Building a self looping "SMOT"

[tinman]

I'm not lying either, then why are you still a mile high?

Michael
I found that in 99% of cases,MH has been correct,along with TK.
What im saying is ,put forth your case,but keep your argument civil.Name calling or quick punt's at other members,only results in a thread turning to trash.
MH has earned respect in the time he has been here,and although i may not agree with him on all thing's,dosnt give me the right to badger him. In regards to this thread,i will probably find he is right again,but if there is a chance that what i think is correct,then i keep on looking.

This is what you must do. If you believe you are right,then continue with your work,but let the argument remain civil.
I myself believe it can be done-i dont have a CANT DO attitude-unless it is completly obvious that it wont work.

[MileHigh]

Tinman:

There is nothing that you can do about the friction losses except to reduce them as much as possible but they will still be there.  Is that your strategy to decrease the energy losses?  I still can't see how you can increase the energy when you factor in all three components as the true definition for the energy of the ball, KE + GPE + MPE.  One of the problems with the Billmehess clip is he just looks at the GPE.

Your reference to post #393 suggests to me that you want to change the way the downward part of the ramp is formed to preserve as much energy as possible.  Here is where I simplify and just think in terms of energy.  The ball has it's three energy components let's say at point A at the top of the ramp.   Lets say point B is three inches away from that at the bottom of the ramp.  So there is an energy change there for the magnetic potential energy and the gravitational potential energy.  That will determine what kinetic energy the ball has at point B.   In other words, it's "predetermined" how fast the ball will be moving at point B, and it's independent of the form of the ramp.  The form of the ramp is within reason, it can't be a straight drop down.  It's like watching a roller coaster but you also throw magnets into the mix.

I believe that the ball at the start position only has potential energy(due to the magnetic field),and only gains kinetic energy once it starts moving. The ball,once leaving the smot ramp ,has both kinetic and potential energy. The gravity potential is obviously greater than the magnetic potential,or the ball wouldnt drop. Most of the energy in the ball is lost on the exit ramp,where it has to make a 90* change of direction. This is something that must be eliminated. This is the same flaw in all the smot devices i have seen.

That sounds just about perfect.  I would add that the ball also has GPE when it starts.  If you decide that the height where you release the ball is zero, then the ball has zero GPE at the start.  Note that when the ball finally falls down onto the second track, that full dropping distance is the total GPE that the ball has "absorbed."  You are trying to preserve that precious GPE by turning it into KE.  You need the KE to get you back up to where you started.  It's like juggling three "energy balls."

Here is the issue:  When you really get down to the nitty-gritty, no mater how good or unique or alternative-thinking your setup is, as the ball interchanges GPE, KE and MPE through time as it runs down the track, friction is always eating away at the KE and bleeding off some of your available energy and turning it into heat.  You can approach the limit and build it out of ceramics or some high tech composite material, and run it in a vacuum chamber, and you still can't remove all of the friction.

Anyway, you are well on your way and I hope that you have fun doing the build and doing the testing.

MileHigh

[MileHigh]

This makes me think of how to measure the speed of the ball.  Assume you don't use a camera and process video frames which is a hassle in itself.  Is there a system that anybody has come up with?  Perhaps it's already in the Arduino grab bag?

The first thing that comes to mind for me is an optical slot switch, connected an Arduino A/D converter, or perhaps a digital input, and some software.  There may be serious alignment issues with an optical slot switch, I am not sure.  Don't forget it's a ball and has a variable profile as you go off center.  Perhaps there are "smart" optical slot switches where the ball passes through a series of parallel IR beams and so the alignment issue is not a factor.

You could also do something like a guitar pickup.  It's also another op-amp project.  You take a relay coil and carefully remove the core.  Then you put a long and thin cylindrical magnet into the core.  You connect the relay coil to an op-amp configured as a comparitor.  Something very simple something like Conrad's circuit.  Then when the ball rolls past the relay coil the slight change in the permeability of the immediate surroundings will induce a voltage in the coil and trigger the comparitor.

So when the ball rolls past the sensor coil it should trigger the comparitor.  Obviously the faster the ball is moving the shorter the comparitor is triggered.  So you connect the comparitor output to an Arduino digital input, turn the crank, and the Arduino displays meters per second on the display.  You could easily use the hardware timer(s) built into the Arduino so that the software just has to read a count register, which makes life easier.  There is the issue of calibration, and probably still the issue of alignment, to be determined.  Even if it only made relative measurements, it would be a fun project.

It's a fun little challenge; how do you measure the speed of the ball in a cheap and reliable home-brew kid of way?

MileHigh

[LibreEnergia]

The ball has both kinetic and potential energy-the ball is moving,and gravity is acting apon it.
Force has direction associated to it,and a given force over time requires a given amount of energy.

What part dont you understand?.

The bit that I don't understand is why you would persist in displaying such basic errors of understanding when I have already pointed out that you should at least  be using the commonly accepted definitions when talking Newtonian mechanics.

The quantity force over time is known as impulse, not energy. 

A "given force over a given time" does not require a given amount of energy. It only results work done if it causes an object to move.

[tinman]

@MH
I was thinking the same thing,in regards to setting up a test exit ramp,and measureing how much the ball is slowed when makeing the 90* turn.By useing my HD camera,and having a 3 decimal point timer behind the ramp,i could calculate the speed loss of the ball after the turn. If the ball lost half it's speed,that would mean the ball lost half it's kinetic energy + friction losses.

I am also supprised that you cannot see the other action takeing place,that could be turned into an energy gain. At the moment with setups like the video i posted last,not useing this potential gain is resulting in two losses within the system. No extra work has to be done by the system to get this gain,and as far as the system go's-this will be a big gain.
The fact that you cant see it(or anyone else so far),gives me reason to press on. Could it no be possable that i see something others have not?

Like i said befor,i have never paid much attention to the smot device,until Chet asked me to have a look at this thread. Within the first couple of video's i watched,i saw the enegy gain possibility in the system-which removes two losses when applied.

What i would like,is for you to also look into the energy loss as the ball makes that 90* turn on the exit ramp.i already have a way to remove all that loss,but we need to know what% that loss is. This will give us an idea as to how much we will gain. Maybe TK(if he has the time) could look into this loss aswell.

I have just got back from our plastic factory here,and have all the material i need to build the ramp.I also just cleaned out the hobby store of all there PM's lol. I wont be useing an aluminum track,as we know that places drag on a moving magnet-which the ball becomes when in the smots magnetic field.

So now,off to start my test ramp,and try and get some speed reduction calculations on the ball.