Turning an E Core Power Transformer into a Tattoo Gun

I think I can convert an E core AC power transformer into a tattoo
gun.

If I sliced off the top of the E core, that would make two gaps. It's
now an electromagnet if I apply DC.

I'm going to also drill a hole down the center of the core.
This hole would be for the needle.

A spring is used to pull the needle up.
Magnetic force pulls a metal plate and the needle down.

I plan on driving the electromagnet with a power oscillator.

Questions

Will this work?

How big of a transformer should I hack up?.. I have a pile of all
sorts in the junk box..I'm guessing 20watts.

I don't mind taking the transformer to it's max temperature...whatever
that might be..

Any other design ideas?

For reference
http://en.wikipedia.org/wiki/Tattoo_machine

Actually I'm not tattooing.. It's to perforate 4mil vinyl.
I can't afford a laser.

As I was writing this I came up with a better idea..

I think a needle stuck in a steel rod stuck in a solenoid might be
much easier to construct..


D from BC

 

The '20 watts' means the core can take roughly an amount of magnetic
energy equal to

Estored = 20 W/(120 per second) = 0.16 W-second = 0.16 Joules

That is (again, roughly) the amount of force x distance (work) that
is available to drive your point into the vinyl. This is slightly
complicated
by the spring (it has to compress the spring at the same time,
and the spring has to be stiff enough to pull the point out).

I'd think in terms of a hot knife to score the vinyl, if it was me.
Noise
is just as annoying as hot-plastic-odor.

 

I've been thinking about the hot knife technique for cutting 4mil
vinyl.
I could heat up a power resistor and use the hot lead.
The lead is then dragged on the vinyl to cut it.

But...I think vinyl makes an acidic goo that'll eat through the
wire..but not sure.
Also...the heat emission I think makes a fat cut.

I've been looking at ultrasonic cutting methods too..
For example:
http://www.sonotec.com/cutter2/SF60en.pdf

I can probably make an ugly but functioning generator in 1 day.
I just don't know about getting the transducer.
D from BC

 

Good grief, just stick the sheet in an old 24 pin dot matrix printer
with no ribbon.
4mil thick vinyl is the same thickness as a sheet of paper. Worst case
you'll have to disassemble the print head and sharpen the pins... But
you like that kind of stuff right?

 

Yeah...I had a similar thought..
The problem is that the 4mil vinyl needs to be cut after it's mounted
on a sheet of plastic.. That won't feed through a printer.

I'm trying to think of scrap equipment that has powerful solenoids
with >4mil movement and capable of 10Hz.

I have a car scrap yard nearby...so maybe:
fuel injector?
door solenoid?

Also..I got adventurous enough to email a factory ...in China!
I'm curious about a 60W solid state IR laser... Arrrfff! Arrrfff!
All those people selling laser diodes on Ebay probably got all this
stuff from china anyways...
D from BC

 

Flatbed plotter.