Making a more powerful PVC sugar rocket motor - A complete tutorial

[@keithdavis00]

Grown men doing what we would have liked to have done as early teens, but now we have the resources. (I am one of those, guessing maybe you are, too.) Great job, and thanks for the exact specs for this model.

[@stuartpowell449]

Great video! Thanks 😊

[@kingofplasma9489]

Good video

[@hunnybunnysheavymetalmusic6542]

Your radial arm saw looks like mine. They are rare, and other than my own, yours is the 3rd I've seen anywhere at this point.

[@rotaryrocketry]

I bought that at an estate auction several years ago. Guessing from the look of it, it's a bit old but it works really well.

[@Hulk195]

Super Video! Grüße aus Deutschland

[@LT72884]

well, my buddy just purchased some sorbitol and he is going to try this exact motor out. Have you guys used sorbitol before with these pvc motors? thanks

[@rotaryrocketry]

I have not used sorbitol but I know a fellow rocketeer that does use it... You can check out his stuff here: www.youtube.com/@therocketeer

[@LT72884]

@rotaryrocketry i follow him as well, i just need to test his formula in your case haha. I think my main question and concern is if his fuel will work in your case following the exact same process.

[@rotaryrocketry]

It will work... BUT... Might need to change the nozzle size depending on the burn rate of the fuel. However, it's my understanding that his sorbitol fuel has a slower burn rate than the flexi-fuel fuel used in this motor. If it does burn slower then you should not have an "explody" problem.

[@LT72884]

@rotaryrocketry it does burn slower. I was using some software for making motors and using regular sugar, the pressure is much higher, but when i use sorbitol, the pressure is lower. So it does burn slower.

[@LT72884]

@@rotaryrocketry my replies my have not shown up. i was in a bad reception area on the train. Ok, yes, sorbitol has a slower burn rate and produces less chamber pressure, so i should not need to change the nozzle size... unless the current 11/32 is to large and produces no thrust for the motor.. then i will change it. but i will throw it in a simulation first and see how it reacts to the 11/32 nozzle

[@LT72884]

ill build this one second or third. I know the supermonkey and the class 1 motors are very reliable. Im hoping this supermonkey+ is just as reliable

[@rotaryrocketry]

A few ground tests and a few launches so far and it's looking really good.

[@LT72884]

@rotaryrocketry *sigh* great, another project for me to begin hahaha. In all honesty, i really like this version, low altitude, easy to recover, powerful enough to enjoy.

[@rotaryrocketry]

I hope you video your tests and/or launches... Let me know if you post a video for them, I'd love to see.

[@LT72884]

so is the 11/32 hole in the washer considered the nozzle throat diameter? and im guessing since the 7/16th hole is larger in the end cap than the 11/32 washer hole, this is what creates the angled divergent nozzle sort of speak? The reason i ask, im putting all the specs in a motor design software so i can see some graphs. thanks

[@rotaryrocketry]

Yes, the 11/32 washer hole is the throat or nozzle diameter. That is a #22 nozzle (22/64") The 7/16 hole in the cap is just to hold the ear plug in place. As you see, the ear plug expands to fit snug into that hole. There is really no significant convergent or divergent when the motor is built. The exhaust gasses actually form a convergent and divergent while the motor is burning. It's actually kinda neat to look at the nozzle after the burn and see how it has been shaped by the exhaust.

[@LT72884]

@rotaryrocketry ill have to look at the motor end when it burns so i can see what you mean. I understand what you are talking about, i just have not seen it visually yet. I went ahead and used some motor software and this motor is a progressive burn motor. Its kind of cool to see the graph, surprisingly, the pressure is about 700psi at its max but average is 470. This motor is the equivalent to a H350 with max thrust of 530

[@rotaryrocketry]

You are absolutely correct that it is progressive burn. Not the most efficient burn curve but making one single fuel cell makes this motor super simple to build. It's surprising to see what the PVC case can actually handle... for a very short period of time.

[@JETHO321]

Im just curious if you're aware that the atf regulates rocket motors containing more than 62.5 grams of fuel, even if its sugar fuels?

[@rotaryrocketry]

I am aware.

[@LT72884]

only for commercial. For non-commercial use or experimental use, they do not regulate unless you are making giant motors. Plus sugar fuel is a LOW energy motor in the grand scheme of things. APCP is MUCH higher energy and atf does not regulate that for personal use.

[@TheTankFG]

⁠@@LT72884you are 100% incorrect. Same rules apply when you pass into the HP realm.

[@gmanshackshack6822]

Now just greater thrust duration. Larger diameter?

[@rotaryrocketry]

Yes, diameter would equate to longer burn time. But that was not the goal of this particular motor. I'm already planning ahead to the "Super Duper Monkey" motor that will likely be 2" diameter fuel instead of the 1.3" diameter fuel used here.

[@zerofps4796]

Does it goes to space ?🤔

[@rotaryrocketry]

Not quite... The rocket had a launch weight of around 2000 grams with this motor installed and got to around 1400 feet. Just slightly short of reaching space :)

[@sigar_lix]

Put multiple of these

[@rotaryrocketry]

Maybe a multi-motor launch is lurking in our future... Maybe...

[@Ericlfimate]

What type of corn syrup do you suggest for the fuel? Fructose or Glucose or Maltose??

[@rotaryrocketry]

Here in the USA, you can typically find "Light corn syrup" and "Dark corn syrup" in the grocery store. I use light corn syrup. I don't believe you can select from a fructose, glucose or maltose versions of the product. My understanding is that light corn syrup contains glucose & maltose. In short... Anything that says "Corn Syrup" on the label should work just fine. In fact, we've used molasses, rice sugar & honey and they worked also.

[@Ericlfimate]

@rotaryrocketry ok thanks. I look up into online market because they don't sell locally. And i found all these different corn syrup, so instead of blindly buying them i just wanna confirm it first.

[@cannon440]

So how can the ejector charge be {fixed} so as not to explode. In other words what happened?

[@rotaryrocketry]

Two things... 1. I may have put a bit too much black powder in that ejection charge. 2. I'm gonna look into making a new ejection charge design that has a weak diaphragm over the black powder instead of a complete layer of hot melt glue. That way there will be an immediate breach of the diaphragm without trying to explode the CPVC cap holding the powder.

[@adikisela409]

nice thing..

[@GunsNGloryShow]

A lathe would be almost a necessity for building these.

[@rotaryrocketry]

I just showed you how to build it with a hand drill and/or drill press... Right here... Right in this video. A lathe is nice but completely unnecessary.

[@GunsNGloryShow]

@@rotaryrocketry I went through it again and didn't see a lathe.

[@xxx_8292]

Can you show me how to make an engine from an aluminum pipe?

[@rotaryrocketry]

Here are a few videos that might help... 1. Large aluminum & steel motor - multi-part series. This started out as an aluminum casing but changed to a steel casing during development. Probably still could use this technique with an aluminum pipe. Note: I DO NOT recommend this motor for a beginner... It's too large and too powerful for beginner level. kzbin.info/www/bejne/bl6vm3WCZ512hbs 2. RoboMonkey aluminum & steel motor. This was a VERY successful motor that we used a lot before the development of our newer PVC motors. kzbin.info/www/bejne/b3q0Xnx7lsx5fqM 3. Single use steel motor but this design could likely be made using aluminum tubing. kzbin.info/www/bejne/hHe8mIx_erVpqKs

[@RobbertDIYprojects]

channel would be awesome it it uses the metric system as well. the "rest" of the world doest use imperial values

[@rotaryrocketry]

True, but there's not really a lot of numbers to convert here.

[@T10Lu]

Why finish so fast ?

[@rotaryrocketry]

What else did you want me to talk about?

[@T10Lu]

@@rotaryrocketry It was just a great job but it burns very quickly. I would like to see him go further.

[@rotaryrocketry]

oh... You mean why does the FUEL finish so fast... I thought you meant why did I finish the video so fast... LOL Well, I have plans for a future motor that will have 2" diameter fuel instead of the 1.3" diameter fuel used in this one. That will provide a longer burn time.

[@T10Lu]

@@rotaryrocketry Exactly, LOL. I understand that combustion is fast, but it would be incredible to hear that sound and see it travel longer in the sky.

[@lukebaker1167]

What does it class on Burnsim??) Can show you some insane pvc motors if u like, high Ks, n Ls N flexi fuel is inferior , let me know if you want to learn Lastly!!! That’s the most complicated, heavy pvc airframe design ever { Dan Pollinos ) MUCH better is Richard Nakkas

[@rotaryrocketry]

I don't use Burnsim. The problem I have with that is that sugar fuel will burn very differently depending on the cooking temperature. I can make this motor burn for 2 seconds when fuel is cooked to 210F but I can make the same motor and fuel burn for only one second if I cook it to 260F. I really enjoy using Flexi-Fuel. It's simple to make and contains common and safe ingredients that just about anyone can purchase easily and cheaply. I think that's one reason why people like my motor tutorials because anyone can make them. I don't see myself changing to a different fuel.

[@lukebaker1167]

@@rotaryrocketry no not true. Ur way off. Use dextrose only. Go to Nakkas site and study it like the bible. Then you’ll build REAL pvc high impulse, high class reliable motors. Dont believe me tell me to fuck off

[@rotaryrocketry]

There is absolutely no reason to get rude here. What part am I wrong about? Sugar fuel does burn differently depending on the cooking temperature. I have proven it in several experiments.

[@lukebaker1167]

@@rotaryrocketry I’m not being at all rude. Just try a 65/35 +1% RIO mix, as for temp, when it’s fully melted n a nice consistent viscosity, pour the grains, don’t let it brown off. Simple

[@rotaryrocketry]

Sorry, it's just your use of the F* word in the original comment didn't go over well... Although you've edited it and removed that part. I have a long to-do list of projects... One future project is a comparison launch to see if adding a small amount of iron oxide to flexi-fuel will provide any noticeable difference in launch speed or altitude.

[@Science-Vlog]

the thumbnail shows a failed rocket.. shouldn't the fire look like a laser beam instead of burning car tires?

[@rotaryrocketry]

You might be reading too much into a comical thumbnail :)

[@daveerickson7607]

You should do george bush impersonations.

[@rotaryrocketry]

Funny, you're not the first person to mention that I look like him. I don't see it.