Fire piston.

[Bob W]

Here's my quickly made fire piston with parts readily available from B&Q.

The raw materials, 6mm brass rod and aluminium tubing with a similar internal diameter.

http://i75.photobucket.com/albums/i316/arkaywat/IMG_0592.jpg

Cut to length.

http://i75.photobucket.com/albums/i316/arkaywat/IMG_0593.jpg

Centre punch and drill the kindling hole, do this before cutting "O" ring recess (undercut is the engineering term) as the hammer blow from the centre punch will narrow your recess if done later.

http://i75.photobucket.com/albums/i316/arkaywat/IMG_0595.jpg
http://i75.photobucket.com/albums/i316/arkaywat/IMG_0596.jpg

Cut recess for "O" ring using hacksaw and drill, the belt loop on a tape measure makes a good steady for this.

http://i75.photobucket.com/albums/i316/arkaywat/IMG_0603.jpg

You need to be patient with this stage and use your hacksaw blade at different angles to achieve the width and depth of recess. The "O" ring should just fit in the recess with the minimum of leeway either side.

http://i75.photobucket.com/albums/i316/arkaywat/IMG_0605.jpg

The depth of cut was arrived at by trial and error and a few split "O" rings, but has been established as 1.5mm leaving a 3mm seat for the "O" ring. There is a calculation to work this out but I did it belt and braces.

http://i75.photobucket.com/albums/i316/arkaywat/IMG_0607.jpg

Now to seal the chamber. I found some bolts that were in one of my biscuit boxes full of acquired bits and pieces, like you have. I simply used one as a tap and cut the thread in the aluminium tube using the bolt. Wrapped some PTFE tape around the thread, screwed it back in and cut the alan head off.

http://i75.photobucket.com/albums/i316/arkaywat/IMG_0608.jpg
http://i75.photobucket.com/albums/i316/arkaywat/IMG_0609.jpg
http://i75.photobucket.com/albums/i316/arkaywat/IMG_0612.jpg
http://i75.photobucket.com/albums/i316/arkaywat/IMG_0613.jpg
http://i75.photobucket.com/albums/i316/arkaywat/IMG_0615.jpg
http://i75.photobucket.com/albums/i316/arkaywat/IMG_0617.jpg

Lubricate the bore and ring with a bit of lip balm and away you go.


http://www.youtube.com/watch?v=SHBh77aoq9U

I did everything without a vice in my kitchen just to show it's possible with minimal gear.

I hope you find it of interest.

[luresalive]

Bloody brilliant !!!

[JEEP]

Excellent!

[fish]

well done mate ime impressed! now start selling them!

[DaveBr]

Thats awesome!! all you need to do is make some packaging and evilbay will eat it up!

Dave

[Savagewolfrm]

that is some piece of work, and presumably you can make it a little shorter. what a great idea, my weekend is now complete. thanks for sharing that.
atb
Rick

[Bob W]

Thanks for the feedback.

The next step, when I can be bothered, is to drill out and mount it in a nice piece of Wood/bone (I know it doesn't need drilling;) )/antler or any other suggestions will be welcome.