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Posted: Wed Jan 23, 2008 10:15 pm
by bigbob12345
Id be intrested in some rifled 1in type M copper if thats possible

Posted: Wed Jan 23, 2008 10:31 pm
by judgment_arms
Seems to me that ½ inch rifled for marbles
And 2” for taters would be popular, am I right?
I think I’m might go with these, I’m going to give it three day, after that I’ll figure up which’ll be the most popular and go from there.

As for sales, once I settle on what size, or sizes, I’m doing I’ll let y’all know then you can e-mail me with your order, more details on that then.

Bigbob12345, possible, but unless a lot of others like that size it’ll be a custom run, which I won’t do for awhile.

Posted: Wed Jan 23, 2008 10:37 pm
by DYI
2” will be $2.00U.S. a foot for PVC $34.00U.S. a foot for type k copper
Asshole... :lol:

Hmm... that comes to ($34/foot x 4')+($98 for pipe)+
(~$60shipping costs)= :shock:

For about $300, that had better be one DAMN good barrel. :P

Posted: Wed Jan 23, 2008 10:41 pm
by bigbob12345
judgment_arms wrote: Bigbob12345, possible, but unless a lot of others like that size it’ll be a custom run, which I won’t do for awhile.
Okay sounds good how much would it cost to get five feet
I want it for an 8x hybrid I plan to make in the future

Posted: Wed Jan 23, 2008 10:44 pm
by DYI
And Judge, calibrate it for a velocity range of 1800 fps, as the ice slugs (~16 gram) will be at about 2400, while heavier stuff may go as slow as 1200.

Posted: Wed Jan 23, 2008 10:52 pm
by judgment_arms
DIY, that’s what I was thinking. But hay copper pipe is expensive and the only place I know of locally only sells be the stick (the whole ten feet), and I got’a turn a profit also.
That kind of money, I don’t know if I got enough grit to fool with that much… well see

Bigbob, probably about 10 bucks u.s. plus shipping, unless I use a die that I’d already have then only 5.

Both of you you’re probably looking at a 2-3 month wait.

Posted: Wed Jan 23, 2008 10:54 pm
by ShowNoMercy
Is there anyway you would be able to rifle some 2 inch conduit? I like the flare on the one end, so if you could that would be cool. I think its the same size.

Posted: Wed Jan 23, 2008 10:56 pm
by bigbob12345
judgment_arms wrote: Bigbob, probably about 10 bucks u.s. plus shipping, unless I use a die that I’d already have then only 5.

Both of you you’re probably looking at a 2-3 month wait.
Thats great much cheaper than expected :D Too bad about the long wait but I guess Ill just use normal copper for the time being.

Posted: Wed Jan 23, 2008 11:05 pm
by judgment_arms
ShowNoMercy, if it’s PVC I don’t see why not.

BigBob12345, sorry, I forgot that you said copper… it’s going to be closer to $15.00U.S… maybe more… sorry for the confusion, The Judge is tired *yawn*.

Posted: Wed Jan 23, 2008 11:07 pm
by ShowNoMercy
Do you have any idea of when you may be able to start production?

Posted: Thu Jan 24, 2008 12:21 am
by MrCrowley
ShowNoMercy wrote:Is there anyway you would be able to rifle some 2 inch conduit? I like the flare on the one end, so if you could that would be cool. I think its the same size.
That flare you speak of should be found on all pipe, it's so contractors and plumbers can connect 6m/18' lengths of pipe without buying extra fittings. And I forgot what it's called, but it's not called a flare, just letting you know :)

Posted: Thu Jan 24, 2008 3:47 am
by Ragnarok
MrCrowley wrote:And I forgot what it's called, but it's not called a flare, just letting you know :)
Think it's called a bell, rather than a flare.
But I think you can tell why it's increasingly called a flared end... the other option has been rather adapted to a risqué meaning.

@DYI: Calibrating for a velocity of 1800 fps is only half the problem. The projectile density and dimensions will affect it as well.
However, I'll be doing some in depth thought into the Greenhill equation in the near future, which would actually allow things like this to be considered.

As far as I understand, that for accuracy it's better to have rifling that is a bit too tight than too shallow, but varying from the ideal by 25% in either direction shouldn't be a problem for stability.

However, there is a problem with steep rifling:
I'm very strongly drawn to the idea of trying to make my own rifled barrel for HEAL - it turns out that that requires 1 turn in 12 inches, a lot tighter than I thought it would be, and that's a rotational speed of 40,000 rpm.

The issue is I'm not sure potatoes would survive that, they'd probably spin themselves to bits.... Larger bores may hold together better, but a tater can only take so much. I've subjected them to incredible compressive stress, but I don't know about tensions.
I'll have to run some numbers.
Anyone know the yield stress of a potato? Google doesn't seem to have much on it.

Posted: Thu Jan 24, 2008 2:35 pm
by judgment_arms
ShowNoMercy, don’t know, so far everybody wants different sized stuff.
I’m beginning to think that I’ll just do custom runs, it’ll cost people more but there doesn’t seem to be as big a market for this as I thought.

Ragnarok, I’m pretty sure that you’d end up spraying mash potatoes. You could always chuck a tatter in a drill press and send it for a whirl, if it flies to peaces you know it’ll not take the centrifugal forces that the rifling imparts.
As for that barrel, if you still want it I’ll make you one at cost once I get the rest of the machine done; only thing I ask is you continue to give me assistance with the math. Math’s not exactly my best subject but I do my best.

Posted: Thu Jan 24, 2008 4:02 pm
by DYI
Okay, I was really tired last night, and the calculations for the mass of the slug were off a bit (read, by a factor of ~16 :roll: ), so the mass would actually be 256 grams, and the velocity 1200 fps, with a density of 0.94g/cm^3.

And Judge, why couldn't you just get the stick from McMaster? If you can't, I'll just get it myself and stick with smoothbore, because the price would get downright ridiculous.

Posted: Thu Jan 24, 2008 4:18 pm
by judgment_arms
Because if I get the stick from McMaster then the shipping has to be paid twice, ether way I was only charging you for the five feet.
But you might be better off buying the pipe your self and leaving it smoothbore, I’m not sure how deep of groves could safely be cut in copper pipe, with your high velocity cannon your projectile will probably just blow straight through the rifling.

By the way, I was tired too, still am.