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hwingo
02-09-2011, 10:36 AM
Hi Guys,

I don't know where I've been all my life but last week I happened upon a site lauding the virtues of a Fire Piston. Most likely, several of you learned of this gadget years ago. Well, I made one and it worked!:cool:

I fabricated mine from aluminum. It takes, on a consistent bases, at least four attempts and sometimes five before the Char Cloth ignites. Trouble shooting (brain storming) the reason(s) for so many attempts before successful ignition, I considered the following as major factors:

1. Stroke of piston too short for diameter of cylinder
2. Loss of compression due to insufficient O-Rings
3. Heat loss because metal is conducting heat away from combustion chamber. Stated differently, several strokes are necessary to warm the combustion chamber before achieving combustion.

The easiest thing to do was to heat the outside of the chamber with a flame. I warmed the chamber end of the fire piston using an alcohol lamp. Not an excessive amount because it was not enough to burn or even remotely burn my hand after warming. I achieved ignition on the first stroke each time I warmed the cylinder. For the reason that aluminum might be conducting heat away from the combustion chamber, I am considering fabricating a fire piston from Lexan.

For those having played with these simple devices, what has been your experience with regard to getting the fire piston to consistently fire on the first stroke?

Harold

Al Messer
02-09-2011, 10:52 AM
I read about them in an early Scouting book published around 1900, I think the author was James Beard or Baden-Powell. It mentioned that natives of someplace made them out of Bamboo, but the one illustrated was made of Brass---I think---been a long time since I've even seen one mentionedand Punk was placed in the combustion chamber to catch the fire. Good luck with your experiments and please, keep us posted.

Al

A.K. Boomer
02-09-2011, 10:54 AM
I built one awhile back - still have it and its a great conversation piece, I used a pyrex glass tube and although it's for the most part worked out I would not recommend it due to it being dangerous,
Had a little bash and one of my weight lifting friends thought it was a put all the effort you can into it and he blew the chamber,
If I want It will light off first time every time regardless of pre-heating the chamber or not,
keep in mind a cool chamber means denser air so if you go to the same stroke compression (which takes more effort) it will actually be a higher temperature...

http://bbs.homeshopmachinist.net/showthread.php?t=34076&highlight=fire+piston

MotorradMike
02-09-2011, 10:56 AM
Very cool! I had never heard of this and also want to make one.

So do you have dimensions and/or pics of yours?

hwingo
02-09-2011, 11:01 AM
Very cool! I had never heard of this and also want to make one.

So do you have dimensions and/or pics of yours?

Hi Mike,

I do have dimensions and pictures. I am preparing to leave for work (62 mile commute one way). When I return this evening, I will have time to post some pictures and dimensions.

Harold

vpt
02-09-2011, 11:26 AM
Another thing on the list of do's. Very cool!

J. Randall
02-09-2011, 04:35 PM
I have some off cuts from carbon fiber arrows saved back for that very project, wonder if they will work?
James

A.K. Boomer
02-09-2011, 06:57 PM
I don't think they will fare to well, they are designed for high linear strength and not at all designed for holding internal compression --- I used a variety for RC airplane parts and some will definitely be better than others but there is extreme internal unit pressures.

DanGunit
02-09-2011, 07:07 PM
Hey Guys,

Here is a link to a couple pages on the PrimativeWays website that tell the history and give a dimensioned drawing for a Fire Piston:

http://www.primitiveways.com/fire_piston.html

http://www.primitiveways.com/fire_piston_for_21st_century.html

I made one out of lexan like this guy sells: http://www.firepiston.com/
and it worked great, started first try most of the time even after being submerged in water. Unfortunately, I lost it on a camping trip in Nevada and haven't gotten around to making another one yet. It is a fun little quick project, so lets see what you can come up with.

Cheers

J. Randall
02-09-2011, 11:59 PM
I don't think they will fare to well, they are designed for high linear strength and not at all designed for holding internal compression --- I used a variety for RC airplane parts and some will definitely be better than others but there is extreme internal unit pressures.

A K , actually did not go far enough in my description, I intend to use it as the liner in a piece of decorative wood or deer antler, I think I will try it anyway. Won't cost anything but a little time.
James

A.K. Boomer
02-10-2011, 07:39 AM
A K , actually did not go far enough in my description, I intend to use it as the liner in a piece of decorative wood or deer antler, I think I will try it anyway. Won't cost anything but a little time.
James

yeah big diff. esp if you make it a tight fit or epoxy it in,
could also make one out of the guts of an aluminum arrow, it will suck the heat off faster and perhaps not work as well as the carbon fiber that way but will have strength in every direction.

For me I would not have built mine if it wasn't see through --- having it see through is very cool and it's kind of like magic to many people who don't know much about simple physics --- they say - WOW how did you do that?
Its really funny to hear that esp. if they drove over in a diesel...
having it see through makes it more than just a fire piston - it makes it a science experiment.

hwingo
02-11-2011, 09:06 AM
Very cool! I had never heard of this and also want to make one.

So do you have dimensions and/or pics of yours?

Mike,
Sorry for the delay. We had a death in the family.

The piston is 4.5" long and .372" dia
O-Ring placement is .250" from end
Depression at end of piston is ~.125" deep.

The cylinder is 4.250" long and compression chamber is .375" ID
Compression chamber is ~4".0 deep

I use Char Cloth as fuel. I made Char Cloth as follows:

1. Obtain empty Altoid can (Kiwi shoe polish can will also work)
2. Drill one (1) single hole in top of can using a #46 drill (could have used a drill one size smaller)
3. Fill can with 1"X1" *100% cotton* gun cleaning patches (cotton bed sheet material will also suffice) and close lid tightly. Keep a close watch on the lid because it may try to open during heating. Need a deprived oxygen environment but not one void of air.
4. Place can on/in low heat. I put my can on the kitchen gas range and used low flame. The can may also be place in hot charcoal while grilling food.
5. Leave can in heat for approx 8 to 12 minutes
6. During the process, a small stream of white smoke will come from the small hole that was created in the top of the can.
7. When smoke stops, you have created Char Cloth.
8. Carefully remove can from heat source and allow to cool.
9. Open can and inspect contents. Cloth should be black.
10. Char Cloth does not usually produce a flame, rather, glowing embers that last several minutes when a piece 1/4"X1/4" is ignited. It doesn't take much Char Cloth to fill the depression in the end of the piston (1/4"X1/4" at the very most)

As previously stated, I need to cycle the piston at least 4 to 5 time before I get ignition. If I first warmed the "system", ignition time is reduced to one or two strokes of the piston. I have not attempted warming the "system" under the arm but a "warm system" seems to greatly improve ignition.

Harold


http://i234.photobucket.com/albums/ee38/hwingo_2007/FirePiston.jpg

dothacker
02-15-2011, 02:25 PM
I made a fire piston in high school once. I used an aluminum body and bored the inside (albeit we were having trouble with the machine and it didn't end well) and used a tool steel rod (only because it was ground to a nice finish) for the piston shaft. I used a parting tool to notch the rod for a gasket and a small center drill for the tip's compartment. It lit up on the second try and worked ok when a bit of oil was added to the shaft. The bore wasn't smooth or all the concentric so it stopped working after a short while. I suppose that it's possible that I'd scratched and bulged the bore, instead, but I don't know. I'm sure I have the pieces somewhere, but I'm only aware of having the cylinder, as I use that to hold a scribe that never falls out due to suction! I do intend to make more one of these days, and I have fancied a see through fire piston...

JoeLee
02-15-2011, 06:20 PM
Hey, how about if you used a little bit of black powder for starters??


JL.......................

aboard_epsilon
02-15-2011, 06:43 PM
The models usually demonstrated are made clear of perspex or acrylic ..

somehow i cant see those lasting very long without melting ..but are fun to see ..

Anyway ...without the bedazzlement of being able to see whats happening they become a very boring gizmo ..but if you like the idea of survival and self sufficiency, then they are the ultimate toy ..even a life saver ...for use for back packing camping etc ..

Could even be a money maker on ebay ..if you could make fancy looking brass mixed metal SS ones .

all the best.markj

macona
02-15-2011, 06:56 PM
Hey, how about if you used a little bit of black powder for starters??


JL.......................

No, Diesel fuel.

Black_Moons
02-15-2011, 07:18 PM
Black powder lol.
'Good news is I got the fire started. Bad news is I lost my piston, And have a piston shaped hole in the palm of my hand..'

JoeLee
02-15-2011, 08:00 PM
Out of all the projects I've read about here this really seems to be one of the more dangerous ones, and for what real reason????
Matches are safer, so is a magnifying glass. This reminds me of when I was a kid....... we were making fireworks, one of the guys had a 3" piece of 1/2" copper water pipe and it was capped off on the bottom. He cut up a bunch of match heads, since we had no access to powder and he was packing them into the piece of copper pipe. He also was compressing them with a short steel rod that just fit into the pipe, like a piston. He smacked it a couple times with a hammer........... and guess what happened.
He almost completly lost a couple fingers, 3 hours of surgury and to this day has only partial use of the fingers and they won't straighten out.
Think about it !!!!!!

JL.................

aboard_epsilon
02-15-2011, 08:16 PM
you're only supposed to put a piece of wadding in them ..soaked in a tiny drop diesel or kerosene..only dangerous if mis-used .

all the best.markj

dothacker
02-15-2011, 09:24 PM
Out of all the projects I've read about here this really seems to be one of the more dangerous ones, and for what real reason????
Matches are safer, so is a magnifying glass. This reminds me of when I was a kid....... we were making fireworks, one of the guys had a 3" piece of 1/2" copper water pipe and it was capped off on the bottom. He cut up a bunch of match heads, since we had no access to powder and he was packing them into the piece of copper pipe. He also was compressing them with a short steel rod that just fit into the pipe, like a piston. He smacked it a couple times with a hammer........... and guess what happened.
He almost completly lost a couple fingers, 3 hours of surgury and to this day has only partial use of the fingers and they won't straighten out.
Think about it !!!!!!

JL.................
I do honestly hope you don't think black powder, oil or diesel goes into these. He was making a joke.

The fuel is paper, moss, cloth, or even finely sliced tree bark, in a pinch, and the ignition source is from the compression which superheats the air, the more the compression, the hotter it will get, provided it is done in a fast enough stroke. The compression ratio tends to be somewhere near 25:1, which is good for most people.

I am redoing a firepiston, and this time I'm really researching it, and have discovered that O-rings are probably not the best idea for a seal. Main cause being that there aren't really any O-rings which are meant for temperatures around say...600-750F, which might be found in a well made (some poor ones get there after a few tries) fire piston. I do realize that these spec sheets are probably based off of a sustainable temperature, and these will only be exposed for a split second each use, while not being directly in the heat itself, but after inspecting the wear on a brand new O-ring that blew out on my last piston, it is definitely getting hot. But hey, O-rings are cheap, why do we care? Well, if this is for survival or even just camping, and your last ring goes, grab a couple sticks and get old fashioned. However, you can line the depression with string, but you will then require something viscous to seal it like animal fat or grease, so you may not be too bad off.

For this similar reason, I can understand the comment about lexan and other plastic casings melting, but because the entire case will be a heatsink in itself (albeit a very poor one in wood or bone), the heat will dissipate and the only damaging heat should come from the rubbing friction, which will be minimal.

Sorry if I got a bit too technical here, just throwing in some info for the curious. After I get my tweaked blueprint finished, I'll post it with a picture/video of the finished model. It may be a little while, though...so much to do and so little time for play.

macona
02-15-2011, 09:44 PM
Silicone o-rings should take the heat.

Also I wonder if switching to a metal with low heat conductivity would help. Something like titanium. It is horrible when it comes to conducting heat.

Don Young
02-15-2011, 09:57 PM
Out of all the projects I've read about here this really seems to be one of the more dangerous ones, and for what real reason????
Matches are safer, so is a magnifying glass. This reminds me of when I was a kid....... we were making fireworks, one of the guys had a 3" piece of 1/2" copper water pipe and it was capped off on the bottom. He cut up a bunch of match heads, since we had no access to powder and he was packing them into the piece of copper pipe. He also was compressing them with a short steel rod that just fit into the pipe, like a piston. He smacked it a couple times with a hammer........... and guess what happened.
He almost completly lost a couple fingers, 3 hours of surgury and to this day has only partial use of the fingers and they won't straighten out.
Think about it !!!!!!

JL.................
Many years ago a friend and I used to pack match heads in a nut partially screwed on between two bolts. When tightened and dropped on cement it would blow the bolts apart. We learned that a thicker nut with more match heads, more tightening, and higher drops gave a bigger bang but somehow quit before having any injuries despite once tightening with a wrench and vise! We were actually afraid to try that again.

A.K. Boomer
02-15-2011, 10:52 PM
One of the unique things I seen when I got my clear one going was the contrails it produced after compressing a little and then pulling it back some - very cool.


Another neat thing is the way an O-ring conforms to its groove at extreme pressures.

gmatov
02-15-2011, 11:51 PM
Try making it out of wood and be a bit more authentic. They didn't have all your exotic materials 3000 years ago when they were supposedly first used, nor did our frontiersmen have Lexan and the like.

Wood is an insulator, so the heat won't be dissipated.

For tinder, try the lint from your dryer. Lots of loose cotton fibres.

Should be about 25 to 1 stroke to bore, 1/4 inch piston 6 inches long, good palm piece so you don't bust your mitt driving it. Or, smaller piston end and smack it into a tree rather than smashing the piston down.

http://en.wikipedia.org/wiki/Fire_piston

Cheers,

George

dothacker
02-16-2011, 12:00 AM
Macona, not according to Parker O-rings, they fall just short. But again, I believe that any O-ring should last for at least a few dozen uses; it just depends on how finely you want to split the hairs of efficiency. Also, you want the metal to conduct very well.

A.K. Boomer
02-16-2011, 12:22 AM
I believe I have an extremely good combo using a Nitrile (from auto A/C) O-ring,
A delrin AF piston (teflon delrin) and I used silicone grease (non igniting).

So far no wear on any components...

2ManyHobbies
02-16-2011, 12:23 AM
Silicone o-rings should take the heat.

Also I wonder if switching to a metal with low heat conductivity would help. Something like titanium. It is horrible when it comes to conducting heat.
Lol, somebody thought that was a good idea.
http://tisurvival.com/main/products/fire-pistons/

darryl
02-16-2011, 12:25 AM
I've been trying to think of a suitable 'modern' material to use for one. I keep coming back to ceramic- maybe a ceramic coating inside a stainless tube.

JoeLee
02-16-2011, 09:36 AM
If these things were made and used thousands of years ago with bamboo and other such natural materials how did they achive such a precise fit and seal ?? I just find it a bit hard to believe since some experimenters are having a hard time to get a modern made one to work.

JL.................

hwingo
02-16-2011, 10:48 AM
If these things were made and used thousands of years ago with bamboo and other such natural materials how did they achive such a precise fit and seal ?? I just find it a bit hard to believe since some experimenters are having a hard time to get a modern made one to work.

JL.................

My thoughts are, the ones made hundreds and hundreds of years ago were NOT consistently successful. Nor is striking flint rocks together to creates sparks with intentions of ultimately creating useful embers. Both may be "hit & miss". However, both are alternate ways to "create" fire if one perseveres.

I think the point of this exercise is to create a "better mouse trap" that's consistently "on target" ..... and to have fun doing it.

Harold:)

JoeLee
02-16-2011, 11:10 AM
My thoughts are, the ones made hundreds and hundreds of years ago were NOT consistently successful. Nor is striking flint rocks together to creates sparks with intentions of ultimately creating useful embers. Both may be "hit & miss". However, both are alternate ways to "create" fire if one perseveres.

I think the point of this exercise is to create a "better mouse trap" that's consistently "on target" ..... and to have fun doing it.

Harold:)

OK............. understood, but from what I've read the ones made by some of the other guys posting have'nt been consistently successful either.
Just wondering, since back then they had no real understanding of what they were doing, today we do.

JL............

A.K. Boomer
02-16-2011, 11:18 AM
I think it kinda the opposite -- although maybe lacking the means to get things done the way we have today I think in general they had a far greater understanding of what they were doing.

2ManyHobbies
02-16-2011, 11:36 AM
If these things were made and used thousands of years ago with bamboo and other such natural materials how did they achive such a precise fit and seal ?? I just find it a bit hard to believe since some experimenters are having a hard time to get a modern made one to work.

JL.................
To me, it looks like ones made from modern designs and materials have larger diameters and reproductions of originals using naturally available materials all look to have smaller diameters. The overall required force increases as a square of the diameter. Double the diameter, the force required goes up by four. At sea level, 25:1 compression is 367.4 PSI.

The required forces would be:
18 lbs @ 0.25" diameter
45.56 lbs @ 0.375" diameter
72.1 lbs @ 0.5" diameter

For many people, 18 lbs could be done between the arms, 45 lbs would require 2 arms and a good surface, 72 lbs would require acrobatics or a good stomp.

If I was designing one with modern materials, I would probably remove material behind the o-ring on the piston and add a flanged collar that mates with the cylinder to keep everything more or less square. The cylinder would need to be made of a material that would take and hold a good polish. The piston would have to be something that wouldn't mar or gall.

aboard_epsilon
02-16-2011, 11:39 AM
Some Ive seen demonstrated on TV documentaries etc .. they use a hammer on them ..

so what you want for convenience is a sort of spring loaded contraption ..like one of those centre punches

all the best.markj

macona
02-16-2011, 01:13 PM
Macona, not according to Parker O-rings, they fall just short. But again, I believe that any O-ring should last for at least a few dozen uses; it just depends on how finely you want to split the hairs of efficiency. Also, you want the metal to conduct very well.

Hmm, OK. Maybe the teflon encased nitrile o-rings. They have teflon around a nitrile or other softer rubber core.

Guido
02-16-2011, 02:27 PM
Just passin' through, and I can agree/see that what with the quick shove of the piston into the cylinder, an instantaneous heat of compression is generated. This heat is immediate to the air which is captured/compressed and will eventually heat the walls of the cylinder, IF'N the piston is held into it's downward most position.

Again, and IF'N the piston is allowed to immediately, freely move backwards, allowing the compressed air to expand, does not the heat of compression simply exist as a cooling/expansion of the previously trapped/compressed air?

Whut I'm asaying is, these things will work as long as their is minimal to non existant loss of compressed air twixt the piston and the cylinder walls. 'O' ring piston seals of any material are a luxury the first users of these gadgets did not have.

--G

GNO
02-16-2011, 02:36 PM
Look up model T fire piston I made one ,and it works!!! I would recommend carrying extra O rings as they take a set,and stop working