Solenoid engine

[Davidz90]

A little proof of concept of using electromagnet as a piston in combustion/steam engine model. My goal was to recreate the cool looks and sounds of pneumatic engines, but without the hassle of air compressors or huge air tanks.

One particular challenge I had to overcome was a very short stroke of the electromagnet (5mm) which necessitated the use of additional lever to attach it to a crankshaft. Another problem was turning the current on/off - all switches I tested had too much friction, so in the end I'm simply bringing two wires together. Not sure how long will they survive with all the arcing, though...

Whole thing is terribly inefficient (uses almost 2 watts of power and produces close to 0 torque), so I uppose that it is good only as a display model.

 

Edited August 10, 2023 by Davidz90

[Mr Jos]

Electrboom vibes seeing that switch! But if it works, it works. Always fun to experiment.

[Davidz90]

4 minutes ago, Mr Jos said:

Electrboom vibes seeing that switch!

Haha yeah, it is as sketchy as it gets.

I wonder if anyone tried to use Lego piston engine parts like this; in principle, it should be simple to glue small magnets to the pistons and wrap the cylinders with coils.

[2GodBDGlory]

Very interesting project!

[Davidz90]

I found a way to simplify and improve the design. Now current is passed through solenoid core. As the lever reaches its lowest position, it closes the circuit. Solenoid pushes the lever, maintaining the contact until it reaches maximum extension. Lever continues its motion a little further, opening the circuit.

 

[lcvisser]

Cool project.  Reminds me of a electro kit I had a as kid. It also included building a motor with some magnets and coils, I thought it was amazing. 

[Davidz90]

17 minutes ago, lcvisser said:

Cool project.  Reminds me of a electro kit I had a as kid. It also included building a motor with some magnets and coils, I thought it was amazing

Thanks! I'm working on a 4 cylinder variant right now. My plan is to build 1920's style car with this engine (something along the lines of Fiat S76).

[Davidz90]

...and here's the inline-4. Wire management is a nightmare and I'll definitely need to properly solder everything together, but it works! The only issue is that after few minutes, coils get quite toasty (70 degree C or so). I tried to reduce voltage from 12 to 9 volts, but then there's not enough power to run.

 

[Johnny1360]

Time for a fan, lol, great concept to work out, good luck, I will be closely following. An actual working vehicle is an ambitious project.

[Davidz90]

7 minutes ago, Johnny1360 said:

Time for a fan, lol, great concept to work out, good luck, I will be closely following. An actual working vehicle is an ambitious project.

Thanks! Today I bought a new set of solenoids with 2x longer stroke (1 cm) and more force (0.6 kg). They won't need the long levers and should work fine at a lower voltage, which solves the heating problem. I'll also test if a potentiometer can be used as a throttle.

[Davidz90]

I finished wiring up the motor. I'm still gonna test the stronger coils when they arrive, but even in the current form the performance is quite satisfactory.

 

[Davidz90]

Here's a full 1920's style chassis.

A failure on multiple aspects: engine is woefully underpowered, leaf spring suspension is too soft and I put a steering wheel on one siide despite having a single seat  But it does have a working clutch, chain drive to rear axle and engine that is started with a hand crank.

 

 

[Davidz90]

One additional, fun thing: how it would sound shifted down by 1 octave and bass boosted

 

[2GodBDGlory]

I love the creativity, and the crank start is awesome! Too bad about that power, though

[Davidz90]

4 hours ago, 2GodBDGlory said:

I love the creativity, and the crank start is awesome! Too bad about that power, though

Thanks! Yeah, it seems to be only suitable as display model and maybe for vintage aircraft, spinning a propeller.

I think I'll try to build a steam locomotive, it can be much smaller than the car while keeping correct proportions to the "cylinders", maybe  that will work out.

[LEGO Train 12 Volts]

Interesting idea!
The crank starter is very nice

[Davidz90]

Another little update. This one has better timing, but due to the added mass of moving components, overall efficiency is worse.

 

[glowytheglowbug]

On 8/28/2023 at 6:43 PM, Davidz90 said:

Another little update. This one has better timing, but due to the added mass of moving components, overall efficiency is worse.

 

damn loving these engines hopefully you can create a lightweight version that can simply run on flat ground :D (differential optional as its usually easier to run 1 wheel only)

[Davidz90]

A few more attemts to squeeze a bit more power out of them, mostly failed. I moved to a slightly more complicated design with separate timing mechanism. While it does increase efficiency and RPMs, whole thing is just inherently very inefficient.