Flywheels achieving linear motion

[mechanicalbrain]

Thanks both. yeah I meant a disk with most mass on the outside. Thats an interesting idea about turning a flywheel to transfer to a electromagnet though I wonder if I guess it would work better then an electromagnet powered directly from a battery since the potential power can possibly be greater then that of the battery alone if I'm efficient. Yeah as to the machine press I'm not surprised, if you do the mathematics you realize flywheels can store massive amounts of energy. Actually the centripetal force on it is so great that they can explode if not balanced right (happens in the racing cars sometimes ) I'm looking at carbon composite but I'm also looking at using a medium power motor to power it, hopefully I won't have to worry about it. If I were to use electromagnets would I want to repel the rod or attract it? I'm kind of unsure on how that part would work, this is starting to sound like a rail gun.

[dlavery]

What is the stroke length of the rod motion you are trying to achieve (as an absolute length, and a percentage of the flywheel diameter)? Depending upon the desired output, there are a few neat little examples that I may be able to point you toward.

-dave

[gniticxe]

If dlavery has some examples for you, I'd go with them. But from what you said about the electromagnet, I don't think that I was clear in explaining the idea.

A battery is connected to the flywheel via a commutated shaft and brushes. Once the disc is up to speed, a switch is thrown to allow power to flow from the battery, through the commutator, and through an electromagnet. The magnetic field then pulls a ferromagnetic rod out past the outside of the disc. The rod you want to transfer the energy to is positioned so that the ferromagnetic rod will impact it.

Because of the centripetal force you spoke of, a spring will need to be attached to the disc and the rod to prevent it from extending prematurely.

Be careful in using this especially if you're turning it at speeds where the stress on the materials is close to their yield strength! Is your “medium size” motor a hobby or industrial “medium” ie 0.25hp or 100hp?

[Elgin Clock]

Hmm....

I think I know what you mean. maybe.

Would a modified version of a Geneva Wheel work?

I could be way off base in this I know, if I am, I'm sorry.

[Rickertsen2]

What is this device intended to do? Could you give us some more specifics?

[sciguy125]

This is sort of along the same lines as gniticxe's idea, but what about making the disk with teeth, something like a saw blade. Then, you push the rod toward the disk and it catches on the teeth.

Or, if your rod has relatively low inertia (and friction), you could use a friction disk to connect the flywheel to your rod assembly. Same idea as the clutch on a car, but with a thrusting rod of death.

[mechanicalbrain]

What I want to do is take a 2' bar and move it 1' forward with a ton of force. Yeah I'm looking at using a motor with roughly 100 rpm. My goal it to be able to puncture 1/10" to 1/8" steel. Right now its part of science fair project for centripetal motion but I also am doing this to really learn about flywheels... oh and eventually im going to apply it to a Battlebot

[Rickertsen2]

Originally Posted by mechanicalbrain

What I want to do is take a 2' bar and move it 1' forward with a ton of force. Yeah I'm looking at using a motor with roughly 100 rpm. My goal it to be able to puncture 1/10" to 1/8" steel. Right now its part of science fair project for centripetal motion but I also am doing this to really learn about flywheels... oh and eventually im going to apply it to a Battlebot

Maybie you could have the flywheel coupled to a rack and pinion via a clutch of some sort. It seems to me that somewhere i have seen some electric clutches.

[greencactus3]

Originally Posted by mechanicalbrain

What I want to do is take a 2' bar and move it 1' forward with a ton of force. Yeah I'm looking at using a motor with roughly 100 rpm. My goal it to be able to puncture 1/10" to 1/8" steel. Right now its part of science fair project for centripetal motion but I also am doing this to really learn about flywheels... oh and eventually im going to apply it to a Battlebot

100rpm isnt enough info. my cellphone vibration motor can be geared down to 100 rpm and my truck can also run its wheels at 100rpm.
and 2 feet bar to move it 1 foot?
the lighter the "ram", the more speed it will gain. but well. less mass.
will it just be a bar? or sharpened?
andas for going into battlebots. i would just use the flywheel itself as the weapon rather than add extra stuff which will be less efficient.

nother idea... with not exactly a disk but maybe a disk with large "bars" coming out as the flywheel.. and then somthing moves the "ram" into contact with the flywheel bars. so the bars crash into the back of the ram and it flies forwards. the cool thing about this would be multiple shots.

or just friction on the edge of the flywheel touching the ram. i had a foam dartgun that worked on this priciple a long time ago. although it had 2 flywheels. on on each side of the dart.

[KenWittlief]

you need to start working out the physics equations for this: Force, energy, power...

if you want to puncture 1/8" steel the rod only needs to move about 1/4", right? The idea you are grasping at is getting all the energy from the flywheel into the 1/4" movement of the punch

work out the physics: a 12" movement with one ton of force the whole distance takes 48 times the energy as a 1/4" movement with one ton of force.

[Rickertsen2]

Originally Posted by greencactus3

100rpm isnt enough info. my cellphone vibration motor can be geared down to 100 rpm and my truck can also run its wheels at 100rpm.

Why is 100 rpm not enough? depending on the design of the flywheel, 100rpm could be more than enough. How much energy would be contained in a planet spinning 100rpm!!!!!

[Andrew Blair]

Ah, I've got an idea! You could just use the HotWheels priciple. Have a spinning flywheel with some sort of grippy surface on it, even knurled slightly. Then have it spin a bit below 2" above a slide table. Then just slide the bar into it! Along the table. However, unless you like blood, you will want some sort of very strong stop behind the bar to prevent it from going AWOL.

[Gary Dillard]

Hmmmm.... I see all the previous posts here were before kickoff.

Dave Lavery offered that he has some ideas.

Chef Bill's company has been doing this for years.

Too bad the only application for this (achieving linear motion from a flywheel) is to punch holes

[greencactus3]

Originally Posted by Rickertsen2

Why is 100 rpm not enough? depending on the design of the flywheel, 100rpm could be more than enough. How much energy would be contained in a planet spinning 100rpm!!!!!

i never said its not enough revs. please reread my post. it says not enough info on the motor he wants to use.
that hotwheels principle is what i was attempting to explain too.

KenWittlief has a good point. other than the whole coolness of a rod flying 30feet to go through a sheet of metal, why do you need it to move so much?
and how about having a spike on the flywheel itslef and move that flywheel closer to the sheetmetal. and then itll more rip the sheet than just puncture (well not necessarily i know)

[mechanicalbrain]

First and foremost I'm doing a project to show the given force in centripetal motion, I wanted to develop this whole concept as a side project for future use, yes I do have reasons for wanting it to work this way. I think I have some general ideas for what I should look at doing and I have some ideas to play with.
So far my biggest worry is that to take the amount of force stored in a flywheel and transfer all at once would shred whatever I used...