61 replies to this topic

[Sambo]

Nice rockets there phill, that CuO is really raspy. I would have thought that a faster burning propellant would generate the most thrust though, so the CuO may not be the best choice for a rocket with header.
I've got a PicoScope set up for testing the thrust now, just working to eliminate background noise; if you touch any metallic components it gives a reading lol. I'll give it a test this week and report back, it should be very accurate if it works...

Sam

[knackers]

I've got a PicoScope set up for testing the thrust now, just working to eliminate background noise; if you touch any metallic components it gives a reading lol. I'll give it a test this week and report back, it should be very accurate if it works...

Sam

Ho sambo,
hows the picoscope going ? got any results yet ?

[Sambo]

Hi Phill, not to bad, it needs some other bits but i've got 2 hols coming up so money is a bit tight.
It runs fine on the home pc but i need a USB-Parallel Port Adaptor to run it from my laptop on the test site.
Hopefully will get it sorted soon...

[Sambo]

Rite then chaps, I'm looking for some sodium salicylate and still on the hunt for copper oxychloride, does anyone know of a supplier of either at a reasonable price or anyone have some they want to sell?

I'm moving up from benzoate whistle, I just want more power!

[Vic]

It has become an annual ritual at this time of year for me to make and test whistle rockets, having a week off work as usual, I can only party and entertain for so long and then my thoughts turn to pyro.
This is more of a continuation of the last years work with conventional short cored 4oz whistle motors (not of pusher design) after last years failures what with no whistle and nose dives I am happy to say, success at last.
Using a hotter 76-23-1 mix with sodium benzoate and Iron(III) oxide catalyst and with 1/2” delay on top and no bulk head, and with total weight of only 34g, they were quick off the mark not like Sodium salicyate with copper(III) ) Oxychloride though, but fast enough. It did a fair bit of whipping around but that can be sorted out.
Once again the camera person is on a work to rule, that is I'm in charge of filming as well as firing hence the backward walk
I have 1” ¾ space above the delay with the 4” long tubes, what can I do with that
4oz whistle

[Invogue]

I let my rockets go in farmers fields around where I live. 3lb rockets ( 1" ID x 10" Long x 4mm Wall from www.charcoaldust.co.uk ) when these come down there is still some weight. Another thing I have been doing is making 3lb stingers with a big report. Flash breaks the casing up so I can let these go anywhere. I really would like to do whistle stingers now. I have Pot Perc with Sodium Benzoate, what formula would be best for it? Tried some pressed comp in a tube and no whistle - I want a really good scream...

[Vic]

I let my rockets go in farmers fields around where I live. 3lb rockets ( 1" ID x 10" Long x 4mm Wall from www.charcoaldust.co.uk ) when these come down there is still some weight. Another thing I have been doing is making 3lb stingers with a big report. Flash breaks the casing up so I can let these go anywhere. I really would like to do whistle stingers now. I have Pot Perc with Sodium Benzoate, what formula would be best for it? Tried some pressed comp in a tube and no whistle - I want a really good scream...

This link may help you, happy whistling My link

[dr thrust]

top link Vic,
is the iron oxide catalyst correct it seems a lot at 3 grams,or have you tuned it for stingers?
i believe the optimum mix for Na benzoate whistle is
kcl04... 70
Na benzoate.. 30
Fe oxide .. 1
Vaseline.. 3
mill the kcl04 so it passes a 100# screen
coffee grind then mill the fe and na benzoate together for a few hours
as particle size is the secret with whistle

[Vic]

top link Vic, is the iron oxide catalyst correct it seems a lot at 3 grams,or have you tuned it for stingers?i believe the optimum mix for Na benzoate whistle is kcl04... 70 Na benzoate.. 30 Fe oxide .. 1 Vaseline.. 3 mill the kcl04 so it passes a 100# screen coffee grind then mill the fe and na benzoate together for a few hoursas particle size is the secret with whistle

It is not my work, it is by Harold Bentley who used to be on the U.S pyro scene some years back.
Don't forget these have clay nozzles so you are not going to need a hot mix but I do find the 3 parts Red Iron Oxide curious.
I would start off with 64/32/1/5 the 5 being Petroleum Jelly and go from there.

[dr thrust]

sorry vic, the "my link" thing threw me!
yes the 3 gram fe is curious? worth investigating to see how it affects burn rate
yep forgot about the clay nozzle, but to me whistle and clay don't go well together,and the whole thing looks like a lot of work!

Edited by dr thrust, 03 April 2011 - 11:40 AM.

[Invogue]

I have only ever seen 1g FE added, I'll try this new formula out when I feel a bit better (on antibiotics for ear infection). Love doing stingers with a decent flash header, once I get these babies working I'll post a vid or two. Feels like it's been weeks since I smelled the smoke - I hate being ill especially when you have to work while feeling like crap.

Out of interest, do any of you guys have some advice for getting these things balanced a bit better. Rockets are easy but stingers can kind of wobble while spinning up and can go off a bit sideways. I have tried sticking on an end disk with a hole for the pin. Sometimes that made it worse and they even seemed to have my name on them as they flew right in my direction.
I made a launch pin with slightly thicker diameter and that helps but I still see a bit of a wobble some times - or shouldn't I worry about it?

[Deano 1]

Do you have one side hole in your stinger? if so, put another opposite. Try balancing your header like you balance a car wheel, the best you can. With the speed these things spin it doesn't take much to throw them out of balance.

[Invogue]

Do you have one side hole in your stinger? if so, put another opposite. Try balancing your header like you balance a car wheel, the best you can. With the speed these things spin it doesn't take much to throw them out of balance.

single vent, I'll add another. I guess this will affect flight duration.

[Potassium chlorate]

Has anyone tried KClO₃ as an oxidizer instead, and how much more powerful and dangerous respectively is it?

Is it possible to make whistles with ammonium perchlorate?

[dr thrust]

kclo3 has been used as a whistle oxidizer,and yep you've guessed it.. more powerful as it gives up its oxygen easier than a perchlorate ,and way more sensitive not ideal when you have a tube full of it on a press!.
as for ap, its reputed to be very sensitive to mechanical action! properly why most ap propellants are cast in resins etc. heres a good link on how a "whistle" works, ap is mentioned whistles

Edited by dr thrust, 16 February 2011 - 10:01 PM.