The definitive HUMMER thread!

[stckmndn]

I'm looking for LOUD hummer inserts for my rocket headers. I've searched high and low but the info seems to be sparse or perhaps the hummer gods are coveting their formulas.

 

From what I have gathered so far: 1/2" ID, 50/50 whistle / BP mix, 1" tube length? Not too much to go on. Is it possible to make a hummer with a partially unfilled cavity inside to make the whistle louder? Just grasping at straws here. Maybe cplmac can chime in...

 

Compositions, diagrams, theories, and snarky comments welcome.

 

 

 

[Ralph]

I tend to use BP sometimes I even add charcoal to slow it down and add a metal for spark (depending on what flavour im fealing like) high quality meal has often made my hummers cato (I guess it all depends on your nozzle hole size the diameter and other stuff)

 

hummers do not get their sound from whistle mix the sound is caused the the source of the sound rapidly moving towards and away from you.

 

They are good fun make sure you make twice as many as you think you will want

 

also if you wish you can make them fly on their own if you drill(manually) the hole facing slightly down/up than place the hummer on the ground on its end with the hole facing down when you light it most the time they will fly to between 1 and 6m

[dagabu]

I tend to use BP sometimes I even add charcoal to slow it down and add a metal for spark (depending on what flavour im fealing like) high quality meal has often made my hummers cato (I guess it all depends on your nozzle hole size the diameter and other stuff)

 

hummers do not get their sound from whistle mix the sound is caused the the source of the sound rapidly moving towards and away from you.

 

They are good fun make sure you make twice as many as you think you will want

 

also if you wish you can make them fly on their own if you drill(manually) the hole facing slightly down/up than place the hummer on the ground on its end with the hole facing down when you light it most the time they will fly to between 1 and 6m

 

Just the ramblings of my feeble mind here but wouldn't it be possible to merge a whistle insert with a hummer? After all, a hummer needs end plugs right? Why not use whistle to make the plugs then BP for the core? The way I see it, the hummer lights, the whistle starts screaming and then the hummer lights and starts spinning. Would the oscillations of the hummer give warble to the whistle as well?

 

DANG!!! Now I have to go to the shop and try one! Drat!

 

-dag

[Peret]

AFAIK, the easiest way to make a hummer louder is to make it bigger, but it wouldn't be long before you reach a point where they're too big to put in a header. Or you could make them more energetic, but then you have to make them stronger, which leads to the same problem -these tubes from pyrocreations are 1/2 inch internally but have 1/4 inch walls, and these from Skylighter are even thicker. A whistle end would need resonance space so the tube would need to be much longer, taking up even more room, and in the end you'd be using most of the space for inert cardboard and have little left for the effect. You could try filling the hummer with whistle, but I suspect it would explode.

 

Here are some hummers I made, using 1 inch lengths of half-inch tube with 1/8 walls. They perform on the ground as well as in the air, so experimenting is convenient and easy. They make quite a lot of noise and I can fit six of them in a 3 inch ball shell, or 12 in a canister. I haven't experimented much with different fuels. A hot 60:30:10 rocket fuel works quite well. These in the pic have 70:20:10 slow BP made with commercial airfloat instead of willow charcoal, with +5% flake aluminum. I made some with titanium last year, but although that gave a good display it seemed to reduce the thrust too much and the sound is the thing with hummers, not the display. I've tried them with one hole and two. With two holes it doesn't light both sides simultaneously and when the second one kicks in the sound changes too much, so I settled on a single hole, 3/64 drill, which is just enough to fit a black match. There's about a half second delay before they start spinning. With the first few I made, I reinforced the jet hole with water glass, but the burn is so short that even if the hole enlarges some it doesn't change the effect, so now I don't bother.

[Mumbles]

Peret, do you have a jig, or do you drill them free hand?

 

I've always used mill dust usually with a little something for tail. 5% extra charcoal, airfloat or coarse, atomized Al, etc. I tried Ti once, but didn't really like it. The crackling seemed to be distracting from the hummer sound. Maybe if I used atomized or flake Ti instead of sponge it'd be different. I got the best results from 5/8" NEPT tubes, 1" long. They fit 9 in a ring in a 4" shell, and 6 in a ring in a slightly oversized 3" shell (2 5/8" former). Some machine cores such as for shrink wrap are slightly oversized, and can be wrapped with chipboard if needed to get that diameter.

[pyrojig]

I have a jig for a 3/8" id tubes. It was for a stinger missile kit. I think that the hole is to small (unless a toned down fuel is used) and will lead to a cato. A jig can be built for cheap out of metal tube and some angle iron

Peret, do you have a jig, or do you drill them free hand?

 

I've always used mill dust usually with a little something for tail. 5% extra charcoal, airfloat or coarse, atomized Al, etc. I tried Ti once, but didn't really like it. The crackling seemed to be distracting from the hummer sound. Maybe if I used atomized or flake Ti instead of sponge it'd be different. I got the best results from 5/8" NEPT tubes, 1" long. They fit 9 in a ring in a 4" shell, and 6 in a ring in a slightly oversized 3" shell (2 5/8" former). Some machine cores such as for shrink wrap are slightly oversized, and can be wrapped with chipboard if needed to get that diameter.

[Peret]

I made a simple jig by drilling a hole in a piece of angle iron half an inch from the end - it's the same one I use for stingers. I just hold the tube in the angle with one hand and drill with the other. It could be improved if I drilled it over size and pushed in a roll pin to act as a drill guide, but I don't have any problem holding the drill level by eye. I've never had an explosion with a 3/64 hole, though I expect there's a first time for everything including that. After firing the hole is burned out to about 1/8 inch (8/64) but if I start with a hole that size, they don't spin up enough to make much noise.

[dagabu]

A whistle end would need resonance space so the tube would need to be much longer, taking up even more room, and in the end you'd be using most of the space for inert cardboard and have little left for the effect. You could try filling the hummer with whistle, but I suspect it would explode.

 

Its raining here so no video today but the 1" long hummer with whistle plugging both ends works fine. I was able to shoot two from a 1" star gun today. There is no need for a sounding tube as the whistle makes the noise anyway but does get louder as it burns. I agree with the whistle fuel for the hummer portion though, it would be too much for the tube I would think.

 

-dag

[stckmndn]

AFAIK, the easiest way to make a hummer louder is to make it bigger, but it wouldn't be long before you reach a point where they're too big to put in a header. Or you could make them more energetic, but then you have to make them stronger, which leads to the same problem -these tubes from pyrocreations are 1/2 inch internally but have 1/4 inch walls, and these from Skylighter are even thicker. A whistle end would need resonance space so the tube would need to be much longer, taking up even more room, and in the end you'd be using most of the space for inert cardboard and have little left for the effect. You could try filling the hummer with whistle, but I suspect it would explode.

 

Here are some hummers I made, using 1 inch lengths of half-inch tube with 1/8 walls. They perform on the ground as well as in the air, so experimenting is convenient and easy. They make quite a lot of noise and I can fit six of them in a 3 inch ball shell, or 12 in a canister. I haven't experimented much with different fuels. A hot 60:30:10 rocket fuel works quite well. These in the pic have 70:20:10 slow BP made with commercial airfloat instead of willow charcoal, with +5% flake aluminum. I made some with titanium last year, but although that gave a good display it seemed to reduce the thrust too much and the sound is the thing with hummers, not the display. I've tried them with one hole and two. With two holes it doesn't light both sides simultaneously and when the second one kicks in the sound changes too much, so I settled on a single hole, 3/64 drill, which is just enough to fit a black match. There's about a half second delay before they start spinning. With the first few I made, I reinforced the jet hole with water glass, but the burn is so short that even if the hole enlarges some it doesn't change the effect, so now I don't bother.

 

The size of those tubes was a concern for me. My inserts will be in a 2.6" ID rocket header and those are just too big.

 

Wouldn't 4 oz rocket tubing work with some waterglass on the hole? Or does the fat tubing really enhance the sound?

[stckmndn]

I spent some time on Passfire and found this formula attributed to Tom R. It's the loudest I've seen yet. I'll only post the chems in case I'm out of line here.

 

86 7Fa -30 mesh

9 808 Al

5 Ti -40 mesh.

 

Can someone tell me how to arrive at 7Fa deliberately?

Edited June 20, 2011 by stckmndn

[Mumbles]

7FA is graded as -40+100 mesh. It's used somewhat interchangeably with Meal D. I don't know how much it really matters in this case, as it should be pressed solid. Any granulation should be irrelevant. Mill dust or the fines from granulating/corning BP should be acceptable substitutes. I never thought of using bright Al to up the burn speed, but it makes a lot of sense.

 

Rocket tubes are all I use to make hummers. I'm not sure where the thick tube usage came from, but I assure you that rocket tubes work just fine. I use NEPT tubes personally, but others should work alright.

[stckmndn]

7FA is graded as -40+100 mesh. It's used somewhat interchangeably with Meal D. I don't know how much it really matters in this case, as it should be pressed solid. Any granulation should be irrelevant. Mill dust or the fines from granulating/corning BP should be acceptable substitutes. I never thought of using bright Al to up the burn speed, but it makes a lot of sense.

 

Rocket tubes are all I use to make hummers. I'm not sure where the thick tube usage came from, but I assure you that rocket tubes work just fine. I use NEPT tubes personally, but others should work alright.

 

Thanks. Would it be OK if I posted the whole formula here with instructions? Or is that bad form?

 

It is very informative...

[Mumbles]

Go ahead. Formulas aren't as good without the appropriate instructions.

[stckmndn]

This hummer design was attributed to Tom R (The Master):

 

86 7Fa -30 mesh

9 808 Al.

5 Ti. -40 mesh

 

Dampened with 10% water / alcohol (75/25) Dried before pressing. This helps to keep the 808 incorporated in the mix.

 

1/2" ID x 1" L x .680 OD tubes (home rolled)

 

1/4" clay, 1/2" comp, 1/4" clay pressed to 1800 psi

 

1 mm visco .073" vent hole

 

 

 

[stckmndn]

Mumbles, I don't know what 808 Aluminum is. Could you please look at this link and tell me if the Aluminum Flake Bright -325 mesh is comparable?

 

Hobby Chemical

 

EDIT: Never mind. I just found your post in the database. It is comparable.

Edited June 21, 2011 by stckmndn

[Mumbles]

Yes, 808 is bright flake. 810 is another form of bright flake, but typically more coarse. Some of the more traditional would not agree, but 810 is sometimes sold as "fine flitter". Firefox has something they sell as German bright/fine flitter (#C099C) that would be a good product. It makes nice tails in silver streamers and water falls. The mixed firefly from skylighter may work as well. I personally would call 813 medium flitters.

 

No. 809 - American dark pyro - greyish-silvery powder, -325 mesh

No. 808 - Light pyro - silvery powder, a finer bright grade, -200 mesh

No. 810 - Bright - a little coarser than 808, the classic varnish or paint

aluminum

No. 813 - Fine flitters, 30-80 mesh

No. 812 - Coarse flitters, 12-40 mesh

[stckmndn]

Picked up the sodium silicate in the form of liquid glass at Autozone today.

 

Have one last question about the titanium. I have spherical ti 80-150 mesh. Will this work?

 

Is there a real difference between this ti and ferro ti 60-240 mesh?

 

You guys can have a laugh at my expense but a super loud hummer has been my holy grail of pyro for a few months now. I'd like to make a silly and whimsical rocket header with hummers and several colors of flying fish fuse. I think it'll really impress the kids (including myself of course).

 

I'm going to make these with the 3/4" ID NEPT rocket tubes I already have first and see how that goes.

 

[Ralph]

80-150 mesh ti is alittle fine but will work (you will have a denser cloud of smaller short lived sparks) there is a real difference between the FerroTitanium the FeTi burns with a golden spark the Ti with a white also the FeTi is apparently suseptible to dangerous corrosion (Ive never observed it or heard of it happeneing to anyone though several pyro books mention it)

[qwezxc12]

Another wrinkle to throw in is a KP / resin hummer... very energetic. The original formula is from Hardt, but more detail can be found in "Notes on Hummers," in the 12/99 PGI Bulletin. IIRC, I got this from rec.pyro:

If using Weldwood (dry catalyst) it's best to add the dry catalyst to the perchlorate and Ti, screen-mixing them, then weigh out the liquid resin and mix it with the dry ingredients. If you use Cascophen 2-part liquid, like from Aircraft Spruce, mix the Perc and Ti, then add to the already mixed resin & hardener. With the 2-part liquid you may need to adjust the Perc ratio so it's not too runny.

 

 

Hummer mix:

 

 

Potassium Perchlorate........................56

 

Resorcinol resin................................28.5

 

Paraformaldehyde catalyst.................7

 

Titanium sponge 60-100 mesh............8.5

 

 

No end plugs are necessary. Pre-drill the hummer tubes, and insert the fuse prior to filling, then fill the tubes with the mix, either with a caulking gun or (easier) by filling a plastic ziploc bag and snipping of the corner like a disposable pastry bag. After filling, depress the goop flush with the tube ends at the edges, but slightly concave in the center of the tube's diameter. When the composition has cured, paint the exposed composition at the hummers' ends with white PVA glue (Elmer's or similar). This is enough to prevent the filling from catching fire from the shell burst.

 

You will need a hot visco to ignite the hummer comp. Attached pic are of a 4in can with 16 1"x1/2" hummer inserts I made a few years ago.

The shell's lackluster performance and ragged ignition of the inserts is probably due to me skimping and using a quick 'n dirty cut/prime method on the hummer fuses rather than cross-matching.

 

[guntoteninfadel]

I gotta I gotta I gotta..... He left it sooooo open! Just can't pass it up!

 

[quote name='stckmndn' timestamp='1308697037' a super loud hummer has been my holy grail

 

Ummmm mine too

[stckmndn]

he he

[giod]

Made my first hummer tonight , I know this is an old thread btw.. It worked perfect! Rammed the bentonite, into the hummer tube, then the gran BP, then more bentonite , then drilled the hole just off center toward the top ( not end) of the cylinder wall.. Added a fuse. Spun up nice and loud, about 3 ft off the ground. However it only lasted about 3 secs. So I built another out of a 5/8 salute use by 1.5 inches. Followed the same regimen, but this one cato'd , I'm guessing twice the powder should have had a larger that 5/16 vent hole?

Fun, nonetheless ..

[psyco_1322]

Made my first hummer tonight , I know this is an old thread btw.. It worked perfect! Rammed the bentonite, into the hummer tube, then the gran BP, then more bentonite , then drilled the hole just off center toward the top ( not end) of the cylinder wall.. Added a fuse. Spun up nice and loud, about 3 ft off the ground. However it only lasted about 3 secs. So I built another out of a 5/8 salute use by 1.5 inches. Followed the same regimen, but this one cato'd , I'm guessing twice the powder should have had a larger that 5/16 vent hole?

Fun, nonetheless ..

 

Hummers are not meant to last a long time, 3 secs is actually quite lengthy. The idea is to give a quick burst of the sound they make. With the sound of multiples overlapping, and mixing in different timings, you can create a nice effect. And yes, your cato was probably because of the vent hole being too small.

[Col]

I use two 2.5mm vents for 1/2" id hummers. A 5/16" (8mm) vent is pretty big for a 5/8" id, two smaller vents 180 degrees apart would likely solve the cato issue without affecting the spin rate.

[giod]

I use two 2.5mm vents for 1/2" id hummers. A 5/16" (8mm) vent is pretty big for a 5/8" id, two smaller vents 180 degrees apart would likely solve the cato issue without affecting the spin rate.

 

how do you fuse multiple vent holes? also my 5/8 tube was only like 1/8inch wall as opposed to the 3/8" thick hummer tube..