problem kno3/sugar rocket

[THEONE]

Hi guys, ( i am sorry about my English ), now i am trying about 2 months to make a successful kno3/sugar rocket but only on time i have success!!

I am using a wooden dowel with 24mm, paper casting, and powdered cat litter.

I make a 14cm long casting with 3cm plug-nozzle and the other 8cm is propellant with kno3/powdered sugar.

 

construction:

i make a 3cm long nozzle with fine powdered cat litter (ramming making it good and solid)

after i fill the rest tube (8cm) with the propellant (ramming making it good and solid)

after i make the 3cm cat litter plug (ramming making it good and solid)

after i take a 6mm drill and i drill it about 9cm in the senter

after i take a 12mm drill and i open the nozzle about 2cm so it have 1cm throat (but i dont know kow much big the throat of the nozzle must be!)

after i put a very long-light stick to balance it

 

 

My 80% of my rockets make CATO, and the nozzle cames out!!

please help

Edited March 23, 2011 by THEONE

[dagabu]

There are a few things you can do to improve your success with these.

 

Ram only 10-12mm of cat litter for the nozzle and the plug, there is no need for 30mm. Pound it so hard that you can see the paper tube bulge slightly.

Sharpen your ram a little so the end has 30° angle on it, that will help the gasses escape the motor easier.

Only ram 10mm of the fuel at a time. Ramming more will make the fuel grain soft.

Use a 6mm drill bit for the nozzle all the way up to the cat litter plug.

Only drill 6cm into the motor, see how it works, if it works good, drill the next one to 7cm.

[THEONE]

There are a few things you can do to improve your success with these.

 

Ram only 10-12mm of cat litter for the nozzle and the plug, there is no need for 30mm. Pound it so hard that you can see the paper tube bulge slightly.

Sharpen your ram a little so the end has 30° angle on it, that will help the gasses escape the motor easier.

Only ram 10mm of the fuel at a time. Ramming more will make the fuel grain soft.

Use a 6mm drill bit for the nozzle all the way up to the cat litter plug.

Only drill 6cm into the motor, see how it works, if it works good, drill the next one to 7cm.

 

Thank you my friend, i will try it.

I thing that the problem is the nozzle throat, maybe it is very long so the gases can not escape easy but if it will be very short the pressure may it will not be enough for make the rocket fly

[dagabu]

Ill bet that it is the fuel being too soft.

[THEONE]

Ill bet that it is the fuel being too soft.

 

Maybe you have right my friend, sometimes i want be hurry and maybe indeed he fuel is soft, but what is the problem if the fuel is not solid enough

[mabuse00]

but what is the problem if the fuel is not solid enough

It will burn discontinous and faster.

It may also disintegrate, laying open much more burning area - boom.

 

You can also melt down your propellant, especially when replacing normal sugar with sorbitol, and pour it into the tube.

Drill the core on very low rpm when the fuel is fully solid.

[THEONE]

It will burn discontinous and faster.

It may also disintegrate, laying open much more burning area - boom.

 

You can also melt down your propellant, especially when replacing normal sugar with sorbitol, and pour it into the tube.

Drill the core on very low rpm when the fuel is fully solid.

 

Thank you mabuse00 i will try and i will tell to you.

About that you told me, i am afraid than the core will not be strait and in the middle, i believe better it will be make the core when the fuel is like a butter

Also something else, when people use multiple grains of rocket candy, the space between the grains is not a problem ?

[mabuse00]

when people use multiple grains of rocket candy, the space between the grains is not a problem ?

As far as I understood this is done on purpose, so that the propellant also burns on the sides.

 

Normally the burning surface of the propellant is getting larger towards the end as the cores volume enlarges.

That is countered when the grains burn at the sides also and thus get shorter towards the end.

Trust and pressure get linearised that way.

 

But your tubing has to cope the fire right from the start.

[THEONE]

I want also ask something else, why we must put corn syrop into the rcandy? can we put something else were it will do the same jod ? and what rations ?

[donperry]

Pure sugar will harden up pretty quickly after cooking.

The composition of the syrup allows it to be softer for longer.

Thus allowing you to form them into BATES grain

IF you plan on ramming your rocket you dont need the karo syrup.

THats just my understanding of it

[dagabu]

As far as I understood this is done on purpose, so that the propellant also burns on the sides.

 

Normally the burning surface of the propellant is getting larger towards the end as the cores volume enlarges.

That is countered when the grains burn at the sides also and thus get shorter towards the end.

Trust and pressure get linearised that way.

 

But your tubing has to cope the fire right from the start.

 

There are inhibited grains and uninhibited grains, inhibited grains have a wrapping around them or are dipped into something like epoxy to inhibit the burn. Uninhibited grains are difficult to deal with since the thrust curve is unpredictable due to variations in grain surface and preparation.

 

With an inhibited grain, the ends and outer portion do not burn right away giving a flatter thrust curve which is desirable for modle rocketry.

 

This is why I am exited about granulated r-candy motors pressed on a UT spindle. The thrust curve should mimic that of mild BP and lift quite a bit of weight.

[donperry]

dagabu we need to jump on that

explain how you are thinking of doing it. What's a UT spindle?

Edited March 24, 2011 by donperry

[VintageRacer]

dagabu we need to jump on that

explain how you are thinking of doing it. What's a UT spindle?

 

Maybe he meant a UH (universal hybrid) spindle, if not then I too am curious. We are talking about pressing the powder form correct? I never did any more than burn the cooked form of sorbitol/KNO3 on the ground, once I moved on to BP. I'd like to make some core motors to test both on the scale and in the air...some day. My first impression is they are very heavy motors.

 

DanB

[Updup]

Maybe he meant a UH (universal hybrid) spindle.

 

DanB

 

Or more likely universal tooling spindle.

[dagabu]

According to Laduke, its Universal Rocket Tooling, or UT LINK so I'll call it UT if that OK?

 

Onward ! Nope, we are going to make R-candy and then grate it, then press it in over a UT spindle and see how it flies! I will do a nozzleless first and then try a nozzle if I feel that the thrust isnt too much for the casing.

 

You two figure out the camping yet?

[donperry]

Kool. Just remember to zip loc bag the leftover in a freezer.

[dagabu]

Kool. Just remember to zip loc bag the leftover in a freezer.

 

I will be making just enough to press a few rockets and make poi sticks for my son from the extra

 

I will be storing the motors in a zip-lock though, along with a desiccant pack. Man those things suck up the water!

[THEONE]

Boys today i have tried to compress very good the kno3/sugar fuel, and indeed CATO didnt make, but it doesnt have enough thrust to fly hi, also it Burns very slowly, maybe, 4-5 sec, i tryed with 5mm nozzle but it make CATO

I have realy dissapointed!!!

[donperry]

Did you cook it or just mixed them? Did you weigh it or eye balled it?

Give us more details and we'll solve it for you

[THEONE]

Did you cook it or just mixed them? Did you weigh it or eye balled it?

Give us more details and we'll solve it for you

 

i mixed them, i weigh it, and i check it if it have a lot of carbon i put some kno3 and if it have a white solid think, after i burn it, i put more sugar.

Also i have made rcandy with 65/35 ratio without any syrop, but i try a nozzless rocket without success!! i realy dont konw!!! i have realy dissapointed!! i am trying about 2 months and only i have one success and i dont know how!! i have spent about 5 killoes of kno3 !!!

 

Here i have some photoes how i made and 2 CATO videos and my firsy-last success

CATO1.zip

CATO2.zip

MY FIRST AND MY LAST SUCCESS.zip

Edited March 26, 2011 by THEONE

[donperry]

Ur doign it wrong. Weight 65 grams of KNO3 and 35Grams of sugar. Mix those with mortar and pestle for 5-10 minutes. Add 1 gram red iron oxide if u have it.

Mix that in and u have a decent fuel.

[Updup]

i mixed them, i weigh it, and i check it if it have a lot of carbon i put some kno3 and if it have a white solid think, after i burn it, i put more sugar.

Also i have made rcandy with 65/35 ratio without any syrop, but i try a nozzless rocket without success!! i realy dont konw!!! i have realy dissapointed!! i am trying about 2 months and only i have one success and i dont know how!! i have spent about 5 killoes of kno3 !!!

 

Sounds like your not cooking it...

 

I know you can get it to work, I made 2 uncooked KNO3/Sugar rockets when I first started, and they worked. Try following the instructions on these videos

 

http://www.youtube.com/watch?v=HtOGfrgVuF0

 

http://www.youtube.com/watch?v=TqWXtjBciTw

 

And if you are already doing that, you said you got one rocket to work, try and clone that rocket and see if you can get the clone to work.

[donperry]

wait a minute, a 5mm nozzle and what size tube?

[THEONE]

wait a minute, a 5mm nozzle and what size tube?

 

I have see all the videos about the sudject, and i have download them.

I have never use a rcandy rocket with nozzle, i want to try..., but i want to make a kno3/sugar rocket motor.

No I told before that when i use 5mm nozzle i have CATO and when i use 6mm nozzle the rocket flyes but not very far it didnt go to the sky but goes strait to the road, like the cars go ( i am sorry about my english) it doesnt have enough thrust. I thing when the rocket have good thrust the nozzle cant stay as it was

The tube is exactly 23mm

 

Also something else, can i put red iron oxide into the knoe/sugar powdered mix ? (no cooking)

The propellent i use is powdered kno3 and powdered sugar, i believe it doesnt need to use mortar and pestle. I use 5mm drii for the core and 6mm for the nozzle.

 

The success rocket was a 14cm long 23mm tube (inside diametre) powdered kno3-sugar fuel 65/35, 3mm core diametre, 6mm nozzle diametre. 3cm long nozzle and abou the 2cm of the nozzle i open with a 8mm drill, 2cm long the end plug. I have tryed it again and again without success

 

I really want one person come here and show my how to do!! i think i cant do this, i donk know that mistake i do

Edited March 26, 2011 by THEONE

[dagabu]

That second video is James Yawn's. I think it is the single best video tutorial on R-candy that I have ever seen and I make mine exactly the same way but I make around 1000g at a time. Also, while red iron oxide works well to increase the burn rate, so do others such as copper oxychloride.

 

I use a 5mm (3/16") nozzle on a 25mm (1") casing for R-candy with no catalyst and 7mm (1/4") with red iron oxide.