Mixing And Casting Rocket Propellant - Simplex Ep 2
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- Опубликовано: 16 июн 2024
- Thanks to Bespoke Post for sponsoring this video! Head to www.bespokepost.com/bpsspace20 and use code BPSSPACE20 to grab your “box of awesome” and get 20% off your first box.
Thanks to Charlie Garcia for teaching and helping me build this motor: @AstroCharlie
You can sign up for an Onshape account by clicking this link: onshape.pro/BPSSpace
Some places to look if you want to learn more about solid rocket motors:
www.rocketryforum.com/
/ rocketry
www.nakka-rocketry.net/
ntrs.nasa.gov/
Charlie also has a great series of videos about solids on his channel: @AstroCharlie
Every-two-weeks updates happen here: / bps_space
Second channel, mostly for KSP: / musicmakr
0:00 - Intro
0:46 - APCP Components
6:19 - Bespoke Post Ad
7:33 - Safety
10:35 - Mixing Preparation
12:14 - Mix Paddle Issues
12:50 - Mixing the Liquids
13:33 - Vacuuming the Liquids
14:09 - Adding the Solids
14:39 - Adding the Curative
15:07 - Vacuuming the Propellant
15:29 - Pourable vs Packable
16:55 - Prepping Liner for Casting
18:01 - Casting Hardware
18:37 - Prepping Hardware for Casting
19:04 - Packing Propellant
19:29 - Removing Casting Hardware
20:47 - Voids in the Finocyl
22:15 - Other Resources
22:55 - Outro
For more info:
/ joebarnard
/ bps_space
/ bps.space
/ bps.space
www.bps.space 
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This is insanely interesting content. No intention of making a solid rocket, but still here to watch
Same!
I totally concur with you 😉. Fascinating content and obviously very intelligent presentation. That being said it's DEFINITELY NOT A "Hold my Beer challenge" jm2c 👍
I would love to try this, but I'm just smart enough to not try it as in best case I would fail, worst die :D
Sure is!!
@@flying0graysons 👉🔴What Do Muslims Believe about Jesus?
Muslims respect and revere Jesus (peace be upon him). They consider him one of the greatest of God’s messengers to mankind. The Quran confirms his virgin birth, and a chapter of the Quran is entitled ‘Maryam’ (Mary). The Quran describes the birth of Jesus as follows:
(Remember) when the angels said, “O Mary, God gives you good news of a word from Him (God), whose name is the Messiah Jesus, son of Mary, revered in this world and the Hereafter, and one of those brought near (to God). He will speak to the people from his cradle and as a man, and he is of the righteous.” She said, “My Lord, how can I have a child when no mortal has touched me?” He said, “So (it will be). God creates what He wills. If He decrees a thing, He says to it only, ‘Be!’ and it is.” (Quran, 3:45-47)
Jesus was born miraculously by the command of God, the same command that had brought Adam into being with neither a father nor a mother. God has said:
The case of Jesus with God is like the case of Adam. He created him from dust, and then He said to him, “Be!” and he came into being. (Quran, 3:59)
During his prophetic mission, Jesus performed many miracles. God tells us that Jesus said:
“I have come to you with a sign from your Lord. I make for you the shape of a bird out of clay, I breathe into it, and it becomes a bird by God’s permission. I heal the blind from birth and the leper. And I bring the dead to life by God’s permission. And I tell you what you eat and what you store in your houses....” (Quran, 3:49)
Muslims believe that Jesus was not crucified. It was the plan of Jesus’ enemies to crucify him, but God saved him and raised him up to Him. And the likeness of Jesus was put over another man. Jesus’ enemies took this man and crucified him, thinking that he was Jesus. God has said:
...They said, “We killed the Messiah Jesus, son of Mary, the messenger of God.” They did not kill him, nor did they crucify him, but the likeness of him was put on another man (and they killed that man)... (Quran, 4:157)
Neither Muhammad nor Jesus came to change the basic doctrine of the belief in one God, brought by earlier prophets, but rather to confirm and renew it.
Every time I see that void filled finocyl my eye lets out a single tear...
Next mix we're gonna nail the density!
As a baker who has scraped down many a mixing bowl… consider getting a bowl scraper to clean the sides! It’s much easier to use and much more through than an actual spatula. 15:00
metal on metal is not a good idea...keep in mind that is is not dough but rocket fuel, if you ignite it while handling it - you get incinerated
@@AKAtheA bowl scrapers are typically a kidney shape piece of hard plastic. no metals involved
@@zakhenry depends, the ones used to get smaller amounts of softer dough out of the bowl are usually pastic, but the ones much more frequently used including to scrape dried dough from the sides are actually stainless steel
I was specifically thinking of the Ateco plastic bowl scraper! Mostly since they’re already wearing gloves. Just seemed easier.
Ggg
The safety precautions you stress so much are absolutely valid!
When I was 20 (13 years ago), I also made solid rocket propellant (Amonium perchlorate) with my friend who is chemistry PHD today. I mixed the aluminium powder with the amonium perchlorate powder when they were still dry powder. Dust must have settled in the air and a spark must have been generated somewhere. There was a huge explosion and my right hand was completely destroyed, my left hand only partly. My eardrums were ruptured and I had chips of the ceramic mortar we used in my eyes. As it came close to a fragmentation grenade the chips also went into my chest and almost killed me because they came close to my lungs besides the extreme blood loss I had.
10 surgeries and 4 months inpatient later I was in my rehabilitation phase and I am just so grateful to this day that I survived, that I can hear and see and that I can still enjoy this amazing life. Btw today I am an aerospace engineer :)
that day was not your time...
That sounds like a pipe bomb
jesus christ dude
Your friend needed to have his PhD revoked for that one. That's like an electrical engineer sticking a fork in an outlet to see what happens.
...never mind. I just described ElectroBoom's entire channel.
@@talyrath I don't think his friend had a PHD at the time, says he has it now, not then. At that time, he likely was only in his first or second year of college.
One more nuance to the propellant making legality: in the US, transporting a live motor on the road and transporting a motor across state lines can expose you to new and exciting regulation like the DOT and rules around interstate commerce. If possible, making the rocket at your launch site can dramatically simplify the legal framework.
This is correct. You have to do a bunch of paperwork to do it. And have licenses and such from the ATF (which is actually now the AFT&E, the E being explosives. Yes, solid propellant is classified as an explosive).
Even a LEUP doesn't mean you can transport across state lines.
If making again in the future, maybe having a massage gun or something similar nearby, for if it becomes a packable motor. Could vibrate the casing like when casting concrete, to help liquification and reduce bubbles around the more complex geometry.
The mixture is way too viscous for that to make a difference. The less electrical devices you have near propellant, the better.
Edit: With a mechanical device going back and forth extremely rapidly, there's a distinct possibility to:
1. Build up static charges that could discharge into the propellant
2. Cause small sparks from metal-to-metal contact within the device.
I'm not saying that would happen. I'm not even saying it's likely to happen. But when the consequences are that you die or at the very least your face burns off and you're horribly disfigured, do you want to take those chances? No.
@@wgoulding I disagree, the right vibration can liquify extremely viscous and aggregate heavy concrete when pouring into molds.
@@wesselscreations concrete is different because you have a whole bunch of solid particles (aggregate) suspended within the liquid cement. When you vibrate that you achieve something called liquefaction. With solid rocket motor propellant, it's much more of a gooey plastic mixture that responds elastically to vibration. Vibration will help, but the problems they have cannot be solved just with vibration. I can't say more because otherwise I'd possibly be breaking federal law.
@@wesselscreations testing your theory on both substances would be a great experiment.
I've been building my own APCP motors for a while now, this was great to watch. It's kind of funny watching you go through all the same hurdles that I went through, like the intended pourable fuel that turned into a packable fuel, the PITA vacuum process of trying to keep the fuel off the vacuum lid, the voids in the finocyl and the liner OD not matching the case ID, it's all part of the learning process lol. If your fuel is only packable, i found that its necessary to vacuum fill the case, where you make a vacuum chamber that the case fits into, and at the top you have a funnel and ball valve which you pour your fuel into, then once the chamber has been evacuated you open the ball valve to allow the fuel to start pouring in. Once it is fully filled, any voids in the fuel will collapse after releasing the vacuum, and you take it one step further by inducing vibration into the tube as it fills to allow better settling.
"keep the fuel off the vacuum lid"
Use smaller batches. If that is not an option, pull vacuum as much as possible, then quickly vent, which will collapse the upper bubbles. Repeat until you can pull a full vacuum.
Regarding the vacuum filling: Take a look at vacuum infusion for glass / carbon fibre with epoxy. Using the same bagging (simple plastic bag, but really strong) and sealing should not just be cheap, easy and fast, but also allows you to manually push the stuff in the tube to help the vacuum.
When I was a senior in high school my chemistry teacher decided to sponsor our student rocketry club. He was one of these old-timers who wasn't fazed by much, and just wanted us to have fun learning. And he let us do all sorts of cool stuff with static thrust tests and airframe designs, and casting our own Sugar/KNO3 motors. But the whole club had shut down when we blew our test stand (a tree stump) in half because of voids in the propellant grain.
Well done. I'm really enjoying this series. Personal note: In the mid 90's I worked for a company that produced software for visualizing 3D volumetric data. We received an inquiry from NASA asking if we would be willing to do an analysis of a phantom (non reactive) rocket motor CT scan that was part of a study they were performing. The goal of the study was to identify effective non-destructive testing techniques for man rated solid fuel rocket motors. The data set was from a test article that had experienced a malfunction in the thermal controls while the propellent analog was curing. This resulted in massive stresses building up in the fuel that literally tore it apart. They wanted measurements of the tear surface area and volume of the open space. This was a really neat project and got me a trip to Huntsville AL to demonstrate how we did the analysis.
When I was an intern for ISRO (Indian Space Research Organization) they used TDI (Toluene Di-Isocyanate) as the curing agent and was treated the most carefully out of all the chemicals. It reacts violently with moisture to solidify so if you inhale it it solidifies in your lung and windpipe. (So yeah pretty bad) Tho it can be neutralized using ammonia so everyone had a bottle of ammonia and water mixture (they called it Anti-TDI) and another intern there dropped the bottle and the whole room smelled rancid for a week, and the cleaning staff was not pleased.
Are you still persuing rocketry or related stuff in India? (Fellow indian here)
@@theweblover007Well as lucky as I was getting that internship, my field of interest was in biochemistry and biotechnology so I'm pursuing further studies in those fields.
Joe your content paired with several others who produce educational content has inspired me to commit to a higher education, i'm finishing my finals in my second semester of my freshman year at uaptc,
ive wanted to do these type of projects for over 4 years and now i'm on a path to a stable career in the discipline of computer science as well as a path that allows me to do these cool projects and hobbies. Thank you.
cherry limade sounds so good, i mean, its literally just cherry, lime, and lemonade mixed together. its also really hot.
It’s super weird to see something you’ve been doing for 4 years explained so eloquently. Awesome video Joe! Can’t wait for you to discover more about the mixing process!
I'll note that space-shuttle SRBs are made with PBAN as the binder, because it cures a LOT slower than HTPB. They could literally commence a pour on Friday, have the booster sit over the weekend, and then continue the pour on Monday. PBAN is also marginally cheaper.
I made some composite motors using PBAN back around 2001 and I recall the mix being much more a pain to work with then HTPB was.
They used PBAN for several reasons. The space shuttle was designed in the seventies, and PBAN propellants were standard during that timeframe. Price and availability was another factor. Polyurethanes can be tailored to all kinds of curing reaction speeds, but considering the sheer size of the cast segments it was much safer to use other cure mechanisms, since traces of moisture creates gas bubbles in polyurethanes and exothermic cure reactions might cause problems during casting such big grains. And the main reason PBAN was chosen wa sits mechanical properties. There is a lot of stress on the propellant grains due to the sheer size, especially once it burns. The PBAN propellant was more durable in that regard.
It's so cool to see this process with all the stumbles and learning points rather than just a cleanly-edited highlight reel!
As part of the Rocket Test Group (a mutual aid society for rocket propulsion safety) I got a VIP tour of ATK's Promontory facility where they were making space shuttle SRBs. The major casting rooms had emergency escape slides that were in deadly earnest purpose, and frankly terrifyingly steep- and I'm a guy who has jumped out of planes, off a building, and flown aboard a rocket plane.
I'll stick with my liquid rocket engines, thank you. We didn't have to manufacture our propellants and could reload them in just minutes, our team even flew the X-Racer seven times in one day.
Yeah, other solid rocket motor facilities have walls that you can run though like the kool-aid man; so you don't have to get to an exit that might be blocked or crowded, you just have to run away.
Well done, guys!
I had commented on a prior video about using a wagon wheel design we used long ago, 56" diameter 25-30' long, and we had to use 2 forklifts with everyone finding a place on the forklift to try and pull out the forms. All 12 of them. We used pressurized LOx (from pressurized helium) as the oxidizer, and polybutadiene+carbon as the fuel. Your work here brought back memories as this was in the mid-1980's. Thanks! Great job.
One of the best videos you have uploaded.
You can’t find anyone else who explains and literally shows how rocket fuel (APCP) is made in detail .
👏👏👏🙌🙌🙌👍👍👍🔥🔥🔥
I *love* these deep dive videos! As you’ve emphasized, they don’t provide nearly enough info to replicate what you’re doing, but they lay out the important issues including a lot of non-obvious ones and *point you in the right direction*! I doubt I’ll ever actually make a rocket motor (but who knows?), but I *LOVE* learning about how it’s dine! Fantastic(!!) content! 👍👍😃
As a Baker, when you only have a dough hook, put all dry in first and add the liquids in slowly. In your case, make sure that any " Grinding " of the dry ingredients will not ignite the mix as you are adding in the liquids, curing agent last.
Ammonium perchlorate is a bit impact sensitive, if I remember correctly. I use potassium nitrate. Not as potent, but it works. Richard Nekka Epoxy
That approach with APC will lead to a large hole in the ground.
Bad idea. If you atomize AP or metals in the air it's an explosion hazard. You always mix liquids (minus binder) first then particulates, wetting out each as you go. It's a risk mitigation thing.
@@SparkRocketLab "risk mitigation" is such a bland word for avoiding blowing up the entire building you're in.
@@SparkRocketLab If you go slow enough ( or had a paddle so you could avoid dry first with some liquids ) you end up with a putty like mixture and I did mention the potential of it igniting on it's own. I admit I don't make my own rocket engines or mix such chemicals, I am a baker. With a Dough Hook, you get the dry to incorporate smoothly with the reverse of how you mix with a paddle. All precautions should be taken as the ingredients can potentially use the Aluminum Dough Hook as yet another fuel for ignition.
Thoroughly enjoying this series, and I look forward to the next episode. Keep up the great work!
Do you measure the containers after pouring to get the exact amount you actually used in the mix?
weigh the container and material inside, then subtract the container and leftover material after pouring
We did not but that is a phenomenal idea, thank you!
A good technique for weighing liquids is to pre-wet your container with the ingredient, drain it, tare it, and then add the amount you require. When you have added the ingredient to your mix, re-weigh the wet container to check that you have added the right amount.
Thank you so much for this. I'm living vicariously through your adventure. Maybe someday I move my pursuits closer to aerospace!
Your a good man making sure to go over safety as in depth and thoroughly as you did. It shows you care and understand the value of a life. Well raised young man right there. Parents did a good job. 👍
Great breakdown on the procedure, easy to follow along and entertaining for those that have made ACPC.
Thank you for being so serious about safety in this video!!
This is so inspiring. I can’t wait for the day I do this! Love the vids man. keep it up ❤
Thank you for all the safety and tiny bits of cool information. This video was very entertaining to watch.
Thank you for specifying the safety stuff and that this isn't a tutorial. Keep up the good work Joe and good luck.
You're good at this. It's a pleasure to watch your videos and watch your progression... You wouldn't have been doing this 5 years ago!
Such an interesting video! No intent of building such a rocket (+ it's highly illegal where I live) but just watching you do it is amazing!
Outstanding presentation. You clearly know what you are doing.
Cooking with Joey B is a lot darker than last time I watched it!
Loving this series so much thank you for these 😍🥰
This series is awesome most of the time I have no idea what your talking about but its still interesting to watch. Reminds me of my youth making rocket engines from sugar and potassium nitrate mixtures... still surprised we never blew our self's up pounding those mixtures into cardboard tubes with dowels and hammers. The good ol' days before RUclips. 🚀👍
Hello! I'm a professional, I work at one of the handful of companies in the US that make solid rocket motors for NASA, the DoD, and the DoE. Watching this was extremely difficult. Yes, everything worked out, but there was so many opportunities for things to go very badly. I didn't see proper PPE (flame retardant lab coats, face shields), I didn't see de-ionizers, I didn't see personal grounding devices, and I didn't see the casting tooling and motor be grounded when it was pulled. The separation of the tooling from the propellant grain can create large static electricity charge build-ups. Also, sawing a propellant grain of that size, yikes. I'm not in the safety department, I do design, so there's probably more than that.
As a worker in a small high school in the middle of the french countryside, watching this video wasn't particularly difficult for me ;)
what you don't know can't hurt you... right? No?? 💥
@@dfgaJK right
The moment he started talking about getting in a hurry, I started writing the root cause report in my head.
As kind of a collegue of yours from abroad you are absolutely right. To add the one thing tha bothered me most: Extracting the casting tools was really hard to watch. There is an IMMENSE mechanical stress on the propellant in terms of friction, and that could have easily gone off directly next to your face. These kinds of operations MUST be done remote-controlled, especially at the size we're talking about here. There has been more then one deadly accident in the industry at this very step...
We used on of these flavors to make thermal lithium batteries. A couple times during the first year or so of running the presses to make the powder into pellets we had flash fire events.
A pound of two of powder would go off during those events. It was always over in less then a second. No bang. Not even much of a sound at all. But melted belts on the machine were pretty much SOP after a flash.
No one was ever hurt and luckily we eventually figured out what was initiating the fires.
your videos are so well produced everytime i see a new one it makes my day
Respect for the materials and the process will save your life. Fear will get you hurt or dead. If you’re afraid walk a way.
Really cool and interesting video. I appreciate that you explain all the safety measures in such great details! Better safe than sorry 😅
Totaly Enjoyable, pleasant voice, an, no background Crap..........Tks 4 That......
I'm a Space Potato from the future here to let you know that while Elon may be the one that got us to Mars it was Joey B that got us to Pluto
Hello Space Potato.
Did we find a Mass Effect relay there?
(Edited for autocorrect)
@@silmarian I'm not permitted to say more in case I alter the timelines, but keep an eye on Pluto.
I'm a potato salad. May we be friends
@@potatosalad68 in the future all potatoes put aside their differences and join together in camaraderie and starchy living
OMG, tell me. Was that the legend himself I just saw!!!??? The one and only Rick Mascheck!!??? He has helped me A LOT, sometimes just talking. A wonderful man, oh and ur "little" project is absolutely brilliant, Luke & Charlie boy. (Tasmania!!!!)
in a pinch you can always add a little more plasticizer. A vibrator for concrete strapped to the outside of your motor tube will help get air bubbles out while you pour the mix glhf
This content is fire. Thank you, keep pushing
Sweet! Now I know how to make a rocket motor. New plans for this weekend!
Side note, I just love that you keep saying "No, I'm definitely trying to scare you". Good idea :)
One pointer I would like to input. During preparation, to deal with clumpy-ness, and for the sake of my OCD tendencies, I tend to do fine powder for every solid, I use my finest sifter for all solids. If it is not powder sugar small I keep going. The extra time to truly refine your initial solid ingredients cascades into time saved throughout the whole process, always take your solids to their smallest possible surface area. Unless the conditions require specific surface areas (mainly when making nano particles) I always go to smallest size possible SPECIALLY THE ALUMINIUM which should be stirred constantly into the mixture while a shaker attached to the mixer rotor evenly pours. Then you can call you aluminized mixture acceptably stable.
Im gonna follow this video step by step.
Not even 3 minutes into the video and have already genuinely laughed out loud twice. I needed that.
In pasta making, the way you account for all the vagaries of temperature, humidity, density, etc, is to use weight (mass) instead of volume measurements, even though the latter are far more common, even in rocketry apparently. Just a thought.
I love that workbench.
There is also the NFPA standard 1125 - Code for the Manufacture of model Rocket and High-Power Rocket Motors
00:38 silly Joe! it's pointy end UP flamey end DOWN!
Always remember the way things go!
For cars, it's shiny side up, rubber side down.
Super cool stuff as always!
Perhaps one idea for vacuum expansion issues, you may consider to have an intermediary vacuum vessel between the mix vessel and the Vacuum pump! This way any inadvertent material would flow into the secondary vessel as a safety measure.
Those are called 'catch pots' or 'resin traps'. Very useful indeed! However i'm a bit unsure if they'd even want to mess with it in this specific situation, because it being used means APCP all over the inside of the lid and in the tubing. Better than inside the vacuum pump, for certain, but still a pain in the rear.
Great video and explained excellently.
It was great meeting you at the Evolution space event Joe and discussing this motor! This was a great video, looking forward to following along. I wouldn’t underestimate the poor mixing you achieved with that dough hook and it’s affect on the propellant’s rheology. I’m sure you’ll get your propellant and processing dialed in, but reach out out if you want additional thoughts, as this is in my wheel house. Cheers.
I postponed watching this because I thought it would be somewhat boring, wow how wrong was I! Super-interesting video and the level of details you add is sublime. I particularly appreciate your safety advice, it's exceptional content. Also, when you whispered, I had a proper lol. Top stuff!
I love the sense of humor this person has.
Love your content. Wish i had some cool stickers or a tshirt. Next payday. Esoteric rocket science is tragically underrated and super cool. Wish you the best.
Thanks Joe, I'll personally never need this info but I enjoy it all the same.😊
Additional safety points when handling energetic materials. High humidity keeps the chance of static build up in the air to a minimum, preferably above 60% if the materials are sensitive. Another is the use of cotton clothing and NOMEX overalls. These will reduce static build up on yourself and also if a fire or flash does happen it should provide enough protection for short duration events and or enough time to get to safety.
Thanks for the info! I have never done anything like this before but you gave me enough info to play around on a small scale. I know how to be safe for the most part. I think some backyard testing would be fun. I think a rocket motor with no nozzle would be more entertaining to watch at a distance. Got to be careful what materials the case is made out of to not brake any laws.
I love these videos. If it's worth doing, it's worth filming well!
more to the point.. if it's possible it might blow you, it's worth filming :D seriously though glad nothing happened but always concerns me when they admit they dont have the right tools and they go anyway....
2:13 Now that is some dedication to youtube content!! I bet the idea of drawing it by hand was a good idea when you started!
12:00
babish 🤝 bps
mise en place
Do you know what type of of pen he uses?
The fact this man can put togther such high quality videos about rockets blows my mind. All the other rocket channels are most certainly not as well designed. So, do you have any tips for a small channel? Thanks.
Dude, you're the best. love your videos.
yeahhhhhh came as soon as i could!!!
Really enjoying this series. Id imagine those ingredients are pretty hard to come by
Very cool.. Next time for that propellet to be extracted, you could fab lid for one end to attach an air nozzle and use air to force the propellent out with that. Just another way you could explore. I enjoyed this content you are a good speaker.
This was a cool episode of cooking with Joe!
I learned everything I need to know from this video. I learned that there is no way I am going to ever do anything like this, and that's all I need to know.
excited for launch😊
YESS this has to be my favorite project yet.
love the others a lot though...
That is a sweet Mill that Charlie has!
Guys, i am really happy meet you, because i have a hobby - this is space. Most interesting, this is i learn english, because i want to move to US and there study space theme. You are can to make everything, i belive you. DO IT!
You are brilliant!
I love the time to get back on track.
I'm sure you know this, but a taper on the core is super important. I knew a guy who lost 1.5 fingers trying to remove a parallel core from a rocket he made; too much friction equaled boom.
if it goes boom, he's not using APCP
@@memberHD I did not assert that he was.
@@bjf10 But, we all know you were and now you've decided you weren't after getting called out on it.
On the off chance you are not full of shit. What propellant was this person mixing? I can not think of any propellant that anyone would mix at home that would be that sensitive to heating. Or one that would explode in the configuration shown in the video
@@memberHD you can believe whatever bullshit you like. We're done here.
@@memberHD The friction sensitivity of APCP is pretty low when compared to most similar things, but it's totally possible to set it off by friction if there happened to be a bit of grit or something in there. You do not want to be dragging a long pole out a non-tapered channel - the likelihood of an initiation is small but the potential consequences are huge. It's unnecessary risk when you can just do it a better way from the beginning.
Joe, if I may share an idea.... Put the whole rocket inside a larger cylinder sealed at the base, pour the propellant into the mold up to (say) a quarter of the height, and then vacuum it. Add another quarter, vacuum again. Pour a little, vacuum again. The advantages are that you vacuum in place after pouring a more liquid mixture, and progressive / repetitive vacuuming makes the column homogeneous. Good luck!
Id like to suggest that you get a fully integrated face shield with forced air respirator.
Positive pressure eliminates any chance of fumes or dust getting past the mask and prevents fogging of the face shield.
Check the ANSI # to make sure the lens will offer protection, but usually these things are rated for grinder discs exploding.
Ask around at your local auto body supply.
It should be mentioned that hitting the grain in this way is not safe, it is a way to remove the mold, it could cause an accident. Great video by the way
What kind of accident?
@@robertobryk4989 Ignition. APCP can ignite just from being hit hard enough. If you accidentally hit a piece, or if there's a bit that is on the ground and gets crushed when they're dropping the whole grain, it could flare up and propagate to the rest of the motor. Suddenly your rocket is on fire, and as he explained earlier in the video putting it out is not an option. You run and hope that it just burns itself out without too much damage to everything around it.
Good Job!
Cool stuff 🚀
I think I’m on a national watch list now.
If this propellant mix was new to you, i think you probably should have done some small scale test mixes before going this big. The source of the recipe also has clues to your exact problems in the discussion section, so maybe you could have seen this coming: "This was especially obvious on XB where the propellant was barely pourable at ~78% solids, because the procedures were essentially to dump everything into the mixer (...)" and "We attempted to mix a grain for the motor at the beginning of IAP using the CS Rocketry HTPB but found that the propellant cured very quickly and was too viscous to pour as easily as it did in the past. The resulting grain had poor density (-2.5%) and visible voids, so it was rejected." Better luck next time and please stay safe! Cheers!
Yes. Standard energetics practice is to scale up for formulations that you're unfamiliar with, precisely for reasons like this. You can have the best instructions in the world, but nothing ever works like it's supposed to the first time.
King video.
Great video.
very nice work on the safety stuff during the mixing!
only thing that worries me is the demoulding/ removing of the core.... i was told, that APC can be very sensitive to impacts, so even if there would be a tiny bit between the main core and the fin part, that could have ignited! knocking the core out like you did, every professional would have gone running!
in a company building similar motors, the de-moulding is done in a safety room using hydraulic actuators which are manually operated from outside the room
you need one of those cement vibrator tools that helps pack the material down and get rid of bubbles
AP has to be screened right before mixing. It will clump while you look at it. In pyro (not rocketry), we push all chemicals through screens with small mesh sizes before mixing through courser mesh screens.
Fascinating
Wonderful presentation dear...love from India ❤🇮🇳👍👏
Thank you for letting me know how to manufacture high grade explosives!! (I will be using this information for amateur rocketry only 😁😁😁😁😁😁😁😁😁)
for packing and avoiding voids you can try a concrete vibrator tool or some such similar , that will get rid of voids , just need one that suits the scale at which your working with
I'd encourage you to try a different one. Some of the chemicals included, like the expensive binder premix and 200u AP, were selected based on the team's experience or chemical availability at the time and aren't the best choice with the knowledge we have now. Some aspects are still good for a starter formula, such as the moderate solids loading and amount of metal, but knowing what I do now I'd use tepanol instead of HX-752 and replace the 200u AP with a mixture of 400u and 90u.
found out early in this video that is not the recipe im looking for. also, i did watch the entire video. good stuff!!
u can add some acetone to improove flow, or apply vacuum and then add acetone + curing agent and mix manually.