# "Safe" Spinning Circular Saw Blade?



## Haunted Hot Sauce (May 7, 2010)

As part of my Moonlit Hill Mortuary and Cemetery Halloween display I want to create a huge, sawmill like saw with a 2 ft. circular blade where wood for coffins is supposedly cut (and bodies potentially dismembered).

I want the blade to actually spin. The "saw" will be under my deck protected by a metal mesh screen of some sort but I don't want anyone to be able to hurt themselves even if they manage to get past the screen and stick their fingers into the spinning blade.

What do you suggest I make the blade out of?

I was considering cardboard (but I don't want wrinkles in the blade or the corrugated edges to be visible) and I was also considering foam core (but even that can give you a nasty cut if you stick your finger into it while it's spinning) 

Maybe starched cloth? Any ideas?

Thanks!!


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## The Watcher (Sep 13, 2008)

I was thinking about the foam board also. Depending on what kind of motor you use. You might could set it up so if something touches the blade it will Stop turning. If you use double nuts on the main rod and large washers. So you can set it loose. I am sure even if you had to pull the blade to get it going. It would keep running once you start it. But If you touch it then it would stop and the drive will just spin. Like a clutch drive.


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## scream1973 (Dec 23, 2007)

use a motor with a really low stall speed ( ie deer motor) and then foam core and if someone stuck thier hand in there it would stop the blade.


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## niblique71 (Dec 2, 2009)

I think you should just use your instincts for the blade but put more effort into securing the area. NOBODY should be able to access any violently moving prop of any kind weather it's Pneumatics, motor driven, or just a possible electrical hazard. ANY Blade you make has kinetic energy weather it's made of foam or 440 stainless steel and has potential for harm. Even fabric that is spinning could wrap around a finger and yank it off if the fabric is frayed and it's spinning fast enough.


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## Ryan Wern (Dec 3, 2009)

I like the foamboard idea too. A deer motor might spin too slow for what you want. How 'bout a wiper motor? Just cover the area with chicken wire and but the blade a few feet back. Nobody's fingers are that long.


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## The_Caretaker (Mar 6, 2007)

I would use 1/2 inch extruded pink/blue foam for the blade, I then would mount it on a motor, where the hole in the blade is a slip fit. You would need to spin the blade by hand to get it going but with the motor going it should continue to spin. that way if some on would but there hand, finger other body part in to the blade it should stop, may hurt like hell


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## Haunted Hot Sauce (May 7, 2010)

Thanks for all the ideas! I think the slip motor or clutch drive idea might work the best for what I want to to. I don't want to have to start the blade by hand as I want to be able to turn the effect on and off randomly. The sudden noise provides the scare factor (provided by an actual hand-held circular saw with the blade removed hidden behind the "crankcase" of this contraption.) I was going to use a fan motor to make the actual "blade" turn and perhaps I'll slip a thin ring of that black insulation foam used to insulate A/C pipes to the spinning shaft and then hot glue my "blade" to the outside of that so if anything tries to stop the blade, the sleeve will just slip on the shaft. I'm also toying with the idea of making the "blade" a perfectly round circle out of foam core and then gluing on the saw teeth made of that thin foam rubber. It'll make the blade look beefy and ominous but then there'll be no sharp points of any kind. (although I still wouldn't want to get a paper cut from a spinning disc of foamcore so The_Caretaker's idea of using extruded foam might be the way to go) Niblique71's point of safety first, First, FIRST should probably guide this project.


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## DarkLore (Jan 25, 2009)

I was thinking along the lines of what The_Caretaker was saying. I'd try thin foam board with a hole about the size of a pvc pipe. I'd "pinch" the foam blade with two washer type disks on each side...so the pvc goes through all three. Spin the pvc to turn the washers, which turn the blade by friction. With the blade traveling totally on the pressure of two washer pieces...even if a person put an arm in there, it wouldn't hurt them.

Paint the blade flat black, then dry brush silver to give it a metal look. Add a bit of rust and some dry blood if you want to improve the look.


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## The Watcher (Sep 13, 2008)

If your motor starts out turning fast and the blade starts with it. The amount of force you would need to get foam to jump with it. It isn't going to stop fast enough. So if some one is dumb enough to stick their finger in there they could get a paper cut. I didn't know you were trying to use it as a scare. Now if you are using a slow motor it still might work.


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## Denhaunt (Aug 18, 2006)

Is there any reason you couldn't just use silver cloth? It would be pretty easy to make it look real if it was spinning and you could even add rust or blood. I would imagine that centrifugal force would keep it looking "saw-like".


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## deathstaste (Apr 20, 2007)

*just use*

Just use a real blade they deserve cut if they want to touch your props hahah
just kidding if this is for a startle scare and you are going to have a real saw for sound just use plywood disk for the blade skip the spinning and paint your blurred teeth on add a strobe and they wont be looking to see if its real or spinning "of course its spinning can't you here it" power of the mind


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## CB_Christmas (Aug 12, 2009)

possibily a large sheet of craft foam (the thinn stuff you get at craftstores) ? mabe even spray it with a slight dusting of silver spraypaint.... if you glued two sheets together, it could work. It is afterall what they make those fans for little kids from. I always stuck my fingers into the fans and it never hurt... just an idea....


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## Devils Chariot (May 23, 2007)

I have seen saw blades in pro haunt that are just a wooden circle with a saw blade painted on a black background. you could use a round disc, wood, plastic, whatevs, paint it silver, lay a real sawblade on it as a mask and then spray black around it. Pull away the blade and wah lah! perfect blade shape on a non cutting circle.


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## billman (May 3, 2006)

I was watching the special features on the dvd "30 days of night". For the tractor saw blades they said they used Soft Foam. Which I guess is Soft Polyurethane Foam.


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