Two-stage hybrid

[jackssmirkingrevenge]

Actually, self-ignition is not what I pursue.

To be honest I think it will be hard to avoid, if we can use a fire piston to ignite something manually, what is a combustion driven piston going to do...

[hectmarr]

Actually, self-ignition is not what I pursue.

To be honest I think it will be hard to avoid, if we can use a fire piston to ignite something manually, what is a combustion driven piston going to do...

I agree with you Jack.
What I try is not to have to redo the entire chamber and pistons, again, if the autoignition does not occur, especially in the first tests at low pressure. I mean that it will be impossible to add the rod with the ignition contacts, without having to redo the piston and the cover of the side of the chamber "A", which needs a pair of o'rings. The strategy is: Better to have the ignition installed, than not to have it and need it!
I think this phenomenon is going to happen when I compress at about 6 or 7X, or more, but at 1X or 2X, I don't think so. It is difficult to calculate this aspect, at least for me, so it seems reasonable to have both options at hand. If the design thrives, it will be a very important simplification to dispense with the stem, extra contacts and the lid with the o'rings.
I believe that if auto ignition occurs at low compression levels, I can simply turn off the ignition, since it does not interfere at all with the operation of the double hybrid.

[jackssmirkingrevenge]

The strategy is: Better to have the ignition installed, than not to have it and need it!

A wise decision looking forward to your results!

[hectmarr]

It is a thought of mine only, all this. In the future I will try. At the moment I am building the autonomous hybrid V, the "HA-V", trying to work on the power aspect. Thanks to all who contributed ideas and information for this topic.

[mrfoo]

It's off topic, but there's another thing that springs to mind as being similar in principle; the free piston engine.

[jackssmirkingrevenge]

It's off topic, but there's another thing that springs to mind as being similar in principle; the free piston engine.

Today I learned, interesting!

[hectmarr]

It's off topic, but there's another thing that springs to mind as being similar in principle; the free piston engine.

Great engine, I didn't know, and it must surely be a pretty old engine. Very good contribution, bring it here, for us.

[mrfoo]

The idea's been around for over a hundred years, I done made a thread with plans for what's probably the best known "hobbyist" example here : http://www.spudfiles.com/offtopic-relat ... 27010.html

[hectmarr]

One option, to simplify the construction, is to use an adjustable, pressure-operated electric switch. It is simply screwed into chamber "B", and regulated to close the contact at the necessary pressure.
It's something like this, which supports up to 20,000 psi. It could be self built.
https://www.ruelco.com/es/products/inte ... delo-4e02/

[mrfoo]

Not sure how well a pressure switch will handle the kind of rapid pressure spikes you're going to hit it with. It's worth a try, though - it not only reduces the mechanical complexity, it's also going to reduce mass, and thus inertia, and remove a potential leak / rupture point.

[hectmarr]

I have thought about this basically. It must be tough, and surely, it would have enough regulation work.

[hectmarr]

A simpler solution, and thinking outside the box, is to use an electronic ignition type fly back. When the trigger is pressed, the ignitions of the two cameras are energized at the same time. As the distance is a lot, there is no spark between the electrodes of the "B" chamber. When it gets close enough, (this distance is what you have to regulate), the spark jumps. In the "A" camera contacts, the spark jumps immediately when the trigger is fired to fire.
The "insulating separator, keeps away from the spring, the conductor that ignites the combustion chamber" B ", and the tube has a groove, which is never exceeded by the pistons, where the conductor goes outside. This works equally, to maintain the atmospheric pressure between the two pistons while they move. I mean to avoid depression and compression by varying the volume between them.

[Moonbogg]

Whoa, this thing is complicated. Would be so awesome if it worked!

[hectmarr]

Whoa, this thing is complicated. Would be so awesome if it worked!

It could work, in my opinion. The system to ignite the second combustion chamber tries to simplify the construction. A single type of ignition, without stem and internal o'rings in the chamber "A".
What seems to me that it will take away performance, is that the cameras expand when they explode and the pressure decreases. The two chambers vary in volume during combustion. I was thinking about this ...
The solution is complicated, and is to make a locking system for the recoil of the piston of the chamber "B". I imagine that without this block, the performance would be better, although not so much.
 

[hectmarr]

Definitive solution to simplify everything.
The combustion chamber piston "B" has a metal bolt "S". The contacts of the "B" chamber are far enough away so that the spark does not occur when the ignition is energized, which is only one for the two chambers. When the tamper moves towards the contacts, a bridge occurs between the two electrodes and the spark jumps, turning on the chamber "B". The metal bolt can be threaded into the piston to regulate the ignition point.
The "E" orifice keeps the volume between the two pistons at atmospheric pressure when they move.
(Open to see the animation)