Solenoid engines

[Mephitus]

I fully admit that this is impractical and possibly something that has been around for a long time. But I have recently come across a number of videos on Youtube showing off solenoid engines. Such as the following:
 

While the electronics design is comparitively simple to most projects here. I became curious if there was a way to make the power side out of solid-state components. Such as: is it theoretically possible to replace the copper wipes/cam with PWM and/or some micro-controllers? Or perhaps some high-speed solid state relays and transistors? As a rather newb to EE, I admit that even these approaches might not be practical or even possible. But as a practice in problem solving and learning, this seems like a rather fun approach to problem solving and brain storming different methods of application.

How would you approach this? What kinds of changes to the concept or limitations might you put on the design that you would find engaging or challenging? It may even be fun to have a friendly competition on the board with Dave being the judge  Or maybe I am just over excited and blinded by a novel application of science 

[SL4P]

The challenge you are proposing, is exactly what happened through the evolution of the steam engine, internal combustion engine -- through to modern engine management systems with sensors, encoders, and variable timing to optimise the combustion cycle!

[Mechatrommer]

it can be refined the solenoid engine, the main problem imho is how get the highest energy density than gas in the vehicle... or how to convert gas energy into electricity at sensible efficiency...

[SL4P]

The first obvious (?) direction is to use non-contact sensors (optical?)... then optimizing the energy delivery to the solenoids, and ultimately, the firing angle - to reduce angular losses when the 'piston' is pushing and retreating from the crankshaft...

No exhaust, a little air for cooling, and a bit of power input.
I wonder how much energy can be recovered for 'recycling' without affecting the crankshaft power output...?

I love it!

[Gyro]

I dreamed of doing this as a kid (emulating a piston engine with solenoids), I'd spend hours dreaming up all sorts of schemes (probably all involving contacts). It's great to see that people have actually don't it and stuck them on youtube! 

[vk6zgo]

Totally impractical device--it has all the bad points of a conventional piston engine & none of its good points.
A fun thing to make,though!

[Tandy]

Efficiency wise it would be no good as you are using electromagnetic energy to push a piston that has to then be turned into a rotary movement mechanically with resultant losses. So you are better off using the electromagnetic energy to directly create rotary motion, i.e a motor.

[Jeroen3]

As product it's useless. But as project it's highly educative.
I'd see this as a challenging project to remove the "camshaft" and replace it for an encoder and a microcontroller. How accurate would this model a real engine?

To be honest, I've never heard or seen such device until now.

[max_torque]

Moving to "smart" phase firing is basically the same as moving from a brushed DC motor to a brushless one.  Pretty much exactly the same techniques will work, but of course you will have much lower efficiency due to the extra mechanical friction etc

[Yansi]

This one even sounds quite convincing, when going.... as somebody pointed out in the comments: "SOunds like R4 Diesel engine" 

[eneuro]

The first obvious (?) direction is to use non-contact sensors (optical?)..

Only two optical sensors and 2 bit gray encoder to be able know all the time shaft position-if we wanted know absolute position that more bits gray code, but it is a toy so 2 bits gray code should be fine.

I like more those star configurations more, since it reminds more aircraft engines than ICE cars 

[langwadt]

The first obvious (?) direction is to use non-contact sensors (optical?)..

Only two optical sensors and 2 bit gray encoder to be able know all the time shaft position-if we wanted know absolute position that more bits gray code, but it is a toy so 2 bits gray code should be fine.

I like more those star configurations more, since it reminds more aircraft engines than ICE cars 

a ton of cars use a single magnetic sensor with a wheel with 60 teeth minus 2. detecting the longer period from the two
missing teeth provides sync

[FrankenPC]

I don't care how impractical this is.  It's VERY cool to enjoy watching the mechanism in action.  Nicely done.

[Mephitus]

I don't care how impractical this is.  It's VERY cool to enjoy watching the mechanism in action.  Nicely done.

There are many mechanical designs that are rather artisticly beautiful. If you want a similar one that I could just watch for a long time, check out the "constant escapement" watch mechanism by girard-perregaux. An amazing work of engineering. (attached is a breakdown of the parts)