Steam Powered Retropie Console -- Episode 397

Hi DJ,

Love the project you have done here but I like to point out one glaring mistake you made with using the stepper motor, you had a bipolar stepper motor, so essentially a 2 phase motor.  But you used a single phase into a regulator circuit.  If you used a 3 phase style rectifier circuit, you would have generated additional current and made the circuit more efficient. https://www.electronics-tutorials.ws/power/three-phase-rectification.html  This is a link to an explanation of a 3 phase rectification circuit, of course with a bipolar motor you just drop a phase off, so you have more AC pulses in the output providing more current for the same rotational motion.  And a more efficient use of the motor, it would not take much to alter to use both phases of the motor and provide more input current to the regulator.  But as part of your testing you should also check your output current whilst the motor is running, not just the voltage.  So if you alter the circuit to utilise both phases for energy you will find it will generate the power needed to be rectified.

On the steam side of things, it is possible to machine a small steam engine if you have access to a metal lathe and the patience to build one, I have built one in the past, you need patience and an eye for detail.  But to add the steam engine you selected was far too small for the torque output required to drive the stepper motor, you need at least one that is 70% bigger to have sufficient torque output to drive the stepper especially once you start to draw at least 1 amp of current from the coils.

On another note, you could 3D print a similar style steam engine and power it with compressed air, to demonstrate the principle of using such a concept to get it working in the absence of using a steam engine. I would recommend using Polymaker Polysmooth for the main piston chamber or similar off the style container for the main piston chamber.  As pressurised air is just as easy to obtain if you have a bike pump handy to pump air into an air tank as your fuel. And an air reservoir pressurised to approximately 100PSI (depending on size) would give you approximately 5 to 10 minutes of run time, as long as the pressure output is regulated to deliver this pressure evenly, to maintain run time.

If you like I could email you some more detailed information to get this side of things working.

Regards

Paul

Hey Paul,

Thank you for the input. You're right about the rectification and I definitely could have sourced more current from my one motor.

As for the engine, I'm still confident it would have worked had the engine worked at all. Off camera after the initial test I tried quite a few times to get the engine running unloaded, but to no avail. Even with proper lubrication and varying levels of water, I couldn't start self running action, but I suppose that's what I get for using the cheapest engine kit I could buy!

I appreciate the offer and may reach out when I reinvestigate this build.

Thanks,

DJ

Hey Paul,

Thank you for the input. You're right about the rectification and I definitely could have sourced more current from my one motor.

As for the engine, I'm still confident it would have worked had the engine worked at all. Off camera after the initial test I tried quite a few times to get the engine running unloaded, but to no avail. Even with proper lubrication and varying levels of water, I couldn't start self running action, but I suppose that's what I get for using the cheapest engine kit I could buy!

I appreciate the offer and may reach out when I reinvestigate this build.

Thanks,

DJ