My first Newman Motor replication

[Careica]

Hello!

Now I have done my first replication about this machine. Its are not perfect, because I just wanted to know, that it can even run. Now I know, and can make it even better and better.

But the main thing is, that when I first time started it up, the whole work bench started to shake and 2kg heavy PC monitor shaked too. I feeled force coming out of that motor. I was wondered, I run this machine on dead 12V battery, which was containing 8V and it did that much force! Very interesting machine!

But question to Stephan: If I want to see OU on this machine, do I need to do commutator which make much of sparking and Back EMF? I tought I could use reed swiches to make timing, but then it will not work as OU machine. What exactly commutator I need? I was think that I will make it from cooper, will it work? And what caind of input current I'm looking for? 10-20 milliA?

Here is video about my first motor:http://uk.youtube.com/watch?v=nVgiJShyyhM

[Careica]

Hello!

Now I have done my first replication about this machine. Its are not perfect, because I just wanted to know, that it can even run. Now I know, and can make it even better and better.

But the main thing is, that when I first time started it up, the whole work bench started to shake and 2kg heavy PC monitor shaked too. I feeled force coming out of that motor. I was wondered, I run this machine on dead 12V battery, which was containing 8V and it did that much force! Very interesting machine!

But question to Stephan: If I want to see OU on this machine, do I need to do commutator which make much of sparking and Back EMF? I tought I could use reed swiches to make timing, but then it will not work as OU machine. What exactly commutator I need? I was think that I will make it from cooper, will it work? And what caind of input current I'm looking for? 10-20 milliA?

Here is video about my first motor:http://uk.youtube.com/watch?v=nVgiJShyyhM

And also question about cooper wire. I have woundet 0,65mm wire on it. And when I measured Ohms, there was only 1,1 ohms. Is it too small amount if I want get this motor OU?

[hartiberlin]

Hi Careica,
well done,
yes, but you need to do it this way.

If you want to stay at 12 Volts supply voltage,
which is a bit low,
try to wind much more wire onto the coil, so you have at least 200 to 250 ohms
DC ohmical resistance from the coil.
This way at 12 Volts it draws, if the coil is connected without commutator
only around 50 mA.
This is a value you should not go over.
Then if the commutator is connected and the machine
runs, the input current draw will go down to about 2 to 5 mA only
and also have many negative current spikes which recharge all the time
your battery, so your battery does not see much of a load,
but is in effect recharged by these negative current spikes.


Build the commutator from multiple graphite-copper segments all put in series,
so that you break and make contact not just with 1 graphite-copper segment,
but with many in series.
This way you will get a faster di/dt current break and thus more induction voltage
and thus better back current spikes.

You can put several commutator discs with the copper segments and brushes onto the axis
in parallel and wire them then in series, so the current has to go through all
the segments and brushes and when this rotates on the axis the on/off and off/on
switching times will be reduced, cause you have several switches in series.

Be sure to use copper segments and graphite brushes,
as this is still the best mnaterial for the sparks at the commutator,
which are very important to get these negative current spikes,
which recharges your batteries.

The objective is, not to have a fast motor,
but to produce enough back current spikes, so your batteries
never need to be recharged somewhere else
and have some free mechanical power also from the rotating
magnet.
The Newman machine can be optimized for motor output or
for generator output, so better first go for generator output,
as you need to produce enough back current spikes to keep
your batteries recharged.
So better let it run slower but it will produce then more back current
spikes, when you tune and setup the commutator
on the shaft ( phase angle firing versus rotor position).
Be sure to find the right position on the shaft for the commutator,
so it produces enough back current spikes,
which is not always the position where the motor runs
fastest, but at a slightly other degree.
Just check with your scope and a shunt resistor to see the input current, 
in which position of the commutator versus magnet rotor
the back current pulses have the biggest amplitude.

Hope this helps.

Regards, Stefan.

[Careica]

Hi Careica,
well done,
yes, but you need to do it this way.

If you want to stay at 12 Volts supply voltage,
which is a bit low,
try to wind much more wire onto the coil, so you have at least 200 to 250 ohms
DC ohmical resistance from the coil.
This way at 12 Volts it draws, if the coil is connected without commutator
only around 50 mA.
This is a value you should not go over.
Then if the commutator is connected and the machine
runs, the input current draw will go down to about 2 to 5 mA only
and also have many negative current spikes which recharge all the time
your battery, so your battery does not see much of a load,
but is in effect recharged by these negative current spikes.


Build the commutator from multiple graphite-copper segments all put in series,
so that you break and make contact not just with 1 graphite-copper segment,
but with many in series.
This way you will get a faster di/dt current break and thus more induction voltage
and thus better back current spikes.

You can put several commutator discs with the copper segments and brushes onto the axis
in parallel and wire them then in series, so the current has to go through all
the segments and brushes and when this rotates on the axis the on/off and off/on
switching times will be reduced, cause you have several switches in series.

Be sure to use copper segments and graphite brushes,
as this is still the best mnaterial for the sparks at the commutator,
which are very important to get these negative current spikes,
which recharges your batteries.

The objective is, not to have a fast motor,
but to produce enough back current spikes, so your batteries
never need to be recharged somewhere else
and have some free mechanical power also from the rotating
magnet.
The Newman machine can be optimized for motor output or
for generator output, so better first go for generator output,
as you need to produce enough back current spikes to keep
your batteries recharged.
So better let it run slower but it will produce then more back current
spikes, when you tune and setup the commutator
on the shaft ( phase angle firing versus rotor position).
Be sure to find the right position on the shaft for the commutator,
so it produces enough back current spikes,
which is not always the position where the motor runs
fastest, but at a slightly other degree.
Just check with your scope and a shunt resistor to see the input current, 
in which position of the commutator versus magnet rotor
the back current pulses have the biggest amplitude.

Hope this helps.

Regards, Stefan.

Thank you much about this useful data!

I have counted that if I use 0,2 mm wire @ 360 meters it will give 197,64 ohms. Is it enought?

I didn't understand directly about commutator whit multiple cooper-graphite segments. Can you send me some photo about that commutator? And where I could get graphite brushes?

Also what I noticed out, that I don't use any caind of bearings, I maybe should find some to smaller friction right?

Also, if you have saw my video, you see how long is that PVC tube, maybe it is too hight? Maybe I need make it smaller? What you think about that?

Thank you!

[hartiberlin]

Well, yes, your 2 partial coils
are a bit too far away from the magnet.
Also get a second magnet and stick it onto the side of the axis,
so you get a good running axis without much imbalance as you now have.

The closer the coil is to the magnet the better.

Yes, about 200 Ohm for the coil at 12 Volts should be okay.

You can first use one commutator from an old DC motor.
It has copper segments and graphite brushes.

Just disassemble an old toy DC motor and pull out the commutator and the graphite brushes
and fix the copper segment ring onto your axis and have the graphite brush
touch it from outside as you do it now with your wire onto your axis.

Be sure to have needle sized tips of the graphite brush,
so it makes only a loose contact and will not shortout the copper segments.
You need to break the current also several times during one revolution, so
the current is pulsed into the motor.
This then gives several back current spikes per revolution
and these recharge your battery.

Regards, Stefan.