# Halloween decorations and tricks - lights - sound.

#### Tonyr1084

Joined Sep 24, 2015
6,954
On an unrelated thread someone was asking about how to build some sort of airflow interrupter. Though I couldn't directly help, something he said made me think of something I'd like to try for Halloween. Take a tube and put a free rotating disk on a shaft in it. Blow air through the tube and allow the disk to rotate, much like Mick Dundee did when he was calling for Aborigines helpers. He used a flat stick on a string and swung it over his head and it produced a whirring sound. I've done the same thing and it's pretty cool. However, I don't want to sit outside in the shadows swinging a stick over my head. Rather, the airflow from the afore mentioned tube might be a pretty cool trick.

I also have a drip irrigation system in the wife's garden. Every fall I blow it down to winterize it. Quite by accident I discovered that when it's blowing down it hisses (expected), but as the air pressure drops off it starts to whistle like that of a falling bomb. Only with a couple dozen drip irrigators making the sound at the same time it sounded rather ghostly.

So what are you thinking of doing for Halloween? I know I have a new idea to mess with. Will let you know how it turns out.

#### killivolt

Joined Jan 10, 2010
829
On an unrelated thread someone was asking about how to build some sort of airflow interrupter. Though I couldn't directly help, something he said made me think of something I'd like to try for Halloween. Take a tube and put a free rotating disk on a shaft in it. Blow air through the tube and allow the disk to rotate, much like Mick Dundee did when he was calling for Aborigines helpers. He used a flat stick on a string and swung it over his head and it produced a whirring sound. I've done the same thing and it's pretty cool. However, I don't want to sit outside in the shadows swinging a stick over my head. Rather, the airflow from the afore mentioned tube might be a pretty cool trick.

I also have a drip irrigation system in the wife's garden. Every fall I blow it down to winterize it. Quite by accident I discovered that when it's blowing down it hisses (expected), but as the air pressure drops off it starts to whistle like that of a falling bomb. Only with a couple dozen drip irrigators making the sound at the same time it sounded rather ghostly.

So what are you thinking of doing for Halloween? I know I have a new idea to mess with. Will let you know how it turns out.
I was going to do this one year. I was going to put it into my flood light with motion detector to power it when it detected motion.

https://www.hauntedillinois.com/lightningflash.php

#### shortbus

Joined Sep 30, 2009
9,525
Blow air through the tube and allow the disk to rotate, much like Mick Dundee did when he was calling for Aborigines helpers. He used a flat stick on a string and swung it over his head and it produced a whirring sound.
That thing is called a "bull roarer" or "bull roar". How is a disc going to make the noise? In the bull roar it's the flat blade spinning on it's long axis that causes the vibrations. When I was a preteen you could buy them in the dime store, the blade was made of a dense pressed cardboard, like what we call MDF today.

#### Tonyr1084

Joined Sep 24, 2015
6,954
Well, I don't know that it would work. But I'm imagining a disk in a PVC tube. The disk on a shaft, balanced so that it doesn't favor any particular position. As air pushes through I'm hoping there might be a spinning effect, which will modulate air pressure, causing a roar of some sort. Depending on the size will probably vary the frequency.

Bull roarer. Interesting. Never knew that name before. Took a ruler, drilled a hole, tied a string and swung it over my head. Depending on which way it happened to spin it would either create positive lift or negative lift (tend to fly up or down).

Will have to experiment with this idea though. Will have to find out if it works or not. I'm hoping it will. The principal should be the same whether a flat stick or a flat disk. I may even try a flat disk on a shaft and see if it wants to spin in the same way the bull roarer does.

#### AlbertHall

Joined Jun 4, 2014
12,116

#### Tonyr1084

Joined Sep 24, 2015
6,954
@AlbertHall: motion detector controlling a small fan to push air through the tube. When someone approaches, it begins to growl. As they get closer it switches into a higher airflow making a higher and louder growl. Now, if I can figure a way to store up energy and then release it to make a really loud and ominous growl.

Maybe hide in the bushes with one of those air ring blasters and blast unsuspecting passers by with a mysterious blast of air. Ghosts? Phantasm's? Invisible goole's?

https://www.amazon.com/Airzooka-Air...hvlocphy=&hvtargid=pla-4584207577117914&psc=1

#### shortbus

Joined Sep 30, 2009
9,525
Bull roarer. Interesting. Never knew that name before. Took a ruler, drilled a hole, tied a string and swung it over my head. Depending on which way it happened to spin it would either create positive lift or negative lift (tend to fly up or down).
http://www.jonsbushcraft.com/bullroarer.htm Made one for the grandkid's and now daughter in law doesn't like me doing things with them. One of the twins walked into it when the other one was using it and had to get stitches. She won't even let me make them some "stilts" to use. Kids today are missing out on so much.

#### djsfantasi

Joined Apr 11, 2010
8,443
How much space do you have? A straightforward replication of a classic bullroarer might be possible. Hidden behind some bushes, you have a circular area protected by hardware cloth. Inside, connected to a powerful motor, you connect a bullroarer to the motor with a rigid “string”. When triggered, the motor spins the bullroarer behind the bushes.
A couple lap joints hold the hardware cloth cage in position, while the motor is mounted at the intersection. Some marine stays connect the bullroarer to the motor.

You can drive the motor directly, or use a controller to modify the speed using a μprocessor. The latter motor control may give you some sort of control of the sound.

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#### killivolt

Joined Jan 10, 2010
829
How much space do you have? A straightforward replication of a classic bullroarer might be possible. Hidden behind some bushes, you have a circular area protected by hardware cloth. Inside, connected to s powerful motor, you connect a bullroarer to the motor with a rigid “string”. When triggered, the motor spins the bullroarer behind the bushes?
A couple lap joints hold the hardware cloth cage in position, while the motor is mounted at the intersection. Some marine stays connect the bullroarer to the moyir.

You can drive the motor directly, or use a controller to modify the speed using a μprocessor. The latter motor control may give you some sort of control of the sound.
Ya, we would want someone coming in contact with it. Instant lawsuit.

kv

#### djsfantasi

Joined Apr 11, 2010
8,443
Ya, we would want someone coming in contact with it. Instant lawsuit.

kv
That’s why I said to enclose it in a hardware cloth cage. Hardware cloth is similar to aluminum screrning, except the squares are 1/2” square openunung. And it’s made out of s heavy gauge steel wire. The only way anyone could come in contact with i is if they where destroying it. Which makes a lawsuit unlikely

#### killivolt

Joined Jan 10, 2010
829
That’s why I said to enclose it in a hardware cloth cage. Hardware cloth is similar to aluminum screrning, except the squares are 1/2” square openunung. And it’s made out of s heavy gauge steel wire. The only way anyone could come in contact with i is if they where destroying it. Which makes a lawsuit unlikely
I knew you would know and was reading it's enclosure. I agreed with you, I was waiting for someone to suggest it but, was way to busy today to respond.

Good Job.

kv

#### shortbus

Joined Sep 30, 2009
9,525
So what are you thinking of doing for Halloween?
I know, how about a car horn blowing under water?

#### Tonyr1084

Joined Sep 24, 2015
6,954
@shortbus FUNNY DUDE! Actually, I have a few horns to try now that I'm back home. However, I've been busy fixing things that have gone unattended while I was away on job assignment.

Hang three bat houses, build a cover for the pond, sanitize the drinking water system (RO), fix the washing machine (IMPORTANT)! Having the house appraised, so there's a lot of projects I've started that need finishing; kitchen lighting for one - have two switches that control each one light. Would like both lights to be controlled simultaneously with three way switches at either end of the kitchen. HANG NEW LIGHTS! Fix the under cabinet lighting. Build shelves and drawers for my wife's built-in walk-in closet. Fix the smoke detector (that one should be at the top of the list for sure!) It's battery backed up with main power (main has failed again). Lots of things to get to. Shouldn't be sitting here in socks and shorts fooling around with the internet. But it's early still. Mountain time zone.

#### Tonyr1084

Joined Sep 24, 2015
6,954
Thanks. But I don't need a handyman. I'm my own handyman. I do plumbing, minor electrical, carpentry, cabinet making, built a Pavilion, installed a pond, done my own landscaping, sprinklers and drip irrigation - to name a few of my talents.

#### AlbertHall

Joined Jun 4, 2014
12,116
Thanks. But I don't need a handyman. I'm my own handyman. I do plumbing, minor electrical, carpentry, cabinet making, built a Pavilion, installed a pond, done my own landscaping, sprinklers and drip irrigation - to name a few of my talents.
How much do you charge?
I've got some jobs that need doing!

#### Tonyr1084

Joined Sep 24, 2015
6,954
@AlbertHall I'll do the job for free if you'll fly me and my wife there and back, pay our hotel and meals. If you have room at your place, we could stay there.

")

Latest kitchen cabinets I built from scratch:

#### shortbus

Joined Sep 30, 2009
9,525
I'm my own handyman.
Me too. When still working and working too many hours of overtime to do the things needed at home. I hired out 2 jobs a new roof and some cement work. Both guys were well respected in the area by people supposedly did excellent work. Both jobs could have been done better by monkeys. Still p!es me off every time I think about it.