Very detailed video. You've earned my subscription.

An inductive heat plate would be perfect here, no exposed heat element, Thanks for an extremely thorough and high quality video! 👏👏

@rotaryrocketry

7 ай бұрын

Oh don't I know it! Inductive cooktop is on my list of things to buy... Eventually :)

Every step of the process is well thought out and efficient and then followed up with a launch. Now that is good stuff! What others don't see is all the time spent making prototypes and getting everything to work as it should. Thanks for sharing your tutorial with us and all your hard work!

@markmannhansen

4 ай бұрын

Hdmp

get a tube small enough to fit in the motor. stand the tube up on the table. place the paper disk on top of it glue side up. slide the motor down over the tube with paper disk on it. press down and it's done.

Great showing, great tutorial.

Awesome video @RotaryRocketry. Very informative.

Excellent,very clear.

What a well thought out instructional video. Thanks so much.

@rotaryrocketry

2 ай бұрын

Thank you... And you're welcome.

from costa rica , good job man , look forward to see your next project

Thanks!

Good video, Popcical sticks come in handy.

I’m an engineer and have been binging on these DYI videos. It seems a lot of extra steps are being taken to create a nozzle when perhaps it doesn’t need to be that way. Could you machine a single nozzle then attach it to each engine as needed? Perhaps with screws through the outside where there will be a flange. The nozzle will be partially inside the pipe creating a void around it and the walls so the screws can be long enough to penetrate the walls and not damage anything inside. Now all you have to worry about the engine is packing the fuel.

@rotaryrocketry

21 күн бұрын

You are thinking like an engineer and that makes perfect sense. A few years back, that is exactly what I was doing. In fact, we have a video on the channel for making a similar motor to this that uses a re-usable, metal nozzle. I was also making one piece metal nozzles on my lathe. The problem is, most people don't have the equipment to make such nozzles so this type of nozzle using anchoring cement and a washer is much more popular for the amateur.

@MrMelvinSchlock

20 күн бұрын

@@rotaryrocketry You know what? You’re exactly right. Heck, I don’t have a lathe either. And I’m sure the most of us are dabblers and couldn’t justify either making one from expensive stock or paying the hefty price for one. So I’m with you. Thanks for the great videos.

LOWES sells SPECTRUM brand stump remover. $8. Home Depot does not carry it.

Beautiful deployment and landing. Wondering which parachute from your how-to videos that is.

@rotaryrocketry

Ай бұрын

I do believe it's this one: kzread.info/dash/bejne/rJtps9Kwir2_ZLg.html However... This one is very similar and a bit simpler to build: kzread.info/dash/bejne/fJNrl7uRmpCue9o.html

is it possible to add a pigment to the fuel to make it a different color? Like say a blue flame from a blue iron oxide?

@rotaryrocketry

3 ай бұрын

Interesting question. I know there are some pre-made fuels that produce colored smoke bit I've never tried it. It's not unusual to add iron oxide to sugar fuel, it changes the burn rate. But you would normally add such a small amount that I don't think it would make any noticeable difference in the smoke.

Thank you - very clear instructions. Could you please describe the motor mounting that you use with this motor? Since it is PVC pipe the standard commercial motor mounts would not be appropriate. I can think of several ways to do this...but your experience would save me some trial and error. Thanks!

@rotaryrocketry

Жыл бұрын

I had the same issue when designing the motor retaining system for this. I had about 10 different ideas but didn't really like any of them. It would be easier for me to send you a photo of how I am holding it in the rocket. Send me an email and I will send you a some pictures. rotaryrocketry AT gmail DOT com

@rotaryrocketry

Жыл бұрын

Our next video will be a short video showing the centering rings, stop bulkhead and motor retaining hardware.

Anyone have a source where I can buy light weight cardboard tubes 1"- 2"+ inexpensive. Office max has 2 pack mailing/ blueprint tubes for $14. I think that's expensive for a 1 time rocket. Not to mention these tubes are often found in dumpsters.

Wich is the parachute deployment method chosen and how do you measure your delay time? I couldn´t see any ejection charge during the motor building process. How do you ignite that ejection charge?

@rotaryrocketry

9 ай бұрын

We use a flight computer to detect apogee and fire the ejection charge. I don't like using ejection charge built onto the motor because it is not likely to eject at apogee. Maybe it ejects way before apogee, maybe it ejects right at apogee, maybe it ejects way after apogee. It's always just an estimate with motor ejection delays.

Please list weights of fuel ingredients for easy reference. Thank you.

Question: How do you make the parachute eject? I don’t see anything in the motor for that.

@rotaryrocketry

4 ай бұрын

Great question... There are two typical ways to handle ejection charge. The method you are thinking of is a delayed ejection change at the top of the motor. That is common for smaller rockets and motors like Estes. For larger rockets, using a flight computer is much more common. The problem with motor ejection charges is timing. You don't really know exactly when the rocket will reach apogee and the ejection may go off much before or much after apogee which is not really a good thing. A flight computer will detect apogee and eject at the appropriate time. I have two videos covering flight computer and ejection charge that I think will show you everything you need to know about this technique. Building the EggTimer Apogee Flight Computer kzread.info/dash/bejne/mHyu2LmJhqirdJs.html Building an ejection charge: kzread.info/dash/bejne/gGuGzsd6ireqeKg.html

dumb question im sure but what do you do if you want to fly higher

@rotaryrocketry

4 ай бұрын

Make a bigger motor. But each time you change the motor design, you have to do ground testing to be sure it works well (specifically to make sure it doesn't explode).

So you made the motor at home then drove to the launch site? I have heard that was not allowed after a certain fuel weight. Is that rule not applicable to this amount of fuel you made?

@rotaryrocketry

4 ай бұрын

I'm not gonna delve deep into that subject but I will say this... The regulations you are referring to are both vague and inconsistent. They exist primarily to prevent and prosecute bad people doing bad things. To impose such rules on the weekend hobbyist is ludicrous... In my opinion.

what is the point of the washer and why raise it up a few mm into the nozzle?

@rotaryrocketry

2 ай бұрын

Excellent questions... The washer is the orifice for the exhaust gasses. We need to use something that will not get eroded so the nozzle opening stays the same size throughout the burn. A steel washer does that perfectly. Why is it raised up into the anchoring cement... This is actually a bit more obvious AFTER the motor is used. This nozzle design does not have a convergent or a divergent. But motors work better when they DO have a convergent and a divergent. BUT... What happens is that as the motor burns, it actually creates a convergent at the top of the nozzle and a divergent at the bottom. Therefore, we need to have an amount of anchoring cement above AND below the washer so these angles can be formed by the exhaust gasses.

why does it have to be schedule 40 though? Personally i dont like suing PVC due to the shrapnel, is there anything else i can use?

@rotaryrocketry

3 ай бұрын

There are a lot of rocketeers that don't like PVC but the reality is, if the motor is designed properly, it shouldn't explode. We have done the testing to ensure that this works fine if built exactly as we build it. Something a fellow rocketeer pointed out to me one time... Even though PVC may explode into shrapnel when experimenting, it doesn't have a lot of mass so the pieces are pretty harmless as long as you maintain a safe distance of a few hundred feet when testing. I've used steel casings and aluminum casings and they work well too but that's a lot more work. This motor is designed to be pretty quick and easy to make.

@LT72884

3 ай бұрын

@@rotaryrocketry good point. pvc is light so its not going to go very far. its not like im 10 feet away haha. 100 to 200 feet and i should be good. Do you have a link to the remote system you use? thanks for answereing all my questions. starting to buy stuff now

@rotaryrocketry

3 ай бұрын

Remote ignition system: www.ebay.com/itm/325500694728?itmmeta=01HS6SMH4QJEKKKDM926A5MPES&hash=item4bc95a70c8:g:QAwAAOSw7ApjFwtY&itmprp=enc%3AAQAJAAAA0HkytQsVIQ5KVELLxhUXLcj7Bo2COdkvuvanmlH%2FOP9FeKNbar7YvXK4OuKBFCFpNVsTv5oEI3JXVY6BjCBoguBdcYe6xHDe%2B4nu2ygYUTHYxit6uj5lcynddoUYNF09RhcHCpkaTg%2BrIyQIKLDvmYacRGUk5BaaVV70J2HJbtpUluEO61TY3SoQiCW9Jr%2F4tnvA%2BwiWKr5HaTCCxuUMeIQYioF7MzSRT9QQ4p5G80yGqgjsBpZwKY1OYLtNWUFiHPn2UidxK506iP91i%2B9Q75k%3D%7Ctkp%3ABFBMwJLS2clj

what is your ratio of kno3 to sugar to corn syrup?

@rotaryrocketry

2 ай бұрын

65% Potassium nitrate / 17% Powdered sugar / 18% Corn syrup

INSTEAD OF USING THE DIGITAL THERMOMETER TO MEASURE THE TEMPERATURE AT THE SURFACE OF THE FUEL MIXTURE WHEN HEATING IT WHEN BUILDING THE K500 ROCKET MOTOR, SINCE IT IS A SUGAR FUEL YOU WOULD GET A MORE ACCURATE READING FROM A CANDY THERMOMETER WHICH IS DESIGNED FOR MEASURING THE TEMPERATURE OF MELTED SUGAR.

@rotaryrocketry

Ай бұрын

Certainly a good idea... Tricky part is how to hold the thermometer in place in the wok. Might just have to hold it with one hand while stirring with the other.

One question, can the fuel become solid at 30C or 86F. It pretty hot at my place

@rotaryrocketry

11 ай бұрын

That is not a problem. Where I live it can get to 43C. Just make sure you cap or tape the nozzle closed when the motor is complete. You need to keep moisture in the air from getting to the finished fuel.

@quannguyenle2330

11 ай бұрын

@@rotaryrocketry Another question how long can we stored that motor, with all the protection you have said, one month or maybe more??

@rotaryrocketry

11 ай бұрын

If you seal it air tight then you could store it for a very long time. I know you live in a humid part of the world so just make sure it is sealed very well. I tested some fuel that was wrapped in plastic for 2 years and it worked just fine.

@agoogleuser3787

9 ай бұрын

Should just use a chunk of dowel for your little paper glue thingywhatsit. Just invert the tube over top till you touch bottom...

Can I just launch the motor itself as a rocket?

@rotaryrocketry

7 ай бұрын

No, it would just fling around violently. A rocket is designed for stable flight. It's the design of a rocket that makes it fly straight. I love your user name!

I have tried a different types of tutorials none of them worked out for me . I used the powdered fuel and it didn't seem to work . Next i used r candy , one flight was successful but somehow others are not working. I think it was because i didn't put a nozzle as the tutorials didn't contain it . The flame starts to get thicker at the end . Please help me out

@rotaryrocketry

7 ай бұрын

This video is a complete tutorial for PVC case with nozzle and sugar fuel... Did you follow these instructions? We also have a very similar tutorial but for a smaller motor here: kzread.info/dash/bejne/oq5_mrSKlK26g6g.html If you follow either of these tutorials and then have a specific question, I would be happy to try and help.

Why mix the dry ingredients separately, when all three (including the Karo syrup) are apparently mixed thoroughly later as the solids melt and are mixed with the liquid Karo under heat in pot - therefore, isn't this pre-mix step redundant?

@rotaryrocketry

5 ай бұрын

It's really about thoroughness. You want those dry ingredients to be well mixed. Maybe it's redundant but it's worth the extra few minutes. I'm not the inventor of this fuel type but everybody I have ever seen making it will pre-mix the dry ingredients.

OKAY...before I even watch the vid, I see you have a piece of PVC pipe, that's cheap as chips and can be found as scrap. BUT-and it's a big BUT, I see two more expensive PVC end caps, don't buy these, you won't need them. Instead, do this. Select the length of tube that will be your rocket body, allowing say 1 cm at either end for the plug at the top and the nozzle at the bottom. Graf a sharpie, knife, spike or whatever and use this to rough up the inner tube at both ends.Go grab a cup with say an inch or so over plaster of Paris powder in it, wet this just a little stirring all the while until you get the thick paste, NOT watery, add more powder if it is watery. now grab some of this paste and just smear it into the roughened up surface at the bottom end of your tube, now roll up a ball of this stuff just big enough that when you poke it in the end, it would settle out to give a thickness about 1 cm, maybe a little more it won't hurt. Put some masking tape over the hole and now gently but firmly tap it down onto the bench so as to make the plaster flatten out and form a 1cm thick plug. Leave it to dry for an hour .next take a drill to the dead center of the plug and carefully drill out a small hole , 2 or 3 mm drill to start with, work your way up to the size you want for your nozzle, typically about half the total diameter of your rocket body, you can try and shape internally if you want to be fancy but it's not necessary. Use the same technique to close off the top of your rocker, minus the drilling of course. A noticeable difference in burn power is easy to achieve by adding say 0.5 percent to one percent iron oxide to the molten fuel mix, just be sure that the iron oxide is of the powder variety and dry of course, the oxides can be colored red, orange or even yellow, they all work fine, they work as a catalyst and speed up the burn....

@rotaryrocketry

8 ай бұрын

I find your information interesting but I have concerns regarding the strength of the plaster ends. The two caps only cost about $2 in the U.S. so I would not really consider that to be "expensive". That said, you've peaked my interest and I will give your technique a try some time. Thanks.

@rsschdd

8 ай бұрын

Yoy should make your own video. You seem very competent on the subject.

Why the rocket motor is kept hollow in between?

@rotaryrocketry

7 күн бұрын

You mean the center core hole? The motor is ignited at the top of the core hole so the entire core is ignited very quickly. That provides a powerful thrust for lift-off. This fuel configuration is called a "bates grain".

@Bhavuk_Varshney

12 сағат бұрын

@@rotaryrocketry Thank you!

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