Substitute For Fuse

[Col]

i count five people including the cameraman, easy pickings for pvc shrapnel at that range

[ddewees]

Wow, open doors and everything...

 

Now that's what I call No Fear... or just plain dumb.

 

Looks like you could reduce your nozzle size... but remember that'll make it even more likely to CATO.

 

You shouldn't be lighting rockets (especially that large) right next to buildings/houses/property... show some respect for the hobby.

Edited December 14, 2014 by ddewees

[stix]

Col, I think the sideways view threw me a bit and I forgot about the cameraman and the brief appearance of someone opening a door. Or am I the only one that's seeing this! (ie. sideways view).

 

ZonerAsh, You said your initial motor was done as a 'static test' which I applaud you for. Why then, or what did you do, that made you think that this motor was going to perform any different or better and then decide that moving to an actual launch would solve any issues you were having...?...?...?...

 

I know I'm being critical, but I'm also trying to be constructive. It's not easy though. I accept that you are experimenting, so even more reason for caution and regard for safety. Apart from the possibility of CATO, I'm glad it didn't take off. Imagine if it only half (or quarter) took off - it could easily go sideways... then CATO - not good, not good at all.

 

Also, I take it that your "rushed school project" was an obvious and complete, absolute BIG FAT FAIL!!!..... Ok, fine, perhaps it gave you the drive and determination to experiment further with sugar rocket motors?... Well that's great

 

But please please please, read ALL the information that others on this forum have taken the time to post. If you want to rush into it, and take no notice of the advice given, then members will be very unlikely to help you because no-one wants to be blamed for your stupidity. It also comes across as a bit disingenuous (suss).

 

If you are in another country where English isn't your first language, then ok, perhaps I'm being too harsh. Then get someone to translate properly.

 

 

Wow, open doors and everything...

Now that's what I call No Fear... or just plain dumb.

Looks like you could reduce your nozzle size... but remember that'll make it even more likely to CATO.

You shouldn't be lighting rockets (especially that large) right next to buildings/houses/property... show some respect for the hobby.

 

+42 , but perhaps you could reword line 3 of your above post - sometimes "a little knowledge is a dangerous thing".

 

Stay Safe.

Cheers.

Edited December 14, 2014 by stix

[ZonerAsh]

Thanks for the advice. I will take precautions next time..... But I am very disappointed by the results of my sugar rocket. I was very excited for this but...
I tried the melted method but did not make a motor with that. Just made a burn test. It was burning very well, at least better than the powdered one. But literally very disappointed with my sugar rocket.

[stix]

Don't let your disappointment lead you to create even more potentially dangerous situations. That motor in your video is way too big to start off with, and where you lit it... well, I'm still kinking out about it!! You should start off small (around 1/2 inch diam. or smaller) then find a big clear space to do your experiments, otherwise you shouldn't be doing it.

 

Sometimes things that seem easy aren't, and making sugar rockets isn't as simple as it looks.

 

I find the "rammed powdered sugar method" a bit quick, dirty, unpredictable and above all, just lazy. It took me about 2yrs of reading and experimenting to come up with my own method (melted r-candy) that I'm satisfied with - and as you may have gathered, I'm not very easily satisfied - perhaps that's why I'm single .

 

It's also about the journey and experimentation - when you do get there, you will get a greater sense of satisfaction that will be worth way beyond your current disappointment.

 

It's all been done before, and very well documented - but you have to develop your own (safe as possible) methods.

 

And again, Check out:

http://www.thefintel...rocketindex.htm

http://jamesyawn.net/candyrocket/

and the Master: http://www.nakka-rocketry.net/

 

Take what you need, and do your own thing safely.

 

Stay Safe,

Cheers.

Edited December 14, 2014 by stix

[vizzer]

 

Not once does he mention that the "white mix" should be added in increments. To the uninitiated It's as though it should all be piled in at once and rammed. Well, I have very big issues with that. As with bp, if the fuel is not compacted enough it could easily result in CATO and shards of PVC flying everywhere!!!!... Especially a concern if lighting closely with an unproven fuse.

 

Thank you for posting this. That video is what got me started about 6 weeks ago. My impression was he implied that the white powder should be packed in incementally, and I did do so the first rocket I made - which worked for a few hundred feet. But since I'd only inferred that process, since then I've made them by filling in more fuel at a time, and they've started to explode about 40 feet up. I wasn't sure if my nozzle diameter was the culprit or not, especially because his diameter isn't half the ID of the motor - a ratio I understand is used in black powder rockets.

 

I wish he'd spoken out more on the need for monitoring the fuse making process, and how important consistency is. Approaching a rocket when you think the fuse has gone out, and it hasn't, is interesting. Now it's electric matches for me, made from copper scrubby pads and heat shrink.

 

Also, drilling out the nozzle wasn't nearly as easy as he made it seem. It was quite a task working my way through the compressed powders by hand.

Edited January 5, 2015 by vizzer

[stix]

 

Thank you for posting this. That video is what got me started about 6 weeks ago. My impression was he implied that the white powder should be packed in incementally, and I did do so the first rocket I made - which worked for a few hundred feet. But since I'd only inferred that process, since then I've made them by filling in more fuel at a time, and they've started to explode about 40 feet up. I wasn't sure if my nozzle diameter was the culprit or not, especially because his diameter isn't half the ID of the motor - a ratio I understand is used in black powder rockets.

 

I wish he'd spoken out more on the need for monitoring the fuse making process, and how important consistency is. Approaching a rocket when you think the fuse has gone out, and it hasn't, is interesting. Now it's electric matches for me, made from copper scrubby pads and heat shrink.

 

Also, drilling out the nozzle wasn't nearly as easy as he made it seem. It was quite a task working my way through the compressed powders by hand.

 

Hi vizzer, "That Video" makes it look all too simple - which concerns me, so I'm glad you posted on this forum.

 

Imagine if you had approached the rocket thinking the fuse had gone out, but it hadn't - then it took off about 6ft, then exploded in your face... . It may seem unlikely, but it's absolutely possible. It should ALWAYS be safety first. There is always going to be an element of risk with this hobby but you can do things to lessen that risk. I like the idea of e-matches especially when testing unproven motors because you can easily hide behind some sort of barricade, then press the button...

 

I really don't like the idea of drilling through any sort of solid fuel grain - it scares the shit out of me. i wouldn't do it.

 

I've always made some form of tooling, ie. a spindle/rod for the core and a rammer with a hole to suit. If you're serious about making your own rockets motors - which imo is a very satisfying and rewarding hobby - then I suggest you either invest some money in buying some ready-made tooling, or invest some time in making your own. You'll then be able to build much safer, reliable and better performing motors.

 

There are too many factors involved to determine why your motors are now exploding 40ft after take-off, but from what you said I would guess that you are not compacting the fuel enough. Basically, if you don't compact the fuel enough then it will burn too quick to expel from the nozzle, in effect making a salute (cracker). Also, with the fuel not being compacted enough, the pvc pipe could expand under pressure allowing the flame to propagate up the outer edges, and boom!!

 

What diameter body/nozzle are you using? - maybe you could try one without a nozzle.

 

There are various methods for making sugar rockets. Dry compressed powder (like you are using) melted crystals which are then compressed under great pressure, melted inhibited & inserted bates grains (my method), and others...

 

As far as fuses go, I can't remember the actual standard ruling but it's something like don't approach for a least 10mins if it fails to light. I use electronic matches myself but have made some black match fuses because my e-matches took a lot of effort to make.

 

Check out these links already posted:

http://www.thefintel...rocketindex.htm

http://jamesyawn.net/candyrocket/

http://www.nakka-rocketry.net/

and browse these forums - do some more homework/research and then ask some questions here - most people will be more than happy to give good advice.

 

Stay Safe. Cheers.

[vizzer]

Thank you! I was following the PVC video, with a 3/4" ID, and a 7/32 nozzle.

 

Instead of drilling I went to a wooden spindle glued into a 2x6, and a hole drilled into the compression rod.. The spindle kept breaking when I tried to pull it out so I used the drill bit as the spindle, no drilling, and tried to pull it out. Of course that didn't work. Now I've been reading through everything and learning about metal spindles covered with graphite. I suppose I could wax the wooden spindle with bar soap, a candle, or ski wax at some point to see how that works. Or just buy the tools.

 

I've read up here on a few tracks to follow in learning this art, and I'm going to take time away from rockets and make some black powder. I just kind of want to get this right.

 

Thank you.

[dagabu]

Thank you! I was following the PVC video, with a 3/4" ID, and a 7/32 nozzle.

 

Instead of drilling I went to a wooden spindle glued into a 2x6, and a hole drilled into the compression rod.. The spindle kept breaking when I tried to pull it out so I used the drill bit as the spindle, no drilling, and tried to pull it out. Of course that didn't work. Now I've been reading through everything and learning about metal spindles covered with graphite. I suppose I could wax the wooden spindle with bar soap, a candle, or ski wax at some point to see how that works. Or just buy the tools.

 

I've read up here on a few tracks to follow in learning this art, and I'm going to take time away from rockets and make some black powder. I just kind of want to get this right.

 

Thank you.

 

If you are interested, I make tooling and am currently helping a researcher with some tooling. I think I can help you out with tooling that wont break the bank and will release from sugar without too much fuss. One of the issues I had with R-candy and loose sugar powder pressed rockets was making the core and like you, I messed up a lot of rockets drilling the core out and/or pulling the spindle out. A few things that made it easier over time were getting the materials right for the tooling, learning how to effectively wax the spindle (it's harder than it seems) and getting the core to nozzle ratio right.

 

Keep in mind that there are many ways to skin a cat, this is no exception, ask 10 pyros how to make a rocket, you will get 100 answers...

[vizzer]

If you are interested, I make tooling and am currently helping a researcher with some tooling. I think I can help you out with tooling that wont break the bank and will release from sugar without too much fuss.

Sure, I'm interested. As you know, I've started on the 3/4" ID PVC, and the nozzle is 7/32". It'll be fun to put some together while I'm working towards BP. You might as well price in the tools for a similar BP motor. If you want to steer me towards lead for my eventual ball mill, I'm open to that. Though it might be a while until I need them.

 

Regarding the ways to make a rocket, I thought the trick was to get them to explode consistently, and then start backing off?

[stix]

. . . Regarding the ways to make a rocket, I thought the trick was to get them to explode consistently, and then start backing off?

 

Is that a joke vizzer Anyway, that certainly wouldn't be my approach.

 

You could start with a shorter fuel length, which is safer, ie. less pressure. Then then start increasing the length in 1/2 inch increments until you reach cato point - then back off. The main problem (apart from your neighbours) will always be the consistency of your fuel.

 

That's pretty much what I did except for the cato bit. I only ever had a couple of nozzles blow out due to not pressing them enough.

 

I also did a lot of static testing first, that way I was able to measure the results against existing data, ie. specific impulse and total impulse and therefore knew in a scientific sense exactly where I was at. My motors perform very well, and although I know I can push them further, I'm happy to err on the side of safety.

 

If you can, definitely follow up the tooling offer from Dave. You'll have something long lasting and consistent which will give you a great starting point, then you can go from there.

 

Cheers.

[vizzer]

 

Is that a joke vizzer

 

Yes, absolutely it's a joke. I'm pretty dry about things.

 

I ordered the motor dagabu was kind enough to list on another forum, and I've got a friend who can help me not make too many mistakes putting together a ball mill. I may buy Lloyd Spnoenburgh's book, but if I can find plans for one I'd rather just do that. I'm getting just how sensitive things can be in this field. I'm a math and computer graphics guy, but I'm tired of thinking that hard, that way.

 

Putting together my first rocket was surprisingly fun. Researching pyrotechnics has been surprisingly fun. My neighbors can't complain about what I'm doing: one of them has a deer blind set up, and we're in the city limits. It's incredibly easy to take a leak on a Saturday morning sometimes when you hear his rifle go off.

 

You know, if anyone has good plans for a ball mil and two section box I'd be glad to negotiate a fair price for a copy.

 

And yes, I'm looking forward to following up on Dave's offer.

 

--

John

[stix]

 

Yes, absolutely it's a joke. I'm pretty dry about things.

 

I ordered the motor dagabu was kind enough to list on another forum, and I've got a friend who can help me not make too many mistakes putting together a ball mill. I may buy Lloyd Spnoenburgh's book, but if I can find plans for one I'd rather just do that. I'm getting just how sensitive things can be in this field. I'm a math and computer graphics guy, but I'm tired of thinking that hard, that way.

 

Putting together my first rocket was surprisingly fun. Researching pyrotechnics has been surprisingly fun. My neighbors can't complain about what I'm doing: one of them has a deer blind set up, and we're in the city limits. It's incredibly easy to take a leak on a Saturday morning sometimes when you hear his rifle go off.

 

You know, if anyone has good plans for a ball mil and two section box I'd be glad to negotiate a fair price for a copy.

 

And yes, I'm looking forward to following up on Dave's offer.

 

--

John

 

 

I actually thought it WAS a joke at first! - but then I thought about it too much .

 

It's interesting that I'm in a similar line of work. My paid job is as a graphic designer for a printing company, I'm learning web dev. and enjoy programming.

 

I've wavered in and out of pyro for the last 30yrs or so. There's a certain thrill that pyrotechnics and model rocketry have that most other hobbies don't provide. Not just on the visual aspect, but also learning about a lot of things that you would never even consider.

 

Have fun, keep safe.

Edited January 7, 2015 by stix

[dagabu]

Sure, I'm interested. As you know, I've started on the 3/4" ID PVC, and the nozzle is 7/32". It'll be fun to put some together while I'm working towards BP. You might as well price in the tools for a similar BP motor. If you want to steer me towards lead for my eventual ball mill, I'm open to that. Though it might be a while until I need them.

 

Regarding the ways to make a rocket, I thought the trick was to get them to explode consistently, and then start backing off?

 

I'm sure you were joking about the CATO and then back off but that is EXACTLY what Steve LaDuke recommends for the highest impulse out of any particular motor. Establish the tipping point and then pull back until they NEVER CATO.

 

As far as PVC goes, there are a lot of reasons why it is an inferior material for rockets including the integral safety factors such as static and shrapnel issues. When doing HPR, PVC was all the rage for the experimenter then, because of CATO problems and the links to the pyro community, PVC fell off and aluminum became the almost exclusive material for motors.

 

IF you choose PVC, you will have to take steps to keep the flame from migrating around the propellant grain as the nature of PVC is to become 'plastic' when heated and enlarging, allowing the flame to surround the grain causing over-pressure and CATO.

 

If you are suing Bates style grains and inhibiting them or inhibiting the pressed grain by adding a heavy wax coating before pressing the comp, then the over-pressure may be controlled.

 

Another thing to be careful of is running afowl of the HPR guys, Tripoli or NAR. Stay under the designated weight & Newtons.

 

From Wikkipedia:

The National Fire Protection Association (NFPA) definition of a high-power rocket is one that has a total weight of more than 1500 grams and contains a motor or motors containing more than 62.5 grams of propellant and/or rated at more than 160 Newton-seconds of total impulse.

 

Also, LEO's have surprisingly no sense of humor when a motor CATOs or a salute is mounted on the top of a model rocket in a public park.

Edited January 7, 2015 by dagabu

[vizzer]

That guy sure made it look easy and simple in his PVC video. I'm getting how badly misleading that was.

 

And I noticed how the PVC was soft after one of my rockets performed its own horizontal test. I read recently that confetti is better than shrapnel, and wow, there's just so much to know. Anyway, I can see paper cylinders in my future. I still want to master this PVC rocket though.

 

All the LEOs in town know my name... There's only 5 of them. One more than the number of stoplights we have.

 

Thank you for the wikipedia info.

[dagabu]

That guy sure made it look easy and simple in his PVC video. I'm getting how badly misleading that was.

 

And I noticed how the PVC was soft after one of my rockets performed its own horizontal test. I read recently that confetti is better than shrapnel, and wow, there's just so much to know. Anyway, I can see paper cylinders in my future. I still want to master this PVC rocket though.

 

All the LEOs in town know my name... There's only 5 of them. One more than the number of stoplights we have.

 

Thank you for the wikipedia info.

 

In the end, its all up to you to weight the pros and cons then go with what you decide. It's an obligation of those that know the pitfalls to share them with you all when we have had experiences with those situations.

 

Good luck, use e-matches.

[stix]

That guy sure made it look easy and simple in his PVC video. I'm getting how badly misleading that was.

 

I'm sure that guy didn't suddenly wake up one morning and thought "You know what - I might try to build a sugar rocket today, video it and post it on youtube" He would have spent considerable effort perfecting his method - as should we all. What works for him doesn't necessarily mean it works well for someone else.

 

It reminds me of those cooking shows on TV.

 

For example "Jamie Oliver's 15 minute meals" 15 minutes indeed! - there are things left out that are assumed.

 

Although I do quite like those shows, but if I ever attempted one of the recipes I'm sure it would quickly turn into "Stix's dreaded 15 hour epic meal saga's" where the guests get so hungry, frustrated, drunk and bored that they start smashing up the furniture.

 

Cheers.

Edited January 9, 2015 by stix

[ddewees]

^ that's a hell of way to work up an appetite.

[dagabu]

Yupper, look at his blog, he spent two weeks on another 10 minute video about casting aluminum. He is very talented

[vizzer]

It's interesting that I'm in a similar line of work. My paid job is as a graphic designer for a printing company, I'm learning web dev. and enjoy programming.

 

I have to hand it to you design guys. I put a lot into coding graphics, trying to make something visually arresting. Too often - almost every time - people would say "That would make a GREAT screensaver."

 

Which I suppose is ok, but not what I wanted.

 

What do you code (or is this too OT for this discussion?)? Fireworks are actually kind of straightforward for graphics coding. You figure out the behavior over time for one particle and then apply that with some variation to all of them. The computers we used for coding had something like stinger rockets for their screen savers.

 

John

[Milyan720]

Try drying out your sugar and kno3 before making the propellent if it's still not working