fully working .22LR pistol. How's that for improving the design?

[@VD-cc4hx]

how big would you need to print this in order for it to fire real nerf bullets? and would they be half size bullets?

[@asdfghyter]

another method for mass production would be how mark most likely made the metal one: with a water cutter or laser cutter or similar. the downside of that it’s that you’ll get sharp edges that will need to be smoothed out

[@ZacharyRodriguez1]

Would love to see a follow up where an improved design was printed and we could see a head to head!

[@Sivarion]

I wonder if something like Creality CR-30 wouldn't be fix for the size issue? You can print as big as you want with it.

[@TheCelticbeast]

For mass production on a single bed could you stack them. That is Raft-Gun-Gun-Gun or Raft-Gun-Raft(separator)-Gun. Or would this most likely lead to print failure?

[@MadsterV]

how would you keep the springs separated from a backplate during printing?

[@gwenrichard7507]

Make the handle a folding and locking part. You then can use it for ammo storage.

[@Jok3r00]

4:28 perfect circle for first layer is ideal. The less complex the better My ender 3 refusing to do circles as the first layer, but a random shape say the bottom of a skull (it really loves to print skulls) no problem. I gotta let it rest and talk sweet to it to get a circle, but i can print skulls back to back like nothing even different files, shape, place, and orientation.

[@leanazulyoro]

Just subscribed and I'm binge watching all your videos, very informative and lots of great ideas for designing objects for 3d printing!

[@slant3d]

Welcome aboard!

[@chris993361]

I would like to see an improved version please!

[@jkdubb]

Would like to see the cad process for making an improved version too.

[@OmegaGamingNetwork]

I printed one of these for my son and had wondered if there was a way to make the bullets better. I hadn't even considered dual density. I think I'll have to try and figure out exactly how to do that in bambu slicer and fire off a few.

[@robertfenney]

Please show us the improved version!

[@robertpatrick5861]

I would add a cocking leaver at the back that when you close your hand.. pulls the spring back. Then add a spring loaded mag at the front for the lighter darts that you sumised. Also you could make like s spiral tip on the bullets to add spin? Then when adding width.. when you make the spring mechanism wider ist should also have more power? this would be solved by the mentioned leaver at the back.

[@jaredgreen2363]

You could still screw the handle on, right?

[@carlburkhard9320]

Strongly disagree that this is difficult to manufacture in anyway but 3d printing. This would be super easy to injection mold or even extrude and chop if you change the cocking mechism. I think that the underpass on the cocking mechanism is the only thing preventing it from being stamped out of sheet metal. And that really doesn't need to be an underpass it just wasn't a problem for the process it was designed for. I hear you about using rafts to reduce 1st layer failures but I think youre underselling how often the blaster will be inoperable because something over fused to the raft and either got stuck or created a rough surface that is now interfearing with the action.

[@justdoityourself7134]

Awesome! When will the updated files be available? ;)

[@McRootbeer]

Can you design one with a magazine?

[@lajoyalobos2009]

The solid portion in the front could be hollowed out and another spring could be designed into it with a follower, at least in theory.

[@anthonyflores9609]

I scaled this print up on my p1s using pla and it's very difficult to even cock it back. When you finally do get it to latch, when the trigger is pulled the mechanism does like a half shot not firing all the way. It's so hard to pull back that the frame bends instead of the springs. Any input on why that happened?

[@Axunen]

"This cant be done with any other process" ? yeah right. The issue with those is also that if it breaks, you can't just swap out a new part. Often then whole construction is then busted. To get the spring tension, one could make it by laser or cnc plastic sheet. From carbonfiber, from metals that hold shape instead of permanently bend and even some woods. Nooks and crannies can be made also. Even smart injection molding can do this.

[@1x93cm]

If you thicken it and turn it into a card it can be a plug n play device

[@OneIdeaTooMany]

Id love to see your updated design 😊

[@russellzauner]

Lauf makes a mountain bike fork called the Carbonera that uses a similar exposed spring mechanism instead of the typical sealed and full of oil piston shock.

[@davydatwood3158]

I'm building a full-size R5-D4 replica. An obvious bit of puppetry for Arfive is to have the Bad Motivator pop up, and then be easy to reset. My current plan is to disassemble an old Nerf pistol and try and repurpose the parts. But... something like a pair of these mechanisms on either side of the motivator, with the whole thing mounted to the lid of the droid's dome (ie, head), would also be very fascinating and cool. So, yes, I'd love to see more examples of compliant mechanisms and springs, in whatever shape or form.

[@asafoetidajones8181]

Hey whattya tryin to push on us?!

[@Anthony-c5w]

Use a conveyor printer or make the handle separate so it bolts on then it could be more ergonomic

[@BramCohen]

Your approach to auto-ejection is unclear, but in my experience using a wham bam plate and letting it cool off before taking everything off makes the 3d printed parts simply fall off with no issues. Scraping with a plastic razor blade helps a tiny bit, which of course also could be done for an auto-ejection system.

[@TS_Mind_Swept]

1mm for the first layer? What size nozzle do you need to pull that off? O.0 Definitely wouldn't mind seeing a design improvements version of this though, it's always fascinating to see how things can be improved

[@TS_Mind_Swept]

I already watched this video, why have you recommended it again, YT? o.0

[@TS_Mind_Swept]

Also, I didn't mention last time, but kind of the point of this design was that it could be made at microscopic scale, so that's why a lot of the design decisions exist like they are. Still waiting on that revised video though Keepo

[@lukej9906]

I saw some dude who turned this print into a functional .22lr firearm with just a small attachment on front.

[@KaloyanDobrev]

Why don't you share your latest printer specifications? Share the files fo your printers and so on?

[@Ruhgtfo]

Which filaments materials is suitable for such projects?

[@seanwoods647]

I'd love to see that slant redesign!

[@daveroche689]

Great channel and excellent discussion. I'm eager to see your mods on this toy.

[@Scott_C]

Please make a new and improved version!

[@Frogman7]

Lets do a Slant version. The theory and suggestions are nice but why dont you just print one?

[@calzord]

Would this work in PLA?

[@gauravmanek]

They specify PLA on the project website, which surprised me.

[@Sparkynutz81]

Where is this new version?

[@patricktierney4392]

I know that your printers are under constant revision, can you share if there are plans in place to increase the size of your build plates?

[@Nerd_Projects]

Please design an improved version of that gun. It would be an amazibg gift to get younger people interested in 3d printing

[@nicocesar]

Yes!! make a video with the design!! And upload resulting files!

[@GiulioVonKerman]

Yes! I want the next video!

[@slant3d]

Thanks

[@Queldonus]

You missed the most important improvement. This should be scaled to fit a standard foam dart. There are short darts made by nerf and others that would be short enough to fit in a scaled up version easily and would fly well due to the dual density and better balance than the traditional length dart. The blaster modding community has been making our own half darts for over a decade, but now that there are mass produced ones available in mass retail like Target and Walmart means instead of designing a new projectile, you should use this easily available option.

[@hastyscorpion]

I mean he literally said they couldn’t scale it up any more so I don’t really know what you are talking about.

[@RobertA-hq3vz]

3D prints may have a certain springiness at first, but with repeated activations it will fail. Sometimes you just need steel parts.

[@slant3d]

Incorrect

[@RobertA-hq3vz]

@@slant3d Well, as someone who has tried to use the springyness of PLA and found them to either break, or permanently deform, I challenge your assertion of "incorrect". There's a good reason why people generally use proper steel springs and not plastic springs.

[@luigimaster111]

I think you could bulk print these quite easily if you... Somehow stack the print? Like maybe you could print what'e essentially judt one really wide gun and then slice it into thinner pieces like a loaf of bread.

[@TheAndzhik]

Great review! Waiting to see how you redesign it

[@slant3d]

Thanks! Will do!

[@haraldlonn898]

Yes and I would like to se something that holds the shot so you can shout down and not only up. Love your videos. Learn alot of how to design. Thanks.

[@starwolf3020]

If anyone else is paying attention, u will understand the true potential!!!

[@bujin5455]

Would totally like to see this design taken to its zenith.