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Posted: Mon May 05, 2008 3:37 pm
by psycix
This thread is a bit wandering off.

Some people dont agree with the fact that a bigger cannon can always do the job, so to remove the "size matters" the weight:power is introduced.
But now you guys are discussing that a weight:power rule would compromise safety.

How to solve this:
-Scratch off the weight:power and no more bothering on the safety.
-Let people be responsible for their own safety.
-Put the limits for power:weight badges so incredibly high that someone achieving this knows what hes doing, and thus should be smart enough to care for his own safety.
-Go on discussing about safety....

Posted: Mon May 05, 2008 3:46 pm
by SpudFarm
oh no then i have no chance with my gazilion pound hybrid :(

BTW i am not going to hijack this anymore.. i have no clue because i do not want to spend the evenings on reading replies in this thread

Posted: Mon May 05, 2008 4:05 pm
by STHORNE
BC Pneumatics wrote:David, if you are not careful STHORNE is going to attack you with a banana for taking over his job.
:x NOBODY takes over my job!!!! Banana Away!!!! lol, not bad...but I try to stick around 16x16 pixels for the badges.

Otherwise, nice job (even though you did take my job :evil: :D )

EDIT: Oops, double post....delete wont work :shock: :( Taken care of!

Posted: Mon May 05, 2008 6:34 pm
by Davidvaini
lol funny thing is I made that banana badge, uploaded on photobucket and posted on here in less than 1 minute just for you... so id feel special lol....

Posted: Mon May 05, 2008 6:39 pm
by STHORNE
Davidvaini wrote:lol funny thing is I made that banana badge, uploaded on photobucket and posted on here in less than 1 minute just for you... so id feel special lol....
You are special :tongue: lol, jk

Posted: Mon May 05, 2008 6:49 pm
by Ragnarok
BC Pneumatics wrote:We have a huge group of qualified people, and practically endless information and data, with the resources to make many times more.
I wouldn't quite stretch to qualified, as there is no spudding qualification, but experienced, knowledgeable and dedicated I wouldn't hesitate to agree with.

Posted: Mon May 05, 2008 6:59 pm
by BC Pneumatics
Well, there is no certification, but qualification is simply "having the qualities, accomplishments, etc., that fit a person for some function, office, or the like."

The people around here certainly fit that definition!

Posted: Mon May 05, 2008 7:19 pm
by Davidvaini
yay I have my spudding qualification! lol I wonder If I should put this on my resume? :roll:

Posted: Mon May 05, 2008 7:19 pm
by Ragnarok
BC Pneumatics wrote:Well, there is no certification...
On reading that, I suddenly had an image flash through my head of spudders having to qualify like drivers:
"He's failed his spudding test three times, so he's hired a new plumber to teach him how to do it better."

But I'd say that the regulars and long term members on the forum are the spudding world's equivalent of qualified professionals - if not by the strict definition of the term (someone with a qualification who does it as a profession).

If you need information on spudding, there isn't much further you need to go than here - In fact, the forum as a whole has a pretty decent knowledge of lots of things, not just the specific act of using plumbing supplies to rapidly energize vegetables.

Posted: Mon May 05, 2008 7:45 pm
by DYI
I really don't think all this bickering over safety is worth it. As far as I can tell, there's a simple solution to this; If you can prove that the launcher didn't fail violently on a full power shot, or provide a recording of a hydrostatic test of the launcher to twice its operating pressure, then it's all good.

In my opinion, if it can survive one full power shot, it should still be eligible for a badge like range, penetration, or velocity. The incentive to build better remains, as most people don't want a launcher that they can't come within two hundred yards of when it's firing, which might explode without warning at any time and turn hours of hard work and hundreds of dollars into ashes and shrapnel.

[hijacking]

And about the problems of building on a large scale:
1.Cost- Most components become exponentially more expensive and increasingly difficult to find in larger sizes. Higher pressure rated components are generally specialty parts, meaning they are exceedingly rare, as well as being expensive to acquire, especially if one lives outside the United States. Also, parts that need specific tolerances; if you try finding a tube with a pressure rating of over 2kpsi and an internal diameter of 0.257" at your local hardware store, you will be sorely disappointed. And raw materials are almost non-existent at local supplies. If you for some reason need 3 feet of 1.5" electrical grade PTFE bar stock, you can't just run over to Lowes for it.

2.Mass- The main reason the [redacted] project was cancelled - its projected mass was larger than the rated capacity of any of our vehicles. The barrel for one of my current projects is only 6 feet long, and weighs almost 70 pounds. After the fiberglass reinforcement, it will weigh well over 100, and even then the safety factor will be less than 2 at full power.

3.Noise - Very few people here have ever built a truly loud launcher. I don't mean the kind that makes your a-hole neighbour complain, I mean the kind that makes your ears ring from 50 feet away at half power when you have 20 decibel hearing protection on, and is heard in a town 7km away. You can't simply set it up in your back yard or at the local park, and this combines with 2. to make any shooting a long process. This brings me to 4.

4.Field repairs- You can't fire a big gun near inhabited areas, which means that you need to carry as much with you as you can to repair it should it break down. This may seem trivial, but expedited repairs in a hostile environment (as it invariably is) are unpleasant, haphazard, and often completely impossible if the wrong thing breaks. Add this to the fact that, instead of a 10 or 20 pound device, you're now trying to work on something 17 feet long with a total mass of over 300 pounds, usually on soft, damp ground with only half the parts and equipment you need and a swarm of vicious insect hovering above you, and you get really frustrated, really fast.

5.Reloading- The problems here should be obvious. Systems that worked on normal launchers will be completely useless now. Breach loading systems on a 1.5" bore 200psi launcher are a bit of work, but nothing really horrible. Try designing a breach loader for a 2000psi gun with a 4" bore and a barrel weighing 200 pounds, and you'll either pull out the lathe and 5" bar stock, or give up. If you do succeed, cost is insane, and if you don't succeed, reloading is a royal pain in the ass.

6.Targets and Ammo- Really two separate problems, but at a certain point they suddenly become very expensive and difficult. Vegetable matter will disintegrate in the barrel of a powerful launcher from acceleration forces, and things like 1/8" steel plate that would last for ages with a small launcher will be bent beyond recognition and turned into swiss cheese after two or three impacts, depending on the ammo used.

[/hijacking]

Posted: Mon May 05, 2008 8:05 pm
by Ragnarok
DYI wrote:I mean the kind that makes your ears ring from 50 feet away at half power when you have 20 decibel hearing protection on, and is heard in a town 7km away.
Oh dear, what have you been up to?

Still, I maintain I could have slept through it (were I asleep nearby, although that would just be unlucky)... I've slept through worse.

Posted: Mon May 05, 2008 8:38 pm
by DYI
Oh dear, what have you been up to?
I don't post all of my projects right away :wink:

Posted: Mon May 05, 2008 8:46 pm
by BC Pneumatics
DYI- I understand things are different with larger launcher, but nothing you listed is much more than a case of normal cannon related tasks scaled up right along with the launcher... that would be expected.

Posted: Mon May 05, 2008 10:57 pm
by clide
BC Pneumatics wrote:First, mods do not have to say what the limit is, all they have to say is that they do not consider the cannon safe, and will not longer award it any badges until it is reinforced to their satisfaction.
I don't know about you, but if I was competing and willing to go into unsafe territory then I would certainly want to know a numerical value for the maximum pressure I can go to and still be allowed to compete. I'm sure you could eyeball an unsafe cannon, but you do need a numerical boundary. Honestly if someone like Rag is willing to take the time to crunch the numbers then I guess that takes away my objections.
This seriously, honestly, pisses me off more than most people would be able to.
I apologized about that. I regretted it after I wrote it. I realize that it is sometimes hard to convey ideas through this medium and you have misunderstood my points occasionally. I was just frustrated at the time. Really I have no hard feelings towards you. You are one of the members of this community that I have a deep respect for.

That is a damn shame, since as I said, you have already contributed the most to it.
I never had you pegged from someone who gave up.
It just seemed like we were going back and forth and not gaining any ground in any direction. Sometimes you just need to remember that "arguing on the internet" poster. In this case I guess we just needed someone else to step in to gain some ground.


Since we got people willing to do the work maybe I'll post the information I have on that valve sometime and see if you guys have any idea about the pressure. I haven't even looked at it for years since I haven't had the money or space for a large gun, but I do remember not being able to find any info on it when I got it. I could only find a few valves with similar shapes and they were different enough that the ratings weren't entirely helpful.

@Rag- That example was purposely relatively simple. It was to show that for even a simple case you will need either the the experience to know a numerical value for how much that will decrease allowable pressure or the reference books to be able to look it up.

Like I said, if you guys are willing to do the work of giving consistent rulings of the numerical "safe" limit of guns then I don't have any objections. Just keep in mind that a power:weight launcher doesn't need to be a big one, so it could potentially have a lot of competition.

Posted: Mon May 05, 2008 11:25 pm
by BC Pneumatics
I think we both got a bit heated, and I definitely agree with what you said about the deadlock situation.

You are right that we cannot be so vague as to not even give a numerical value. I suppose I was just trying to make the point that if something was obviously unsafe we could prevent it from going any further, despite not being about to assign a numerical value to it that proved the danger. (Or if it was so obvious that we simply didn't want to waste out time with it.)

I have to say I am glad everything is back to clean with us. If nothing else, I was getting sick of all the typing. :wink:

P.S.- Clide, if I didn't respect so much, I would never have spent so much time writing the replies that I did.