Ring Launcher
 

 

This page contains several of my magnetic launchers, be sure to scroll all the way to the bottom! Note: the launchers are in chronological order so the best will probably be at the bottom.
I have had great success launching various conductive things into the atmosphere! It all started in the summer of 97 when I obtained two Cornell-Dubiler high voltage capacitors. they are rated at 4uF 10kV, and I believe they are filter capacitors (but I am not sure).

EML - 1
Electromagnetic Ring Launcher

Technical specifications:

Power supply:
-Neon Sign Transformer, 120VAC / 7000VAC, 60mA
-Variac, 120VAC in, 0-140VAC out, 8A
-10kV bridge rectifier,  0.1A
-multi-tap 1M high-power resistor

Switch:
-simple spark gap, 2 bolts mounted on lexan supports
-homemade discharge rod, 3/8" steel

Capacitors:
-two  caps (10kV 4uF each) in parallel or series

Launching coil:
-#8 AWG standard THHN copper wire wound around 4" PVC, in a close-wound solenoid of approximately 40 turns

Projectile:
-Copper ring (gasket), very thin

With the above setup and near full charge, we could launch the copper ring approximately 50 feet straight up.

This was our first successful magnetic launcher!  We were very thrilled with the results.  The ring would launch faster than the eye could see.  The bang of the spark gap was very loud!

Conclusions made from this experiment:

This experiment did not provide us with the many answers we sought.  For example, many turns (around 40) seemed to work better than few turns (I was told fewer turns would work better). Also, the solenoid seemed to work better than a flat spiral, also against popular opinion. I was also hoping to find if a series or parallel configuration of the caps would be better, but results were the same for both. I believe that with a more powerful launcher there would be a noticeable difference. I believe a series configuration would provide more current into a shorter pulse, both of which are ideal.

EML - 2
Electromagnetic Disk launcher

This launcher started with the purchase of some slightly larger capacitors in May of 1998 at the Dayton Hamfest.  These caps are Maxwell Energy Pulse Capacitors, each rated 10kV 120uF. One of these holds 30 times the energy of the other caps, and is designed for this kind of work, where as the older ones were not.
 

Technical specifications:

Power supply:
-Neon Sign Transformer, 120VAC / 12,000VAC, 120mA
-Variac, 120VAC in, 0-140VAC out, 8A
-four diodes, each 7kV  0.2A
-multi-tap 1M high-power resistor

Switch:
-simple spark gap, 2 bolts mounted on lexan supports
-homemade discharge rod, 3/8" steel

Capacitors:
-Maxwell Pulse cap, 10kV 120uF

Launching coil:
-#8 AWG standard THHN copper wire wound in a flat spiral of about 10 turns (best coil, many others were tried)

Projectile:
-various copper rings
-ring made out of 1/4" copper tubing
-old hard drive platters (disks)
-aluminum soda can
- 2 x 4's !!!
 

This launcher was built during the summer of 98. The very first test took place in the first week of July, myself (Tristan Stewart) and Heinz Wahl participating. The first few launchers were made with heavy copper rings, and only at a few thousand volts. The rings would launch maybe 20 - 30 feet in the air. As for the rest of the results, read on...
 

 

Q:    What could you do with a MFM hard drive disk??
A:    A MFM hard drive disk isn't good for anything but launching into the roof!  Well, here's how the story goes.  I was launching some copper rings (7-9-98) and I wanted to see how this hard drive disk would work. I didn't expect it to work very good because it was much heavier than the rings we were using and it also has much more air resistance because of its large flat surface area.  So I thought I'd give it a low power test first.  Unfortunately it began to rain so I had to move everything into the garage.  The spark gap was set to fire at 5kV.  The capacitor began to charge.  It kept charging, and charging... seemed like it should have fired by now.  All the sudden the spark gap started arcing across the wooden support pieces so we shut the power off.  I grabbed my good old discharge rod and quickly shorted the spark gap terminals.  BANG! Now that was a big bang, big enough to create a small shockwave in the air that I felt.  So we looked around for the disk...but it was gone?!? After searching the whole garage I noticed that it had traveled strait up and was embedded in the roof!  Here is a link to a good picture of it.
We figure that because the spark gaps were used so much that the char that had built up on the contact points held the voltage off a little higher than it should off.  From now on I'll make sure that the contacts are clean!  Assuming that the capacitor didn't charge above its V rating, I calculated that the maximum amount of energy delivered from the capacitor would at most be around 6kJ (6000 Joules).  As soon as the weather permits, I hope to do some more hard drive launches - but this time they will be outdoors!
 

We ran more experiments a few weeks later. A couple different launching coils were used with almost no differing results.  For the first tests I made a ring from bending a piece of copper tubing into a loop and then soldering it together.  This would not hold up! At only around 5kV charge the ring was thrown into the air and ripped apart at the solder joint! The first launcher was about 15 turns of #12 wire. The second launcher was about 7 turns of #8 wire. The only difference was that the #12 was too flimsy and was eventually destroyed under the force of the launch.

Highest Launch: Approximately 125'
Setup: #12 coil, cap charged to 7kV, hard drive disk

An 8kV launch was made, but the disk & the launching coil were so distorted that the disk spun violently and launched out into a field.  The launching coil was bent so far out of shape it was scrapped. Unfortunately, no other high power tests were made because a diode was destroyed. But we could still charge up to a few thousand volts, so the experimenting continued...

  Experiments with various projectiles:
 

We wondered if the launcher would have enough power (at 5kV) to launch a piece of a 2x4 placed over the disk. We quickly found out that we had to run after firing the coil...as a 2x4 came falling from about 75' up in the air!

Here is a pic of the piece of 2x4 that was launched and also the ring.

Here is a small photo-collection of various disks:



And the launching coils:

   This is EML-2's 12AWG coil after a few launches. This coil was nearly a perfect spiral before the launchings...now it is completely useless.
  This is EML-2's 8AWG coil shown just before launching a soda can.

  This is EML-2's first ever setup (the one that left something in the garage roof).

Well, that's all for now...but more to come soon. I will most likely be experimenting with these and other EM launchers whenever I have time and the weather is good! I hope to get some more experiments in this summer ('99).

 

My Navigation bar is screwed up on this page so here is a temp one:

-Main Page -Project Big Bronco -Downhill Skiing -My Thunderbird -My F-150 Truck Page -My Graphic Designs -High Voltage Page -Quantum One Tesla Coil -Quantum Two Tesla Coil -Quantum Three Dual Tesla Coil -EM Ringlauncher -EM Cancrusher -Railgun -Exploding  Wire -Cleveland Airshow Gallery

 

This webpage originally born on 2-22-99. Last updated on 9-7-01

Webmaster: Tristan Stewart

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