Core burning rocket question

[Foxfire87]

I've been making 4oz core burning rockets and have been loving them, I want to step it up to either 1 or 3# rockets. When you get to a certain size, must they be pressed? Or can i still ram them? Also, will the same fuel for 4oz work in the bigger rockets? I started with 60/30/10, and am making some 65/25/10 to try for more lift with headings attached. Any info is greatly appreciated

[Foxfire87]

So the 65/25/10 didnt work at all, just blows up before leaving the ground, seemed like it should have worked but no luck. Not sure why

[Arthur]

There is a piece in Lancaster's book detailing the mixtures used in rockets of different sizes. The mixes for larger rockets use slower powder. A bottle rocket in a 1/4" tube may use BP, bigger sizes may use BP slowed with added charcoal (the type and mesh size also affects the tail), or even some BP with extra unmilled ingredients plus selected charcoal.

[Foxfire87]

Thanks, what is the book called?..I'd like to find it

[justvisiting]

Ever since I tried damp propellant for all my BP-based rockets, I've had zero problems. I've solved any problem that's come up before trying water too, but using 2 1/2- 3% water, screened in well, gives a propellant that packs better and more densely than anything I've tried. I'm not a hand rammer, but damp propellant presses so well at low pressing forces, I have no doubt it will work perfectly for hand-rammed rockets too. I've flown 1# and 3# nozzleless rockets freshly made, and aged for up to 22 days. 3# nozzled 60-30-10 were no problem, even with an extra long spindle.

 

Water is so easy to try and it's free. It only makes sense to try it 'just in case' I'm not full of it

[Arthur]

Fireworks Principles and Practice

Lancaster, Ronald

ISBN 10: 0820602167 / ISBN 13: 9780820602165

Published by Chemical Publishing Company, Incorporated, 1972

Ron published several editions of his book, all of which are available from Abebooks.com and likely many other suppliers.

Copies of this book seem to exist from 1st, 2nd and 3rd editions in all conditions from collectors quality to "found in a lab -has chemical stains" and even print on demand. Obviously a perfect collectors copy will cost much more than damaged copies which will have all the same info inside.

Abe is far from the only online supplier, it's just a convenient place to search for practically any book.

Knowing Ron, it's unlikely he will author another edition.

Edited September 2, 2019 by Arthur

[Foxfire87]

Great info!...I will try the water method since as you said, it's free, and I will be finding a copy of the Lancaster book. I want to buy books on this hobby but it's so hard to spend so much on a book, I know good info is worth its weight it gold so I just need to suck it up and start buying some good books, especially since I try and try and just cant seem to find in depth info online for free. All the info I've gained from this site is great, such knowledgeable people with experience, and I'm just starting out. So, thanks again

[Foxfire87]

Just wanted to say that I found this book used on Amazon for $30!..very excited!

[davidh]

60 30 10 works great in 4oz core burners. There are simply limits to how much you can lift with a 4oz core burning rocket. FYI, I have hand rammed 6lb rockets and they worked great.

[Mumbles]

Generally speaking, the faster the fuel, the better compaction you need. At the very least, faster fuels have less margin for error. Small air pockets, cracks, wrinkles, etc. become less well handled. Hand ramming will work generally work for basically any rocket size. To squeeze maximum performance out of that rocket, you may need to look into pressing however.

[Foxfire87]

Again, great info, thanks again, I'll be buying larger rocket tooling soon, and with all of your collective information and my new book I think I'm set for a while. I appreciate all of you taking the time to give me some tips. Make being a newbie a lot easier and helps me keep not get frustrated

[Arthur]

Fine tuning a rocket motor means in reality making the fuel faster and faster for increased power and thrust until just before the point where it all explodes.

 

For big motors you need a lot of space until you are sure it will work because a CATO can be damaging.