Composite nightmares

Recently, someone knocked over my tesla coil secondary and cracked off a good chunk of epoxy insulation, before it even got a chance to see its first EM field. Boo. The damage ended up being pretty bad, so I was left with little choice but to build a new one. As my luck would have it though, there is no 12″ PVC pipe to be found in Rochester. So… how about sonotube?

Cardboard works alright as an inductor’s core, but water entrapped in it dissipates RF rather readily. Naturally, this is bad if I’m putting 10kW into the coil, so it must be removed. Since my composites class project wasn’t going to happen since I wasn’t able to use the student available cnc router “formula SAE only” compumill, I figured why not try epoxy infusing the coil?

Fast forward a bit. Once all the materials were gathered, things were going good for a period of time. The vacuum bag was looking pretty nice, and the tube seemed to absorb the epoxy that was being brushed on it. In fact, it might have just worked if we were able to seal the vacuum bag in time… ಥ_ಥ


Alas, composite tube was not meant to be. At least, via the way we tried it.

Lessons learned, I suppose.

Next time I’ll be trying s-glass instead of cardboard.

One thought on “Composite nightmares

  1. Glad to hear I’m not the only student absolutely frustrated by the lack of access to any machines more advanced than a bridgeport for ‘regular’ (i.e. not baja or formula) students at this school.

    What was your setup for this, and what materials were you using? The photos aren’t too clear.

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