|Project by Mork||posted 03-01-2014 11:11 PM||3096 views||32 times favorited||17 comments|
Updated with more videos below…
This machine was invented between 1880 – 1883 by a guy named James Wimshurst. There is all kinds of information on the internet about these machines but not all of it agrees. When I started building my machine I had several question and ended up making several assumptions. As it turns out the machine works fantastic but I could have boosted the performance significantly. For instance, the foil sectors attached to the acrylic disks could have been smaller. This would have increased the voltage and spark length significantly. On the flip side, larger sectors make the machine perform more reliable. The machine has to be charged. To do this I rub a 2 foot piece of 3/4 PVC pipe with a cloth and hold it next to one of the disks while it is turning. After that it stays charged until somebody operates the machine in reverse. Apparently with smaller sectors the machine would be more difficult to charge or start.
My spark is 2 inches or slightly over. There is a wire that connects the two PVC pipe capacitors. With the capacitors connected the spark is a very health snap about every revolution of the crank. Disconnect the capacitors and the spark is almost constant (and the same length) but much weaker (same voltage but less amps).
To answer your question Soapmaker, yes i have touched the spark. With the capacitors engaged it is not pleasant but with them disconnected it is a hair raising experience. If you separate the electrodes and hang on to one of them while turning the machine a blue glow can be seen coming from your hands to the other electrode along with a hissing noise. Move your hand away then everything starts to glow blue (coronal discharge).
This machine has been incredibly amusing and a lot of fun. Its been sitting on my dining room table for about a month now and I can’t walk past it without turning the crank.
It would be a fantastic father son project or if you are like me, a kid at heart, I would highly recommend building one. All the wood used were scrap size and the components cost me about $70 bucks. The only really difficult part was the bosses that the disk mounts to. I had a machinist turn them out of UHMW (a type of plastic) and fit them with brass bushings.
If anyone decides to build one let me know and I’ll gladly pass on what I have learned.