A Massive Three Grain Rocket Motor - Arduino Static Thrust Test Stand - Elementalmaker
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- čas přidán 23. 07. 2024
- Testing the massive THREE GRAIN rocket motor on the Arduino based load cell test stand to get thrust data.
-Please save this link as your amazon homepage, so when you shop its supports the channel: goo.gl/x1ehvA
-Help me continue making science videos / elementalmaker
Parts I used:
Arduino Uno R3: amzn.to/2QhskRv
50Kg Load cell: amzn.to/2DVYHxo
HX711 Board: amzn.to/2lg2r5L
LCD Keypad Shield: amzn.to/2E9q6fN
5V Relay: amzn.to/2SEgqhn
In addition you will also need some jumper wires, and a 10+ foot USB 2.0 Cable - A-Male to B-Male to log the data to your laptop.
Link to PDF by Nick Cinquino and Len Johsnon: archive.org/details/ArduinoMo...
Video Building the Static Thrust Test Stand: • Arduino Rocket Motor T...
The above are amazon affiliate links which earn the channel a small commission and help me to produce the videos.
Special thanks to Luke Foley and his team for providing the rocket motor! - Věda a technologie
Help me continue making science videos www.patreon.com/ElementalMaker
homogeneous or eutectic?
i dub thee rocket shitz
Three grain motor just three ingredients, wheat, barley, and oats. When combined these three grains make a powerful propellant that can also be used to make a healthy loaf of bread. 😂
Hell yeah! Love these motor tests.
I wanted to build a propulsion test stand and didn't know where to start untill I saw your early videos which have me a kickstart of Ideas! Then I check back and wow wee those are some HUGE motors!
"a little bit of schmutz" I always get a big smile on my face when I hear German words in English video :)
I didn't not take a look at your arduino code, but if you are using the analogRead instead of some low level ADC readout you might get some timing jitter with your measurements (hence the unsmooth graph). Its possible to run the ADC at a fixed frequency and read the ADCs value with an internal interrupt. This would let you calculate the measurement time more precisely than storing and relying on the millis() for example
I would love to take a look at your code right now, but first I have to get through my exam period starting next week :|
But I'm no rocket engineer and could be complete wrong, your measurments might be totally correct and the unsmoothness of your data is just the graphite nozzle breaking apart.... :)
o/
That was pretty cool. Another thing to tack on my long list of projects.
Just added that link as my homepage for Amazon. Hope it helps bud keep up the great work.
Truly appreciate your support!
Great work keep them coming!
I'm guessing casting a grain to fit the cannon would be a bad/wonderful idea....?
U know I have been waiting for this, thanks
YuuuS!! Thanks for your vids! Always sick!
Great, great video! Thanks to Luke Foley for kicking it all up a notch. I will use your Amazon link. Last time I was fidgeting with rockets I was using Ammonium perchlorate and epoxy using the readily available NASA rocket booster formula. Using the epoxy formula makes the engines impervious to humidity and you can store them for years without any degradation. They also have a longer burn time. Thanks again for bringing rocketry back into focus.
Glad you enjoyed and I truly appreciate your support. I just got a gallon of R45 resin and isonate curative yesterday, along with 6 pounds of 200 micron AP, so get ready for some composite tests here!
Time for a 4 grain and a bigger load cell love your videos Man
Where has this channel been all of my CZcams life? Subscribed.
Thanks for your sub Logan!
I like the humor as much as the rest.
It is always a fun visit fella. Love how it went.
Just mix stump remover and "log" remover.
Log remover?
@@guythat779 Sorbitol has a reputation for giving people horrible diarrhea when they eat too much of it.
@@tissuepaper9962 I know but... so you call poop logs aight gotcha
Loving these DIY rocketry videos. One minor point, seems something went awry with the specific impulse calculation. However, you scaled the impulse (20600 gFs) by 100 instead of the mass of propellant, which was 225 g according to the spreadsheet, and 300 g according to your batch calculations. So the Isp should be around 90 seconds.
Ah crap I screwed that one up then 😕
just did the calculation... it is 93.433424 seconds
Yep, the Isp is very poor, not much better than you get from compressed black powder. But you have a good start on the basics. It is about time to transition to an AN, aluminum, rubber grain - ratio about 70:15:15. One major advantage is no melting of the uncast fuel - since the rubber fuel is the binder.
That nozzle orifice is far too large for your 3 grain motor - but MIGHT be OK for a 5 grain.
Does the casing have overpressure protection, so the nozzle end blows, rather than the casing turning into shrapnel? This is often accomplished by a relief cut around the inside of the casing, right in front of where the nozzle closure threading ends.
Isp should be around 110-130 for knsb
Wow wicked fast, nice job
Bloody hell that burned up quick! Was expecting slower, good job.
Nice video lots of time and care .
Sorbitol is an alcohol. Maybe that pronunciation clue will help.
At some point;
Would you be willing to run potassium based oxygen-sorbitol mix in a blender or coffee grinder for long enough to become exothermic? Your channel seems like a good place for such an experiment.
Very cool idea! I just might have to try that!
I look forward to these videos everyday
Great video & your humor is second to none, thank you!
You cheer me up and make me laugh, I need that these days, thank you!
P.S. Can you make your link work with Amazon Smile?
Thanks for the kind words Robert! And yes great idea for amazon smile. Here is a link that works with amazon smile: tinyurl.com/yyx2xymv I truly appreciate your support.
Much Respect 💪
"The second best wrist work-out my hands had for a week,... maybe a day." 🤣🤣🤣 Think I just broke a rib.
Spectacular beginning 😂
It shows in your results shown on the computer what happened with the back of the nozzle and from the video it did look like a propellant blockage which caused the the sudden increase and then decrease in thrust.
I'd love to see what that puppy could do with a smaller nozzle.
Great video
I think the nozzle damage was caused by impact from the hard schmutz particles that were observed at the head end of the motor and collected on the nozzle. The pressure spike is usually caused by a void or crack in the fuel but in this case the hard particles exiting the nozzle may have played a role in it. I like to use poster board or file folders as my liner with two wraps to prevent damage to the case. Not enough thermal barrier may cause the case to blister or damage it. Great video and keep up the good work!
I agree with you, the nozzle damage resembles particle impingement impacts. Large particles passing through the throat area would reduce the exit area, increase chamber pressure, and produce thrust spikes.
Great video, I have been waiting a long time to see you do this as you promised. It would of been good to see a comparison test without the Iron Oxide. I hope we dont have to wait another 6 months for more video's.
That’s a hell of a rocket! That as an initial with maybe 2 slower burning rockets of equal or lesser value might a pretty decent candle make!
i suspect that what got spat out of the nozzle was probably the paper liner that was on one of the fuel grains. it would probably be a good idea to use a much thicker carboard, maybe like a cereal box.
did the motor come with instructions for what liner to use?
I have never seen a liner get spat out the nozzle, even when lubricated with Vasoline. The liner is plenty thick for his current propellant, but may need to be thicker for AP chemistry. I think Firefox, or one of the rocketry supply specialists, has some standard diameter liners that are specifically designed for composite propellants. Hopefully the casing is the standard 29 mm.
LOVE YOU TROLL FACE !!!!!! AS ALWAYS THE ULTIMATE BEST
I absolutely don't care what you do in your videos, I just come here to listen to that buttery smooth voice
I do eat alot of butter 👍LOL
a trick I learned is to put a dab of Karo corn syrup in the mix it premelts a bit and the melting starts way sooner and the heat evaporatesthe water in it so it doesnt effect the burn rate
There is a lot of science in the differences between the grains. Grain by the nozzle can have a larger bore and maybe a finned interior surface, the grain near the closed end can have a smaller bore. Remember that the grain by the nozzle must pass three grains worth of hot gas without being abraded by hot gasses, then any abraded material hammers the nozzle.
Mate, love your vids, interesting and entertaining.
With that voice, you should do commercial voice overs lol.
atb from Adelaide South Australia.
Thanks a bunch! Glad your enjoying the videos!
Laxatives inside a long hard tube that spews legendary "potassium based oxygen"? Wow you're a force to be reckoned with, kind sire. :O
Love that rocket tooling!
The inconsistent data spike shows when the erosion happened at the nozzle. Pretty cool.
You are correct the damage was from by product of the fuel. Debris moving that fast can do some damage in short work.
When you move up to a cast Ap fuel using epoxy the burn is very smooth and powerful. Also very clean.
Thanks for the video. Always entertaining!
Go to firefox.com they have everything you need. Then go to pyrochemsource.com to get the AP.
Funny timing... I just was contacted by a fan who had bought a huge lot of chemicals at an estate sale. Included were 6lbs of AP and a gallon of R45-M along with a quart of isonate curative. Luck had it he wanted to donate these to me and was within driving distance.... So composite motors will be coming soon!
@@ElementalMaker O man that is great!
You will really love these. I have formulas if you need any.
I can help you out with anything you might be missing.
@@ElementalMaker If you can find it, get your aluminum in multiple particle sizes. The major difficulty in making AP propellants is getting the approximately 15% aluminum into the mixture.
Also, depending on the binder, you may want to get a vacuum pump and make a vacuum chamber to de-gas the propellant as it cures.
I beleive that we are gonna have to watch this one twice also. ;)
lol crack me up. Love watching your videos.
Know any tricks for a long burn time at medium thrust?
Wow I can't believe that didn't fail they machined that thing really good
Bah, at that low pressure, there is no failure risk.
Have you thought about putting a little grease in the nozzle to give it a little more oxidative resistance?
If I could only KNOw what your secret ingredient is LOL
potassium nitrate? never heard of her.
@@tissuepaper9962 he probably meant KNO3
Awesome man. I wanted to watch your video on Patreon when it came out, but I've been pretty busy processing the remaining rock etching waste solution containing the thallium salts. It's the most scary crap I've had to deal with to date.
Yeah man that's some scary stuff! Stay safe
would you compare a center burning core vs an end burning core?
next time you do one of these, can you measure the mass of the paper before you load it as well as the leftover mass to calculate combustion efficiency? Also are you going to publish the thrust curve data like you did with other tests?
just curious but, how would changing the bottom inner diameter to same size as nozzle and the top inner diameter larger like a cone.
When you’re done you can make a form 1 from that casing.
Since black powder has such a fast burn rate (enough to classify it as an explosive) I wonder if that's what caused the blowout of the nozzle. If you feel your ignitor needs help maybe try using just a bit of some type of smokeless powder. Something like a pistol powder which burns faster. I would maybe try something like universal or unique. But that's just because that happens to be what I have on hand. What are your thoughts on this?
I'd highly recommend using a thicker liner of sorts to help insulate the motor casing from the heat of the motor. Smaller motors you might get away with it but as you get bigger you'll start having failures of the motor casing and it would be a shame for such a nice casing to end up in pieces.
A 206s Isp for a sugar rocket is insane.
A small tweak to your code for the arduino can allow you to launch it from your laptop where you collect your data.
Basically you would be replacing the button with a code word, and using the serial monitor from the arduino to light your candle
Crazy awesome video. Just throwing this out there... But have you thought about looking in to recording the chamber pressure of the motors? I have no idea how high the chamber pressure will be. But there are tons of repetitively cheap pressure transducers on ebay. I will even tackle modifying the code to output the extra data. If you think it is worth it let me know and we can go from there. Again... Crazy awesome video. Keep it up.
Its thrust like sugar engine did you try to make sugar engine before?
Wrist workout leads to brief thrust, ending with crusty gunk. You know what content your audience likes.
That is an Excellent Specific impulse, almost on par with NASA's Space Shuttle Solid Boosters.
No, he calculated it wrong, somewhere in the comments someone calculated the isp to be around 80, well below the over 200 for shuttle srbs. Sugar propellent should be around 110, so his isp is actually pretty low.
I was thinking it was a strong H or a low power I at the thrust you mentioned for a second or so....
I haven't worked with it yet, but how do you think compressing a puck of satanite and machining a nozzle out of it would work?
Don't know if a harder binder could be added??
Very interesting idea! I need to get a proper hydraulic press for it to work though I'd think
A bottle jack and some pipe to cram it in.
Again I haven't worked with it yet so I have no clue how hard it gets. Being in a upstairs apartment, I'm already pushing my luck with the lathe, anvil and animalistic sounds coming from here at odd hours.
Amazon link saved!
Thank you so much! 👍
You could try using wax paper to wrap your spindle to prevent sticking
It expands... more wraps of paper to account for expansion...?
Occasionally I get a Similar thrust factor from 3 bean mix in a can.
I find that Grains generally make my performance sluggish.
Would love to see foley defense offering those casting casings to consumers willing to buy them.
and when you're not making model rockets, you can make pancakes for the wife.
In that hotplate, wifes gonna think she got the flu.
Can you make a mock LAW rocket with shoulder fired tube or is that illegal? No charge, just the rocket.
I would love to but I think CZcams would immediately strike my channel
keith moore, that would be cool, I’d love to see elementmaker do that, get an old LAW tube to launch his model rockets through.
As if the subject wasn't enough to get me onto gov't watch lists, the innuendos will no doubt place me on a very different kind of "watch" list
Already on file, with a few notes going back to when I was a Kid. The last interview Pi$$ed Me Off so much! I asked if they knew how to read or if they bothered to run a file check 1st. They can't tell the difference between my Grandfather, my Father and Myself. The Only one I had any respect for being professional used too be the Secret Service.
Nice set up. I think you might find that by applying a thin coating of petroleum jelly to your motor mold's core spindle, the grain/propellent will be much easier to remove. The petroleum jelly won't contaminate and affect the burn rate.
Thank you John. I do need to give petroleum jelly a try next go round!
y e s, more forbidden chocolate
forbidden caramel
I wonder how fast you can fill one of those huge balloons if you stuck it over the end of one of these things
Great work!
I would like to know 3 things: is it possible to get the same moulding tubes that you use (I am unable to make my own)?
- How can I make the same 3-grain motor as yours?
-How can I make nitrocellulose for my igniters?
Thank you
Can you slow the burn rate? A long burn rate with about 2k-3k grams of thrust average would be nice.
I have to ask since i couldn't find the answer to this question: Why make 3 Grains instead of one big grain? Whats the advantage?
How about a black powder motor? Would be interesting to compare it to the KNSB propellant.
Oh boy. Black powder motors burn FAST. I made a small one once. One second it's on the launch pad. Next second there's a smoke trail presumably following its trajectory, because I never even saw it move. Even with my homemade powder. I decided to switch to tamer stuff after that.
Yeah, you want to do any kind of compression of it while it's wet, if at all possible.
I wonder if 100% ethanol would work to stabilize the grain while you pack it. Evaporate it off after you're done.
I've pounded more tubes of black powder than i can count. Its not going to light from pounding. You need to use extra charcoal to slow it down.
@keith moore could have been whistle mix. That stuff you should never pound.
The primary job of the casting tube is to inhibit the outer surface of the grain.
Observations... To prevent cracking a grain, you should pull the coring rods while the grains are still slightly warm.The "hiccup" in your thrust curve is due to a small internal crease in a grain created by your packing technique, and your nozzle(s) will benefit from the use of graphite inserts.
And you might want to back off on the RIO a taste. 2% is a LOT of catalyst, even in candy.
I have been re-watching your vids and I just started into my own little project. would Fe3O4 or black iron oxide work just as red iron oxide???
I do believe black iron oxide will work as a catalyst.
@@ElementalMaker That is correct, either works fine. When fine tuning the mixture, a small adjustment in the amount of oxide is necessary.
How can we increase the burn time.....
Plzz help
I wonder what the PSI is from the nozzle of the motor. Amazing the determination of nature, the elements if you will. How would you figure that ? Time to make my brain hurt.
Do the grains expand when out of the mould due to the humidity?
The composition is quite hygroscopic so they will rapidly absorb water out of the air to the point of becoming a syrupy liquid mess. Keeping them in a desiccant bag keep the humidity down so they dont absorb water.
Wow that was quick and powerful!
Wonder if the burntime further decreases when pointed downwards and mounted to the ground.🤔
Now try sending it😅😂
No, the burn time is independent of orientation. Nozzle up makes it easier to mount the motor to the load cell.
Where can I find the mold and the rocket casing?
They are from Foley Defense. You can email them for the rocket motor parts price list.
@@ElementalMaker where can I find them on Instagram or do they have a website?!
thats a hell of a rocket my man, i'm kind of wondering what would happen if you used a tungsten nozzle instead of graphite, would its weight be an issue? it would undoubtedly be very expensive unfortunately but i cant see it being damaged by any of these tests.
This is my idea of whole grains
So. I was watching some rocket guys flying one of their commercial F rockets, and they seemed to get a much longer burn time. Me being ignorant would like to know what the difference is.
Those engines are probably a slower burning composition. Basically this motor burned super fast, but gave out alot of thrust during that short burn. Their engines likely give less thrust, but for a longer duration. The motor classification deals with the total force exerted by the motor over time.
I believe your thrust was actually higher than what you measured. Your test stand showed some considerable deformation under load, meaning energy was lost and the normal force on your load cell was diminished. Because the normal force was diminished, your load cell did not deform as much as it should have, resulting in a loss in measured load/thrust.
Hello,
First I love your videos. Very instructive and fun !
I'm playing for years with rocketery using aluminium tube to make motors (still using KNO3+Sugar for propelant).
The one your testing is amazing. I would love to get in touch with Luke Foley to buy some. Do you think it's possible ?
Kindest regard
*builds a pipebomb*
surprised that nozzle didnt like that
Put a thin film of Vasoline inside the casing before assembling. The grains will go in more easily and it will make the casing easier to repair.
The nozzle damage looks like normal erosion due to the supersonic gas flow.
Would a ceramic nozzle be more durable ?
Thats an awesome idea! Something like zirconia would make for an incredible nozzle. Only issue would be availability and machining.
May I suggest you weight your ingredient in increasing order of quantity when you do an addition?
It does not matter, since he melts the fuel on his electric grill. If I were using a sorbitol motor, I would mix them before starting the melt.
I personally used to measure the components separately, so there was no chance of getting too much through an inadvertent overly ambitions dump.
Would love to see an AP+AL+binder motor in the future. I would definitely pitch in for that one!
Just got a gallon of R45 resin and 6lbs of AP. So buckle up because its coming!
@@ElementalMaker yeeehaw! Don't make any rocket grenades though
@@ElementalMaker I've had a huge urge the last year to get started with rocketry to eventually end up launching a rocket from a weather baloon at 80K plus. Made some pretty energetic stuff happen with *Oxygen* and pure Paraffin which I had a few pounds of laying around. But, I hear NASA has a pretty good idea of how to make a solid rocket so next stop, aluminum and oxygen.
I've always wondered about launching a rocket from a weather balloon! That would be awesome!
I've always wondered about launching a rocket from a weather balloon! That would be awesome!
Graphite can be compromised by oxidation. I've seen propane torches burn a hole in graphite crucibles.
I wonder if one can nitrate sugar (or sorbitol) with fuming nitric acid?
That's definitely a possible cause as well that I neglected to mention 👍 I found a couple old articles that tested the nitration of sucrose and they stated that it had little value as an energetic as it is extremely sensitive and prone to spontaneous decomposition.
@@ElementalMaker Bummer. I guess that would have been literally too easy.
Luckily there are tons of other easily available options for nitrations.
@@ElementalMaker Like toluene and urea?
HAHAHAHAHA "Thats 1 sticky turd formation" hahaha epic.
That rocket blast reminded me of the sugar free (sorbitol) haribo gummy bear reviews on amazon
I've tried them and I can tell you it's identical 😂
What would happen If you dissolved both the sorbitol and potassium into water and mixed them so they’re combined kn a molecular level
I think the solubility in water is too low. And they would tend to crystallize out separately which defeats the purpose. This trick DOES work on blackpowder though, because it allows the nitrate to recrystallize _inside_ micropores in the carbon. But that's because the carbon doesn't dissolve.
Two things:
First off, if you used one hollow grain at the nozzle followed by two solid grains you'd get a longer burn using your current propellant.
Secondly, if you added some smokeless powder to the mix, by kneading it in to the propellant after the KNO3 and Sorbitol have been melted and are starting to cool, you'll get a lot more power. This high energy hybrid propellant would allow you to use 3 solid grains for a pure back-burn setup. However, one long grain would be better for back-burn. You should leave out the Iron Oxide in this hybrid mix.
I have some really old Estes solid rocket motors from early mid 70's they are not very stable.
If they are the old D motors, they were not very stable even when new - very prone to grain cracking of the BP, which resulted in CATOs. After 40+ years, the C motors may be developing the same problem if they have received a lot of temperature cycling.
Last time I used some of my old Estes motors from the early 70s, up through C were fine. But every one of the remaining D motors were bad. I should probably dig them out one of these days and use up the rest of them.
On a side note, did the griddle heat up and cause the green cutting mat to not want to remain flat anymore like heat did to mine? Guess it sure helped having a air spacer between the mat and the heat involved. Careful with that people or you will become disgruntled accordingly!
No mine didn't warp at all from the heat