dark side of Mjöllnir

Harness the power of precision mixtures of pressurized flammable vapor. Safety first! These are advanced potato guns - not for the beginner.
chaos cannon
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Sun Oct 28, 2012 6:34 pm

I have talked with Mr.C and gotten his permission and am going to build a similar version of Mjöllnir with a few changes namely in dimensions and aesthetics.
here is the ignition system (not finished im waiting on the wireless receiver to show up)
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this is with the system off
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this is with the master(key)switch on
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this is with manual firing option selected
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this is the spark (sorry for the blurry pic i was having to rush the shot to catch the arc)
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and here is the dark Mjöllnir's chamber. i still have more parts to get but here 2" pipe is ungodly expensive here 1 usd a inch.
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MrCrowley
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Sun Oct 28, 2012 10:44 pm

Looks like it's coming along great! I especially like the darker chamber, soon Mjöllnir will have an evil twin :D

Not sure what you're going to use for electrodes (can't remember if you mentioned it to me), but I've made a few changes that might be of help to you: see the second page of this thread.
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jackssmirkingrevenge
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Sun Oct 28, 2012 10:55 pm

Please tell me one of the changes is an adequate piston :)
hectmarr wrote:You have to make many weapons, because this field is long and short life
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Lockednloaded
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Sun Oct 28, 2012 10:58 pm

Looks like it's coming along great, maybe when you're finished LeMaudit can machine you a mini-mini boy for you to never fire :lol:
I love lamp
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jackssmirkingrevenge
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Sun Oct 28, 2012 11:11 pm

Lockednloaded wrote:maybe when you're finished LeMaudit can machine you a mini-mini boy for you to never fire :lol:
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:D :D :D
hectmarr wrote:You have to make many weapons, because this field is long and short life
chaos cannon
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Sun Oct 28, 2012 11:23 pm

jackssmirkingrevenge wrote:Please tell me one of the changes is an adequate piston :)
For now it will just be a aluminum one like Mr.C's until i know it works then ill start tweaking and peaking various things.
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jackssmirkingrevenge
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Sun Oct 28, 2012 11:28 pm

Just don't make it a solid cylinder if you have machining facilities.
hectmarr wrote:You have to make many weapons, because this field is long and short life
chaos cannon
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Sun Oct 28, 2012 11:45 pm

jackssmirkingrevenge wrote:Just don't make it a solid cylinder if you have machining facilities.
i don't but there are at least 5 machinists in a 10 mile radius of my house.
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update on my ignition system its all put together except the wireless side. even has ac recharging (that the brown cord sticking out the bottom

double post:
Lockednloaded wrote:Looks like it's coming along great, maybe when you're finished LeMaudit can machine you a mini-mini boy for you to never fire :lol:
hugh u lost me???

triple post:
MrCrowley wrote:soon Mjöllnir will have an evil twin :D
3 words "SONIC BOOM BABY"
Go big or go home.
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MrCrowley
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Mon Oct 29, 2012 1:14 am

chaos cannon wrote:
Lockednloaded wrote:Looks like it's coming along great, maybe when you're finished LeMaudit can machine you a mini-mini boy for you to never fire :lol:
hugh u lost me???
Don't worry, it's just a jealousy-incited dig at me and my safety standards :D

It's a reference to this lovely projectile machined by a generous member named LeMaudit. As you can see, it has been designed with aerodynamics in mind... so much so that we need a sophisticated tracking device so that it can be found when it is launched.
Range estimates vary but if all goes well, I would consider ~2 miles a complete success.
Unfortunately, due to my financial situation that is typical of most university students, I can't afford a tracking device that is reliable yet can fit inside the boy of the Miniboy. The name comes from a bomb it was designed after (I think it was the Tallboy).

We flirted with the idea of a smoke trail (can't discuss specifics on this forum) to help track the projectile but it would require an ATV (so that a large area can be searched and so that it can reach the location of the last reported sighting promptly) and several spotters. My friend's ATV, which is up at the shooting location, isn't in working order and I would put our chances of everything going well and the smoke trail being initiated and visible at least than 10%.

Not really sure what I'm holding out for, unless I decide to invest a few hundred in suitable GPS tracking equipment, but I promised LeMaudit I wouldn't fire it without having a more reliable tracking system in place.
chaos cannon
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Tue Oct 30, 2012 2:49 pm

ok so hurricanes gone and i was able to get out and buy more parts for the cannon. now all that's left is to cut and epoxy the seating face, make the pilot valve, have the piston machined, and acquire some ball valves and the cannon will be done for the most part. then comes the fueling station, and finish working out the bugs in the ignition system. what a long list. :x :x
but of course i shall not leave yall wanting for more pics
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so far chamber is loking to be around 38-40 inches long, depends on how much i loose when i torque it all down
Go big or go home.
If its worth doing its worth over doing
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jackssmirkingrevenge
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Tue Oct 30, 2012 4:00 pm

chaos cannon wrote:ok so hurricanes gone and i was able to get out and buy more parts for the cannon.
What an amazing quote :D
hectmarr wrote:You have to make many weapons, because this field is long and short life
chaos cannon
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Tue Oct 30, 2012 6:07 pm

jackssmirkingrevenge wrote:
chaos cannon wrote:ok so hurricanes gone and i was able to get out and buy more parts for the cannon.
What an amazing quote :D
Yet so so true
Update solved problems with ignition system. Turns out that the original battery wasn't able to supply enough power to to 10000kv transformer. Solution replace that battery with two 9v batteries in parallel. This things a beast with the right power supply, i can even smell the ozone now
Go big or go home.
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MrCrowley
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Tue Oct 30, 2012 6:41 pm

That's quite a long chamber, you might have DDT concerns because it is so long for its diameter. I believe a long tube relative to the diameter is a factor in causing DDT. The long length of the 1" cross bar may also cause problems with mixing. My cross bar is about 30cm long, so it probably doesn't affect mixing too badly, whereas yours looks to be twice as long. Members like DYI, Fnord, ramses, JSR, D_hall, and SpudBlaster15 probably can weigh in better than I but I thought I'd share my concerns anyway.
chaos cannon
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Tue Oct 30, 2012 7:16 pm

Ok so what length would you recommend.
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MrCrowley
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Tue Oct 30, 2012 7:34 pm

Well, I only recommend the 30" chamber with 1"x12" crossbar because that's all I know that works. What you have might not be a problem, so perhaps wait until some other members weigh in before making any changes.

By the way, is that the barrel adapter and seat I see also in the photo? Is it going to be modified from how it is now? Just looks a little long, think I said to you that my seat sits a little less than half way in to the tee to maximise flow.

Modifying your seat isn't an issue as the end threads of galv. iron fittings tend to leave a surface that isn't perpendicular to the length of the fitting. So cutting a bit off the seat will allow you to make a straight cut for the piston to seal against.

For reference, here's what mine looks like:
http://i75.photobucket.com/albums/i290/ ... C00587.jpg
http://i75.photobucket.com/albums/i290/ ... C00590.jpg

Of course, you don't have to copy what I have done (same goes to the cross bar and chamber length). It is just my thinking that with piston hybrids, a seat that doesn't extend past halfway in to the tee is more ideal to maximise flow. Likewise, I worry that the long chamber and crossbar may cause issues with fuelling and increase the risk of DDT.
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