So! I finally got some cash so I've ordered everything I need(I think..) to finish the electronics for the 2stage rifle besides the charger(I'm gonna use the 230VACCC to start with), I'm just waiting for some logic and SCR's to arrive then I'll get right at it ... So hopefully I can post some nice vids and stats of it if I manage to get it together..
Just letting you know the blog isn't dead, yet. :P
Just did a quick vid to show off the "firepower" of the V1.1..
I did some testing and calculating earlier to achieve better efficiency, it is currently at a reasonable efficiency of 2.4% @ 8.6Joule(Kinetic energy)(Cap bank is 358J(Electrical energy, obviously)). Speed is 17.54m/s and bullet in the video weighs around 56 grams, used the acoustic record method..
I was bored and decided that I wanted a semi-mobile coilgun .. So this is coilgun V1.1(1 stage, version 2).
It's the same coil that I've used in previous vids and same circuitry as in the "230vaccc-voltage-tripler-single-stage" post, except all mounted on and inside it so it doesn't take my entire deskspace in order to use..
Here's when I started meazuring out the MDF board, making sure everything fit..
With coil attached:
Testing the rather bright 5mW laser module:
Thyristor trigger switch and projectile start position adjustment:
"Finished" product with multimeter glued to it and 230VACCC attached to it.
Other side:
Notice how every cut and attachment just looks quick and dirty, that's because that's exactly what it was...! I wanted to get it done in a day so I could have more 'playtime' than time spent constructing it, like I do with my 2stage coilgun rifle..
Here's the heavy duty switch again, nicknamed VFDS(Very Fucking Dangerous Switch).. Did a few test shots at ~250-300VDC with a 3300µF bank and the performance was sporadic, sometimes most energy was wasted in the shape of sparks and sometimes it fired just fine.. I ended up scrapping this as it was in-effective. Here's a vid of it anyway.
The previously shown 230VAC capacitor charger wired up to a voltage tripler producing a theoretical voltage of 975VDC, however since the diodes I'm using in the tripler are only rated at 600V they seem to limit the voltage to around 615VDC, going to buy better diodes whenever I can afford some.. Mounted a 5mW laser module on the coilgun in order to see a bit better where I'm about to hit, the projectile I'm mostly firing is a ~55gram sharp-tipped bolt.
Capacitor bank is two 2240µF 400V banks wired in series for 1120µF and 800V, the 600V shots in the vid are roughly 200 joules and at the full 800V it'd be 358 joules.
I'm getting pretty tired of my thyristors welding together everytime I mess about with low-resistance single-stage coilguns... So I thought I might as well try a big mechanical switch instead.
Started out with a sheet of plexiglass, some pieces of aluminium, screws and a spring This setup gave a satisfying snap sound when closing but it didn't take me long to realize how dangerous this would be to operate at the voltages coilguns use..
To increase safety a bit I added a non-conducting latch designed to hold the switch in 'loaded' position and not let go until lifted.
Next step was finding out how to attach cables.. This stage was pretty much a no-brainer.
I added a handle to the latch and springloaded it to stay in position safely, made the spring for the actual switch extend a bit to clear the latch and give a little more tension. Also drilled out some more pieces of aluminium to be able to attach all the cables.. Insulated the outside of the switching piece(red) with electrical tape to be able to load it without major shock hazard, although the chance of getting a shock from this thing is still pretty big but hey, what's life without a few hazards ey? Unlatched(On):
Latched mode(Off):
And a little video of it in varying stages of completion:
I guess all that's left now is to test this thing with a few hundred volts and amps.. If there's no more blogposts after this, then the shock hazard probably got to me ;)
