Making my second tennis ball mortar, Need help!

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Dtaktics
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Sun Nov 22, 2009 11:33 pm

Alright, this is my first post so be easy on me. I want to make a second tennis ball mortar. My last one was a POS to say the least. It was made out of pringles cans and duct tape (you get the idea). I want my new one to be made out of PVC and to be gas powered (hair spray, deodorant ect.). So I have some questions.

How many baffles does this thing need?

Does it need a baffle at all?

Does anyone have a tutorial on how to make one out of PVC?

Not to many questions but any help is greatly appreciated! :D
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Technician1002
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Mon Nov 23, 2009 12:02 am

No baffels needed. The most simple is thinwall PVC 2.5 inch pipe with a clean out on the end. The tennis ball defines the end of the chamber and beginning of the barrel (like the pringles variety). Use your choice of ignition through a double layer (barrel and threaded adaptor), some sort of stand to make it a mortar, and it's done.

For a shorter overall length, a larger diameter and thus shorter combustion chamber can be used. From there a coaxial combustion adds complexity and makes a nice short overall length mortar that looks more like a mortar. Venting and fueling coaxial combustions are tricky. This would be a poor first choice.
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hi
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Mon Nov 23, 2009 1:14 am

take about 3 feet of 2.5'' pvc. then glue on a female adapter and put a bolt a little less than halfway down to stop the tennis ball. drill a hole and put in a lantern lighter, spray some propane in there, screw on and cap and let er' rip.
"physics, gravity, and law enforcement are the only things that prevent me from operating at my full potential" - not sure, but i like the quote

you know you are not an engineer if you have to remind yourself "left loosy righty tighty"
Dtaktics
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Mon Nov 23, 2009 1:54 am

Sounds good guys, thanks for the info! keep the suggestions coming!
Dtaktics
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Mon Nov 23, 2009 1:56 am

hi wrote:take about 3 feet of 2.5'' pvc. then glue on a female adapter and put a bolt a little less than halfway down to stop the tennis ball. drill a hole and put in a lantern lighter, spray some propane in there, screw on and cap and let er' rip.
What is the female adapter for if you don't mind me asking? you would put a cap on on end if I get you correctly but where would the female adapter go?
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grock
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Mon Nov 23, 2009 2:33 am

a female adaptor refers to a threaded adaptor. there is a male one that goes on the other side of it, making your vent door. you might have a hard time finding one in that size at homedepot/lowes etc, but a plumbing store should have one. actually, any place that caries 2.5" pipe should have appropriate fittings
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Technician1002
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Mon Nov 23, 2009 2:36 am

grock wrote:a female adaptor refers to a threaded adaptor. there is a male one that goes on the other side of it, making your vent door. you might have a hard time finding one in that size at homedepot/lowes etc, but a plumbing store should have one. actually, any place that caries 2.5" pipe should have appropriate fittings
Often if you can't find the proper parts in PVC pipe, you can find them in PVC conduit. Check the electrical section for hard to find fittings.
Dtaktics
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Mon Nov 23, 2009 5:17 am

grock wrote:a female adaptor refers to a threaded adaptor. there is a male one that goes on the other side of it, making your vent door. you might have a hard time finding one in that size at homedepot/lowes etc, but a plumbing store should have one. actually, any place that caries 2.5" pipe should have appropriate fittings
I know what it is, its just I don't know where it would go on the PVC pipe.
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hi
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Mon Nov 23, 2009 2:54 pm

it goes on the end of the pipe, then you screw a plug onto it to close the chamber after you put fuel in.
"physics, gravity, and law enforcement are the only things that prevent me from operating at my full potential" - not sure, but i like the quote

you know you are not an engineer if you have to remind yourself "left loosy righty tighty"
Dtaktics
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Mon Nov 23, 2009 3:46 pm

hi wrote:it goes on the end of the pipe, then you screw a plug onto it to close the chamber after you put fuel in.
Ohhh, ok so its just to allow the cap to screw on?
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hi
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Mon Nov 23, 2009 11:08 pm

thats how i've always done it. it would be kinda difficult if you couldnt take the cap off wouldnt it?
"physics, gravity, and law enforcement are the only things that prevent me from operating at my full potential" - not sure, but i like the quote

you know you are not an engineer if you have to remind yourself "left loosy righty tighty"
Dtaktics
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Mon Nov 23, 2009 11:36 pm

hi wrote:thats how i've always done it. it would be kinda difficult if you couldnt take the cap off wouldnt it?
Alright thanks that makes sense.
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