Arduino Rocket Motor Thrust Test Stand! - Elementalmaker

[@crispynugget3616]

i love it when the youtuber doesnt care about monetization so just says all the hilarious shit

[@Ken-rk3by]

yes I love it just say 321ignighoun

[@atourdeforce]

He said Penis!!🙊

[@atourdeforce]

Wooah I just said Penis!!🙊

[@thugasaurusrex6004]

Crispynugget even after all that, he still got ads on his video lol. Feelsgoodman

[@ElementalMaker]

For now at least. They just demonetized my top video :(

[@MushVPeets]

Estes vs. suborbitol vs. rocket candy. Need to see it.

[@ElementalMaker]

Let's make that happen 👍👍

[@PyroThunder]

Haha. I hear some of that AvE Schtick! Lol. You both combine the right balance of information and comedy! great channels!

[@bstrickler]

Yup! Before I knew he watched AvE, I was pretty dead set on it, because of the way he speaks!

[@braydeny]

i agree

[@lightman500]

Thanks for the great video! I took your design, referenced Nick and Len's PDF file, and built my own version of the rocket test stand. It works fantastic!
I'm using a 10 kg load cell and added a large 4" seven segment display sitting next to test stand with a rotating red light on top. I installed an igniter enable switch (safe/arm) that also checks continuity of the ematch. After modifying the graphical user interface code, I purchased a 50 ft active USB cable so I can sit 50 ft away and Trigger the system through the laptop.
I then added a plexiglass blast Shield that I placed in front of the test stand to catch any Rogue fragments coming off the motor.
It's amazing how sensitive the system is. Kudos to you and those who help develop this Arduino system!

[@bradleyfountaine664]

your commentary is all time!

[@kennethyoung1980]

So sweet when you see a plan come together! My kind of power. Keep up the language brother! This channel only gets better .

[@ElementalMaker]

Thanks Kenneth!

[@GrimStarr]

If you notice when the rocket goes off the base actually flexes downward because of the soft grass. You may get better results beings on a more stable/ harder surface. Awesome video man, love your content.

[@ElementalMaker]

Yeah I did notice that when editing the video. I am sure it did somewhat skew that data, might have shown a bit more thrust if not for that grass compression. Good eye!

[@GrimStarr]

@@ElementalMaker yea man thats what i was thinking, i doubt it would have made much of a difference but hey man the motors kicked ass thats what matters.

[@AjLloyd-uy2tr]

As a math teacher who despises common core your last comment was hilarious. Thank-you for posting - I just recently found your channel and am learning a lot. Take care

[@ElementalMaker]

Glad you enjoyed! Thanks for educating our youth 👍math was never my strong suit, but as an engineer I sure as hell had my fair share of it LOL

[@danielgrantcoleman]

Gotta love electronicals. Great setup. Love that you do all the things we have all wanted to try.

[@7890tom7890]

I watched this video the day after it was uploaded, subscribed and then purchased the UNO shield, load cell and HX711. It arrived today and i can push on with my build!
Excellent channel, great work :) thanks for frequently giving me the giggles "Jingle ma ballz!" lmfao

[@ElementalMaker]

That's awesome Tom! It's a very fun project that teaches alot of the basics of arduino. Always happy to provide a chuckle. Let me know if you need any help with the build 👍

[@peterk8909]

EM, Man you never ceases to impress, drawing inspiration from your subscribers. I usually get more doing for others. And once again, thanks for the post.

[@AAMUQuadChoppa]

This gives me flashbacks of my engineering controls class using LabView and setting up all the damn wires. Undergrad sucked but payed off

[@ElementalMaker]

Lol I feel you on that one. I think I still have my NI LabVIEW module hiding out somewhere around here

[@schelsullivan]

This project really cool. A few years back I help my son with his science project. Homemade rocket motor thrust tested with a kitchen scale and the Galaxy S4 filming at 120 frames per second.

[@ElementalMaker]

Very cool idea! Man that had to be a pain to go in and record each value. Was the refresh rate of the scale anywhere near the 120fps of the camera?

[@theITGuy-no3nt]

Man, that was a fast turn around for that project! Fun video. I would not have guessed that 3/4" would produce 6 lbs. of thrust.

[@ElementalMaker]

Yeah I cobbled that sucker together quick! I too was surprised by that thrust.

[@sciencemodelaboratory7298]

Nice test.

[@mslindqu]

Great video. You can do various comparisons of different fuels and I think most people would be entertained for quite a while.

[@ElementalMaker]

Yeah I plan to do quite alot of tests with this sucker! Even get into some experimental composite propellants 👍

[@davidcool5189]

Dude, you sound a lot like Patrick Warburton (Puddy from Seinfeld). I don't remember exactly how I found your channel, but I'm glad I did. Cool stuff, man!

[@ElementalMaker]

Haha I hear that quite frequently! Thanks! 👍

[@Strelnikov10]

Love this guy's sense of humor.... love it.

[@ch3no2killz]

Very Cool! When we were flying rockets the only computer around was "Univac"! I doubt they would have let us borrow it... )

[@djsnowman06]

Proof of concept:perfect! now pretty her up with a PCB and a project box and make that something real special. Great job man

[@ElementalMaker]

Thanks man! That's the game plan! Already got a nice board soldered up in my shop talk video. I'll 3D print an enclosure for it as long as my old printer is still working LOL

[@HMan2828]

Nice setup!
Would be nice to see if you get better thrust by reducing the outlet from the bigger rocket. Try jamming a hex nut in the end and lock it in with epoxy, should allow for higher combustion chamber pressure, longer more even burn, and higher exhaust velocity, while also adding a bit of weight to the bottom of the rocket, making it more stable in flight.

[@ChozoSR388]

That was som mighty fine pixie wranglin' there!

[@octosquatch.]

Thank you for knowing the difference between a motor and an engine.

[@shanestewart1498]

Heck yeah man!! Blowing my mind with the rockets

[@jonasholtwick5542]

Could you compare normal rocketcandy and your sorbitolbased fuel? I´d love that!! Great video by the way!

[@ElementalMaker]

I'm sure I could do that down the road!

[@jonasholtwick5542]

@@ElementalMaker I'm looking forward to that!

[@oswynfaux]

The trust climbed as the propellant burned from the inside to the outside increasing the burning surface over time, plus the internal pressure built over time, both increasing thrust. Used to make sugar rockets 25 years ago, biggest one I made was around 2.5" id and 8" long, man did it go.

[@ElementalMaker]

Holy crap that had to be a MONSTER! Any idea what altitude you got to?

[@oswynfaux]

@@ElementalMaker It was just a stick rocket (full 48" long 1/2" dowel) and it tipped over a bit as it launched so I would say it went up 500~600 feet and downrange 1000~1500, I would say it took 2~3 seconds to build thrust before it launched, boy did it roar. Glad I did it in the winter and out in the boonies so no chance of a fire. Used Durham's Rock Hard Water Putty for the nozzle, it is very hard and does not shrink when dry, then a forming mandrel and damped it in layers, match stick with wire igniter shoved to the top to ensure ignition at the top of the core.
PS. Pretty sure the tube was from a large roll of plastic wrap, around 1/4~3/8 wall thickness.

[@ElementalMaker]

@@oswynfaux boy that's one huge stick rocket!

[@DesertJeff]

Got maw Arduino goodies coming. Can hardly wait. I'll be happier than a puppy with 2 peters.

[@ElementalMaker]

I may have to steal that line! LOL that's great! Let me know if you need a hand with anything. I'm not the best aurdweener worker, but I got this project down pretty good 👍

[@rizin2213]

Wish this was for raspberry pi. I need to build my test stand.
Also this will always be progressive burn being a single fuel grain with one uninhibited fuel surface.
This is where multiple Bates grain motors come in. You can actually tune your thrust curve. Progressive, neutral, or regressive all by changing the length of a Bates grain with 3 uninhibited burn surfaces.
Thanks for the video. Keep up the good work.

[@stamasd8500]

Actually for little uncomplicated setups like this one Arduino is the best. Read a sensor, send data to serial. Rinse, repeat. Low cost, easy to program and debug. If you choose the right components you can place a whole data acquisition system on a C-engine rocket (done that with an Arduino Pro Mini). Can't see a RPi making that flight. :)

[@rizin2213]

@@stamasd8500 mainly I would like to make a test stand. Bought the Rpi for doing projects with my son. Now I'll have to get a adrino to do my own projects! Data acquisition I'll just use my apogee device to give me the basics.

[@stamasd8500]

@@rizin2213 Both the RPi and the Arduino are adequate for a test stand, but I tend to favor the simplest approach to reach a goal. Arduinos are cheap, plentiful and easier to work with. I have several dozens of them in projects I built. The last one was a digital frequency synthesizer using an AD9850; currently working on building a high-temperature kiln, and the kiln controller will be another Arduino. A RPi would be overkill, unless I decide I want to stream live video from inside the kiln. :D

[@madmarkthepyro5247]

Man that is just slick as hell.would love to see some long spindle rocket test done on it.

[@zypergod]

from my experience working with resistance based load cells i can tell you that small temperatur changes will have an effect so make sure you work in the same temperatur environment
you should also reset it before you make new measurements
and never overload it since you will have to reset it i generally dont go over 80% of the estimated max load
and science mechanical work turns into heat you want to rest the cell in between measurements

[@DrewLewiscreations]

Very nicely done! Now the next step is to make a pcb and custom case/stand for a nice finish. Keep 'em coming! Fyi, your synthetic ruby video blew one of my friends mind lol

[@landroveraddict2457]

strap 50 of the big motors to you , then fly rocket man! Awesome video 👍

[@ElementalMaker]

LOL that would be one hell of a ride!

[@simonsuarez7561]

Hey man you're hilarious! Your videos really helped me with my rocket projects. Thank you, there it goes a thumbs up.

[@ElementalMaker]

Thank you Simon! Glad you found the videos useful!

[@koori049]

Nicely done this is way cooler than the plywood thing you built last time! I suppose next is a series comparing different chemistries for home made fuel with each other and the store bought engines.

[@ElementalMaker]

Thanks! Quite a few videos using this in the future I'm sure!

[@seannot-telling9806]

@@ElementalMaker I like idea that koori049 has.

[@mxcollin95]

Dude I’ve been wanting to do this same thing! Been trying to figure how best to go about doing it. Thinks for throwing in the link. I’m a new subscriber that just found the channel and have been loving it! 🤙 Keep up the great content man.

[@ElementalMaker]

Thanks Collin! Glad your enjoying! It's a very easy setup to build, I definitely recommend it

[@shakdidagalimal]

Might want a concrete block or slab on the grass underneath, the larger engine thrust the whole plate down and it rose back up during burn and data capture

[@anthonycourte1384]

Could the double spike on the small engine be when it moved in the tube? Maybe a poly tube the right size for the engine would give a cleaner curve?

[@stamasd8500]

Or just a piece of crinkled paper shoved between the 2 tubes.

[@ElementalMaker]

Yeah I do need to make a sleeve to keep the smaller motor more constrained. Maybe I'll finally put my 3D printer to use!

[@Laffen47]

From where I'm sitting it looks like your
cone got wallered out again,
which would account for the sudden drop
in thrust shown in your curves.
You may want to consider doing some or
all of these improvements:
1. Upgrade to a hydraulic press
2. Change cone material
3. Make the thinnest part of the cone thicker
I hope you will take this as constructive criticism
as I quite enjoy your videos.

[@ElementalMaker]

Yeah the throat of the nozzle eroded quite a bit again. Working on new nozzle compositions with added refractories to minimize erosion. I did make it a bit thicker this time, but didn't seem to change the degree or erosion.

[@mystamo]

Pretty solid EM.. Pretty damn solid.. you sir are making some stellar videos these days! I like the test rig. I'm curious how sugar powder based motors perform.

[@ElementalMaker]

Thanks! I'm sure I'll test some sugar based engines soon for comparison 👍

[@peterk8909]

ElementalMaker I thought you said they were motors, not engines, lol. Just me acting like an ass because at my "advanced age" I think I deserve it.

[@prudvi01]

Thank you so much for this! Made a few sugar rocket motors gonna test them this week 👌🏼

[@ElementalMaker]

Awesome! Stay safe and keep a good distance from the motors when testing

[@prudvi01]

@@ElementalMaker sure! Thanks again 😃

[@funkr3gulator]

pretty neat! would be interested to see how your rockets compare to a commercially available one!

[@esra_erimez]

Has anyone told you that you are like a normal AvE?

[@ElementalMaker]

Is there such a thing as a normal AvE? LOL
My wife also might have a comment or two about me being "normal"

[@260nob9]

Wow! That's impressive and Fun. Hey just an Idea to create the best of both worlds. How about the 1/2" tube with a smaller bore and try to make the burn rate progressive as opposed to digressive. Thus giving you and longer higher energy burn? Not an expert here in this space though in other areas this can give you an longer more sustained burn while the energy output increases. Keen for your and others feed back on this idea? Cheers and thanks for sharing.

[@OrbitalRose_01]

It'd also be interesting to see what the total impulse of each engine is. also, it would be interesting if you had a real-time clock module and an SD card module so you could save timestamped data directly to an SD card in csv format instead of having to copy out of the serial monitor.

[@_mycroftxxxadamselene922]

The millies() function in the Arduino returns milliseconds since power on.

[@professortrog7742]

Bigger core-gap will give quicker climb in thrust. Also dont make the core-gap too deep or you may blow out.

[@ElementalMaker]

Good tip!

[@jw1065]

You should do this testing with all sort of different mixes of rocket candy, sorbitol red iron oxide, black powder, powdered sugar rocket candy.

[@ElementalMaker]

That's the plan! Also different grain and nozzle configurations 👍

[@EZCyclone]

@@ElementalMaker Yes, good, I expect to see 2, maybe 3 thousand videos on this test stand! lol

[@AtlasReburdened]

No units on the graph huh, let me take look...
Ah yes, it appears the vertical is in millifucks given and your horizontal is in seconds after waking.
It's accurate, but I just don't remember participating in that study.

[@ElementalMaker]

Haha love it!

[@stamasd8500]

My millifucks usually don't get to a maximum before at least 20000 seconds after waking. Yeah pretty flat curve.

[@Ken-rk3by]

I have always found it more fun to say 321 ignision

[@TomokosEnterprize]

WooHoo my friend. I worked with big load cells on logging scales for years. They can be fickle things eh. They were/are 2x2x26 in.and handle 25 ton +. Great fun this post for sure. Love it. Great tests and info my friend. See ya next time around fella !

[@ElementalMaker]

Holy crap 25 ton! That's insane!

[@TomokosEnterprize]

@@ElementalMaker Most or all log trucks have 4. 2 on the main trailer and 2 where the 5th wheel or bunk is. Pain in the hiney as they are aluminium and are fastened with steel bolts to a steel frame. Add some current and you know what you get.I am an expert removing broken 1 1/4 broken bolts my friend, LOL.

[@Carlosfpvmx]

someone who built the test stand?
I am having problems with the operation.
when I connect the arduino the relay is activated and deactivated immediately after the yellow led makes 4 sequences of 4 blinks (as far as I can see), the lcd says "MODEL ROCKET DYNAMOMETER" and the serial monitor says "HX711 Rocket Motor Dynamometer, V .5 Affix motor nozzle up. Place igniter in nozzle. Move away from teststand. Press start button to initialize ignition sequence. "
when I press the button it does nothing. on one occasion it started taking readings (very slow about 1 per second which I think is the calibration of the load cell) and when I opened the serial monitor the code restarted and no longer worked.
I have an XFW-HX711 I desoldered the jumper that I had at 10Hz and I soldered the 80hz one, as it didn't work, I used another XFW-HX711 WITH 10Hz and it didn't work either. Any idea what is happening?
EDIT: Here is the update code
#include
#include
LiquidCrystal lcd(8,9,4,5,6,7);
const int buttonPin = 12; // start sequence button
const int ledPin = 13; //LED indicator and/or buzzer
const int igniterPin = 11; //igniter transistor circuit
int buttonState = 0;
#define DOUT 3
#define CLK 2
HX711 scale;
float calibration_factor = -1120; //-560 works for my 10kg loadcell.
void setup() {
scale.begin(DOUT, CLK);

pinMode(buttonPin, INPUT);
pinMode(igniterPin, OUTPUT);
pinMode(ledPin, OUTPUT);
Serial.begin(9600);
Serial.println("HX711 Rocket Motor Dynamometer, V.5");
Serial.println("Affix motor nozzle up. Place igniter in nozzle. Move away from teststand.");
Serial.println("Press start button to initialize ignition sequence.");
lcd.begin(16, 2);
lcd.clear();
lcd.setCursor(0,0);
lcd.print(" MODEL ROCKET");
lcd.setCursor(0,1);
lcd.print(" DYNAMOMETER");
delay(2000);
scale.set_scale();
scale.tare(); //Reset the scale to 0
long zero_factor = scale.read_average(); //Get a baseline reading
Serial.print("Zero factor: "); //This can be used to remove the need to tare the scale.Useful in permanent scale projects.
Serial.println(zero_factor);
Serial.println(" ");
}
void loop() {
lcd.clear();
lcd.setCursor(0,0);
lcd.print(" Rocket Dyno");
lcd.setCursor(0,1);
lcd.print(" STDBY " );
scale.set_scale(calibration_factor);
lcd.print(scale.get_units(),1);
lcd.print(" g");
delay(500);
buttonState = digitalRead(buttonPin);
if (buttonState == HIGH) {
lcd.clear();
lcd.setCursor(0,0);
lcd.print(" Rocket Dyno");
lcd.setCursor(0,1);
lcd.print(" STAND CLEAR!");
Serial.println("IGNITION SEQUENCE ACTIVATED!");
for (int i=0; i

[@briantw7096]

Best video yet. Good job

[@ElementalMaker]

Thanks! Glad you enjoyed!

[@levioptionallastname6749]

Oh you, This is What my current project is,.

[@oogityboogity6644]

Love this I set up a stand that measures heat and pressure on my second stage but thrust is a bit much for my brain to do

[@TheSkogemann]

This was awesome! Makes it easier to try out different stuff.. :)

[@bentboybbz]

@ 9:00 it will be stiffer and blacker than normal. Some one will be happy.

[@ElementalMaker]

Hahaha 👍👍😂😂😂

[@MultigrainKevinOs]

That data was satisfying! Great test setup, explaination etc... Well done! Curve ball, how about a rocket made from rockets candy?

[@ElementalMaker]

Definitely will be comparing them soon!

[@MultigrainKevinOs]

@@ElementalMaker it's occurred to me you guys call them "smarties" down there, oops i guess that attempt at a joke will fall flat. thanks for the video!

[@Nuovoswiss]

Sorry I'm late to the party, but just by an eyeball average, it looks like you're getting around ~30 seconds specific impulse (closer to 25 for the smaller, 35 for the larger). IIRC, KNS fuels have an upper limit of something like 120 seconds, but I don't recall whether that's a practical limit or a theoretical limit. So there's definitely room for improvement, but it's not bad for how simple those motors were. I saw other questions about how to calculate specific impulse: specific impulse is the exhaust velocity divided by earth standard gravitational acceleration (9.8 m/s/s). Average exhaust velocity can be calculated by dividing the average force (in newtons) by the average fuel consumption rate (in kg/s).

[@Nuovoswiss]

As a sample calculation, I'll start with the larger rocket graph. The bulk of its firing occurs between 0.4s and 1.5s which gives a fuel consumption rate of .034kg/1.1s = .031kg/s. With an (eyeball) average force of ~11 newtons in that interval, that gives an exhaust velocity of 11N/0.031kg/s = 355 m/s. Divide that by 9.8m/s/s to get a specific impulse of about 35s.

[@ElementalMaker]

I always look forward to seeing your comments and as usual you do not disappoint! Thank you for the sample calculation too! That certainly brings it down to a level even I can understand. Let me know if you want to see the actual data, I could send you the excel sheet if you interested.

[@paulameloot9380]

Nice vid but force isn't mesured in g but in Newtons (your 658 "g" peak value correspond to roughly 6.58N of force). Anyway keep up the cool stuff ;)

[@williamlivingstone4326]

B-E-A-utiful! Well done!!

[@linecraftman3907]

Now the real question is how consistent you can get! Also i would hide all the electronics away from the motor before it gets blown up

[@Disinterested1]

someone else watches Ave methinks :)
great video as always :)

[@nicktohzyu]

use hysteresis/averaging for the display values! (while still recording the instantaneous values)

[@ElementalMaker]

This program does average a few values to build in some hysterisis.

[@sleepib]

large engine seems normal, that thrust curve is expected for a cylindrical mandrel. Next thing I'd try with that one is a + shaped mandrel, so the thrust is more constant, and you can optimize the nozzle for a single chamber pressure rather than a changing one.
looks like the nozzle orifice on the smaller engine was too small or got blocked by something, pressure built up, thrust spiked when the nozzle blew out, then as more of the grain was exposed some thrust built up again.

[@ElementalMaker]

Yeah I definitely think the smaller engine got blocked momentarily causing that drop to zero that can be seen on the chart . I definitely want to experiment with different grain and core configurations; great suggestions!

[@sleepib]

​@@ElementalMaker What condition is the nozzle in? I think the blockage was only partial, and happened during that small blip at ~0.75 seconds, causing chamber pressure and exhaust velocity to rise, increasing thrust. This lasted until the throat of the nozzle failed at the very peak of that spike, at which point chamber pressure and thrust drop to basically zero, and only when combustion rate increases with the increased surface area do you get some thrust back.

[@ElementalMaker]

Ill have to take a closer look at the 1/2" nozzle. I was so focused on the 3/4" nozzle eroding again I didn't give the 1/2" one much attention. I agree it was a partial clog, a complete clog and I probably would have had a nice little CATO.

[@corlfranco9371]

cool graphs. +10 science

[@ElementalMaker]

Glad you enjoyed 👍

[@Midnightproductions1776]

Man that's so awesome!!!!

[@Freizeitflugsphaere]

It seems I missed your last few videos😐
I need to catch up...☺️

[@largejuicer8730]

Where do you get those paper tubes for those motors?

[@Sujith_93]

can you explain the electrical components connection setup

[@Made2hack]

Wow, that's some serious power for a few grams of sugar. Not many things give you that much energy from a few grams...

[@ElementalMaker]

Talk about a sugar rush! LOL

[@DesertJeff]

I think it's a very good that you live in the East and I live in the West separated by many states. Because if we weren't, we be doing this stuff together all the time. Looks like I'm going to have to pick up an Arduino. I've built raspberry pi stuff for years time to switch to something with an atmega. Your channel rocks man. I built a scale using a fish scale.that works, but it's not as accurate as yours. Good job good job.

[@ElementalMaker]

Thanks Jeff 👍 I've never messed with raspberry pie, but I'm sure you could do the same thing with one! This was actually my first big arduino project and I was really impressed with it. Bought it years ago but never messed with it aside from some basic programs. This was definitely a fun project, if I'm ever out west we'll have to do a video collab!

[@aks8586]

Hello! Thanks for making these videos. The circuit schematic in the PDF shows a yellow LED and a transistor; I dont see these on your board. Can you please share your breadboard schematic? If possible, can you please email the breadboard schematic? I will really appreciate it. Thanks!

[@MrKclo42112]

thats great ,good job on the arduino

[@ElementalMaker]

Thanks Tony!

[@cphVlwYa]

If you want to use the 12V battery, you could probably just put an inductor in series with the match. That way it'll impeded the current change and heat the nichrome slower.

[@ElementalMaker]

Very good idea. I did design the igniters for use with 9V, so I should have know better than to use 12V, but the inductor idea is great!

[@LastDaysADDaniel]

Excellent, I have always wondered just how much thrust from those little suckers... A series , B and C, don't give a crap about D's or E / G etc..

[@totherarf]

So are we going to see a comparison of different motor shapes power output/time ..... or do you think it is all fairly irrelevant compared with the effort of machining several formers?

[@SupernovaSpence]

The extra spike on the small motor, im my theory, may be due to nozzle erosion. Usually, the grain is larger in diameter to the nozzle, but given the simple nature of your motor, its relatively unavoidable. The heat melts the propellant before it ignites and creates blockages in the nozzle. Be careful for CATO's on the smaller motors with smaller cores because of this!

[@ElementalMaker]

Yeah that's what I believe it was. On the thrust curve you can see it almost dropped to zero, would could definitely be explained by a blockage. Very good insight thanks for the excellent comment 👍

[@suoppsdn9751]

I seen a video on youtube some years ago. It was how to make gun powder from hardware store bought stuff. Can't seem to find it any more. But all I remember it was stump remover, Charcoal, and a gardener stuff for the sulfur. Have you ever done something like this? How would that work? Sorry just can't find that video and don't remember who made it.

[@pyrusrex2882]

I've done this recently. Use this formula: 75 percent (by weight) potassium n*trate, 15 percent charcoal (make your own, don't use Kingsford....I use light wood like pine and sumac) and 10 percent sulfur powder. Dudadiesel.com out of Alabama is the best source for the potassium n*trate and sulfur. 10 lbs n*trate and 1 lb sulfur +shipping/hazmat is about 40 bucks all in. Grind/mill everything in a ball mill or shaker bottle with .50 caliber lead balls (be gentle). Once down to fine powder (airfloat for the charcoal), mix them well. Add a solution of 1 part 91 percent rubbing alcohol to 3 parts water until it forms a paste about like thick cake batter. This works the n*trate into the pores of the charcoal. Spread it out on a cookie sheet and put it under a fan for a day or so. Crumble it up when dry to the desired grain size. You can also add some dextrin (easy to make from cornstarch at home) at 1 or 2 percent to hold the grains together well when you mix in. (Sorry for the asterisks in N*trate, I'm keeping with EM's RUclips PR Policy). You will get some GOOD lift powder out of this.

[@brendanrandle]

an ntc thermister in series with the igniter should let you use the bigger battery reliably

[@Jameson1776]

Already subscribed. I just wanted to say I seen this video on a science news app I use.

[@ElementalMaker]

Oh that's awesome! Thanks for letting me know!

[@Jameson1776]

: go.newsfusion.com/science-news/item/6082686
This was the app and it linked a website hack a day

[@meenabansraj6453]

Very cool

[@robert1589]

I love techniligy!

[@laserfalcon]

Nicely done

[@kareemsalessi]

Awesome. 9:50 2.6 kilos of thrust could lift up how much mass off the ground??? And thanks

[@WeAreThePeef]

Now you have this for testing, be awesome to use it to compare various propellants. I'm personally curious how it fares against kno3/sugar. Could even try the three types of kno3/sugar against each other. Mixed/compressed powder, melted together and that method of dissolving both in water to mix, then boiling off the water, then melting the residue.
I gotta learn how to use arduinos.

[@ElementalMaker]

Great ideas! I've only played with the arduino a few times, but it's definitely a great piece of technology!

[@Semicon07]

Nighthawk sent me!

[@oldrabidus2230]

You need a control to compare. Maybe test an Estes “D” motor and compare to what you made! As an added bonus, show how much the commercial motor cost was vs your homemade motor.

[@ElementalMaker]

I plan to do that shortly! Great suggestion on the cost comparison! I hadn't though of that.

[@oldrabidus2230]

ElementalMaker Love your videos. Science, innuendo, pyrotechnics and fucking swearing!

[@Sujith_93]

how did you make the propellant can you give a detailed information of preparation of propellant

[@ElementalMaker]

I have many other videos showing how I make various propellants

[@davidtan1235]

Hi i have viewed the pdf file and has done the same circuit as the diagram. i copied the code , there is some code problems however i was able to figure it off, howver, now in the serial monitor it only shows Affix motor nozzle up. Place igniter in nozzle. Move away from test stand.
Press start button to initialize ignition sequence.
I tried pressing the button but nothing works, I also tried connecting it directly making the wire as the "button" it still do not work. can you please help me? thank you

[@ElementalMaker]

Hi David, please email me (see about me page for email) and I will send you my code.

[@xialemai6412]

Awesome video.
On the first engine, we can see the base of the scale moving downward because of the thrust, then back up.
While it wouldn't change the area under the curve because the whole setup "rebounds", it makes your curve a bit off. So the actual curve should actually look better (the thrust is highed than shown on the first part, when the base goes down, and lower when the base goes back up).
For higher thrust engines, do the test on harder ground for more accurate results.
By the way, you used a 10kg sensor right ? Did you update to higher load cell later ?

[@ElementalMaker]

Yes both a larger load cell and the ground movement have been addressed in newer tests. Much larger motors behind tested as well. I have done videos on them

[@xialemai6412]

@@ElementalMaker Yep, I've seen your rocket related videos.
Does the larger load cell has a decent sensitivity for smaller engines ?
I saw yours read a 42kg thrust on the 3-grain engine, so, I do guess that's.... a bit over 10 ;)

[@ElementalMaker]

@@xialemai6412 yes the 50kg load cell seems to be just as accurate for smaller engines as the 10kg was. I was expecting some accuracy loss, but nothing detectable occurred.

[@xialemai6412]

@@ElementalMaker Oh damned ! I just received the 10kg load cell....
Well, I guess I'll have to stick to small units for now ;)

[@timdowney02]

Could the sample be backwards on the chart like right to left instead of left to right that would make since on the curve the small motor seemed to be opposite of the chart

[@ElementalMaker]

Nah the data is what the graphs show. Good burns and good thrust, just not optimal thrust curves

[@Molb0rg]

notification did work for me, just information

[@Juliansa537]

I built the hardware for this, but it seems that the sketch for the HX711 has changed from its original form and will not work with Nick and Len's original sketch. Any ideas on how to fix this?

[@ElementalMaker]

I do recall it took some tinkering to get the code to work. If you can shoot me your email address, I will send you the code I have working. I think the big thing was updating the code to call out new libraries, as the ones called out in their original code were not available.

[@Zendail]

This is great, keep it up

[@ElementalMaker]

Thanks!

[@pyrusrex2882]

You just took this all to a new level of geekery. That was fuckin' beautiful. And thank you for being non politically correct in your delivery. It's what sets the channel apart from all the others. I've been blowing nozzles out on my stand (no load cell, just a simple deflection scale), so I'm in the process of building a down firing stand with a curved flame bucket so I can control where they blow out, if nothing else. My neighbor gets worried when he sees burning propellant chunks flying up in the air over the fence. I can't wait until my shipment of "Ammonium/Chlorine Based Oxygen Source" comes in.

[@ElementalMaker]

Thanks Rex! Getting into the AP based propellant is a whole new level! I experimented with it years back, but never quite got a good motor with it. Always had catos and nozzle blowouts. There is a great book called 'experimental composite propellants' by Terry McCreary, I definitely recommend checking it out if getting into that stuff 👍

[@Fusako8]

RUclips hates a channel where you make fun things using HS level chemistry?! Say it ain't so! One of your videos inspired me to chat with a pretty lady about nitrocellulose. . .
Question for you: How would you filter out the water vapor from a NaOH+H2O+Al reaction if reacted in a 6.5gal carboy? Moist cotton plug?

[@ElementalMaker]

I would run it through a secondary drying chamber filled with Silica gel or dried calcium sulfate. Glad your enjoying the videos!

[@theterribleanimator1793]

I wonder how that conversation went.

[@Fusako8]

Energetic? It is a simply way for someone to make hydrogen gas at home. It is quite exothermic, so you get a lot of steam along with your hydrogen. So if you want to do fun things with pure h2 you need to seperate the two. It can also be useful to pre-heat the carboy to extend the life.

[@ddegn]

I'd suggest using a long collection hose with a way to cool hose. Try to arrange it so the water can flow back to the carboy.
I think silica gel or calcium sulfate would get saturated really fast.
FWIW, I had the same problem as a kid making hydrogen for balloons. At the time I just added less aluminum at a time to keep the reaction from getting too hot.
I used a glass *Tab* bottle (the large ones) as my reaction vessel. I had one bottle break because of the heat.

[@Fusako8]

Yeah, some airline perhaps, through an ice-bath.

[@corresandberg]

Awesome video. 3 kg of trust, or more, from that small one. Hmm, have you seen videos of Russian tanks that are released from an airplane? The have a parachute oc, and for the last 10 meter or so it fires rockets to slow it down further. Maybe this baby-rockets could do the same but to help a drone survive propeller failure, just and idea

[@normangilden3453]

Thx that was cool!!!

[@TheTomBevis]

I had a amateur rocketry hand book from the late fifties. They were using sulfur and zinc propellant, in small CO2 cylinders with machined nozzles. Claims of 35000 feet were in the book, for cigar-tube sized rockets. Have you ever tried that propellant?

[@ElementalMaker]

Ah the old sulfur zinc propellant! I've experimented with it a bit, but it's quite low power compared to other propellants and has a strong propensity to explode if the grains have any imperfections or cracks. It's not very effective because it's reaction product is zinc sulfide, a solid. Gas producing propellants will typically outperform ones which produces solids. 35000 feet sounds very optimistic in my book!

[@TheTomBevis]

@@ElementalMaker I thought so, myself. I've never used anything besides commercially produced engines, though.

[@piercer4882]

This is almost like another AvE channel... nice! Subscribed..

[@tibor_a1524]

Thats pretty good for a 15 years old camera

[@ElementalMaker]

yeah it wasn't a cheap on back in the day. Still though was only a few hundred bucks. Its an old Samsung HMX-H100, I think the first year they started making them.