New to rockets (Sugar)

[Jwheld]

Hi all. Im brand new to rockets and plan to start with sugar rockets. My setup to begin with is a dowel ram rod and drill bits for nozzles.

 

In order to be the most successful, I have some questions. So, I plan on doing a dry blended mix of KNO3, Powdered Sugar, and iron oxide. After grinding the KNO3 to a powder, should I bake it or store it with desiccant before mixing fuel to get any moisture out?

 

I plan on using 65:35 with about 1% iron oxide. The rockets will be 1/2 I.d. And Im following the tutorial on Skylighter.

 

Any other considerations?

 

Ive got 50 tubes so I can do some experimenting. As the budget permits Id like to get into 3/4 black powder rockets and send some stars into the air.

 

Thanks again for your helps!

[stix]

When using powdered KNSU, make sure to pack in small increments to get a compact fuel grain. This is probably the biggest point of failure that is not always understood.

 

Keep asking questions here, and you'll get good help and hopefully great results.

 

Have fun, but above all, be safe.

 

Cheers.

[Plasmaniax]

How would you use a zinc/sulphur propellant? New to this as well.

[MadMat]

ZnS is a low specific impulse mixture. It isn't easy to make one of these rockets fly. Not to mention, it creates huge clouds of smelly, semi-toxic gases. It's not worth the trouble. If you happen to have a bunch of powdered zinc laying around, you would be better off making granite stars with it instead of trying to make ZnS rockets

Edited September 15, 2018 by MadMat

[Jwheld]

I was finally able to get out and test the 1/2 rockets. I was 3 for 3 and am addicted.

 

I used powdered ingredients only 65/35 and 2% iron oxide.

 

I packed these in small increments and used a 1/4 drill. It by hand to hollow the core.

 

I think going forward I want to find a cheap set of tools so that the core is hollowed more square.

[MadMat]

3 for 3 on your first rockets? Congratulations and good luck with your future endeavors.

[Jwheld]

Yep! First 3 worked great. Thank you.

[dagabu]

3:3 is very good for someone so new to rockets, most of us had to make dozens of them to get it down. Good for you!

 

You may wish to consider BP instead of sugar fuel although it has a much higher impulse and is very easy to make.

 

For BP just look for a rock tumbler and ceramic grinding media, ball mill each of the three ingredients separately until they are finer than talcum powder then mix them 75:15:10 with enough water from a fine misting spray bottle to knock the dust down and run it through a window screen 4 times or even more if you feel like it.

 

Let it dry and add increments no larger than 1/2 the diameter of the tube, use a rawhide, plastic or bounceless hammer on your tooling and see how much more performance you get!

 

Good luck, keep us in the loop please,

Edited October 14, 2018 by dagabu

[stix]

. . .You may wish to consider BP instead of sugar fuel though, it has a much higher impulse . . .

 

No Dags, BP does not have a much higher impulse than sugar fuel, for the amount of fuel used. On the contrary.

 

If you're referring to specific impulse, then BP is around 80 and KNSU around 130.

 

Didn't you mean to say: "You may wish to consider BP instead of sugar fuel, although sugar fuel has a much higher impulse than BP, I find BP fuel and rockets easier to make".

[dagabu]

Good catch, fixed it.

Edited October 14, 2018 by dagabu

[stix]

Well, I thought you'd lost your marbles

[Jwheld]

3:3 is very good for someone so new to rockets, most of us had to make dozens of them to get it down. Good for you!

 

You may wish to consider BP instead of sugar fuel although it has a much higher impulse and is very easy to make.

 

For BP just look for a rock tumbler and ceramic grinding media, ball mill each of the three ingredients separately until they are finer than talcum powder then mix them 75:15:10 with enough water from a fine misting spray bottle to knock the dust down and run it through a window screen 4 times or even more if you feel like it.

 

Let it dry and add increments no larger than 1/2 the diameter of the tube, use a rawhide, plastic or bounceless hammer on your tooling and see how much more performance you get!

 

Good luck, keep us in the loop please,

Thanks dagabu! Yes, Ive read plenty of testimonials and was surprised they all worked.

 

Was thinking about trying some black powder rockets possibly this winter when I gather the supplies and better tooling for core burners.

 

I will have to keep the plastic hammer in mind. It makes sense to use for a better packing efficiency. All I had was a rubber hammer and a wooden dowel which both probably absorb shock that doesnt make it the the fuel.

 

I will keep updated and ask questions when they arise!

[dagabu]

Oh dude, I have! my mum died Friday night, no sleep, family in and out all weekend long, planning, still have to manage my dozen employees and have to pick up my wife and sister from the airport tomorrow at different times.

 

I am surprised I did that well at 2:30 AM in any case!

 

My real-world experience with BP v.s. KNSU is that they are nearly equal in specific impulse. Willow, Red Cedar and Paulownia charcoal have been making BP with an impulse (real world) closer to 100.

 

In this case, I have to retract my last statement and stick with my initial statement that in THIS case, using raw powders, the impulse of KNSU will fall to 50-70 impulse seconds because of the poor integration when compared to R-Candy properly made dry and in inhibited grains.

 

This is where we experience the actual work the fuels can do, Black Powder, just milled well and properly compacted with good geometry on the tooling, will give consistent results day in and day out.

 

 

Well, I thought you'd lost your marbles

[stix]

Sorry to hear about your Mother Dave.

 

God bless to you and your family.

[Jwheld]

I’m very sorry to hear about your loss.

 

What tooling would you recommend for a good price to quality ratio?

 

What are the units of impulse? Almost double the impulse with black powder... these little puppies shot up quick, bp is probably all the more impressive to beginners.

[stix]

. . . My real-world experience with BP v.s. KNSU is that they are nearly equal in specific impulse. Willow, Red Cedar and Paulownia charcoal have been making BP with an impulse (real world) closer to 100.

 

In this case, I have to retract my last statement and stick with my initial statement that in THIS case, using raw powders, the impulse of KNSU will fall to 50-70 impulse seconds because of the poor integration when compared to R-Candy properly made dry and in inhibited grains. . .

 

 

Common' Dags, with all due respect - Yes, I agree with you in that using raw powders when making sugar rockets, and just blending them by mixing around in a tub (as per some you-tube vids) will yield an inferior result. And milling bp with fast burning charcoal, then burning under high pressure conditions will raise the Isp higher than 80.

 

But that's like comparing a Ferrari running on 3 cylinders compared to a Datsun 1200 running on Nitro. You are not describing a fair comparison.

If I made really shit BP and excellent r-candy, the difference could be much wider than I've already claimed.

 

In "general" terms, I'll stick with what I originally said, but I'll give you 5 each way. BP 85 and r-candy 125, that still leaves a discrepancy of 40.

 

If used to its best (both bp and r-candy) then r-candy has more potential energy. Each have benefits and negatives. Whether one is "better" than the other comes down to personal choice and usage.

Edited October 17, 2018 by stix

[dagabu]

R-candy? Yes, I agree but lets go back to the original post: "I plan on doing a dry blended mix of KNO3, Powdered Sugar, and iron oxide."

 

Ill put up my BP against that and will beat it handily!

 

BTW- do you have recorded thrust stand tests of your best R-Candy and your best BP?

 

 

Common' Dags, with all due respect - Yes, I agree with you in that using raw powders when making sugar rockets, and just blending them by mixing around in a tub (as per some you-tube vids) will yield an inferior result. And milling bp with fast burning charcoal, then burning under high pressure conditions will raise the Isp higher than 80.

 

But that's like comparing a Ferrari running on 3 cylinders compared to a Datsun 1200 running on Nitro. You are not describing a fair comparison.

If I made really shit BP and excellent r-candy, the difference could be much wider than I've already claimed.

 

In "general" terms, I'll stick with what I originally said, but I'll give you 5 each way. BP 85 and r-candy 125, that still leaves a discrepancy of 40.

 

If used to its best (both bp and r-candy) then r-candy has more potential energy. Each have benefits and negatives. Whether one is "better" than the other comes down to personal choice and usage.

[stix]

R-candy? Yes, I agree but lets go back to the original post: "I plan on doing a dry blended mix of KNO3, Powdered Sugar, and iron oxide."

 

Ill put up my BP against that and will beat it handily!

 

BTW- do you have recorded thrust stand tests of your best R-Candy and your best BP?

 

 

Ok, yeah sure. Going back to the original post, It was about dry blended powders. So I agree with you Dags, in that most people just roughly mix it together, therefore it will produce a shit result as in specific impulse.

 

However, even blended dry powders CAN be pressed (under high enough pressure) to give similar results to melted r-candy without the need for RIO. My brother and I did many tests - a challenge of sorts - melted vs dry. The results were similar density and specific impulse. (around 105). Ramping it up to achieve 130 would have only been a matter of making the fuel grain longer, but we both decided to err on the side of caution.

 

As far as bp goes, it's been many many years since I've made a bp rocket motor. If I had data to show, it would be on graph paper and I would have to convert it. I could probably get together that data and show graphs, but there is no point as they were end burners (like Estes) and produced a similar result of around 75-80 isp (I think).

 

One thing I will say is that bp is/was used for bullets. They certainly wouldn't use r-candy, even in its best form.

 

If you make a bp motor with a core and nozzle-less, then I'm sure it will take off like the powers of piss (for want of a better term) and a higher isp, but we are not talking about bullets, we are discussing Rocket Motors under "normal" conditions.

 

[EDIT]

You may also want to check out the sugar rocket to space project: http://www.nakka-rocketry.net/sspace.html

An unlikely pursuit, but nevertheless, more likely with a sucrose based rocket motor the black powder.

Edited October 22, 2018 by stix

[Jwheld]

Sounds like I may have to upgrade my setup for better results.

 

Stix, do you melt and mold the fuel grain over core burner tools or granulate and press?

[stix]

Jwheld, the fuel I currently use is more of a putty/plasticine consistency. I use dextrose/glucose powder (KNDX) which melts at around 145C.

I then let it cool slightly, and whilst still warm and flexible, roll it into snake like strands and press it into the inhibitor sleeve apparatus around the central spindle:

 

 

The image above is 3/4" tooling. In the middle of the image is a manilla card sleeve that goes over the spindle thingy to the left, then inserted into an aluminium tube for support.

 

Then I insert the whole thing in the apparatus shown below, carefully re-heat in an oven until soft and hammer press to ensure there are no voids. I usually get a density of around 1.73gm/cm3.

 

 

 

In my last fuel experiments, I've been using Sorbitol (KNSB) which melts at around 115C therefore making it even easier to handle. I made some 3/4" grains more than a year ago but got sidetracked and haven't even tested in an actual motor yet.

 

Cheers.

 

[EDIT]

 

Thought I may as well show results from this size motor. This wasn't the best test because I was testing different nozzle mix formula's and this one suffered from severe erosion as can be seen just after peak thrust, which also resulted in a low specific impulse of 83.6.

 

Edited October 23, 2018 by stix