Search found 113 matches

by GalFisk
Tue May 08, 2007 6:25 am
Forum: Off-Topic Hobbies
Topic: Saltpeter!
Replies: 6
Views: 723

You'd get pretty sparks.
Dyes can't be used with this smoke mix since it burns to hot.
Some working formulas: http://www.pyrocreations.com/smoke_compositions
by GalFisk
Tue May 08, 2007 6:21 am
Forum: Off-Topic Hobbies
Topic: Fireworks, extra effect
Replies: 41
Views: 1129

Polyethylene or polypropylene is resistant to gasoline, and can be used as a container. I'd rather use something more volatile though, such as pure gasoline, ethanol or even acetone. That would spread into a fine mist and ignite when the shell explodes, producing a fireball. You'll want the fuel to ...
by GalFisk
Tue May 08, 2007 6:06 am
Forum: Combustion Cannons
Topic: new way of using camera for ignition
Replies: 20
Views: 2650

It wont shock your hands because your hand has more resistance then the metal thus the electricity just wants to go through the metal contacts equalize... you can hold one of the leads and nothin will happen at this voltage... this is only true with DC. It won't shock you because you're not complet...
by GalFisk
Thu May 03, 2007 4:08 pm
Forum: Combustion Cannons
Topic: Can I get a spark on demand?
Replies: 33
Views: 1629

The cap will have a voltage rating, I'd guess less than 400V. The actual voltage should be somewhat lower. You can block the gap with a piece of plastic. There is a possibility that the charging circuit is not limited to the rated voltage of the cap, but instead relies on the spark gap doing its job...
by GalFisk
Thu May 03, 2007 1:19 pm
Forum: Combustion Cannons
Topic: Can I get a spark on demand?
Replies: 33
Views: 1629

The anode goes to the positive end, the cathode to the negative end of the spark gap (you can measure this with a multimeter, or see which end is connected to which pole on the main capacitor). The trigger is operated by either applying a small voltage between the trigger and cathode, or connecting ...
by GalFisk
Thu May 03, 2007 8:14 am
Forum: Combustion Cannons
Topic: Can I get a spark on demand?
Replies: 33
Views: 1629

Yes, I thought the images themselves were down since my site has been moved, but I see it has been at least partially fixed.
this is the forum thread: http://www.spudfiles.com/spudtech_archi ... hp?t=12401
by GalFisk
Thu May 03, 2007 6:56 am
Forum: Combustion Cannons
Topic: Can I get a spark on demand?
Replies: 33
Views: 1629

you can use a SCR (aka thyristor) to precisely trigger a stun gun. One that will handle the voltage across the internal spark gap costs a couple of bucks at the most. It can also be controlled electronically. --- I posted some ideas on spudtech a while ago about self-venting combustion chamber desig...
by GalFisk
Thu Mar 29, 2007 5:04 pm
Forum: Off-Topic Hobbies
Topic: which people are from spudtech?
Replies: 36
Views: 2424

I was a long time Spudtech member as well (must be more than six years by now).
by GalFisk
Mon Mar 19, 2007 5:38 pm
Forum: General How-To & Discussion
Topic: Great How to...working with copper pipe
Replies: 8
Views: 5568

Same here, never had a problem with 95/5 (Ag) and a good propane torch. A pipe cutter is very nice for cutting the breech end for a barrel sealer, as it creates a verystraight and even edge. A bonus is that your projectile won't be able to fall onto the valve. Good howto, I've seen the original site...
by GalFisk
Fri Mar 16, 2007 12:29 pm
Forum: General How-To & Discussion
Topic: When is spudtech going to be back up?
Replies: 15
Views: 788

You can actually still post in the threads if you have one of the forum views up in your browser from before it closed. The "active topics" page is still up as well (http://forums.spudtech.com/active.asp).
by GalFisk
Wed Nov 29, 2006 5:06 am
Forum: General How-To & Discussion
Topic: 3D renderings for sale
Replies: 28
Views: 1459

You can animate in Rhino with the Bongo addon (if that was what you were asking).
by GalFisk
Fri Nov 24, 2006 7:32 am
Forum: Ammo & Parts
Topic: PSI and materials
Replies: 12
Views: 1449

Burst pressure depends on the material, thickness, and pipe circumference (and temperature, but that is not relevant when it comes to copper and spudguns). Pressure ratings are very conservative (1/3 to 1/4 of burst pressure). Annealed (soft) copper has much lower ratings than drawn copper. Here are...
by GalFisk
Fri Nov 24, 2006 6:36 am
Forum: BB, Airsoft, and Pellet Guns
Topic: Should They Be Banned?
Replies: 23
Views: 3231

What/who are "they"? BB/Airsoft/Pellet Guns?
by GalFisk
Wed Nov 15, 2006 4:50 am
Forum: General How-To & Discussion
Topic: 3D Design Software
Replies: 6
Views: 462

Rhino is great, I've used it to model my last two cannons. 3D modeling is a good tool for catching design flaws before beginning the actual construction, as well as getting a good understanding of how the gun will turn out.
by GalFisk
Wed Nov 15, 2006 4:32 am
Forum: General How-To & Discussion
Topic: BBQ VS Camera Igniter Effectiveness
Replies: 1
Views: 310

I prefer flyback ignition, because you get a constant hot spark. They're more complicated to put together than most other ignition systems though. After that I'd pick camera+ignition coil, becuase it can be made from readily available parts, is pretty simple to put together, and gives a strong spark.