where did you get that 300psi digital gauge ?
FEAR
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Hannzy8664
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- Joined: Wed Sep 24, 2008 10:17 pm
THAT IS AWESOME. it has looaddddsss of power good job matee
sorry to bother you in your awesomeness, killjoy, but could you post pictures of these "modify" couplings, as well as where the pvc barrel joins the metal chamber. a detailed description would be okay too, if pictures are too much of a pain in the ass.
thanks.
thanks.
POLAND_SPUD wrote:even if there was no link I'd know it's a bot because of female name
I would've been happy to provide you pictures, but unfortunately I had to scrap the 2" PVC barrel for safety reasons and how inconvenient it was to set up. The steel coupler also now has a threaded steel nipple welded to it so I could attach a 2" union so a picture of it won't provide much help.
Basically for the barrel couplers though, I sanded out the inner lip of the coupler and then glued it on to one barrel section. I then drilled four 1/8" holes around the couple equal distances from each other, and partially screwed 4 machine screws. Finally, I would slide in the other barrel section and tighten down the screws so the barrel section wouldn't slide out. It was kinda ghetto but worked fine.
The steel coupler the PVC barrel connected to had four holes drilled equal distance from each other, but they were big enough for 3/16" bolts. I then welded 3/16" nuts over the holes so I could screw in the 3/16" bolts. The PVC barrel also had holes drilled in it that were the same as the ones in the coupler so the bolts could pass through the barrel and when I screwed in the bolts, the ends would rest IN the barrel walls and keep it from sliding out.
I hope that helps, if something still isn't clear just holler and I'll try and clear it up.
Basically for the barrel couplers though, I sanded out the inner lip of the coupler and then glued it on to one barrel section. I then drilled four 1/8" holes around the couple equal distances from each other, and partially screwed 4 machine screws. Finally, I would slide in the other barrel section and tighten down the screws so the barrel section wouldn't slide out. It was kinda ghetto but worked fine.
The steel coupler the PVC barrel connected to had four holes drilled equal distance from each other, but they were big enough for 3/16" bolts. I then welded 3/16" nuts over the holes so I could screw in the 3/16" bolts. The PVC barrel also had holes drilled in it that were the same as the ones in the coupler so the bolts could pass through the barrel and when I screwed in the bolts, the ends would rest IN the barrel walls and keep it from sliding out.
I hope that helps, if something still isn't clear just holler and I'll try and clear it up.
Stanford Class of 2012
"In the end our society will be defined not only by what we create, but what we refuse to destroy"- John Sawhill
"In the end our society will be defined not only by what we create, but what we refuse to destroy"- John Sawhill
thanks a bunch, but I still have a few questions. at the steel-pvc coupling or whatever, how far from the end of the pvc pipe are the holes? and between the barrel sections, it was just friction holding it on?
did you get yourself a new barrel?
thanks.
did you get yourself a new barrel?
thanks.
POLAND_SPUD wrote:even if there was no link I'd know it's a bot because of female name
They were like 1/4" to 1/2" of an inch away. Surprisingly it held, but the PVC did bend and crack a little. I'm sure there is a much better way to do it then how I did it.
Well friction plus 4 little machine screws (1/8" in diameter) that screwed slightly into the barrel.
I have the parts for a new 4" diameter barrel, but it is too cold here for me to reinforce it with fiberglass and epoxy so it will remain unfinished until summer.
Well friction plus 4 little machine screws (1/8" in diameter) that screwed slightly into the barrel.
I have the parts for a new 4" diameter barrel, but it is too cold here for me to reinforce it with fiberglass and epoxy so it will remain unfinished until summer.
Stanford Class of 2012
"In the end our society will be defined not only by what we create, but what we refuse to destroy"- John Sawhill
"In the end our society will be defined not only by what we create, but what we refuse to destroy"- John Sawhill
Well unfortunately being in college has completly ceased all work on it until the summer.
Here's a brief overview of whats been done and what still needs to be done or bought:
-Converted FEAR to breach loading. Bolt for loader needs to be reworked and a locking mechanism needs to be finished but it's more then 50% done. If I can get into a machining class in the spring, then I will build the bolt on a lathe instead of using 3" sch40 caps filled with Durhams Rock hard water puddy as I currently have done. This would be a big plus cause then I could use O-rings to seal the breach.
-FEAR is now an over-under type cannon. Because of this I designed and built a a special sliding mechanism to allow me to slide the union back, place a burst disk, and then slide the union forward and tighten it. Pretty nifty and O-ring sealed.
-Re-built spark gaps. 10X testing completely shredded my old one so I built a new one that screws in the side about midway in the pipe. Another spark gap will be screwed in the back giving a total of two ignition points.
-All steel to build frame and recoil mechanism has been acquired. Springs for recoil absorption still need to be bought, most likely a combination of garage door springs and big compression springs (from car maybe?). Current recoil absorption design is still up in the air. Trailer to mount FEAR on still needs to be acquired.
-Everything to build barrel has been acquired. Current design calls for the first of 10' ABS barrel to be encased in and epoxy/fiberglass/steel shell; However, the design allows the ABS barrel section to be slid out and replaced encase it begins to erode from constant firing.
And that's about it. I'm guessing there's probably about 2 to 3 solid weeks of work needed to finish this and another 500 to 750 dollars needed to buy the few remaining things.
Here's a brief overview of whats been done and what still needs to be done or bought:
-Converted FEAR to breach loading. Bolt for loader needs to be reworked and a locking mechanism needs to be finished but it's more then 50% done. If I can get into a machining class in the spring, then I will build the bolt on a lathe instead of using 3" sch40 caps filled with Durhams Rock hard water puddy as I currently have done. This would be a big plus cause then I could use O-rings to seal the breach.
-FEAR is now an over-under type cannon. Because of this I designed and built a a special sliding mechanism to allow me to slide the union back, place a burst disk, and then slide the union forward and tighten it. Pretty nifty and O-ring sealed.
-Re-built spark gaps. 10X testing completely shredded my old one so I built a new one that screws in the side about midway in the pipe. Another spark gap will be screwed in the back giving a total of two ignition points.
-All steel to build frame and recoil mechanism has been acquired. Springs for recoil absorption still need to be bought, most likely a combination of garage door springs and big compression springs (from car maybe?). Current recoil absorption design is still up in the air. Trailer to mount FEAR on still needs to be acquired.
-Everything to build barrel has been acquired. Current design calls for the first of 10' ABS barrel to be encased in and epoxy/fiberglass/steel shell; However, the design allows the ABS barrel section to be slid out and replaced encase it begins to erode from constant firing.
And that's about it. I'm guessing there's probably about 2 to 3 solid weeks of work needed to finish this and another 500 to 750 dollars needed to buy the few remaining things.
Stanford Class of 2012
"In the end our society will be defined not only by what we create, but what we refuse to destroy"- John Sawhill
"In the end our society will be defined not only by what we create, but what we refuse to destroy"- John Sawhill
larda used pneumatic springs from car hoods.
perhaps you could make a few out of copper and pump them up with a fridge compressor. pistons for them should be easy enough to make on a lathe if you get access, and they could have a very long travel. even just lathe the end from aluminum, bore it, then tap it for 1/2" threaded rod. or make the from steel and weld on rebar.
perhaps you could make a few out of copper and pump them up with a fridge compressor. pistons for them should be easy enough to make on a lathe if you get access, and they could have a very long travel. even just lathe the end from aluminum, bore it, then tap it for 1/2" threaded rod. or make the from steel and weld on rebar.
POLAND_SPUD wrote:even if there was no link I'd know it's a bot because of female name
I was think about making my own shocks, I even went as far to draw up my own plans. But I felt springs would be a simpler and more maintenance free solution (no seals to deal with and no refilling incase some leakage occurs). Even with access to a lathe at school, its a 16-18 hour drive back home (where FEAR is), so if I f*cked up making it or something broke on a shock, In all likelihood I wouldn't be able to fix it.
I may do a combination of 1 or 2 big dampers I drew up made out of 4" Sch40 PVC pipe (which I can make with what I have) and heavy duty springs, kinda along the same line as some old artillery pieces used to use to dampen recoil.
I am open to any ideas people want to throw up about recoil absorption. Remember though, FEAR will weigh in at over 450 pounds and is intended to fire 50+lb projectiles at around 400ft/s.
I may do a combination of 1 or 2 big dampers I drew up made out of 4" Sch40 PVC pipe (which I can make with what I have) and heavy duty springs, kinda along the same line as some old artillery pieces used to use to dampen recoil.
I am open to any ideas people want to throw up about recoil absorption. Remember though, FEAR will weigh in at over 450 pounds and is intended to fire 50+lb projectiles at around 400ft/s.
Stanford Class of 2012
"In the end our society will be defined not only by what we create, but what we refuse to destroy"- John Sawhill
"In the end our society will be defined not only by what we create, but what we refuse to destroy"- John Sawhill