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LRP (V 1.0)

Posted: Mon Apr 07, 2008 2:21 am
by Carlman
Hi all,

I havnt posted a 'cannon' for quite some time as i just made them to have fun with so i could do without the flaming in the looks department lol

so i decided to make one that took looks into account.

So i hereby give you the 'LRP - Long Range Plinker'

Specs:

Chamber:
about 35cm all up of 50mm PN18
Valve: Modded high flow 25mm sprinkler
Barrel: either 180cm or 90cm of 20mm poly pipe
FPS: at 100psi with a marble as ammo and the long barrel = 687fps
Main ammo: marbles or darts

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and here it is with a shortened barrel

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This is only version one, i am planning to make a better bipod and a silencer.

comment at will :D

EDIT: ggdt printsreens

EDIT EDIT: correct ggdt screens

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Posted: Mon Apr 07, 2008 2:39 am
by THUNDERLORD
That looks good Carlman, I like the simple,smooth design. Looks like a laser sight you've got mounted on top?

Posted: Mon Apr 07, 2008 2:59 am
by jackssmirkingrevenge
Looks a bit flimsy with the longer barrel, I would have gone with a larger chamber but in the interest of noise abatement you probably got it about right ;) and where, pray tell, are the obligatory damage pics? Marbles at 500 fps+ are bound to cause some mayhem worth sharing :D

Posted: Mon Apr 07, 2008 3:07 am
by Carlman
jackssmirkingrevenge wrote:Looks a bit flimsy with the longer barrel, I would have gone with a larger chamber but in the interest of noise abatement you probably got it about right ;) and where, pray tell, are the obligatory damage pics? Marbles at 500 fps+ are bound to cause some mayhem worth sharing :D
yea but mayhem from a 500+fps marble in a suburban backyard isnt worth it lol :D

and as to the larger chamber i like the noise this makes, no whoooosh just a bang

the barrel is not flimsy at all except at the coupler, and that is because i dont want to screw it in all the way otherwise id neva get it out lol

the pipe is 3mm thick!

I promise all that next time i go to my 5 acre block and have my trackpump i will shoot through many appliances with 140psi :D
THUNDERMAN wrote:that looks good Carlman, I like the simple,smooth design. Looks like a laser sight you've got mounted on top?
its just a laser pointer but i will get a red dot scope soonish

Posted: Mon Apr 07, 2008 6:05 am
by sniper hero
cool gun can you post some pics of your darts
I am making a marble shooter so maybe I can make some darts too.

I agree post damage pics :D :D

Posted: Mon Apr 07, 2008 9:09 am
by POLAND_SPUD
the whole design is simple and neat but that barrel spoils the effect a lot... but hey I understand that - I have 180 cm piece of 3/4" steel pipe that I use somethimes as a barrel and it is so heavy that it makes aiming difficult

Do you really need a 180cm barrel ? 150 would be good enough...
I think you have to make a silencer for that :twisted:

last question, why don't you use a female-female adapter instead of a union ?

Posted: Mon Apr 07, 2008 9:15 am
by bigbob12345
That looks like a fun little gun.
And i agree with POLAND_SPUD you really need a silencer on that thing

Posted: Mon Apr 07, 2008 9:16 am
by Gippeto
No flaming in the looks department from me.

Very clean and concise, great job!

Damage, oh yes...there will be damage! :lol:

Do you have something inside the chamber? (referring to the 2.165" inner diameter)

Posted: Mon Apr 07, 2008 9:21 am
by Ragnarok
Looks like a fun cannon, if not the most beautiful - but it doesn't look bad though.
I have to wonder how useful the taped on laser pointer is. The thing is, when I tried that, I was lucky if it ever pointed in the right direction - my later versions were fixed much more sturdily, including the touch-the-trigger electronically controlled version :wink:.

However, we still need those damage pics... I can't say much more without them...
jackssmirkingrevenge wrote:Marbles at 500 fps+ are bound to cause some mayhem worth sharing :D
Oddly enough, it was only last night when I dug out the remnants of the floppy drive I shot in the HEAL video. On closer inspection, the ~900 fps marble did significantly more damage than I originally noticed.

Posted: Mon Apr 07, 2008 9:31 am
by SpudFarm
how can you have 100psig in the chamber and a pressure drop of 50bar?

Posted: Mon Apr 07, 2008 9:50 am
by Ragnarok
spudfarm wrote:how can you have 100psig in the chamber and a pressure drop of 50bar?
For some reason, GGDT switches all the names of the units alongside the output boxes from metric to imperial when Metric lengths are set on the config panel, and only when this is done.

However, it doesn't change the actual output values with this. What it actually means is a pressure drop of 50 psi.

Basically, if you want all the right units for the right values, you have to change all boxes from imperial to metric, no half measures.

Posted: Mon Apr 07, 2008 10:53 am
by Carlman
sniper hero wrote:cool gun can you post some pics of your darts
I am making a marble shooter so maybe I can make some darts too.

I agree post damage pics :D :D
My darts are actual darts...like the throwing kind :lol: (with wadding ofcourse)
POLAND_SPUD wrote:the whole design is simple and neat but that barrel spoils the effect a lot... but hey I understand that - I have 180 cm piece of 3/4" steel pipe that I use somethimes as a barrel and it is so heavy that it makes aiming difficult

Do you really need a 180cm barrel ? 150 would be good enough...
I think you have to make a silencer for that :twisted:

last question, why don't you use a female-female adapter instead of a union ?
Ther barrel is super light so it doesnt bother me with aiming.

nah i want the full 180cm :twisted: (mainly cauz of the pre threaded end of the pipe ready for my...

Silencer which will be a baffle type.

I mis posted, i meant to say female coupler instead, thnx for pointing that out
bigbob12345 wrote:That looks like a fun little gun.
And i agree with POLAND_SPUD you really need a silencer on that thing
Thanks and will do
Gippeto wrote:Do you have something inside the chamber? (referring to the 2.165" inner diameter)
No just the pipe by itself, it is aussie pipe...its wierd :roll:
Ragnarok wrote:Looks like a fun cannon, if not the most beautiful - but it doesn't look bad though.
I have to wonder how useful the taped on laser pointer is. The thing is, when I tried that, I was lucky if it ever pointed in the right direction - my later versions were fixed much more sturdily, including the touch-the-trigger electronically controlled version :wink:.

However, we still need those damage pics... I can't say much more without them...
The laser pointer doesnt do much more than a 'general direction pointy thingy' lol, im getting a red dot scope or a zooming rifle one

damage pics will be up when i get them...soon



Jesus christ that took a while :lol:

Posted: Mon Apr 07, 2008 11:59 am
by SpudFarm
and the inner diameter box of GGDT should be empty if it is not a coaxial.
what you have done is to subtract the inner diameter of the outer diameter so the program think the id of your chamber is the od of the pipe and the id is taken away from the chamber volume.

just try one more time with 0 at inner diameter on chamber..

mabe i am wrong

Edit: i think that is only with barrel sealer

Posted: Mon Apr 07, 2008 12:10 pm
by Carlman
care to elaborate more? what should i do, or is it all good?

Posted: Mon Apr 07, 2008 12:25 pm
by SpudFarm
i am going to look at my GGDT and edit the answer in this post later

Edit: you do have to set the "reservoir data, inner diam" to 0

try it and look up for results.