My friend runs a haunted house, and like all good haunted houses, there is a chainsaw...

I purchased a chainsaw and my vision is to put some kind of spark generator concealed where the blades are to be located. I will be located in front of the attraction near the road. When I drag the saw across the blacktop road, I want sparks to fly as if the blades are scratching the road. This concept is similar to that of the chicken wire-metal pipe spark shooter that you can find here, but I have the following issues:

- This system has to be portable as I will be mobile with a gas powered chainsaw.
- I need to be able to conceal the system so that if you aren't looking for the system at hand, it will not be obvious to the eye in the dark night. (I am a creative person so as long as the materials are not huge to the eye, I should be able to pull this off.)

Overall, I am thinking the system should include some kind of momentary switch that is triggered by the dragging of the chainsaw, or some kind of circuit that allows the road to complete the circuit.

I think it should go without saying that this system should be safe for the operator and the crowd as well

Thank you for the replies!

 

There are several fundamental design issues that would need to be overcome to achieve what you want. Firstly the road material is unlikely to be conductive, such that when the chainsaw blade touches the road – there would be no conductive circuit that would be made (as in the chicken-wire video). Therefore having the spark generator self-contained within the chainsaw would appear the best option.

Secondly it takes quite a bit of energy to produce impressive sparks. Consider a fair-ground bumper-car overhead pick-up spark, the current producing these sparks is likely to be in excess of 100A.

Rather than using electricity to generate sparks, it’s likely that professional chainsaw props use a mechanical spark generator of the type seen in toy guns of yesteryear – but on a larger scale generating ferrous material sparks.

You could consider something like this, with the electrodes positioned to give the required sparks.

https://www.ebay.co.uk/itm/10grades...097405?hash=item4d7cab857d:g:Wu4AAOSwQDdbmlPc

Note that this is a self build kit that requires assembly and a DC supply to operate it of a nominal 20V at around 3A (supplied from a lithium battery pack).

The output voltage/current of the unit is very likely at lethal levels, such that great care should be taken using it.

 

This might sound boring, but why not a cardboard box chainsaw with speaker, and a LEDs simulated chainsaw blade. (variable rotation)

 

How did this work?

Was it just something rubbing on a flint?

 

Some unsolicited advice: keep live sparks (of any kind) out of a haunted house. These things tend to become fire traps.

A Google search highlights some examples.

 

Was it just something rubbing on a flint?

Yep. A flint like in a lighter. Which really isn't the mineral called flint like in the old flintlock rifles.
https://en.wikipedia.org/wiki/Ferrocerium