New hybrid concept

Insomniac · Wed Mar 21, 2007 12:23 am

Walking home from school today I had an idea for a burst disk free hybrid. It is like a chamber sealing valve that uses Neodium magnets to hold the piston closed. Do you think it would work???

deathholm · Wed Mar 21, 2007 1:39 am

This is the magnets I suppose you would use? http://www.unitednuclear.com/magnets.htm After the pressure in the chamber drops wont the piston snap back into place?

Recruit · Wed Mar 21, 2007 1:43 am

This could work might need a bit of tinkering before you get it to work.

hi · Wed Mar 21, 2007 1:55 am

What, a spring isnt good enough for you? just kidding. The piston would have to be steel or iron, which would require a lathe, but it would work, if you were really carful and knew what you were doing. The only problem would be that you could only use it to a certain mix, then it wouldnt seal. I would think that you would want an electro magnet, that way you could adjust it. It would also cost less and help with instulation.

Insomniac · Wed Mar 21, 2007 1:57 am

You can also get the magnets out of old hard drives. http://www.dansdata.com/magnets.htm a little way down the page there are some pics.
The piston snapping back would be a problem, as these magnets are fragile and shatter easily. I dunno how you could fix that problem.

deathholm · Wed Mar 21, 2007 2:31 am

Also: How are you going to stop the piston snapping back while the gasses are still leaving the chamber? I've had a similar idea to this but a) I can't prove it and b) I couldn't see how it was feasible

Insomniac · Wed Mar 21, 2007 2:46 am

I think the vast majority off the combustion gas would be out of the chamber by the time the piston hit the bumper. Even if it wasn't, the escaping gas should keep the piston open.

Edit: To keep the piston back you could have a 1 way valve on the little vent hole behind the piston. It would let air out but not in. The piston would fly back, and air would vent. The valve would stop the air getting back in, and keep the piston back. So long as the piston wasn't completely airtight, you could then tip the gun fowards so the piston falls back into place, and the air that has to go past would slow it down enough that you don't smash the magnets.

@hi
Why would the piston have to be iron or steel??? There is a set of magnets on the piston as well as the set around the chamber pipe.

dongfang · Mon Apr 09, 2007 3:15 am

Hi,

I like the idea. Just 2 things:

How are you going to fix the magnets to the surfaces?

If there is a gap between the magnets in the closed positions, their holding force varies steeply with the width of the gap. You must be sure that it doesnt open by itself, and that it still opens by the right pressure.
I'd say, let the magnets touch. Then you are sure about the force. If too large, you can insert plastic / cardboard spacers.

But a nice idea.

Soren

Insomniac · Tue Apr 10, 2007 12:14 am

To attach the magnets you could superglue them to a steel disk. It would give an incredibly strong bond, because the magnets are strongly attracted to the steel, and are also glued there. The disk could then be bolted onto the piston, like in the picture.

Pete Zaria · Tue Apr 10, 2007 1:36 am

hi wrote:What, a spring isnt good enough for you? just kidding. The piston would have to be steel or iron, which would require a lathe, but it would work, if you were really carful and knew what you were doing. The only problem would be that you could only use it to a certain mix, then it wouldnt seal. I would think that you would want an electro magnet, that way you could adjust it. It would also cost less and help with instulation.

I think you're onto something here. An electromagnet could be released by a relay on the same circuit as the stungun (the stungun would ignite the mix and the electromagnet would release the piston at the exact same time). The "sealing force" could be easily adjusted. The only problem with this is that it would require a decent power source. I'd try to wire the whole system for 12v and run it on a deep cycle battery... Could work wonderfully.

Peace,
Pete Zaria.

imjustpk · Tue Apr 10, 2007 2:03 am

I think it's a wonderful idea. I have wondered how magnets could be used in spud guns and this is the best idea by far. The use of electromagnets could also make this an electrically triggered piston valve in a pneumatic. I will say that it would take a great deal of know how, but if someone knowledgeable in magnets and electromagnets put there mind to it they could make it work. Also, isn’t the force of a magnet exponential? So the moment the valve opened the force to open it further would be lessened even more and so on and so on until the force needed to keep it open would be minimal.

All in all great idea. I don’t know if I would be smart or skilled enough to make it work just right, but it has potential my friend.

Insomniac · Tue Apr 10, 2007 3:05 am

Electromagnets would be great for a pnumatic, but I don't see the need for them in a hybrid. The neodyum magnets would easily hold a 3x mix (so long as you used enough strong magnets, and that the tube leading to the chamber wasn't too wide), but they would release at the sort of pressure a hybrid operates at. Eg a 3x mix is roughly 42 psi, but this would combust at well over 200 psi. There is such a huge difference between these pressures that the presiscion of an electromagnet is overkill. In the example above, a piston that holds anywere from 43 to 199 psi would be fine (Although you would probably want one that held somthing like 50-150psi, so that you don't get too close to the limits of the piston.

A good type of magnet to use would be an old hard drive magnet, like the one in this picture (the green stuff is magnetic film)