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Re: Jam Jar Car Fun

Posted: Fri Jul 14, 2017 2:17 pm
by PyroJoe
:wink:

Re: Jam Jar Car Fun

Posted: Fri Jul 14, 2017 5:00 pm
by Mike Everman
Yeah, that is fun. And seriously, we need to do a jamjar helicopter. I may have to start a thread for that.

Re: Jam Jar Car Fun

Posted: Fri Jul 14, 2017 7:41 pm
by Mark
I remember seeing that episode of Mythbusters some time ago and wished they'd tried to perfect a real jam jar jet barrel instead of just another pulsejet albeit they used a barrel for the combustion chamber. I once saw some 55 gallon drums going to a dumpster and thought about trying a drum jam jar jet but there's the consideration of size, how the bottom would flex and how too small of a hole or snorkel could be catastrophic. And too I didn't have any way to attach a snorkel securely and you'd have to reinforce the lid to prevent flexing there too. I've a 5 gallon gas can though with two threaded holes in the lid that will fit a 2 inch NPT pipe and a 1 inch diameter pipe but again I suspect the lid would flex too much with the added weight of plumbing pipe and it would wear out in no time aside from having to watch out for a blast wave. Flexing bottoms and tops sometimes create a sudden backfire effect for some reason, mixing the fuel and air in some exotic energetic way. Also there've been a few deaths from people who have used the drums to weld on and inadvertently lit the barrel or other foolish cases such as this barrel ride. But wouldn't a real 55 gallon jam jar jet or snorkeler be fun to watch chuffing away steadily?

An acetone drum that had been rinsed.
https://www.youtube.com/watch?v=9DP5l9yYt-g

Man burned in Sedro-Woolley explosion dies
"Perez was burned while trying to “barrel ride” in a parking lot Sunday night by putting four gallons of fuel in a 55-gallon barrel and lighting it on fire. Fire officials say the barrel was apparently supposed to slide across the lot like a rocket, but it blew up."
http://www.seattletimes.com/seattle-new ... sion-dies/

PS Lighting a barrel like this with methanol vapor in an ideal fuel/air ratio on a cool dry air day and the hole size seen here would make nervous big time. But if designed right maybe the statement " even with all of our modifications there is no way we could get it to go fast" might not be true. I bet you could get one to scoot along fairly well with some low friction bicycle-like wheels such as the ones they used and the thrust from a barrel jam jar jet snorkeler.
https://www.youtube.com/watch?v=lktyx9HHesQ

Re: Jam Jar Car Fun

Posted: Fri Jul 14, 2017 8:12 pm
by Mark
Mike Everman wrote:Yeah, that is fun. And seriously, we need to do a jamjar helicopter. I may have to start a thread for that.
Sounds like a fun if not daunting project. Along those lines I've thought a self-levitating jam jar jet would be cute if you had light and stiff enough materials for the build. I think if you did, it would be something rather attention getting.

Re: Jam Jar Car Fun

Posted: Sat Jul 15, 2017 2:35 pm
by Mike Everman
I'm thinking beer can with tangential jet exits or a diverter to make it spin, and fix some superlight rotors to that. Sit it on a bearing so it can get up some spin before lifting off. Theres the issue of being a burning fuel sprinkler, though.

Re: Jam Jar Car Fun

Posted: Sat Jul 15, 2017 4:52 pm
by Mike Everman
I just posted a pajama science video of a soda can heli try on my build log.

Re: Jam Jar Car Fun

Posted: Sat Jul 15, 2017 9:20 pm
by Mike Everman
A little better rig, trying for a torque motor:
https://www.youtube.com/watch?v=WkxUnm0thwA&sns=em
Fuel sloshes up,but is fortunately not on fire when it does the rainbird

Re: Jam Jar Car Fun

Posted: Tue Oct 03, 2017 6:05 am
by Ghrey
That little spinner is hilarious. It would probably be to hard to balance with a proper extractor on it....

Stop giving me crazy ideas :D