Hello! I am hoping to safely spin a 4' 1x4 piece of (soft) wood very rapidly. Or some material of similar size.
Does anyone have any advice on what DC motor could easily handle this? Or will I have to use an Ac motor? And what I am looking for in regards to controlling it with arduino (some kind of robust transistor?).
My goal is to make a larger version of this for installations:
So maybe you will have some better ideas haha
I'd appreciate any help/guidance, thank you!!
Start with putting a screen around it to catch flying parts.
Then make sure your piece of wood is perfectly balanced.
Then get a motor that can do the rpms you need, and provide the power needed to spin that kind of wood.
Don't forget to add an encoder of sorts - so you know where you are in the rotation. Otherwise you'll never be able to get your timing right.
Hey thanks, especially the encoder tip!
Actually I am asking in large part to get an idea of what rpm/voltage motor I should be looking at, and if I would have to look into higher power AC motors for rotating this size of an object at a fast enough speed to accomplish effect.
You can get very powerful DC motors.
Control units for high-power motors (whether AC or DC) are going to be expensive.
...R
ndivuyo:
Actually I am asking in large part to get an idea of what rpm/voltage motor I should be looking at
don't the videos and other tutorials/writeups about these projects (it's been done many times) give you an idea of the rpm you need?
Next you need to know the torque required to spin whatever object you want to that speed. That torque is related to the air resistance encountered plus other resistances - while you can at least in theory calculate this, it's going to be a bit of experimenting to get a powerful enough motor. Look at what others used, copy that.
DC is much easier to control than AC (though for this project you don't really need to control the speed, as long as it's fast enough and you know how fast it spins). 12-24V DC is much safer than 240V AC. So unless you have a very good reason to not use a 12/24V DC motor, that's what you should aim for.
Anyway, for any useful motor advice: get numbers. What rpm do you want? What torque do you need?
And your motor mounting system has to handle the exact same torque, in the opposite direction, as the propeller. So the thing must be really heavy or fastened to the ground with anchors.
Also your motor will be generating a large amount of heat that must be dissipated.
Paul
I think that the timing is based on the hall sensor and the stationary magnet.
A motor that can spin at a bit over 1000 RPM gives 18 frames per second.
You might be able to get away with less if you are doing less animation and simply displaying text.
4' home made object spinning 1000rpm is not something I want to be near! 
Edit: Before you tackle your large scale POV project, make a small one.
To form a visible message, you need near 24 frames per seconds (a little less might be enough, depending on your need of quality).
So you want 24 frames per seconds, each frame is a round.
24 rounds x 60 seconds = 1440 rounds per minute
A DC motor around 1440 rpm will do the job.
Don't forget the take security precautions!
I see plenty of AC motors that run at 1725 rpm. Just change the frame timing to match.
Paul
Wow thank you all so much for the advice!
Yes I know it is a dangerous project, and I definitely will be making a small scale version first ! (already ordered the parts for that). Yes once I get the right motor I will definitely figure how to secure it very safely to the wood and floor.
I am pretty much brand new to understanding motors (only played around with some lower voltage dc motors before), so that's why I was asking more. I will take the info you gave me and see if I can find the right motor, and hopefully figure out which hardware I can use the control it.
Thanks again for all the tips!