Flywheels achieving linear motion

[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...

[Bill Beatty]

Our company has been designing and building flywheel driven punching and shearing machines for more than 85 years. To produce a good punched hole you must have a die opposite the punch on the other side of the material. The force necessary to punch mild (C1020) steel is approximately 50,000 lbs per square inch of sheared area. Therefore to punch a 2 inch diameter hole through .125 thick steel will take 2 x 3.14 x .125 x 50,000 lbs. of force. This is the force in a blanking operation. Mild steel will fracture after approximately 33% break through. The energy to produce this hole will be the force X .125/3.

Hope this helps.

Mr. Bill

[KenWittlief]

Originally Posted by mechanicalbrain

First and foremost I'm doing a project to show the given force in centripetal motion...(

Im not sure the system you have been describing demonstrates the force in centripetal motion

we have been talking about converting the inertia in a flywheel into a linear motion

a good demonstration of centripetal motion is something we use to do on those little merry-go-round things they USE to put in playgrounds. You get about 8 people to hang off the edge, pushing their behinds out as far as possible. Then one person spins the ride around as fast as he can, then jumps onboard.

Now the fun part: everyone pulls themselves towards the center. You would not believe how fast the thing starts spinning, and how hard it is to hang on if you are the last person hanging onto the outer part of the railings.

They dont put these in playgrounds anymore (I wonder why?!)

[DonRotolo]

Originally Posted by mechanicalbrain

I need a little help with an idea of mine. I want to take a flywheel (10 pound disk with 10" diameter) and apply all of its stored energy into a single linear movement of a rod. ..... I really want to put quite a bit of force into a single thrust, and I really need to be able to spin this up to full potential fairly quickly.

Two issues here:

First, spinning it up quickly: The stronger the motor, the faster it spins up. Remember there's a maximum speed for your disk, maybe 10 or 20,000 RPM. Build a safety cage just in case it does blow up...

Second, extracting the energy: Some kind of a clutch. You need to move your rod ('punch') only 1/4"

A magnetic clutch (like used for a car's air conditioning compressor) will allow far too much slippage, even though it can transmit 7 or 8 Horsepower, not as a shock load.

Trying to mesh gears will only break the gears. Again, shock load it far too high.

How about how big punch presses do it? They take the flywheel energy and gear it down a zillion times, and the 'punch' rod moves only 1/4" every five to 10 seconds. When you're ready to extract the energy, just put a 1/8" piece of metal between the punch and die and WHAM (or more like Crrrunch). Need very strong gears though - wide teeth at the slow speeds, can be expen$ive. Belts and pulleys at the fast speeds should be OK, since you are trading torque for speed.

Oh, to make the demo really cool, you can set the "full" speed of the flywheel to some point where the energy extracted is nearly 100%, so the disk almost comes to a complete halt while punching the hole... Very dramatic.

Good luck

Don

[greencactus3]

Originally Posted by Don Rotolo

Oh, to make the demo really cool, you can set the "full" speed of the flywheel to some point where the energy extracted is nearly 100%, so the disk almost comes to a complete halt while punching the hole... Very dramatic.

and very painful for those last few gears.

[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

[Jimbo5051]

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

Very good Idea I think that it would be feasible. But I do think you should gear it up to 350 rpm.