Just might, I really don't know enough about magnetics’ to say.

After I’m done experimenting, I my have enough time in the next lifetime, to build something.

Carl

MeThinks the scotch yoke idea is getting a little traction.

As far as sizing of components is concerned, I have no clue.
The concept, as drawn, has a………

2.5 stroke
1 inch dia core
3” dia X 2”h coils

As to wire size, and number of turns, still no clue. Must be some math somewhere, that can figure this all out.

Hate to build it, and find out after I choked it with a leather strap, that it didn’t have the power to push a canoe downwind.

Carl

Carl, thanks for the reply
Here's my point. Sounds good, don't work. You are correct that speed needs to increase by 2x to get 1+ speed. The motor, no matter which torque transfer you use, will not develop enough HP to make a difference. I wish it would, I'd use it! Please take a look at Doc Peter's posts, or his video, you might see why you might be on the wrong track. Like I said the transverse piston is the way to go. Sorry I can't remember the web site. Even that, which will give you more torque, it won't be enough. Now if the Lindemann attaction motor could be modified........
Dan

Carl,

If you are interested in the Scotch Yoke setup, I'd recommend posting a question to David here:
The Bourke Engine

An optimum geometry of the Scotch Yoke setup has been figured out by Bourke, who simply had the best Scotch Yoke setup, ever. By geometry, I don't mean the concept in general, I'm talking about the ratios of relationships of the parts between each other.

I understand I don't know what I don't know so there could be some of Bourke's engineering that might apply to his engine that might not necessarily apply to the solenoids....however, David would be the best to kick those ideas around. He has probably the best blueprints and maybe the only ones...for this as he actually has a Bourke in his possession. They are for the engine and the Scotch Yoke setup isn't unique to Bourke but David offers a great resource and I'd recommend checking out his site thoroughly to get a deep feel for the whole concept.

If anyone else wants to kick around ideas about the mechanical engineering part of the Scotch Yoke...might be best in this thread:
The Bourke Engine

I'll start a separate thread on the cam engine so it can have a life of its own as well...because when and if it does, anything useful that can be applied by anyone with the wherewithall to do it can of course bring it back here in the application of an attraction motor.

Many people won't be building either of these at home but there are many gifted engineers here that could build either of these in their sleep from the incredible work I've seen....and a CNC built from scratch!!!??

For further discussion on the cam drive engine concept, please see this thread:
Revetec Cam-Drive Engine

I'm with Peter on this one because I anticipate few obstacles that would have to be solved.

1. One shouldn't use two solenoids per yoke because one would really want to use keeper in order to minimize stray flux and thus significantly reduce losses.

2. Airgap between yoke and solenoid should be as tight as possible to reduce magnetic losses through air. With rotary design it's a question of precise machining. With solenoid design it's a question of choosing the appropriate durable friction reduction material while at the same time reducing gap as much as possible. Those are two opposing requirements.

3. Again you would have to convert linear motion into rotary and introduce more parts, more friction and thus more losses.



To be honest I found solenoid design to be too demanding for average home hobbyist. On the other hand Peter's design if done properly is also too demanding for home hobbyists.

Lighty,

I appreciate what you are saying. These points are obvious and givens.

Anyone contributing to this forum will have studied Peters DVD.
What is contained therein is also a given.

The motor I build for marine use will be an attraction motor, with CEMF suppression, energy recovery, keepers…..etc.
Maybe I’ll just build a great big geesly trolling motor.
Rotary attraction would probably work fine.
But….
I like the look and feel of the quaint scotch yoke solenoid type.(reminiscent of it’s steam grandfather)

You may not have noticed but the SYS (ScotchYokeSolenoid) it a very open design.
Once you have the crank and yoke set up, you can mount all manner of coils, cores, and keepers on it. (good test platform, very accessible. The con rod can be lengthened easily, to mount more stuff)


As far as the home builder is concerned, I think Jetijs has set the bar.
I hope you are not implying that a build shouldn’t be attempted, if it can’t be built with a hammer, saw, and a bicycle wheel.

Nothing burns more fuel than power boats.
If I don’t build something efficient, I’m going the have to start rowing.


Carl
Motor.jpg
Always check the pretty picture

@hh1341

No, of course I'm not suggesting that it shouldn't be attempted. I'm just pointing out the obvious obstacles that would have to be solved before design would work even remotely efficient on the bigger scale. Some obstacles like the lack of keeper could be solved with the outer coil having a full keeper and the inner one with having at least partially closed keeper. The friction obstacle could be (at least theoretically) solved with extremely precise and thin layer of teflon inside solenoid or better yet with thin layer of teflon inside solenoid and teflonised (I don't know the correct English term) yoke. Of course that would add to the gap between solenoid and yoke but with the proper selection of yoke material and keepers on solenoids that could be reduced somewhat (theoretically).

So, I'm not saying that it's not doable but I personally don't see the advantage of adding several problems to be solved in addition to the ones introduced in Peter's design. Also, Jetijs is hardly a home hobbyist no matter what he says- his experience and accessibility to machining tools are beyond scope of most of the people on this forum (not all though).

Anyway- I will contribute with advice if I have something relevant to say. Good luck.

Lighty,

Your observations are appreciated, keep them coming.

I have the keeper, friction, and close core to coil tolerance, covered.

It’s component size that has me stalled. Don’t have a clue what size to make parts, including wire size and number of turns, as well as core/piston size.

Might just have to guess.

Carl

Power measuring is essential when estimating the COP, and I'm thinking how to do it easier. Well the basic idea goes like this.
Maybe I'm simplifing too much, ha?!

Attached Images

power.jpg (100.0 KB, 32 views)

H1341;
If you can standard-size any of the components on your device please let all of us know. One of the things I have learned on this thread, is that there is no standard. Each motor, unless it is produced by a company, will be subject to the parameters given by the creator, if not there will be sacrifices in the design. I wish you well in your experiments, but you gotta remember, they are your experiments. There is a wealth of information on this thread, but you need to use that information to your own advantage. When I first started learning about alternative energy, specifically a motor to drive a bicycle, I thought I would find a design that I could put together and then just drive! After a year of research, I found this thread, and found I knew nothing about motors. Jetjis, Peter,, Lighty, Elias , were light years ahead of me. Dang-it. At least the motor I was trying to design. Watch out for designs delegated to the dust-bins of history.
Dan

Ok, I finally got the spring scales, they seem axactly like Peter used in his dvd. A friend helped me with the measurements. While he loaded the wheel, I monitored the RPM's, volts and amps. Amp meter was put before the insulating diode, so that it showed only what the motor actually consumed and not what the power supply was showing. Also the voltmeter was attached across the capacitor. It always showed about 1V less voltage than the power supply voltage. I did numerous tests with two different input voltages. All the tests showed that the more I load the wheel, the better efficiency I get, but the efficiency is still too low. For example, here is one set of the test measurements:

Input voltage - 11.42V
Input current - 2.45A
RPM's - 2655
Scale1 deflection - 100 grams
Scale2 deflection - 10 grams

So the input power is 27.979 watts or 0.0375 HP.
The wheel circumference is 0.5 feet, so at 2655 RPM's there are 22.125 feet per second.
If I sum up both scale readings, I get 110 grams. If 1 gram is 0.00220462262 pounds, then 110 grams will be 0.242508 Lbs
To get the foot pounds per second, I must multiply the pounds with the feets per second. That would be 0.242508x22.125=5.3655 foot pounds per second.
Now, if we divide the foot pounds per second by 550, we get the output HP.
So 5.3655/550=0.009755HP
This means that the efficiency is HP(out)/HP(in)x100 or 0.009755/0.0375x100=26.01%

I got similar results with all the measured values. So what could be wrong? Are there a mistake in my calculations or measurements? Or could the problem be somewhere else? How could I find the problem?

Jetijs,

Congratulations on finally getting all of the parts together to make your own dynamometer! You are now in an excellent position to start testing you experimental motor.

From what you said in this post, there are still a few things you don't understand about the process, so I'd like to help you through it.

The first thing is, I am unclear exactly WHERE you have placed your input ammeter. Could you please post a complete schematic of your circuit and show me where the ammeter is placed?

Second thing is the method of reading the scales. The proper reading of the scales is the DIFFERENCE between the scales, not the sum. Also, to get the best results, the pressure applied by lifting the scales should be backed off until the low reading scale reads ZERO. That way, the high reading scale is the full deflection. This is the method I demonstrate on my DVD.

Third thing is that you and Lighty have already determined the best conditions for running your motor, where the recovered energy is the highest. This is the speed we want to run the motor UNDER LOAD on the dynamometer.

Fourth thing is under these conditions, we only want to monitor the power (current and voltage) actually coming from the supply to keep the system going. We don't care how much the motor actually uses, which we KNOW is COP<1. All we care about is how much WE have to put in to keep the process going. THIS is what can be COP>1!!!!!

If your motor can produce 60% mechanical efficiency AND recover 60% of its electricity and return it to the capacitor in the front, then we should be able to measure the motor's efficiency at COP=1.33 because the motor will be able to produce 60 units of mechanical energy for every 40 units of REPLACEMENT electricity we need to supply!

Let's just take this one step at a time, and see how far we get.

Great work!!!

Peter

Peter,
http://www.emuprim.lv/bildez/images/..._1/shema12.GIF
this is the circuit I used with the amp meter in it. It shows the current that the motor is actually using. If I connected the ampmeter between the insulating diode and power supply negative terminal, it would show less current (only the part that is taken from power supply). When I made these tests, I used the same commutator wheel as before, it has one 65 degree gap on each side (180 degree apart). There was no LED pulsing, so the energy recoverey was at about 30-35%
I also made changes in my calculations so that only the difference in both scale readings is used to calculate the torque, this gave even worse results with efficiencies around 20%. Test results where there was a deflection only in one of the scales, remained the same. I used a rather narrow leather strap, about 4mm wide (did not have anything better). Using this strap I could load the motor with up to 25 grams till the other scale also started to deflect.

Anyway, the calculated efficiencies are so low, that either I did a mistake in measurements/calculations, or there is something wrong with the motor.

Thank you!

@Jetijs

What ampermeter do you use for measurement? I mean for anything in kHz range with any kind of distortions you should really forget about DMMs because even capacitor won't filter out all the spikes and distortions. If you don't already do it you should measure RMS current with oscilloscope but I guess you're already doing it that way so I'm just reminding you of that fact.


P.S.
I just checked your schematic and you really ought to place your ampermeter directly on battery + and measure total current going into the system.

Hi lighty
I am using those cheap multimeters that can measure up to 10A of current. I tried to get a shunt out from a cheap meter, but there was just a thick copper wire used as a shunt with no specs on it, so I can't use that. I also searched for some shunts in local electronics shops, but they do not have anything around, I can just order some from them, but they are charging about 50$ a piece for a 5A, 60mV shunt, like this:

So I really have not pursued the shunt measuring idea
What about these shunts:
20A 75mV DC Current Shunt Good4 Digital Analog meter - eBay (item 350072790126 end time Jun-29-08 09:16:37 PDT)
do you think they would be suitable? If yes, I will buy them now!
Of course, I am not an expert, but do you really think, that all those spikes would make an error this big on my cheap amp meters? The power supply current reading is about 30% less than the amp meter reading, but that, of course, is because of the recovery. I mean, to get at least 60% efficiency in my calculations, it would require a current draw of about 1A (instead of 2.45) for the same other readings. Could those spikes make an error this big on the meter?
Maybe the problem is somewhere else
Thank you!

It really depends on the ampermeter and on the ammount of transients getting to it that it's capable of registering. As for those shunts- yes they would do fine if your oscilloscope is capable of measuring signals with resolution of at least 3.75mV or better (75mV/20A = 3.75mV/A).

I'm not saying that ampermeter is making erroneous readings but rather that you should eliminate that possibility in order not to start making adjustments on the motor that are possibly not needed. Consider it a precaution.

Hi All,

I am so glad I found a link to this forum. I call this thread the Zen of R & D.

I am in China and not able to get the Attraction Motor DVD, but I have some of Peter's books in my library at home.

For those of you who are interested in a solenoid piston type motor, go to this link:

Green Steam Engine Home Page

I refer to it as the "Lean, Mean, Green Machine". Perhaps Aaron can start a new thread for discussion. I feel this is the one to build.

Tishatang