This fire piston ignites the char cloth in the end by principle of a diesel engine. The high compression creates enough heat to ignite the half burned cloth. This one is made from maple burl and is 5 " long. I have an Abe Lincoln dollar in the in the end of the plunger. There is an O ring in the brass piece at the end of the plunger and it requires some grease to maintain a good seal. To have the grease handy, I made a compartment on the top of the plunger with 1 1/8" -12 thread chased into the wood so I can screw the cap on. I chased the thread in my Southbend metal lathe using a Dremel mounted in a tool holder and a 60 degree cutter that I had to make because there are none available with a 1/8" shank. I could not even find one with a 1/4" shaft. I added some shots of the making of charcloth. I first cut some strips of a cotton T shirt. Then I put them in a tin can and put tinfoil on top and secured it with a wire with a hook in it for handling.
Then I put the can in the fire and the cloth is burned but no consumed because of the lack of oxygen in the can. The cloth was not totally converted to charcloth because I pulled it out of the fire early because the tinfoil was melting. I should have put it over hot coals without the big flames. But it will still work. Cheers, Jim
Cheers, Jim ........................ Variety is the spice of life...............Learn something new every day
Very well done and thanks for explaining the build. It was something I wanted to try, back in my wood turning days, but like many things never got to it. Trouble with yours, almost too pretty to use.
Thank you for all the nice comments !! Hi Tony, it is used to start a fire if you have no matches or lighter. Just drop that burning charcloth into paper or tinder and it lights up quickly, Hi Dave. I did not mention that inside the cylinder I have a piece of copper pipe with a plug soldered in the end for a complete seal. I use that because it is smooth on the inside with no seams. Just having a hole bored in wood would leak air into the pores and may not work at all. Cheers, Jim
Cheers, Jim ........................ Variety is the spice of life...............Learn something new every day
A solid, air tight cylinder is essential, since the piston relies on the heat generated from air being compressed to ignite the char cloth. The one I built, long ago, was a solid brass cylinder with a bore cut into it for the piston to fit into. The o-ring and grease are needed to keep that seal. Ones that are built well work great…I could never get the hang of using it, but the buddy I gave it to love it.
Ryan/// ~sigh~ I blew up another bowl. Moke told me "I made the inside bigger than the outside".
Very nice turnings here, this devise looks great. The theory of operation is quite interesting too, so a wooden cylinder actually creates sufficient heat of compression to ignite the cloth. Never would have guessed that, thanks for posting, I learned something new today.
It’s not the piston itself that generates the heat, it’s the rapid compression of air inside the bore when the piston is pushed quickly into the bore that generates the heat. The piston and bore just has to contain the air so that it can be compressed. With the optimized fuel (char cloth) in the chamber, the rapid depression of the piston into the bore generates momentary heat and the fuel ignites. You basically get a glowing ember in the char cloth, and you dump/place that into your tinder. Blow on it a bit and bob’s your uncle.
Some simple YouTube videos on it. Much easier to watch than explain.
Ryan/// ~sigh~ I blew up another bowl. Moke told me "I made the inside bigger than the outside".
Saw these used in a show called "Naked and Afraid" and thought about making one because I thought it was so interesting. Never got around to it because I can't think of any reason it would be useful to me. I still think it's cool and the one you made is beautiful, nice job Jim.
Cool project JJ, though the concept had me running around in circles.
Jim Jakosh .... it is used to start a fire if you have no matches or lighter. Just drop that burning charcloth into paper or tinder and it lights up quickly,
Fire up a burning cloth to start a fire... Initially though it was a whistle and now I'm wondering if your blowing smoke with a tune.
Piqued my interest when you mentioned thread chasing. Been a great fan of the Beall wood threader, (though seems to have been basterdised by Lee Valley), however, that has it's size limitations. I'm sure there must be a vid on the process, however, Is there any you could recommend?
If your first cut is too short... Take the second cut from the longer end... LBD
Thanks Tom, Ken and Alex!! Hi John, never been on Naked and Afraid and I do have matches. I just like to build cool things to see if I can make them work. I have working a V-gate magnetic motor for 3 years and have not gotten it to keep going. The friction always kills the movement. Hi Alex. I have made the thread chasing tools ( out of thread inserts for a pipe threading machine) for the wood lathe and they kinda worked but seemed to chip the threads. The same thing happens when I chase thread in my metal lathe with conventional threading tool bits. They are essentially scraping and do a bit of tear out. BUT, with the spinning cutter, I can cut very clean threads all the time. I looked everywhere for a 60 degree V cutter for a Dremel or a router bit and can't find one. So I made a couple of them using O1 tool steel and hardened and hand ground the clearance and they work pretty good. This little one gets into small places like the end of a fire piston ram!! I don't know what Beall and Lee Valley have for threading tools. One of them makes one with a tap and a die like for broom handles. I have one like that but not from their companies.
That is right on, Ryan. That rapid compression make enough heat to continue the cloth burning. That is a good video. I saw one where the guy had a glass tube and you could see the clot burn right as he slammed the piston in.
Cheers, Jim ........................ Variety is the spice of life...............Learn something new every day
JJ, you did't look at the Beall when you could and now it may be too late. Their kit comes with a 60° 1/4" tungsten router bit. Designed to use in a trimmer with their jig,
They make a pretty mean thread,
unfortunately they only offer the set common sizes.
