Search found 113 matches
- Wed Jan 09, 2008 2:14 am
- Forum: General How-To & Discussion
- Topic: 101 Ways (Not Really) To Use a Camera Flash...
- Replies: 21
- Views: 7682
The output frequency of the inverter is in the >10 kHz range (it's the frequency of the whine you hear when the circuit is charging, and it's higher the less load you put on the circuit). The trigger cap is a normal type of small high voltage cap, possibly with polyester or polypropylene dielectric....
- Sun Dec 09, 2007 11:49 am
- Forum: Hybrid Cannons
- Topic: valve hybrid design
- Replies: 16
- Views: 3944
You can build a variation of the DFTV (http://antennalaunchers.com/dftv19/) that opens when the chamber pressure rises. My copper hybrid uses this, it has been dry-fired successfully a few times but I haven't had time to finish it completely (it cn also be used as a pneumatic and there the valve per...
- Thu Aug 02, 2007 4:28 am
- Forum: Hybrid Cannons
- Topic: Camera flash on metal hybrid
- Replies: 18
- Views: 4743
2 mA is harmless. A flyback is well suited for hybrid ignition. With a metal cannon, something to note is that you will have high voltage between the cannon body and most parts of the circuit (including the low voltage parts). This is if one end of the circuit is grounded to the metal, you can elimi...
- Sat Jun 09, 2007 7:28 am
- Forum: Off-Topic Hobbies
- Topic: Space shuttle launch!
- Replies: 7
- Views: 1711
jrrdw: thanks, I've been looking for that link forever. I saw the launch on NASA TV, made me want to be along for the ride. A space rocket launch (shuttle or otherwise) is one of the things I want to witness in real life before I die (the others are a total solar eclipse, a volcano eruption and (if ...
- Thu Jun 07, 2007 4:01 am
- Forum: Off-Topic Hobbies
- Topic: Making sodium?
- Replies: 11
- Views: 2672
Details and success reports about electrolysing melted NaOH here: http://www.sciencemadness.org/talk/view ... p?tid=2103
Beware that hot melted lye is very corrosive and will eat your skin and blind you. Take appropriate safety precautions.
Beware that hot melted lye is very corrosive and will eat your skin and blind you. Take appropriate safety precautions.
- Wed May 23, 2007 1:15 pm
- Forum: Off-Topic Hobbies
- Topic: Fireworks Launching Platform
- Replies: 16
- Views: 3323
0.25W 10 ohm carbon film resistors glow red hot at 9-12 volts, and usually survive multiple firings. They're also dirt cheap. The paper clip method sould also work nicely, but you need thick leads (jumper cabler or similar) or they will heat up as well. Nichrome ignition works as well, is probably m...
- Mon May 14, 2007 3:48 am
- Forum: Off-Topic Hobbies
- Topic: Rapid Desoldering?
- Replies: 15
- Views: 3641
- Sun May 13, 2007 9:35 am
- Forum: Off-Topic Hobbies
- Topic: Rapid Desoldering?
- Replies: 15
- Views: 3641
- Sun May 13, 2007 4:11 am
- Forum: Off-Topic Hobbies
- Topic: Rapid Desoldering?
- Replies: 15
- Views: 3641
- Fri May 11, 2007 6:13 am
- Forum: Off-Topic Hobbies
- Topic: the BEST way to make sugar/kno3
- Replies: 49
- Views: 9308
Depends on where you're living, I live in Sweden and can get KNO3 fertilizer under the brand name Krista K-plus (25 kg for about 200 SEK). The chemical name is often not obvious on fertilizer bags, look for 13-0-46 fertilizer. If farming supply stores don't carry it, you may be able to get it from a...
- Thu May 10, 2007 9:52 pm
- Forum: Off-Topic Hobbies
- Topic: the BEST way to make sugar/kno3
- Replies: 49
- Views: 9308
Ammonium nitrate can detonate if properly sensitized and initiated, but as an oxidizer it's not that much different from KNO3. IIRC it's less used because it's hygroscopic. If you want cheap and pure KNO3, buy it as fertilizer, not stump remover. The latter is both more expensive and has more crap i...
- Thu May 10, 2007 9:40 pm
- Forum: Off-Topic Hobbies
- Topic: making a smoke grenade inside a good pot help..
- Replies: 7
- Views: 1995
- Wed May 09, 2007 6:38 am
- Forum: Pneumatic Cannons
- Topic: GB Semi
- Replies: 118
- Views: 109779
Interesting valve, I think it could be streamlined to fit inside a tee. It seems like the opening time will be much slower than traditional valves though, owing to the much smaller imbalance between the forces acting on the piston. If you're willing to sacrifice the air in the pilot, that could be f...
- Wed May 09, 2007 6:06 am
- Forum: General How-To & Discussion
- Topic: Bicycle Propulsion
- Replies: 30
- Views: 6309
- Wed May 09, 2007 6:02 am
- Forum: General How-To & Discussion
- Topic: rapid fire "shell" idea.
- Replies: 20
- Views: 4191
Re: rapid fire "shell" idea.
Rhino3D.hi wrote:ps- what is a good program for drawing 3D images?