Solenoids

[Bogstandard]

Chuck,

You are doing it the right way.
You are being an experimental engine builder.
Fixing it as you come across problems.

You can only get it near enough while building these little engines, it is the fine tuning afterwards that gets them spot on.

We have a saying for it in the UK.

It is 'suck it and see'.

John

 

[AllThumbs]

I notice on my sol. the face of the coil does a lot to attract iron. In other words, even when only a slight pull could be felt when the iron piston was entering the cylinder, the piston could be made to stick to the face of the coil. I was then thinking that a t shaped piston made to enter the cylinder with the "t" part made to almost contact the face of the coil at TDC may be the way to go. I did not incorperate this into my engine, but perhaps I should have.

E

 

[cfellows]

I notice on my sol. the face of the coil does a lot to attract iron. In other words, even when only a slight pull could be felt when the iron piston was entering the cylinder, the piston could be made to stick to the face of the coil. I was then thinking that a t shaped piston made to enter the cylinder with the "t" part made to almost contact the face of the coil at TDC may be the way to go. I did not incorperate this into my engine, but perhaps I should have.

My gut reaction, and this is far from scientific or even academic, is that the shape of the piston has little affect on the pull force. I think it has more to do with the mass and the way that the mass can conduct the magnetic lines of force as it gets closer to the coil. Given the shape of your cylinder and coil, my opinion, and it's just an opinion, is that a t-shaped piston would be of no advantage. Unfortunately (or fortunately if you like tinkering) the best way is to try both methods and see if it works better.

Chuck

 

[cfellows]

You are doing it the right way.
You are being an experimental engine builder.
Fixing it as you come across problems.

John, your point is well taken, and I've decided to do a sidebar here and make a test-bed engine that will let me change the stroke, the distance of the cylinder from the crankshaft, and other physical parameters as I think of them. There is very little documentation on the internet regarding the parameters of reciprocating engines that use electric coils and this looks like a good opportunity to add to that knowledge store.

While electric reciprocating engines will probably never be practical in replacing other engine types, it does afford a simple method for making model engines that simulate full size engine operation without the complexity of valves, ignition, fuel sources or external power sources such as compressors and boilers. In other words, if you want a small model engine that you can sit on your desk and looks and works like a full size engine, electric solenoid engines could be a good choice.

Chuck

 

[Bogstandard]

Chuck,
I like to try anything once, just for the sake of learning something new.

I am a grubby hands man, and absolutely hate electrics. It is a shame really, I used to service, in one of my previous lives, miniature coil winding machines. Never took any notice of what they did, I just made them work again. The wife used to work on the machines, winding coils for going into card readers in ATM machines.

So this post has got me very interested, not on the coil winding side, but the method of operation.
I am very lucky, I have contacts in all sorts of industries, so this Thursday, I should have a load of surplus solenoids being delivered, for me to play with. But that will be in the distant future, too much work is backing up now for me to play with things.
So what you are doing here will be the sum total of what I know about these fascinating engines.

Keep up the good work.

John

 

[cfellows]

Well, I experimented with the engine some tonight. I determined that the maximum pull my homemade coil exerted on the plunger was when the plunger was between 1/2 and 2/3 of the way in. It seems logical to me that the best efficiency would be gained by having the maximum pull ocurring at about mid stroke where you have the best mechanical advantage on the crank. All this means that I need to increase the distance between my solenoid and the crankshaft by about 3/4". Probably the best way to accomplish that is to increase the length of the vertical columns from 2 3/4" to 3 1/2". I could accomplish the same result by shortening the plunger but that would also shorten the range of the pull which I don't want.

Chuck

 

[cfellows]

Got my solenoid engine to a point where it runs. Started right up the first time. It runs OK on 12 volts, but runs a lot better on 18 volts. I'm going to try some other coil configurations to see if I can get the performance I want on 12 volts.

[ame=http://youtube.com/watch?v=3fBnqWlGc30]http://youtube.com/watch?v=3fBnqWlGc30[/ame]

 

[Bogstandard]

G-R-E-A-T

John

 

[rake60]

Looks Good Chuck!

Nice work!!!

Rick

 

[AllThumbs]

Beauty!

 

[Powder keg]

It even sounds like an engine) Good job!!!

Wes

 

[Powder keg]

Here is a thought on these Solenoid engines. A lot of them pull a plate to the end of the solenoid. This is where the magnetic pull would be strongest. You could then have an iron core in the center of your coil and I think this would make a stronger engine? Here are a couple examples of what I'm trying to say)
[ame]http://www.youtube.com/watch?v=1k9BXvGNOOA[/ame]

[ame]http://www.youtube.com/watch?v=zRQkYWpeMsY[/ame]

Wes

 

[zeusrekning]

The one in the first video is what Cedge brought by to show me today.

I'm going to model it up soon.
Tim

 

[Bogstandard]

I managed to get my claws on a few solenoids recently, and these looked the best of the bunch, the others were massive. They have 24 volt coils, but have very good pulling power at 12 volts.
Do you electric string lads think they will do for a future project, or should I go another route?

John

 

[AllThumbs]

Is there a current rating on them? I am sure they would be awsome for a solenoid engine application.

Eric

 

[rickharris]

Go for it - In the unlikely event of problems - ask again - It's so much easier to fix something that is in use rather than talk theory (which is so often wrong in practical terms anyway)

 

[cfellows]

I managed to get my claws on a few solenoids recently, and these looked the best of the bunch, the others were massive. They have 24 volt coils, but have very good pulling power at 12 volts.
Do you electric string lads think they will do for a future project, or should I go another route?

John

John,

The solenoids you have pictured will work as either pull or push. The long, skinny tip protruding out the other end would operate in push mode. I think the solenoids would work in a small engine, probably better as a multiple "cylinder" version, maybe in a boxer configuration. I would keep the stroke pretty short, 1/2" - 5/8" since these solenoids don't exert much force until the plunger gets pretty well inside the coil.

The bigger solenoids you have could maybe be used in a beam type engine, either horizontal or vertical. I've thought of designs where the solenoids are located horizontally in the base of the engne, with a vertical beam at end connected to a horizontal crankshaft that doubles back over the top and connects to the crankshaft toward the back.

Like this:

 

[cfellows]

Got my solenoid engine finished this weekend. Here's the video:

[ame=http://youtube.com/watch?v=e3tcdiO2HCc]http://youtube.com/watch?v=e3tcdiO2HCc[/ame]

I replaced the aluminum casing on the coil with steel and added a cast iron cap on top. I also shortened the pillars (actually made new ones out of drill rod). All this seemed to give the engine more torque.

Chuck

 

[PTsideshow]

Very very good,runs nice to. Along with looking good.
;D

 

[Brass_Machine]

Cool deal! I like it a lot.

Eric