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Registered Member #3323
Joined: Sun Oct 17 2010, 03:19PM
Location: West Midlands, UK
Posts: 116
I'm making the coil tomorrow from ~1.30-3.50 PM (GMT), I'm not sure whether it will take this long but, I have a custom made lathe for that and I'll be super-gluing each layer as I go and then remove the coil. Before anyone asks, the enamel coating does resist super glue. If I remember correctly the coil dimensions will be:
On a entirely unrelated note, I got my 700mW 445nm laser working yesterday with a SLA battery (12V 7.2Ah) and it certainly burnt through quite a lot of plastic although that was after 4 relatively big sparks which must have vaporized the steel wire because there was copper inside which I didn't even know was there xD
Registered Member #3323
Joined: Sun Oct 17 2010, 03:19PM
Location: West Midlands, UK
Posts: 116
I've finally finished making the coil, I ended up using an aluminium rod, its diameter was 7mm. Before anyone asks, that weird yellow stuff on it is superglue. I will round off my silicon steel projectile as its slightly too big at the moment.
This is the titanium coated silicon steel projectile, soon to be rounded off as it is hexagonal at the moment. Sorry for the bad camera work, I'm using my webcam for these.
Registered Member #3323
Joined: Sun Oct 17 2010, 03:19PM
Location: West Midlands, UK
Posts: 116
On the 6th Jan, I'll be filing a projectile down so that it fits my coil.
If I have time, I might start marking out and drilling holes in a Aluminium bus bar for the capacitors (I would use Copper but my DT department has a relatively large stockpile of Aluminium and therefore I don't have to pay for it).
Registered Member #3323
Joined: Sun Oct 17 2010, 03:19PM
Location: West Midlands, UK
Posts: 116
I've finally got the silicon steel projectile so that it smoothly can go through the coil. Also, I now have the 3 capacitors connected via aluminium bars. I'll insulate them with electrical tape, as my supervisor insists on insulating everything possible, although because of the nature of the project she cannot give any proper advice. The CEMF diode has been soldered onto the coil directly, should I put a heatsink (a spare bit of aluminium in my case) onto the diode?
Registered Member #3323
Joined: Sun Oct 17 2010, 03:19PM
Location: West Midlands, UK
Posts: 116
I am having a bit of a problem about charging the 3 450V 5.4mF capacitor bank.
I haven't actually tried yet, but my supervisor brought up the point of when the capacitors have reached their target voltage, and I turn off the PSU which is charging it, she thinks the capacitors would discharge into the PSU.
Would this actually happen? I'm somewhat doubtful of whether it will because so far I haven't seen anything about this on any other coilgun logs.
Registered Member #3323
Joined: Sun Oct 17 2010, 03:19PM
Location: West Midlands, UK
Posts: 116
Just to be clear, I would be using either an EHT PSU or a HT PSU. Both could be borrowed from the Physics Department. I can probably find out whether they have diodes in, and I guess the voltage of such a diode would have to be above my operating voltage.
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Coilgun Questions
although that was after 4 relatively big sparks which must have vaporized the steel wire because there was copper inside which I didn't even know was there xD
