Spin-Casting: A Better Way to Make Rocket Motors

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[@BPSspace]

Thanks to Incogni for sponsoring this video! To get an exclusive 60% off an annual Incogni plan, use this link: incogni.com/bpsincogni

[@scottwheeler2494]

I was hospitalized for more than a month starting in May. Amazingly with 5 days of my discharge I had individuals with heavily Indian accented English calling supposedly from either a provider, my insurance company or a state or Federal government agency. I even received 4 calls on the 4th of July. Almost all were seeking my primary care doctors name - an information field required to generate a scam bill to be sent to my insurance carrier. Given my hospitalization, random bills would be less likely to be rejected and gaining a profit for the data thieves and their scam "providers". Of course I wonder where the data about my hospital stay had leaked out. Many elderly or otherwise less cynical patients could easily give these scammers the little bits of info they were paid to get. At I simply told the callers to eat Sh$t and die or something about their country's moral standards. In the end, I just told them either Richard Nixon or his equally repugnant Vice President Spiro Agnew and a random address. I really hope they attempt to bill using this info. I say all of this to point to the scams being pulled off in no small part to the data brokers and entire industry for either selling their clients information or allowing it to leak so easily.

[@Rezin_8]

incogni 🤺🫡 hot tip....NEVER USE AUTO FILL FIELD BOXES....metadata is tied to any autofill use; type it out ❤

[@Platypus_Warrior]

Suggestions to stay closer to the original formula: - maybe you don't have to spin that fast preventing the ceramic powder from separation - heating the tube while it spins can shorten the curing time

[@approt7881]

are wizards even legal?

[@ThreeAngrySquirrels]

1:51 I can't be the only person who wants to see a "Here in my garage..." meme but it's you stood in front of a rocket not a Lambo. "KNOWLEDGE!"

[@BretHall]

My favorite saying about the dangers of a lathe came from my stepdad, who said that a lathe would rip your arm off and slap you with it twice before you could react.

[@PrebleStreetRecords]

One of the worst things I ever saw was someone leaning over a lathe wearing a sweatshirt with the dangling hood-cinch cords. She survived, but not unaltered.

[@Lizlodude]

My favorite way to put how dangerous a powerful lathe is in context is to remind people that if you're injured by a lathe, getting degloved or having your arm removed is a *good outcome*

[@atvheads]

Common sense is the rule. I have worked with lathes in 40 years, and after having some minor injuries in the beginning, i have the deepest respect for them, and also milling machines. Common sense, not having the eye for it is dangerous.

[@johndoepker7126]

One good rule my grandpa taught me... not just for lathes, but ALL power tools. "Don't fear the tool, respect it."

[@Z3DT]

My long-haired friend who owns a small table lathe for making stuff to use in woodworking owns one hoodie he calls his shop hoodie. Whenever he uses his lathe, he ties up his hair, braids it for good measure, then pulls up the hood and tucks his hair into the hood. No cords of course.

[@curtiscapdeville6011]

I work for Northrop Grumman where we make the SLS solid rocket boosters, and my job is exactly this, mixing liner material to line a steel casing with. We do it in over 200 lb mixes at a time. So I am very knowledgeable on this process and the process you have developed for application is very clever. We do something similar with smaller motors called slush lining, which is essentially what you're doing here but we don't spin at high speed until it cure. Another thing to point out, yes you are using this material to chemically bond the propellant to the liner, but with how thick it is, you're creating your insulation at the same time, very smart!

[@Volkeu]

I find myself obliged to point out that the mixture name "Mystery Goo" is an excellent KSP reference. Even if not intended.

[@sportenapfeltorten2095]

Mystery goo. Produced by the one and only Joe B. Kerman. The sanest Kerbal of them all.

[@homebrew07]

The Goo jiggles and wobbles as the craft flies.

[@FailSpace2]

You know it’s a good day when John Joseph Bizzlington Jr. II, First of his Name uploads

[@darinpringle5611]

Wouldn't that be second of his name?

[@FailSpace2]

@@darinpringle5611 🤫

[@wjspade]

@@darinpringle5611No, he’s clearly the original Jr, the second. Haha

[@RocketVlogs]

I'm in a BPS video. Calling my mom to tell her I made it rn

[@MBSfilms77]

@@RocketVlogs hello

[@prothomasgaming]

Hello

[@TheExplosiveGuy]

😂

[@K_Z_V_B]

NEW BEPIS VIDEO JUST DROPPED📢📢📢

[@noahhastings6145]

The biggest, most beautiful Bepis video I've ever seen. Wow! So Good!

[@usamabinmuzaffar692]

BEPIS!!!

[@Skukkix23]

Pebis

[@marvinoctopusody4613]

Baby lets gooooo

[@kevin42]

Woof

[@sotrh7974]

One video idea that I personally would be interested in would be how do you properly dispose of the varieties of waste that come from making rockets. I'd imagine chucking a failed batch of propellant in the dumpster would get you in trouble.

[@BPSspace]

Indeed it is not good practice to throw out super flammable things - stuff that can't safely, ethically, or legally go into the trash can either be burned, or sent to a chemical waste facility. For propellant that's basically always gonna be burning. Not that I'd EVER ruin a 40lb rocket motor by cracking the phenolic liner... but stay tuned to see how we dispose of that in the next video or two, hypothetically.

[@davidE.90151]

I just use the dumpster in my backyard

[@cmdraftbrn]

carefully is the name of the game. and not get the eye of sauron on you.

[@Lizlodude]

@@BPSspace Just toss it in a hole and light it, what could possibly go wr

[@erictheepic5019]

@@BPSspace Everyone knows the atmosphere is nature's dumpster.

[@danielchan3804]

God bless Borbo the wizard, good to see he's doing better now

[@funnyyylock]

I really appreciate your divulgence into safety. alot of people do not understand how dangerous heavy machinery is. ALWAYS ALWAYS ALWAYS Look out for yourself and your coworkers guys.

[@USWaterRockets]

This brings back memories! Before 3D printers were a thing, I used to spin cast silicone molds for nosecones with a perfect parabola profile. You just spin in the vertical orientation and you have gravity combined with the spinning "centrifugal" force acting on the liquid silicone creating the nosecone shaped void. I'd then use resin in the mold (with a cap on the open end) and do rotational casting to make the hollow lightweight nosecone casting at a uniform thickness. Rotational casting is just spin casting on 2 axes at the same time. I made a rig out of PVC pipe for this that worked well, but you can also just do it by hand because the resin cures pretty fast. This content is top notch!

[@grininventor]

Hell yeah you guys are back ! I was watching your videos when I was a kid and I was kinda sad when you stopped 😢 Now I'm studying engineering (trying to decide between aerospace / aeronautics and mechanical) and I'm glad you are back 😄

[@KegRocket]

Joey B so committed to the aesthetic he even polished the sample tubes!

[@Jessev741]

He's got the biggest, longest caulk tube I've ever seen

[@Mr_Lyric]

Oh hey kegrocket

[@quaker5906]

I really enjoy how you don't make just one large video focusing mainly on your successes, but you make all these separate smaller videos about your failures as you approach your successes. Really shows how much effort it takes to do this stuff and it feels like we're all on the journey with you.

[@muttenmagroo]

Reliant Robin is a reference to Top Gear that strapped one to a rocket.

[@gsfsb693]

TONIGHT I strap some rockets together Richard eats some black goo and James fills some tubes

[@vahpr]

Maybe the funniest episode ever

[@YouTube_username.]

UK's largest ever rocket launch. Oof

[@PrebleStreetRecords]

I do a lot of lathe work for gunsmithing, and there are a couple things I use that could be scaled up to help here. You can get live centers that are truncated cones, intended for doing external turning work on hydraulic pistons and such. I have a set ranging from 2-3” up to 10-14”. Using one of those instead of a steady rest would allow you to apply force from the tailstock to keep any more complex casting plugs or other assemblies from moving in the tube. It could also help hold the extrusion in-round, particularly with something like a six jaw chuck. Also, I have to work with long reamers for barrel making, so I have a system to introduce coolant and lubricant through the spindle bore and down the length of the barrel. I bet you could take a similar approach to feed the casing material (or propellant) into the casing from “behind” while the lathe is running, reducing mess. You could even make the chuck-end mold plug part of the system, with a bearing surface for the goo tube to rest in, keeping it from snagging on the moving case. This is an amazing project, you’re doing incredible work, and also communicate what’s going on clearly. Best of luck!

[@PKMartin]

A potential problem with squishing the tube into round on the lathe is that if it's not being deformed permanently, once it comes off the lathe it will spring back into egg shape and now the perfectly cylindrical liner void will be deformed to non-circular, if not worse results like cracking.

[@abobymous]

The "goo tube" described here is exactly what I was going to suggest. Just be sure to use an airless system to flow the propellant through the system into the liner. You might even be able to cobble a center void that is "connected" to the goo tube and pressed against the live center sealing the liner allowing you to deposit the propellant continuously until forming the nominal motor shape. Just remove the center void after curing.

[@shere_kan8329]

Just gotta say that you are among the 2-3 youtubeurs that give me the most excitment when a videos drops out, along with Stuff Made Here, EZ composites, and Primitive technology.

[@COSMOSIS245]

BEPIS SPACE BACK WITH A BANGER OF AN EPISODE!!!

[@BPSspace]

ITS A REAL SLAMMER

[@KCM25NJL]

TOTAL GOOZY DOOZY

[@MBSfilms77]

I guess we will call him bepis from now on

[@COSMOSIS245]

@@MBSfilms77 we hav been lol

[@MBSfilms77]

@@COSMOSIS245 Oh well i will now XD

[@Hagop64]

Many people do not take safety seriously enough, so thank you for taking the time to stress the importance of it.

[@arunoe1]

dang, you really went crazy with the animations in this one lol. looks good!

[@superbmediacontentcreator]

As a chef why don't you use a big pastry bag or a pastry bag style of thing? They make flat plastic with a tube so you can just dump the mix they pick it up twist it and it will come out of the tube.

[@BPSspace]

Wait this is actually a really cool idea - I might try this! Thank you!

[@superbmediacontentcreator]

@@BPSspace You can use the stuff (parts or components) they sell for vacuum bagging big fiberglass structures like boat hulls and so forth. I felt for you since the cleanup looks staggering and adding another device that makes more mess just to inject your mix sort of "hurt" says the chef with the sink and dishwasher full of "stuff" to be cleaned. Question: can you mix in plastic bowls and then just let the mix dry so you can crack it off to clean the bowl?

[@AlexanderBurgers]

if you're looking for the lazy disposable version, a (ziplock) plastic bag, fill, cut corner, squeeze.

[@superbmediacontentcreator]

@@AlexanderBurgers Are zip lock bags bigger than 1 gallon and have a tube as I suspect that the calking-type tubes hold more than would work in a gallon bag? Gallon bags twisted to disgorge a mix of that viscosity would only hold about a pint or less. Besides the issue is getting the mix deep into the cylinder. The actual casing remember is about 4 feet long. This was just a test. That is why I suggested the sort of flat bags used for vacuum bagging that have a tube so that the mix may be inserted deep in the cylinder and pulled back as the cylinder is filled. There are also 5-gallon bags used for such boxed beverages. Always apply your solution to the actual problem not just a test. You need to make a few canopies or cannolis and learn about pastry bags.

[@matjetius]

Also, use a soup ladle instead of a beaker for pouring out the mix!

[@TheClumsyFairy]

I wonder how many people are going to try and correct the spelling and pronunciation of 'hygroscopic', and say that it should be 'hydroscopic'. Lets just say that I very nearly did exactly that, but decided to google it to make sure first, and I'm so glad I didn't make a total fool out of myself. I just got my most favourite feeling, that of being wrong about something I believed for the longest time, and being corrected. It's even better when I do it to myself .

[@Lizlodude]

There is a clip of Seth from Berm Peak 'dampening' his bike's suspension and it's probably my favorite example of that

[@evilhomer111]

I wont try and correct the spelling of hygroscopic, but I will mention the spelling of "tempurature" at 21:23

[@TheClumsyFairy]

@@evilhomer111 I missed that one, but I'm dailysexic, so I'm terribubble at smelling.

[@oliverer3]

Another classic example of this is people mixing up absorption and adsorption.

[@simongeard4824]

Much like the people who pop up in space forums to argue that "attitude control" is a typo for "altitude".

[@TheNerd484]

At 4:05, I feel like phrasing it as F=mω²r would make it more clear why increasing the radius increases the centrifugal force.

[@gary.richardson]

What is the w?

[@TheNerd484]

@@gary.richardson omega, the rotational rate in radians per second

[@picoplanetdev]

It might be a good idea, but as we can see, omega then needs to be explained. I learned mv²/r first but there might not be a good reason for that. I like the argument for conciseness!

[@thekinginyellow1744]

Yes and no. Depends how much physics your audience has.

[@deucedeuce1572]

He called it centripetal force (or it sounded like centripecal force). I normally hate making corrections in comments, because there's always 1000 people saying the same thing... but I'm surprised I didn't see anyone else mention it. I always called it centripical force like him, but was corrected a long time ago. I'm still surprised people still say it like that though.

[@earld1403]

Regarding Hygroscopic materials, not sure how well it would work but woodworkers use a product called Bloxygen (compressed argon gas) and spray it into opened cans of finish to displace the oxygen to prevent the finish from hardening after the container has been opened. Another more expensive option is to pour the hygroscopic materials into a plastic squeeze bag so that only the desired material is stored and not the extra oxygen, humidity, etc.

[@catabasian]

the SRL rocket explosion being used as an example of what not to do feels slightly personal 😭

[@BPSspace]

I still love SRL, nothing personal! They did however make some poor decisions which created an excellent example of why undercured prop is dangerous

[@gustavrsh]

At our rocket team we use EPDM rubber as the liner. Cut, glue and install. The rocket itself pulls ~15Gs and it has been reliable.

[@ohbeardedone9253]

Yah. This whole thing seems over complicated. Thank you for the comment.

[@jeremystott8188]

6:47 - forbidden popcorn

[@mjdarby714]

You are genuinely one of the most entertaining educators on KZbin. Thank you for all of your hard work making these videos!

[@ChrisHarmon1]

Big safety thing with a lathe is never get in the habbit of putting the chuck key or bits on the headstock. Ive seen printble tool holders for quick change systems that hang on the back guard as well, you are far better off hanging them on a wall nearby or under the lathe in the storage area.

[@testpilotmafia862]

Love your work and had a great time meeting you and the others at Open Sauce!

[@sortaspicey9278]

I worked in a large bakery for a while and I can amend. Mixing paddles are much easier to clean before the stuff on them dries 😂

[@judet2992]

7:23 Love that the mixer is named Bob.

[@wanglydiaplt]

To have less mess when loading the goo into the part in the lathe try using caulking gun cartridges; they can be had empty so you can fill 'em with whatever you have. Aha! You figured it out; bravo! Oh PS I'm not sure if it would help but there's a material called Nalgene that is used to make containers that stuff has trouble sticking to; it might make clean-up less gruesome.

[@justRD1]

I LOVE the recent surge of video releases! One of my favorite channels!

[@allieandevanfriesen]

You can use a multimeter to approximate the water content in automotive brake fluid. Maybe you could use the same method for your chemicals.

[@PrebleStreetRecords]

I wonder if the carbon black would be too conductive for that.

[@blahfasel2000]

@@PrebleStreetRecords They meant to use it to check the hygroscopic ingredient for water contamination, not the final mixture.

[@PrebleStreetRecords]

@@blahfasel2000 ah! That makes more sense

[@Bingothe3rd]

I was there for the explosion of the rocket seen at 13:50. One fragment of the rocket flew a few hundred feet, hit the plastic tile for the light on the hangar, melted right through it, hit UC Berkeley's table, melted through that, and hit a fuel container. We had to drag it out and it was burning for like 4 hours straight. The other pieces thankfully didn't damage anything else, but there were close calls and small brush fires everywhere. I was on the NASA SLI team whose rocket misfired literal seconds before this happened, and I'm glad this didn't happen to our rocket.

[@markmedrano8073]

You could estimate your triethanolamine water content by measuring its density. Since it's density is 1.12g/ml if you can measure an accurate volume you should see it be less and less dense the higher the water content. I've done this to confirm water and resin contamination in isopropyl in the past.

[@Poult100]

Great effort and... great amount of effort! You've not been specific with your spin speeds but your description has lead me to believe that it was too high, at least for your initial mixes. Definitely spin fast to begin with, to spread the mix evenly. But then slow right down to whatever speed would give enough centrifugal force to just oppose gravity at the top of the cylinder. That way, the lighter components of the mix are less likely to be separated from the mix; your assumption about the ceramic beads floating was correct. Great video! Very detailed! Just like a tutorial, but I know it isn't a tutorial! 😉

[@vsmg1877]

0:12 "It's kind of like a Russian nesting doll, but with a lot more explosive potential." So an American nesting doll?

[@jimurrata6785]

Stacking doll? Because mariuska dolls completely envelope each smaller one.

[@allanjarnagin3540]

Supries: is grenad

[@danmur15]

i still love the foreshadowing stuff, tbh it makes it a little easier to connect the concepts to the practical examples. Always funny as hell too

[@airplaneian]

What software are you using for those checklists (shown around 14:20)? that looks super useful!

[@BPSspace]

Epsilon3!

[@airplaneian]

@@BPSspace Awesome! Set up a demo, it looks like something my team could really use even tho we're not doing aerospace :)

[@Epsilon3inc]

@@BPSspace thanks for the shout out!

[@jimjohnson3410]

I stopped the video at that point to ask this exact question. Thanks for asking and so happy BPS replied.

[@GunniBusch1]

@@jimjohnson3410Same

[@BeenThrDunThat]

Well I caught the subtle Sand Person reference to the shaking of the caulk gun above your head 😉

[@AquaticCat647]

Ahhh yes new video It is 1:45 am as I'm watching this XD

[@nurmr]

12:30 am, now I don't feel so bad about watching it so late 🙂

[@C-M-E]

I certainly like the spin-cast method, though having a lathe is a bit of a requisite. Using tubular preforms for concrete and an air-backed hydraulic grease gun works a treat, too, for moving ooey gooey substances resistant to persuasive/time-sensitive 'go here Now' fabrications. I wondered after your first Whoopsie if the hygroscopic issue would crop up. Most any resin or ceramic binder is highly moisture sensitive, to which I've gone to stupid lengths like prepping inside a sealed inflatable DIY clean room for big jobs and run a whole-room moisture trap/dehumidifier mocked up air handler for 24 hours as prep for bone dry working air. Good catch!

[@npeters97]

20:08 Are you etching the aluminum(oxide) for better adhesion to the surface? Hence the better wetting/lower beading at 20:15? Lovely video as always.

[@BPSspace]

Bingo! And thanks :) 🙏

[@PrebleStreetRecords]

@@BPSspaceSmart! Have you considered scoring the inside of the tube with a boring bar for more mechanical interaction with the liner, or would that introduce too many stress risers?

[@Gotmotts34]

Wetting and contact angle are a great way to measure surface energy. Have you tried Dyne Pens? Perhaps less accurate, but very quick and easy to use.

[@godlugner5327]

8:02 I will always remember by high School shop class teacher who showed the video "idiot versus lathe" (which I believe is still up on YT) to the class and said anyone squeamish come to the front of the class with their backs to the screen and they were forced to watch the reactions of everyone else in the class who saw the video... Our squirming was enough for them to know not to mess with the lathe in motion

[@DRIFTWORKSINC]

After the 2nd fail I would have gone down to a kitchen aid sized mixer. Less to clean and less materials to waste.

[@TheBeardedEngineer]

Use barbecue lighter fluid to clean up, it does a great job at nullifying any bonds the MDI has created before it has fully cured. If you have REALLY dried on stuff, take the mixing bowl and use distilled white vinegar and just let the equipment soak in it. Found that if you give it enough time the MDI to HTPB bond dissolves. You can use a painters screen to reuse the lighter fluid a couple of times and then it can be properly disposed of or burnt off. Hope that comes in handy for you.

[@dsgermack]

awesome video and great to see you getting the spin-cast liner working! please exercise care with MDI, if you inhale too much you can become sensitized (e.g. allergic) to it and that is bad. there is a pretty simple titration for seeing if the MDI is going off, which would be easier/faster than the curing cups. you may get some water intrusion from the surfactant too. in my past making polyurethanes and propellants we always monitored and recorded the humidity and temp of the lab. a cheap datalogger with humidity set up can be found on amazon. you are doing great and this organic chemist appreciates your commitment to pronouncing the chemical names correctly!

[@youngbloodbear9662]

I’m so tired of people saying centrifugal force isn’t real its perfectly well defined in a rotating reference frame

[@thekinginyellow1744]

Yep. Same. To paraphrase Einstein, "any frame of reference is is as valid as any other, so pick one that makes the math or the physics, or ideally, both, easier to understand"

[@deucedeuce1572]

He said centripetal force (or sounded like centripical force). That's what I used to call it when I was a child myself... but was corrected a long time ago. Haven't heard anyone get it wrong or say it like that in a long time, so I didn't know people still made that mistake. I've never heard of anyone saying that centrifugal force is not a real force though. That just seems weird.

[@youngbloodbear9662]

@@deucedeuce1572 centripetal force is any real force towards the center of rotation, centrifugal force is the ‘imaginary’ force experienced by an object in rotational motion. The rock is held into the sling by the centripetal force of the string tension, and you’re thrown off the merry go round by centrifugal force. Except any time you actually feel a centrifugal force it’s necessarily balanced by a physical centripetal force, and if you don’t assume an inertial reference frame there’s nothing wrong with centrifugal forces they appear directly as a term in the math

[@francogaretto2479]

I think a good idea for a video that not many people think about is the design and construction of efficient parachutes

[@Cohiba2]

Feel like it was missing an intro

[@BPSspace]

Helpful feedback - thank you!

[@benburnett8109]

@@BPSspace Yes. The lack of an intro left me trying to "catch up." Great video. Just needs and intro................like you did on all your other videos for the last 200yrs.

[@tarnkaktus4887]

I actually liked how it jumped directly into the video, but i get your point if you‘re not familiar with the series

[@JonahGreve-bn6jc]

That's what I was just about to say

[@benburnett8109]

@@tarnkaktus4887 I'm talking about the technical data. The intros help me follow along with the technical data..............not everybody is a rocket scientist.

[@KritchieXX]

I was so confused by the end of the video; you said "now before I show you how this all comes together in a rocket motor, I would like to thank the sponsor of this video...", and then it's the end of the video after the sponsor read haha. Loved the video though!

[@nurmr]

leaving us hanging for the next video, no doubt.

[@zachjeffcoat3959]

ay yo new video?

[@BPSspace]

🆙🆙🆙

[@haydenbrophy9460]

cool

[@LoneHawk]

Love that there’s no intro. The other comment is very wrong about that. Average attention span is low and intros turn away viewers. Keep doing what you’re doing!

[@odeode4338]

Absolutely. I hate intros and more than once clicked away from the video. Especially if the intro is a short supercut of the video.

[@dev-debug]

Nice choice for a home shop lathe. I don't understand all the chemicals in use but find your videos very interesting in the way you find and solve the problems.

[@Sora._Cloud]

Shorts brought me here and I know everything space and rocket related and I can’t believe I have not seen this channel till now. You sir has gain yet another subscriber keep educating while having fun

[@wesselscreations]

Hey! was great to meet you at opensauce on the Friday night! The process of this reminds me a lot of resin casting, which also seems to be part science and part magic. A super non-scientific way to check if there is moisture in the triethanolamine would be to take an air tight container and place some silica bead that change colour as they absorb moisture in it and leave it for a day or two, and then while trying not to allow too much of the dry air out, place some more beads and a sample of triethanolamine in it and wait for another day or two. Adding a hydrometer in the container could help too, to see how the humidity changes after added the triethanolamine. I have done a couple of resin pours where I needed to spin the resin inside a tube and found it helpful to let the mixture start to kick so that it I don't have to spin it as fast; it could help with the separation due to the G loading. I would also turn down the speed as the mixture thickened later on, leaving it on a really slow spin for the remainder of the cure time. My speeds were a lot less, I used a pottery wheel sat on its side, but I think the process should work in a similar way. Also a random addition, you recently talked about all the fire extinguishers you have in your house. Not sure if you have or have seen fire blankets. They are great for fires that you can smother, and don't dump a fine powder everywhere, so are much simpler to clean up afterward. Great video as always! Looking forward to the full pour

[@simoncleret]

Was actually recommended this by youtube. Fantastic video, 100% worth a sub. Please keep up the good work!

[@cameronharrington8050]

Bubbles in vid are for acid etching the aluminum case for bonding later. Good water break!

[@newmonengineering]

I knew right away when you had layers it was separating. Centrifuge they use in medical labs is designed exactly for that purpose, to seperate based on density. Anything that is spun fast enough has the possibility of separation like this. Good job finally getting a formula that works.

[@ironhornforge]

Hey, if you scoop the formula into a icing bag, the ones that they use for cakes, it'll really help to keep things clean. Plus they come in packets of over 100 and they are cheap. Hope that helps 😊

[@Blue_Camera_Cat]

3:40 nice timing, overall you do such a good job explaining stuff and making it engaging, I love your videos!

[@jacks19822]

Awesome video, I have a little kido fan here admiring your work ethic. Great work Joe, he's making his own solid motor too, so he get his fair share of failures. Hope we can go to US and meet up some time next year.

[@everybodyants]

The mystery goo liner... i bet it feels right at home at: high space above mun :)

[@rubikmonat6589]

to make handling the kevlar easier: Humidifier. Antistatic gloves and conductive containers. These are all available for electronics work. It's also wise when dealing with metal powders and energetic things. You're actually charging it up shaking it out of the bag too. Metal bbq tongs.

[@Spoon80085]

Why is this in depth chemical rocket video funny

[@deucedeuce1572]

Damn, the amount of work that goes into this is insane. It just seems crazy to me that the video doesn't have at least 10% likes to view ratio, which is good for most kinds of videos... but in this case, I'm surprised it's not much, much higher. It certainly deserves to be. He definitely earns it.

[@thejoetandy]

As far as I recall from when I was researching them, load cells are either made for heavy masses, or for fine measurements. Additionally the more mass you add to a load cell the less accurately it measures. So adding all your liner components to a very large set of scales that has it's load cells pre-deformed by a large mass of components and a huge stainless steel mixing bowl likely affected the accuracy of your mixture.

[@BreakingTaps]

Very cool technique! As an aside, what's the process documentation/note software at 14:19? My sophisticated tech stack of "post-it notes stuck to random surfaces" is, perhaps surprisingly, not entirely reliable 😅

[@Epsilon3inc]

👋

[@BPSspace]

It's Epsilon3! Great program for this kinda thing

[@BreakingTaps]

@@BPSspace Awesome, thanks!

[@brendan8915]

The Borbo bit is absolutely brilliant. 10/10

[@mduckernz]

FWIW I had great success in using epoxy and magnesium oxide and carbon black and phenolic pulp for liners (also spin cast) You can even use it for rocket nozzles if you increase the solids to the point it’s a tough putty, and press them with a hydraulic press and a mold :)

[@TheDonaldHarris]

Just so you know the foreshadowing honestly makes me feel like I understood what you said before. So keep it up! Your story telling is the best part of becoming a rocket scientist :)

[@thomasherbert-jones7607]

Great video. Have you considered setting up some type of fume extraction system at your workstations? A proper fume hood could remove the need to wear a respirator and make things much more comfortable for you. Though a extraction system might not be able to handle the mixer, it would probably depend on how much dust is thrown off when mixing the powdered ingredients.

[@abobymous]

Love the vids, Joe! Thanks for posting your projects. On the liner endcaps, you could design into your 3D print some "tabs" or way to pull it without having to press your fingertips all the way to the inside of the end cap and pulling from there. Cheers from the KC area.

[@WhitmanTechnological]

"While I really love producing videos about these projects, some of the effort that goes into them is genuinely hard to convey." 😆😭 You're awesome.

[@Allan_aka_RocKITEman]

Joe does so much _foreshadowing_ that it might be called _fiveshadowing._ 😉 {Great video, Joe...👍}

[@nicazer]

If you are going to work with staticy things like kevlar and carbon black, I HIGHLY recommend some sort of anti-static gun. I have them in my lab for measuring 1-10mg of carbon black and they are lifesavers.

[@elmfuzzy1]

We had the same problem with the thermacels when testing them in some of our paints. They would always float to the top before the resins were done curing.

[@adikisela409]

i love it how you share knowledge and experience in rocket motors..keep up your great projects and works..thumbs up..

[@toastothetoaster7949]

If you want to check for water in reagents, try heating some copper sulfate (it’s available from most hardware stores) until it turns white, then adding a small amount into your reagent. If it turns blue again then it has water in!

[@brianargo4595]

Nothing like changing multiple variables at once to find the right method and mixture

[@tuxxi]

Great video Joe. One note about safety that I think is worth bringing up, especially since you have such a wide audience that might want to get into the hobby While most parts of APCP are generally pretty safe, the diisocyanate curatives for HTPB are quite toxic, and especially when mixing, the vapors can offgas. Lethal dose of isocyanates is a usually ~ few hundred mg/kg, so while you are very unlikely to get this much via aerosol it’s still worth being very cautious around this stuff. I’m so glad you’re wearing a full face mask for this process :)

[@Epsilon3inc]

Awesome video, Joe! 🚀

[@BPSspace]

Thanks! Love your software :)

[@Z0ctB0x]

That was a beautiful thumnail

[@kvg4790]

You can also think about spinning fluids as “self leveling” in relation to the axis of rotation. Which means a cylindrical surface evenly spaced around the axis.

[@jtcustomknives]

I’m a machinist and I 100% recommend using caution looking up lathe safety videos. You will see things that you cannot unsee. I stand infront of a lathe most every day for my day job and you must give it the respect it deserves.

[@patrickday4206]

Awesome video helps me understand the complexity of high performance solid rockets.

[@Neeboopsh]

lathe accident videos are wild. especially the misty ones.

[@lazyplumber1616]

This was a great video. I wonder of some of the heavier ingredients in the mix were centrifugally pulled to the outer edge. This happens if you vibrate concrete too much, The larger aggerate settles out and the liquid floats up, creating a weaker cement.

[@lazyplumber1616]

Sorry, you already covered this...good work.

[@NeonNijahn]

And the crowd goes mild! 3:02

[@joshua43214]

I do get the motivation to spin cast a liner, but there is actually an easier solution if you stick to phenolic liners. You can very easily make and draw a mandrel down the aluminum tube to force it into the exact size you want. If you bond the phenolic liner to the mandrel, you can pull the whole thing through in one go and get a perfect fit. You could make the whole rig up using cheap metal conduit as a frame, plywood (or maybe steel plate) as a backstop, and a chain fall as the draw.

[@ChatNoirLe]

For adding to the caulking tube try suction, stick one end in and suction on the back, like a bait pump.

[@seanb3516]

KZbin Content Creators - If you use a Full Face Respirator you can purchase models which have a "Voice Box" or something similar. This allows you to narrate with much less muffling caused by the respirator. These systems can be as simple as a type of Kazoo or complex electronics. The variety available these days in full function respirators, even PAPR systems is extensive. Have a look around. Cheers. :)

[@davidwilkie9551]

That example of static charge overcoming gravity is enough to make the safety critic's hair stand on end, so is the amount of moisture in the lab keeping you safer while completing the mixture, but tends to absorb into the mix. Interesting rocket science.

[@JPMontello]

For my big rocket I bonded epdm rubber sheet to the inside of my 8" motor tube! Epdm has excellent ablative properties! Pretty cheap too

[@amogusenjoyer]

I wonder if it would help to put some sort of plastic liner in the mixer (something similar to plastic wraps used in painting) to avoid having to do the cleaning on the metal itself. You could just pull the plastic out and voila. Though im not sure if the plastic would hold up?

[@TLBSBD]

I absolutely LOVE this channel and what you are doing! I can’t wait to see that successful space shot!!! Keep! 👏 It! 👏 Going! 👏

[@studio_buehler]

Still my favorite channel. Can't stress enough how much I love your videos!

[@dhkdlhdyodyoclydtkd96494]

I don't understand much of the contents of this video, but nevertheless, I enjoy learning the little tidbits I am available to pick up and I enjoy your presentation

[@mikeymcginley]

For what it's worth, your "safety parts" are pretty cool. It's awesome to see you take safety so seriously whilst making it look cool at the same time. 🤓